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1.
Contemp Clin Trials Commun ; 26: 100900, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35198795

RESUMO

It has been over 40 years since Lasagna's Law was first introduced and its main postulates are still permeating the clinical trial arena. This article attempts to identify the most pressing roadblocks in patient recruitment, categorizes them based on the stakeholders involved and provides suggestions on how to identify and mitigate the risks involved.

2.
Contemp Clin Trials Commun ; 18: 100568, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32395664

RESUMO

A master protocol is a unifying study construct that includes multiple subgroups and substudies, with patients having same or different diseases and that employ one or multiple drugs to treat it. Initially designed for oncology, master protocol trials are intended to simultaneously evaluate more than one investigational drug and/or more than one cancer type within the same overall trial structure. The ability to use a single infrastructure, trial design, and protocol to simultaneously evaluate multiple drugs and/or disease populations in multiple substudies, speeds up drug development and makes it more efficient. Thus, it is important for the clinical trial professionals to understand both the basic principles of master protocol trials and the way innovative trial designs are starting to change the landscape of clinical research.

3.
Artigo em Inglês | MEDLINE | ID: mdl-31538751

RESUMO

Posttraumatic stress disorder (PTSD) is a debilitating disease with limited available treatment options and for which novel effective interventions constitute a significant unmet need. This case report describes successful treatment of a patient with panic disorder and PTSD stemming from the 2010 Moscow subway terrorist attacks through the combination of script-driven trauma memory reactivation and inhalation of a xenon-based gas mixture. Xenon is a competitive inhibitor of N-methyl-d-aspartate receptors known to play a role in memory reconsolidation, a learning and memory process wherein memories temporarily enter a labile state after reactivation and may be modified. Literature describing current pharmacologic and exposure-based treatments is reviewed and provides the basis for use of this novel treatment strategy to target and modify emotional memories.


Assuntos
Antagonistas de Aminoácidos Excitatórios/farmacologia , Terapia Implosiva/métodos , Transtorno de Pânico/tratamento farmacológico , Transtornos de Estresse Pós-Traumáticos/tratamento farmacológico , Xenônio/farmacologia , Adulto , Terapia Combinada , Antagonistas de Aminoácidos Excitatórios/administração & dosagem , Feminino , Humanos , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Xenônio/administração & dosagem
4.
Theranostics ; 9(2): 477-490, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30809288

RESUMO

Diabetic foot ulcers are associated with significant morbidity and mortality, and current treatments are far from optimal. Chronic wounds in diabetes are characterised by impaired angiogenesis, leukocyte function, fibroblast proliferation, and keratinocyte migration and proliferation. Methods: We tested the effect of exposure to argon gas on endothelial cell, fibroblast, macrophage and keratinocyte cell cultures in vitro and in vivo of a streptozotocin-induced diabetic mouse model. Results: Exposure to normobaric argon gas promotes multiple steps of the wound healing process. Argon accelerated angiogenesis, associated with upregulation of pro-angiogenic Angiopoietin-1 and vascular endothelial growth factor (VEGF) signalling in vitro and in vivo. Treatment with argon enhanced expression of transforming growth factor (TGF)-ß, early recruitment of macrophages and keratinocyte proliferation. Argon had a pro-survival effect, inducing expression of cytoprotective mediators B-cell lymphoma 2 and heme oxygenase 1. Argon was able to accelerate wound closure in a diabetic mouse model. Conclusion: Together these findings indicate that argon gas may be a promising candidate for clinical use in treatment of diabetic ulcers.


Assuntos
Argônio/administração & dosagem , Pé Diabético/tratamento farmacológico , Pé Diabético/patologia , Neovascularização Fisiológica/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Animais , Células Cultivadas , Diabetes Mellitus/induzido quimicamente , Modelos Animais de Doenças , Células Endoteliais/efeitos dos fármacos , Fibroblastos/efeitos dos fármacos , Queratinócitos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Camundongos , Resultado do Tratamento
5.
J Transl Med ; 15(1): 137, 2017 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-28610592

RESUMO

BACKGROUND: Current treatments of panic disorder (PD) are limited by adverse effects, poor efficacy, and need for chronic administration. The established safety profile of subanesthetic concentrations of xenon gas, which is known to act as a glutamate subtype NMDA receptor antagonist, coupled with preclinical studies demonstrating its effects in other anxiety related conditions, prompted us to evaluate its feasibility and efficacy in treatment of patients with PD. METHODS: An open-label clinical trial of xenon-oxygen mixture was conducted in 81 patients with PD; group 1 consisting of patients only with PD (N = 42); and group 2 patients with PD and other comorbidities (N = 39). RESULTS: Based on the analysis of the results of a number of psychometric scales used in this study (SAS, HADS, CGI), several conclusions can be made: (1) xenon is a potentially effective modality in acute treatment of PD; (2) an anti-panic effect of xenon administration persists for at least 6 months after the completion of the active phase of treatment; (3) xenon inhalation is well tolerated, with the drop-out rates being much lower than that of conventional pharmacotherapy (5.8% vs. 15%); (4) the severity of depressive disorders that frequently accompany PD can be significantly reduced with the use of xenon; (5) xenon may be considered as an alternative to benzodiazepines in conjunction with cognitive-behavioral therapy as a safe modality in treatment of anxiety disorder. CONCLUSIONS: These data support the need for randomized double-blind clinical trials to further study xenon-based interventions. Trial registration This clinical trial was retrospectively registered on April 14th, 2017 as ISRCTN15184285 in the ISRCTN database.


Assuntos
Transtorno de Pânico/tratamento farmacológico , Xenônio/uso terapêutico , Adulto , Ansiedade/tratamento farmacológico , Demografia , Feminino , Humanos , Masculino , Xenônio/administração & dosagem
6.
Oncotarget ; 8(17): 28595-28613, 2017 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-28404894

RESUMO

ValloVax is a placental endothelium derived vaccine which induces tissue-nonspecific antitumor immunity by blocking tumor angiogesis. To elucidate mechanisms of action, we showed that production of ValloVax, which involves treating placental endothelial cells with IFN-gamma, results in upregulation of HLA and costimulatory molecules. It was shown that in mixed lymphocyte reaction, ValloVax induces Type I cytokines and allo-proliferative responses. Plasma from ValloVax immunized mice was capable of killing in vitro tumor-like endothelium but not control endothelium. Using defined antigens associated with tumor endothelial cells, specific molecular entities were identified as being targeted by ValloVax induced antibodies. Binding of predominantly IgG antibodies to ValloVax cells was confirmed by flow cytometry. Further suggesting direct killing of tumor endothelial cells was expression of TUNEL positive cells, as well as, reduction in tumor oxygenation. Supporting a role for antibody mediated responses, cell depletion experiments suggested a predominant role of B cells in maintaining an intact anti-tumor endothelial response. Adoptive transfer experiments suggested that infusion of CD3+ T cells from immunized mice was sufficient to transfer tumor protection. Generation of memory T cells selective to tumor endothelial specific markers was observed. Functional confirmation of memory responses was observed in tumor rechallenge experiments. Furthermore, we observed that both PD-1 or CTLA-4 blockade augmented antitumor effects of ValloVax. These data suggest a T cell induced B cell mediated anti-tumor endothelial response and set the framework clinical trials through elucidation of mechanism of action.


Assuntos
Vacinas Anticâncer/imunologia , Endotélio/imunologia , Imunidade , Neoplasias/imunologia , Neoplasias/patologia , Transferência Adotiva , Animais , Reações Cruzadas/imunologia , Citocinas/biossíntese , Citotoxicidade Imunológica , Modelos Animais de Doenças , Células Endoteliais/imunologia , Feminino , Antígenos de Histocompatibilidade/imunologia , Imunização , Memória Imunológica , Imunoterapia , Interferon gama/farmacologia , Ativação Linfocitária/imunologia , Linfócitos/imunologia , Linfócitos/metabolismo , Camundongos , Neoplasias/terapia , Especificidade de Órgãos/imunologia
7.
J Transl Med ; 13: 340, 2015 Oct 29.
Artigo em Inglês | MEDLINE | ID: mdl-26510973

RESUMO

Angiogenesis is essential for the growth and metastasis of solid tumors. The tumor endothelium exists in a state of chronic activation and proliferation, fueled by the tumor milieu where angiogenic mediators are aberrantly over-expressed. Uncontrolled tumor growth, immune evasion, and therapeutic resistance are all driven by the dysregulated and constitutive angiogenesis occurring in the vasculature. Accordingly, great efforts have been dedicated toward identifying molecular signatures of this pathological angiogenesis in order to devise selective tumor endothelium targeting therapies while minimizing potential autoimmunity against physiologically normal endothelium. Vaccination with angiogenic antigens to generate cellular and/or humoral immunity against the tumor endothelium has proven to be a promising strategy for inhibiting or normalizing tumor angiogenesis and reducing cancer growth. Here we review tumor endothelium vaccines developed to date including active immunization strategies using specific tumor endothelium-associated antigens and whole endothelial cell-based vaccines designed to elicit immune responses against diverse target antigens. Among the novel therapeutic options, we describe a placenta-derived endothelial cell vaccine, ValloVax™, a polyvalent vaccine that is antigenically similar to proliferating tumor endothelium and is supported by pre-clinical studies to be safe and efficacious against several tumor types.


Assuntos
Vacinas Anticâncer/uso terapêutico , Neoplasias/irrigação sanguínea , Neovascularização Patológica/tratamento farmacológico , Humanos , Neovascularização Patológica/imunologia
8.
J Transl Med ; 11: 56, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23510656

RESUMO

Heart failure is one of the key causes of morbidity and mortality world-wide. The recent findings that regeneration is possible in the heart have made stem cell therapeutics the Holy Grail of modern cardiovascular medicine. The success of cardiac regenerative therapies hinges on the combination of an effective allogeneic "off the shelf" cell product with a practical delivery system. In 2007 Medistem discovered the Endometrial Regenerative Cell (ERC), a new mesenchymal-like stem cell. Medistem and subsequently independent groups have demonstrated that ERC are superior to bone marrow mesenchymal stem cells (MSC), the most widely used stem cell source in development. ERC possess robust expansion capability (one donor can generate 20,000 patients doses), key growth factor production and high levels of angiogenic activity. ERC have been published in the peer reviewed literature to be significantly more effect at treating animal models of heart failure (Hida et al. Stem Cells 2008).Current methods of delivering stem cells into the heart suffer several limitations in addition to poor delivery efficiency. Surgical methods are highly invasive, and the classical catheter based techniques are limited by need for sophisticated cardiac mapping systems and risk of myocardial perforation. Medistem together with Dr. Amit Patel Director of Clinical Regenerative Medicine at University of Utah have developed a novel minimally invasive delivery method that has been demonstrated safe and effective for delivery of stem cells (Tuma et al. J Transl Med 2012). Medistem is evaluating the combination of ERC, together with our retrograde delivery procedure in a 60 heart failure patient, double blind, placebo controlled phase II trial. To date 17 patients have been dosed and preliminary analysis by the Data Safety Monitoring Board has allowed for trial continuation.The combined use of a novel "off the shelf" cell together with a minimally invasive 30 minute delivery method provides a potentially paradigm-shifting approach to cardiac regenerative therapy.


Assuntos
Transplante de Células , Endométrio/citologia , Insuficiência Cardíaca/terapia , Animais , Transplante de Células/efeitos adversos , Feminino , Humanos , Modelos Animais , Medicina Regenerativa
9.
J Transl Med ; 10: 231, 2012 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-23171397

RESUMO

Despite the successes of recombinant hematopoietic-stimulatory factors at accelerating bone marrow reconstitution and shortening the neutropenic period post-transplantation, significant challenges remain such as cost, inability to reconstitute thrombocytic lineages, and lack of efficacy in conditions such as aplastic anemia. A possible means of accelerating hematopoietic reconstitution would be administration of cells capable of secreting hematopoietic growth factors. Advantages of this approach would include: a) ability to regulate secretion of cytokines based on biological need; b) long term, localized production of growth factors, alleviating need for systemic administration of factors that possess unintended adverse effects; and c) potential to actively repair the hematopoietic stem cell niche. Here we overview the field of hematopoietic growth factors, discuss previous experiences with mesenchymal stem cells (MSC) in accelerating hematopoiesis, and conclude by putting forth the rationale of utilizing exogenous endothelial cells as a novel cellular therapy for acceleration of hematopoietic recovery.


Assuntos
Células Endoteliais/citologia , Hematopoese , Animais , Células Endoteliais/metabolismo , Fatores de Crescimento de Células Hematopoéticas/metabolismo , Transplante de Células-Tronco Hematopoéticas , Humanos , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Nicho de Células-Tronco
10.
J Transl Med ; 10: 207, 2012 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-23038994

RESUMO

BACKGROUND: Endometrial regenerative cells (ERC) and bone marrow stromal cells (BMSC) are being used in clinical trials. While they have been reported to have similar characteristics, they have not been directly compared. METHODS: We compared micro RNA (miRNA) and gene expression profiles, soluble cytokine and growth factor levels and ability to inhibit ongoing mixed leukocyte reaction (MLR) of ERC and BMSC each derived from 6 healthy subjects. RESULTS: ERC and BMSC miRNA and gene expression profiles were similar, but not identical; more differences were noted in the expression of genes than in miRNAs. Genes overexpressed in ERCs were more likely to be in immune and inflammation pathways and those overexpressed in BMSCs were more likely to be in stem cell and cancer signaling pathways. In addition, the levels of IL-8 and ICAM-1 were greater in ERC supernatants while the levels of HGF, VEGF, IL-6, CXCL12, TGFB1 and TGFB2 were greater in BMSC supernatants. Additionally, ERC demonstrated greater inhibition of the proliferation of mixed leukocyte cultures. CONCLUSIONS: These results suggest that the in vivo effects of ERC and BMSC may differ. Multiple properties of stromal cells are responsible for their in vivo effectiveness and ERC may be more effective for some of the clinical applications and BMSC for others. Studies in animal models or clinical trials will be required to more fully characterize the differences between ERC and BMSC.


Assuntos
Endométrio/citologia , Células-Tronco Mesenquimais/citologia , Estudos de Casos e Controles , Citocinas/metabolismo , Endométrio/metabolismo , Feminino , Humanos , Teste de Cultura Mista de Linfócitos , Células-Tronco Mesenquimais/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
J Transl Med ; 9: 34, 2011 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-21450109

RESUMO

BACKGROUND: Many peptide-based cancer vaccines have been tested in clinical trials with a limited success, mostly due to difficulties associated with peptide stability and delivery, resulting in inefficient antigen presentation. Therefore, the development of suitable and efficient vaccine carrier systems remains a major challenge. METHODS: To address this issue, we have engineered polylactic-co-glycolic acid (PLGA) nanoparticles incorporating: (i) two MHC class I-restricted clinically-relevant peptides, (ii) a MHC class II-binding peptide, and (iii) a non-classical MHC class I-binding peptide. We formulated the nanoparticles utilizing a double emulsion-solvent evaporation technique and characterized their surface morphology, size, zeta potential and peptide content. We also loaded human and murine dendritic cells (DC) with the peptide-containing nanoparticles and determined their ability to present the encapsulated peptide antigens and to induce tumor-specific cytotoxic T lymphocytes (CTL) in vitro. RESULTS: We confirmed that the nanoparticles are not toxic to either mouse or human dendritic cells, and do not have any effect on the DC maturation. We also demonstrated a significantly enhanced presentation of the encapsulated peptides upon internalization of the nanoparticles by DC, and confirmed that the improved peptide presentation is actually associated with more efficient generation of peptide-specific CTL and T helper cell responses. CONCLUSION: Encapsulating antigens in PLGA nanoparticles offers unique advantages such as higher efficiency of antigen loading, prolonged presentation of the antigens, prevention of peptide degradation, specific targeting of antigens to antigen presenting cells, improved shelf life of the antigens, and easy scale up for pharmaceutical production. Therefore, these findings are highly significant to the development of synthetic vaccines, and the induction of CTL for adoptive immunotherapy.


Assuntos
Apresentação de Antígeno/imunologia , Antígenos de Histocompatibilidade Classe II/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Imunoterapia/métodos , Nanopartículas/química , Neoplasias/terapia , Peptídeos/imunologia , Animais , Biodegradação Ambiental , Diferenciação Celular , Linhagem Celular Tumoral , Células Dendríticas/citologia , Células Dendríticas/metabolismo , Endocitose , Humanos , Proteínas Imobilizadas/imunologia , Ácido Láctico/metabolismo , Camundongos , Nanopartículas/ultraestrutura , Neoplasias/imunologia , Fenótipo , Ácido Poliglicólico/metabolismo , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Linfócitos T Citotóxicos/imunologia
12.
J Transl Med ; 9: 25, 2011 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-21375761

RESUMO

The history of ascorbic acid (AA) and cancer has been marked with controversy. Clinical studies evaluating AA in cancer outcome continue to the present day. However, the wealth of data suggesting that AA may be highly beneficial in addressing cancer-associated inflammation, particularly progression to systemic inflammatory response syndrome (SIRS) and multi organ failure (MOF), has been largely overlooked. Patients with advanced cancer are generally deficient in AA. Once these patients develop septic symptoms, a further decrease in ascorbic acid levels occurs. Given the known role of ascorbate in: a) maintaining endothelial and suppression of inflammatory markers; b) protection from sepsis in animal models; and c) direct antineoplastic effects, we propose the use of ascorbate as an adjuvant to existing modalities in the treatment and prevention of cancer-associated sepsis.


Assuntos
Ácido Ascórbico/administração & dosagem , Ácido Ascórbico/uso terapêutico , Neoplasias/complicações , Sepse/tratamento farmacológico , Sepse/prevenção & controle , Ácido Ascórbico/farmacologia , Deficiência de Ácido Ascórbico/complicações , Endotélio/efeitos dos fármacos , Endotélio/fisiopatologia , Humanos , Imunidade/efeitos dos fármacos , Injeções Intravenosas , Sepse/etiologia , Sepse/fisiopatologia
13.
J Transl Med ; 8: 133, 2010 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-21159162

RESUMO

BACKGROUND: Apoptosis is an early event involved in cardiomyopathy associated with diabetes mellitus. Toll-like receptor (TLR) signaling triggers cell apoptosis through multiple mechanisms. Up-regulation of TLR4 expression has been shown in diabetic mice. This study aimed to delineate the role of TLR4 in myocardial apoptosis, and to block this process through gene silencing of TLR4 in the myocardia of diabetic mice. METHODS: Diabetes was induced in C57/BL6 mice by the injection of streptozotocin. Diabetic mice were treated with 50 µg of TLR4 siRNA or scrambled siRNA as control. Myocardial apoptosis was determined by TUNEL assay. RESULTS: After 7 days of hyperglycemia, the level of TLR4 mRNA in myocardial tissue was significantly elevated. Treatment of TLR4 siRNA knocked down gene expression as well as diminished its elevation in diabetic mice. Apoptosis was evident in cardiac tissues of diabetic mice as detected by a TUNEL assay. In contrast, treatment with TLR4 siRNA minimized apoptosis in myocardial tissues. Mechanistically, caspase-3 activation was significantly inhibited in mice that were treated with TLR4 siRNA, but not in mice treated with control siRNA. Additionally, gene silencing of TLR4 resulted in suppression of apoptotic cascades, such as Fas and caspase-3 gene expression. TLR4 deficiency resulted in inhibition of reactive oxygen species (ROS) production and NADPH oxidase activity, suggesting suppression of hyperglycemia-induced apoptosis by TLR4 is associated with attenuation of oxidative stress to the cardiomyocytes. CONCLUSIONS: In summary, we present novel evidence that TLR4 plays a critical role in cardiac apoptosis. This is the first demonstration of the prevention of cardiac apoptosis in diabetic mice through silencing of the TLR4 gene.


Assuntos
Apoptose/genética , Inativação Gênica , Hiperglicemia/prevenção & controle , Miocárdio/patologia , Receptor 4 Toll-Like/genética , Animais , Caspase 3/metabolismo , Inibidores de Caspase , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Experimental/patologia , Hiperglicemia/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Miocárdio/enzimologia , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptor 4 Toll-Like/metabolismo , Regulação para Cima/genética
14.
Int Arch Med ; 3: 30, 2010 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-21070647

RESUMO

Cellular therapy for spinal cord injury (SCI) is overviewed focusing on bone marrow mononuclear cells, olfactory ensheathing cells, and mesenchymal stem cells. A case is made for the possibility of combining cell types, as well as for allogeneic use. We report the case of 29 year old male who suffered a crush fracture of the L1 vertebral body, lacking lower sensorimotor function, being a score A on the ASIA scale. Stem cell therapy comprised of intrathecal administration of allogeneic umbilical cord blood ex-vivo expanded CD34 and umbilical cord matrix MSC was performed 5 months, 8 months, and 14 months after injury. Cell administration was well tolerated with no adverse effects observed. Neuropathic pain subsided from intermittent 10/10 to once a week 3/10 VAS. Recovery of muscle, bowel and sexual function was noted, along with a decrease in ASIA score to "D". This case supports further investigation into allogeneic-based stem cell therapies for SCI.

15.
Cell Immunol ; 263(2): 138-47, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20434139

RESUMO

Induction of tumor-specific immunity is an attractive approach to cancer therapy, however to date every major pivotal trial has resulted in failure. While the phenomena of tumor-mediated immune suppression has been known for decades, only recently have specific molecular pathways been elucidated, and for the first time, rationale means of intervening and observing results of intervention have been developed. In this review we describe major advances in our understanding of tumor escape from immunological pressure and provide some possible therapeutic scenarios for enhancement of efficacy in future cancer vaccine trials.


Assuntos
Antígenos de Neoplasias , Vacinas Anticâncer/imunologia , Vacinas Anticâncer/uso terapêutico , Neoplasias/imunologia , Neoplasias/terapia , Células Dendríticas/imunologia , Humanos , Tolerância Imunológica/imunologia , Estresse Oxidativo , Linfócitos T/imunologia
16.
J Transl Med ; 8: 16, 2010 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-20158898

RESUMO

The medical use of low level laser (LLL) irradiation has been occurring for decades, primarily in the area of tissue healing and inflammatory conditions. Despite little mechanistic knowledge, the concept of a non-invasive, non-thermal intervention that has the potential to modulate regenerative processes is worthy of attention when searching for novel methods of augmenting stem cell-based therapies. Here we discuss the use of LLL irradiation as a "photoceutical" for enhancing production of stem cell growth/chemoattractant factors, stimulation of angiogenesis, and directly augmenting proliferation of stem cells. The combination of LLL together with allogeneic and autologous stem cells, as well as post-mobilization directing of stem cells will be discussed.


Assuntos
Terapia com Luz de Baixa Intensidade , Doença Pulmonar Obstrutiva Crônica/terapia , Células-Tronco , Animais , Diferenciação Celular/efeitos da radiação , Proliferação de Células/efeitos da radiação , Ensaios Clínicos como Assunto , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Neovascularização Fisiológica/efeitos da radiação , Transplante de Células-Tronco , Células-Tronco/fisiologia , Células-Tronco/efeitos da radiação
17.
J Transl Med ; 6: 37, 2008 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-18644158

RESUMO

Advances in cancer therapy have been substantial in terms of molecular understanding of disease mechanisms, however these advances have not translated into increased survival in the majority of cancer types. One unsolved problem in current cancer therapeutics is the substantial immune suppression seen in patients. Conventionally, investigations in this area have focused on antigen-nonspecific immune suppressive molecules such as cytokines and T cell apoptosis inducing molecules such as Fas ligand. More recently, studies have demonstrated nanovesicle particles termed exosomes are involved not only in stimulation but also inhibition of immunity in physiological conditions. Interestingly, exosomes secreted by cancer cells have been demonstrated to express tumor antigens, as well as immune suppressive molecules such as PD-1L and FasL. Concentrations of exosomes from plasma of cancer patients have been associated with spontaneous T cell apoptosis, which is associated in some situations with shortened survival. In this paper we place the "exosome-immune suppression" concept in perspective of other tumor immune evasion mechanisms. We conclude by discussing a novel therapeutic approach to cancer immune suppression by extracorporeal removal of exosomes using hollow fiber filtration technology.


Assuntos
Endossomos/imunologia , Hemofiltração/instrumentação , Imunoterapia , Neoplasias/terapia , Evasão Tumoral/imunologia , Apoptose , Endossomos/patologia , Proteína Ligante Fas/imunologia , Hemofiltração/métodos , Humanos , Neoplasias/genética , Neoplasias/imunologia , Linfócitos T/imunologia
18.
J Transl Med ; 5: 57, 2007 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-18005405

RESUMO

Angiogenesis is a critical component of the proliferative endometrial phase of the menstrual cycle. Thus, we hypothesized that a stem cell-like population exist and can be isolated from menstrual blood. Mononuclear cells collected from the menstrual blood contained a subpopulation of adherent cells which could be maintained in tissue culture for >68 doublings and retained expression of the markers CD9, CD29, CD41a, CD44, CD59, CD73, CD90 and CD105, without karyotypic abnormalities. Proliferative rate of the cells was significantly higher than control umbilical cord derived mesenchymal stem cells, with doubling occurring every 19.4 hours. These cells, which we termed "Endometrial Regenerative Cells" (ERC) were capable of differentiating into 9 lineages: cardiomyocytic, respiratory epithelial, neurocytic, myocytic, endothelial, pancreatic, hepatic, adipocytic, and osteogenic. Additionally, ERC produced MMP3, MMP10, GM-CSF, angiopoietin-2 and PDGF-BB at 10-100,000 fold higher levels than two control cord blood derived mesenchymal stem cell lines. Given the ease of extraction and pluripotency of this cell population, we propose ERC as a novel alternative to current stem cells sources.


Assuntos
Endométrio/citologia , Células-Tronco/citologia , Sangue/metabolismo , Adesão Celular , Técnicas de Cultura de Células , Diferenciação Celular , Linhagem da Célula , Proliferação de Células , Feminino , Humanos , Cariotipagem , Ciclo Menstrual , Neovascularização Fisiológica , Fenótipo
19.
Eur J Gastroenterol Hepatol ; 17(1): 33-5, 2005 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-15647637

RESUMO

Budd-Chiari syndrome (BCS) is a rare but potentially life-threatening disorder caused by hepatic venous obstruction, distinct from cardiac causes of hepatic congestion or sinusoidal obstruction syndrome (formerly known as veno-occlusive disease). BCS may be classified as primary or secondary, depending on the underlying process. Most cases of primary BCS are due to an underlying hypercoagulable disorder. A high index of suspicion is required to make the diagnosis. In most case series, chronic, indolent cases of BCS are more common than acute presentations. Doppler ultrasound, magnetic resonance imaging (MRI), and direct venography are useful in confirming the diagnosis. Systemic anticoagulation should be started expeditiously, as long as there are no contraindications. The use of systemic thrombolysis remains controversial. However, thrombolysis may prove effective when it is administered locally following hepatic venoplasty with or without stenting. Guidelines for the management of more complex cases and of patients who fail medical management are currently in evolution. Budd-Chiari syndrome (BCS) is potentially life-threatening, depending on the extent and rapidity of hepatic venous obstruction. A high index of suspicion is required to clinch the diagnosis, since BCS may be quite indolent or even asymptomatic. Doppler ultrasound or magnetic resonance imaging (MRI) is usually definitive. Systemic anticoagulation should be offered to all patients, unless contraindicated. The role of thrombolysis in BCS remains controversial, and thus it should be reserved for cases undergoing hepatic decompression via percutaneous angioplasty. Guidelines for the management of cases who fail standard medical management are currently in evolution.


Assuntos
Síndrome de Budd-Chiari/diagnóstico , Síndrome de Budd-Chiari/etiologia , Síndrome de Budd-Chiari/terapia , Humanos , Infecções/complicações , Trombofilia/complicações
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