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1.
R Soc Open Sci ; 11(9): 240682, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39323554

RESUMO

We tested whether large language models (LLMs) can help predict results from a complex behavioural science experiment. In study 1, we investigated the performance of the widely used LLMs GPT-3.5 and GPT-4 in forecasting the empirical findings of a large-scale experimental study of emotions, gender, and social perceptions. We found that GPT-4, but not GPT-3.5, matched the performance of a cohort of 119 human experts, with correlations of 0.89 (GPT-4), 0.07 (GPT-3.5) and 0.87 (human experts) between aggregated forecasts and realized effect sizes. In study 2, providing participants from a university subject pool the opportunity to query a GPT-4 powered chatbot significantly increased the accuracy of their forecasts. Results indicate promise for artificial intelligence (AI) to help anticipate-at scale and minimal cost-which claims about human behaviour will find empirical support and which ones will not. Our discussion focuses on avenues for human-AI collaboration in science.

2.
Eur J Med Res ; 29(1): 361, 2024 Jul 11.
Artigo em Inglês | MEDLINE | ID: mdl-38992689

RESUMO

BACKGROUND: Liver grafts are frequently declined due to high donor age or age mismatch with the recipient. To improve the outcome of marginal grafts, we aimed to characterize the performance of elderly vs. young liver grafts in a standardized rat model of normothermic ex vivo liver machine perfusion (NMP). METHODS: Livers from Sprague-Dawley rats aged 3 or 12 months were procured and perfused for 6 h using a rat NMP system or collected as a reference group (n = 6/group). Tissue, bile, and perfusate samples were used for biochemical, and proteomic analyses. RESULTS: All livers cleared lactate during perfusion and continued to produce bile after 6 h of perfusion (614 mg/h). Peak urea levels in 12-month-old animals were higher than in younger animals. Arterial and portal venous pressure, bile production and pH did not differ between groups. Proteomic analysis identified a total of 1477 proteins with oxidoreductase and catalytic activity dominating the gene ontology analysis. Proteins such as aldehyde dehydrogenase 1A1 and 2-Hydroxyacid oxidase 2 were significantly more present in livers of older age. CONCLUSIONS: Young and elderly liver grafts exhibited similar viability during NMP, though proteomic analyses indicated that older grafts are less resilient to oxidative stress. Our study is limited by the elderly animal age, which corresponds to mature but not elderly human age typically seen in marginal human livers. Nevertheless, reducing oxidative stress could be a promising therapeutic target in the future.


Assuntos
Transplante de Fígado , Fígado , Perfusão , Proteômica , Ratos Sprague-Dawley , Animais , Fígado/metabolismo , Ratos , Perfusão/métodos , Transplante de Fígado/métodos , Proteômica/métodos , Masculino , Preservação de Órgãos/métodos , Humanos , Estresse Oxidativo , Envelhecimento/metabolismo
3.
Front Immunol ; 15: 1395945, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38799435

RESUMO

Acute cellular rejection remains a significant obstacle affecting successful outcomes of organ transplantation including vascularized composite tissue allografts (VCA). Donor antigen presenting cells (APCs), particularly dendritic cells (DCs), orchestrate early alloimmune responses by activating recipient effector T cells. Employing a targeted approach, we investigated the impact of donor-derived conventional DCs (cDCs) and APCs on the immunogenicity of skin and skin-containing VCA grafts, using mouse models of skin and hind limb transplantation. By post-transplantation day 6, skin grafts demonstrated severe rejections, characterized by predominance of recipient CD4 T cells. In contrast, hind limb grafts showed moderate rejection, primarily infiltrated by CD8 T cells. Notably, the skin component exhibited heightened immunogenicity when compared to the entire VCA, evidenced by increased frequencies of pan (CD11b-CD11c+), mature (CD11b-CD11c+MHCII+) and active (CD11b-CD11c+CD40+) DCs and cDC2 subset (CD11b+CD11c+ MHCII+) in the lymphoid tissues and the blood of skin transplant recipients. While donor depletion of cDC and APC reduced frequencies, maturation and activation of DCs in all analyzed tissues of skin transplant recipients, reduction in DC activities was only observed in the spleen of hind limb recipients. Donor cDC and APC depletion did not impact all lymphocyte compartments but significantly affected CD8 T cells and activated CD4 T in lymph nodes of skin recipients. Moreover, both donor APC and cDC depletion attenuated the Th17 immune response, evident by significantly reduced Th17 (CD4+IL-17+) cells in the spleen of skin recipients and reduced levels of IL-17E and lymphotoxin-α in the serum samples of both skin and hind limb recipients. In conclusion, our findings underscore the highly immunogenic nature of skin component in VCA. The depletion of donor APCs and cDCs mitigates the immunogenicity of skin grafts while exerting minimal impact on VCA.


Assuntos
Células Dendríticas , Rejeição de Enxerto , Membro Posterior , Transplante de Pele , Animais , Células Dendríticas/imunologia , Camundongos , Membro Posterior/imunologia , Membro Posterior/transplante , Rejeição de Enxerto/imunologia , Rejeição de Enxerto/prevenção & controle , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos BALB C , Aloenxertos Compostos/imunologia , Alotransplante de Tecidos Compostos Vascularizados/métodos , Linfócitos T CD8-Positivos/imunologia , Masculino , Doadores de Tecidos , Pele/imunologia
4.
Artigo em Inglês | MEDLINE | ID: mdl-38693698

RESUMO

INTRODUCTION: Uterus transplantation has revolutionized reproductive medicine for women with absolute uterine factor infertility, resulting in more than 40 reported successful live births worldwide to date. Small animal models are pivotal to refine this surgical and immunological challenging procedure aiming to enhance safety for both the mother and the child. MATERIAL AND METHODS: We established a syngeneic bicornuate uterus transplantation model in young female Lewis rats. All surgical procedures were conducted by an experienced and skilled microsurgeon who organized the learning process into multiple structured steps. Animals underwent meticulous preoperative preparation and postoperative care. Transplant success was monitored by sequential biopsies, monitoring graft viability and documenting histological changes long-term. RESULTS: Bicornuate uterus transplantation were successfully established achieving an over 70% graft survival rate with the passage of time. The bicornuate model demonstrated safety and feasibility, yielding outcomes comparable to the unicornuate model in terms of ischemia times and complications. Longitudinal biopsies were well-tolerated, enabling comprehensive monitoring throughout the study. CONCLUSIONS: Our novel bicornuate rat uterus transplantation model provides a distinctive opportunity for sequential biopsies at various intervals after transplantation and, therefore, comprehensive monitoring of graft health, viability, and identification of potential signs of rejection. Furthermore, this model allows for different interventions in each horn for comparative studies without interobserver differences contrary to the established unicornuate model. By closely replicating the clinical setting, this model stands as a valuable tool for ongoing research in the field of uterus transplantation, promoting further innovation and deeper insights into the intricacies of the uterus transplant procedure.

5.
Biomarkers ; 25(1): 62-68, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31701763

RESUMO

Context: Alcoholic liver cirrhosis is a significant risk factor for the development of hepatocellular carcinoma (HCC). The importance of tumour-associated cirrhosis in the development or progression of HCC is not understood. MiRNAs are important regulators for HCC development, but their role in HCC due to alcoholic liver cirrhosis is unclear.Objective: The aim of this study is the detection of miRNA expression in alcoholic liver cirrhosis, tumour-associated cirrhosis, and HCC.Materials and methods: We analysed the differences in the miRNA profiles of HCC, tumour-associated cirrhosis, and cirrhosis without HCC samples from 30 patients who underwent liver transplantation because of alcoholic liver disease.Results: Microarray analyses revealed 40 significantly differentially expressed miRNAs between HCC tissue and tumour-associated cirrhosis tissue. Furthermore, the microarray analysis discovered 56 differentially expressed miRNAs in tumour-associated cirrhosis and cirrhosis without HCC.Discussion: The differences of miRNA profile in alcoholic liver cirrhosis with and without HCC could improve understanding of HCC development, as well as lead to a new diagnostic tool in HCC screening.Conclusion: We were able to show for the first time, the differences of miRNA profile as promising biomarker in HCC, tumour-associated cirrhosis, and cirrhosis without HCC in context of alcoholic liver disease.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma Hepatocelular/genética , Perfilação da Expressão Gênica , Cirrose Hepática Alcoólica/genética , Neoplasias Hepáticas/genética , MicroRNAs/genética , Transcriptoma , Adulto , Carcinoma Hepatocelular/etiologia , Feminino , Alemanha , Humanos , Cirrose Hepática Alcoólica/etiologia , Neoplasias Hepáticas/etiologia , Masculino , Pessoa de Meia-Idade
6.
Tissue Eng Part C Methods ; 24(3): 179-186, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29382276

RESUMO

The need for primary human hepatocytes is constantly growing for basic research, as well as for therapeutic applications. However, the isolation outcome strongly depends on the quality of liver tissue, and we are still lacking a preoperative test that allows the prediction of the hepatocyte isolation outcome. In this study, we evaluated the "maximal liver function capacity test" (LiMAx) as predictive test for the quantitative and qualitative outcome of hepatocyte isolation. This test is already used in clinical routine to measure preoperative and to predict postoperative liver function. The patient's preoperative mean LiMAx was obtained from the patient records, and preoperative computed tomography and magnetic resonance images were used to calculate the whole liver volume to adjust the mean LiMAx. The outcome parameters of the hepatocyte isolation procedures were analyzed in correlation with the adjusted mean LiMAx. Primary human hepatocytes were isolated from partial hepatectomies (n = 64). From these 64 hepatectomies we included 48 to our study and correlated their isolation outcome parameters with volume corrected LiMAx values. From a total of 11 hepatocyte isolation procedures, metabolic parameters (albumin, urea, and aspartate aminotransferase or AST) were assessed during the hepatocyte cultivation period of 5 days. The volume adjusted mean LiMAx showed a significant positive correlation with the total cell yield (p = 0.049; r = 0.242; n = 48). The correlations of volume adjusted LiMAx values with viable cell yield and cell viability did not reach statistical significance. To create a more homogenous study group regarding tumor entities, subgroup analyses were performed. A subgroup analysis of isolations from patients with colorectal metastasis revealed a significant correlation between volume adjusted mean LiMAx and total cell yield (p = 0.012; r = 0.488; n = 21) and viable cell yield (p = 0.034; r = 0.405; n = 21), whereas a subgroup analysis of isolations of patients with carcinoma of the biliary tree showed significant correlations of volume adjusted mean LiMAx with cell viability (r = 0.387; p = 0.046; n = 20) and lacked significant correlations with total cell yield (r = -0.060; p = 0.401; n = 20) and viable cell yield (r = 0.012; p = 0.480; n = 20). The volume-adjusted mean LiMAx did not show a significant correlation with any of the metabolic parameters. In conclusion, the LiMAx test might be a useful tool to predict the quantitative outcome of hepatocyte isolation, as long as underlying liver disease is taken into consideration.


Assuntos
Separação Celular/métodos , Hepatócitos/citologia , Hepatócitos/fisiologia , Testes de Função Hepática/métodos , Neoplasias Hepáticas/patologia , Idoso , Células Cultivadas , Feminino , Hepatectomia , Humanos , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/cirurgia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
7.
Tissue Eng Part C Methods ; 23(7): 412-421, 2017 07.
Artigo em Inglês | MEDLINE | ID: mdl-28537490

RESUMO

INTRODUCTION: Labeling using iron oxide particles enables cell tracking through magnetic resonance imaging (MRI). However, the magnetic field can affect the particle-labeled cells. Here, we investigated the effects of a clinical MRI system on primary human hepatocytes labeled using micrometer-sized iron oxide particles (MPIOs). METHODS: HuH7 tumor cells were incubated with increasing concentrations of biocompatible, silica-based, micrometer-sized iron oxide-containing particles (sMPIOs; 40-160 particles/cell). Primary human hepatocytes were incubated with 100 sMPIOs/cell. The particle-labeled cells and the native cells were imaged using a clinical 3.0 T MRI system, whereas the control groups of the labeled and unlabeled cells were kept at room temperature without exposure to a magnetic field. Viability, formation of reactive oxygen species (ROS), aspartate aminotransferase leakage, and urea and albumin synthesis were assessed for a culture period of 5 days. RESULTS: The dose finding study showed no adverse effects of the sMPIOs labeling on HuH7 cells. MRI had no adverse effects on the morphology of the sMPIO-labeled primary human hepatocytes. Imaging using the T1- and T2-weighted sequences did not affect the viability, transaminase leakage, formation of ROS, or metabolic activity of the sMPIO-labeled cells or the unlabeled, primary human hepatocytes. CONCLUSION: sMPIOs did not induce adverse effects on the labeled cells under the conditions of the magnetic field of a clinical MRI system.


Assuntos
Hepatócitos/metabolismo , Campos Magnéticos , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita/química , Espécies Reativas de Oxigênio/metabolismo , Linhagem Celular Tumoral , Hepatócitos/citologia , Humanos , Coloração e Rotulagem
8.
J Tissue Eng Regen Med ; 11(2): 531-541, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-25185781

RESUMO

One approach of regenerative medicine to generate functional hepatic tissue in vitro is decellularization and recellularization, and several protocols for the decellularization of livers of different species have been published. This appears to be the first report on rat liver decellularization by perfusion under oscillating pressure conditions, intending to optimize microperfusion and minimize damage to the ECM. Four decellularization protocols were compared: perfusion via the portal vein (PV) or the hepatic artery (HA), with (+P) or without (-P) oscillating pressure conditions. All rat livers (n = 24) were perfused with 1% Triton X-100 and 1% sodium dodecyl sulphate, each for 90 min with a perfusion rate of 5 ml/min. Perfusion decellularization was observed macroscopically and the decellularized liver matrices were analysed by histology and biochemical analyses (e.g. levels of DNA, glycosaminoglycans and hepatocyte growth factor). Livers decellularized via the hepatic artery and under oscillating pressure showed a more homogeneous decellularization and less remaining DNA, compared with the livers of the other experimental groups. The novel decellularization method described is effective, quick (3 h) and gentle to the extracellular matrix and thus represents an improvement of existing methodology. Copyright © 2014 John Wiley & Sons, Ltd.


Assuntos
Fígado/fisiologia , Medicina Regenerativa/métodos , Técnicas de Cultura de Tecidos/métodos , Engenharia Tecidual/métodos , Animais , DNA/química , Matriz Extracelular/metabolismo , Glicosaminoglicanos/química , Fator de Crescimento de Hepatócito/química , Masculino , Oscilometria , Perfusão , Pressão , Ratos , Ratos Endogâmicos Lew , Alicerces Teciduais
9.
Biomarkers ; 22(1): 19-27, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27344923

RESUMO

CONTEXT: Bile rather than blood depicts the local inflammation in the liver and may improve prediction and diagnosis of acute cellular rejection (ACR) after liver transplantation (OLT). METHODS: Secretome and miRNAs were analyzed during the first two weeks and on clinical suspicion of ACR in the bile of 45 OLT recipients. RESULTS: Levels of CD44, CXCL9, miR-122, miR-133a, miR-148a and miR-194 were significantly higher in bile of patients who developed ACR within the first 6 months after OLT and during ACR. CONCLUSION: Analysis of secretome and miRNA in bile could improve our understanding of the local inflammatory process during rejection.


Assuntos
Bile/química , Rejeição de Enxerto/diagnóstico , Transplante de Fígado/efeitos adversos , Biomarcadores/análise , Secreções Corporais/química , Humanos , MicroRNAs/análise , Valor Preditivo dos Testes , Proteínas/análise
10.
Biomarkers ; 21(8): 699-707, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27121640

RESUMO

OBJECTIVE: We investigated whether microRNA signatures in whole blood samples are associated with acute cellular rejection (ACR) after liver transplantation. MATERIALS AND METHODS: Blood samples were collected using Paxgene technology and analyzed by microarrays and quantitative real-time polymerase chain reaction (qRT-PCR). RESULTS: microRNA signatures failed to distinguish between 19 patients with ACR and 16 controls. Let-7b-5p and let-7c were upregulated in a subgroup of patients with ACR during the 6th and 7th postoperative days but failed in an independent validation of 20 patients. CONCLUSION: microRNA signatures in whole blood processed by Paxgene technology are not suited for the detection of ACR after liver transplantation.

11.
Tissue Eng Part C Methods ; 22(1): 38-48, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26449914

RESUMO

Primary human hepatocytes are widely used for basic research, pharmaceutical testing, and therapeutic concepts in regenerative medicine. Human hepatocytes can be isolated from resected liver tissue. Preoperative portal vein embolization (PVE) is increasingly used to decrease the risk of delayed postoperative liver regeneration by induction of selective hypertrophy of the future remnant liver tissue. The aim of this study was to investigate the effect of PVE on the outcome of hepatocyte isolation. Primary human hepatocytes were isolated from liver tissue obtained from partial hepatectomies (n = 190) using the two-step collagenase perfusion technique followed by Percoll purification. Of these hepatectomies, 27 isolations (14.2%) were performed using liver tissue obtained from patients undergoing PVE before surgery. All isolations were characterized using parameters that had been described in the literature as relevant for the outcome of hepatocyte isolation. The isolation outcomes of the PVE and the non-PVE groups were then compared before and after Percoll purification. Metabolic parameters (transaminases, urea, albumin, and vascular endothelial growth factor secretion) were measured in the supernatant of cultured hepatocytes for more than 6 days (PVE: n = 4 and non-PVE: n = 3). The PVE and non-PVE groups were similar in regard to donor parameters (sex, age, and indication for surgery), isolation parameters (liver weight and cold ischemia time), and the quality of the liver tissue. The mean initial viable cell yield did not differ between the PVE and non-PVE groups (10.16 ± 2.03 × 10(6) cells/g vs. 9.70 ± 0.73 × 10(6) cells/g, p = 0.499). The initial viability was slightly better in the PVE group (77.8% ± 2.03% vs. 74.4% ± 1.06%). The mean viable cell yield (p = 0.819) and the mean viability (p = 0.141) after Percoll purification did not differ between the groups. PVE had no effect on enzyme leakage and metabolic activity of cultured hepatocytes. Although PVE leads to drastic metabolic alterations and changes in hepatic blood flow, embolized liver tissue is a suitable source for the isolation of primary human hepatocytes and is equivalent to untreated liver tissue in regard to cell yield and viability.


Assuntos
Técnicas de Cultura Celular por Lotes/métodos , Separação Celular/métodos , Embolização Terapêutica/métodos , Hepatócitos/citologia , Hepatócitos/fisiologia , Veia Porta , Sobrevivência Celular/fisiologia , Células Cultivadas , Humanos
12.
BMC Res Notes ; 7: 702, 2014 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-25297646

RESUMO

BACKGROUND: Studies on liver regeneration following partial hepatectomy (PH) have identified several microRNAs (miRNAs) that show a regulated expression pattern. These studies involve major surgery to access the liver, which is known to have intrinsic effects on hepatic gene expression and may also affect miRNA screening results. We performed two-third PH or sham laparotomy (SL) in Wistar rats to investigate the effect of both procedures on miRNA expression in liver tissue and corresponding plasma samples by microarray and qRT-PCR analyses. As control groups, non-treated rats and rats undergoing anesthesia only were used. RESULTS: We found that 49 out of 323 miRNAs (15%) were significantly deregulated after PH in liver tissue 12 to 48 hours postoperatively (>20% change), while 45 miRNAs (14%) were deregulated following SL. Out of these miRNAs, 10 miRNAs were similarly deregulated after PH and SL, while one miRNA showed opposite regulation. In plasma, miRNA upregulation was observed for miR-133a and miR-133b following PH and SL, whereas miR-100 and miR-466c were similarly downregulated following anesthesia and surgery. CONCLUSIONS: We show that miRNAs are indeed regulated by sham laparotomy and anesthesia in rats. These findings illustrate the critical need for finding appropriate control groups in experimental surgery.


Assuntos
Anestesia , Hepatectomia , Fígado/metabolismo , MicroRNAs/sangue , Animais , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real
13.
J Hepatobiliary Pancreat Sci ; 21(8): 607-15, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24733827

RESUMO

BACKGROUND: Innovative treatment concepts targeting essential signaling pathways may offer new chances for patients suffering from cholangiocarcinoma (CCC). For that, we performed a systematic molecular genetic analysis concerning the Hedgehog activity in human CCC samples and analyzed the effect of Hh inhibition on CCC cells in vitro and in vivo. METHODS: Activation of the Hh pathway was analyzed in 50 human CCC samples using quantitative polymerase chain reaction (qPCR). The efficacy of Hh inhibition using cyclopamine and BMS-833923 was evaluated in vitro. In addition, the effect of BMS-833923, alone or in combination with gemcitabine, was analyzed in vivo in a murine subcutaneous xenograft model. RESULTS: Expression analysis revealed a significant activation of the Hh-signaling pathway in nearly 50% of CCCs. Hh inhibition resulted in a significant decrease in cell proliferation of CCC cells. Moreover, a distinct inhibition of tumor growth could be seen as a result of a combined therapy with BMS-833923 and gemcitabine in CCC xenografts. CONCLUSION: The results of our study suggest that the Hh pathway plays a relevant role at least in a subset of human CCC. Inhibition of this pathway may represent a possible treatment option for CCC patients in which the Hh pathway is activated.


Assuntos
Neoplasias dos Ductos Biliares/tratamento farmacológico , Ductos Biliares Intra-Hepáticos , Colangiocarcinoma/tratamento farmacológico , Proteínas Hedgehog/antagonistas & inibidores , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Benzamidas/administração & dosagem , Benzamidas/farmacologia , Células Cultivadas , Feminino , Expressão Gênica , Gentamicinas/administração & dosagem , Gentamicinas/farmacologia , Proteínas Hedgehog/genética , Proteínas Hedgehog/metabolismo , Xenoenxertos , Humanos , Masculino , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Transplante de Neoplasias , Proteínas Oncogênicas/genética , Receptores Patched , Reação em Cadeia da Polimerase , Quinazolinas/administração & dosagem , Quinazolinas/farmacologia , RNA Mensageiro/análise , Receptores de Superfície Celular/genética , Transdução de Sinais/efeitos dos fármacos , Transativadores/genética , Alcaloides de Veratrum/farmacologia , Proteína GLI1 em Dedos de Zinco
14.
Pancreas ; 41(2): 222-9, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22076568

RESUMO

OBJECTIVES: Activation of the hedgehog signal transduction pathway, triggered by hedgehog binding to the transmembrane receptor patched 1 (PTCH1) or by mutations in the PTCH1 gene, plays an important role in the development of various tumors. METHODS: To investigate whether the Hedgehog signaling pathway is also active in human pancreatic adenocarcinomas, we determined the expression levels of the known Hedgehog target genes PTCH1 and GLI-1 in pancreatic tumors. To determine whether alterations in the PTCH1 gene are responsible for this pathway activation, we screened pancreatic carcinomas for mutations in PTCH. To investigate the contribution of hedgehog signaling to the tumorigenicity of pancreatic tumor cells, we blocked the Hedgehog pathway in cultured tumor cells and xenografts using the steroidal alkaloid cyclopamine and the small-molecule Hedgehog inhibitor Hh-Antag. RESULTS: We identified single nucleotide polymorphisms (SNPs) within the PTCH1 gene but no somatic PTCH1 mutations. Pathway-blockage resulted in a significant dose-dependent reduction of tumor cell growth in vitro and in vivo. Moreover, combined treatment with cyclopamine and the conventional antimetabolite gemcitabine revealed a synergistic effect on the reduction of tumor growth in pancreatic adenocarcinoma xenografts. CONCLUSIONS: Inhibition of Hedgehog signaling could be a promising approach for the treatment of pancreatic adenocarcinomas.


Assuntos
Adenocarcinoma/tratamento farmacológico , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Proteínas Hedgehog/antagonistas & inibidores , Neoplasias Pancreáticas/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos , Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Idoso , Animais , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Desoxicitidina/administração & dosagem , Desoxicitidina/análogos & derivados , Relação Dose-Resposta a Droga , Genes Reporter , Proteínas Hedgehog/metabolismo , Humanos , Camundongos , Camundongos Nus , Pessoa de Meia-Idade , Mutação , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patologia , Receptores Patched , Receptor Patched-1 , Polimorfismo de Nucleotídeo Único , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Fatores de Tempo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção , Carga Tumoral/efeitos dos fármacos , Alcaloides de Veratrum/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto , Proteína GLI1 em Dedos de Zinco , Gencitabina
15.
J Health Econ ; 28(3): 728-36, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19344971

RESUMO

This paper investigates the impact of a 'free drug program' on the market equilibrium of drugs. We introduce a screening model of the hard drug market in which dealers use payment and punishment options to screen between high and low risk users. We show that, if a free drug program selects sufficiently many high-risk drug users, the pure-strategy separating market equilibrium ceases to exist and a symmetric mixed-strategy equilibrium results, in which drug users derive a higher expected utility. This encourages new drug users to enter the market. The novelty of the paper is the transmission mechanism for this effect, which is via the influence on market price.


Assuntos
Metadona/economia , Transtornos Relacionados ao Uso de Substâncias/tratamento farmacológico , Humanos , Metadona/uso terapêutico , Modelos Teóricos , Formulação de Políticas , Detecção do Abuso de Substâncias
16.
Transpl Int ; 22(7): 738-46, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19317809

RESUMO

Human recombinant Erythropoietin (rHuEpo) has recently been shown to be a potent protector of ischemia- reperfusion injury in warm-liver ischemia. Significant enhancement of hepatic regeneration and survival after large volume partial hepatic resection has also been demonstrated. It was the aim of this study to evaluate the capacities of rHuEpo in the setting of rat liver transplantation. One-hundred-and-twenty Wistar rats were used: 60 recipients received liver transplantation following donor organ treatment (60 donors) with either 1000 IU rHuEpo or saline injection (controls) into portal veins (cold ischemia 18 h, University of Wisconsin (UW) solution). Recipients were allocated to two groups, which either received 1000 IU rHuEpo at reperfusion or an equal amount of saline (control). Animals were sacrificed at defined time-points (2, 4.5, 24, 48 h and 7 days postoperatively) for analysis of liver enzymes, histology [hematoxylin-eosin (HE) staining, periodic acid Schiff staining (PAS)], immunostaining [terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL), Hypoxyprobe] and real-time polymerase chain reaction (RT-PCR) of cytokine mRNA (IL-1, IL-6). Lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) values were significantly reduced among the epo-treated animals 24 and 48 h after liver transplantation (LT). The TUNEL and Hypoxyprobe analyses as well as necrotic index evaluation displayed significant reduction of apoptosis and necrosis in rHuEpo-treated graft livers. Erythropoietin reduces ischemia-reperfusion injury after orthotopic liver transplantation in rats.


Assuntos
Eritropoetina/fisiologia , Transplante de Fígado/métodos , Traumatismo por Reperfusão , Animais , Apoptose , Humanos , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Isquemia/patologia , Fígado/patologia , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Condicionamento Pré-Transplante
17.
J Gastroenterol Hepatol ; 23(7 Pt 1): 1125-31, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18086112

RESUMO

BACKGROUND AND AIM: It has been proven in various animal studies that recombinant human erythropoietin (rHuEPO) protects renal, cardiac and neuronal, as well as hepatic, tissue from ischemia, and promotes regeneration of adult central nervous system neurons. To date, no data are available as to whether rHuEPO has the ability to stimulate liver regeneration after liver resection. METHODS: Rats undergoing 70% or 90% hepatectomy received an intraportalvenous administration (i.p.) of rHuEPO prior to resection or a subcutaneous injection (s.c.) for 3 days postoperatively, control animals were treated with surgery and saline injection only. Regeneration capacity of remnant livers was studied over 7 days by histology and immunohistochemistry (Ki-67, proliferating cell nuclear antigen [PCNA]). Polymerase chain reaction was carried out to measure transforming growth factor beta (TGF-beta), hypoxia induced factor (HIF), signal transducing activator 3 and vascular endothelial growth factor. RESULTS: Ten-day survival in rats undergoing 90% hepatectomy significantly increased in i.p.-pretreated animals. After 70% hepatectomy the mitotic index was significantly increased in both rHuEPO-treated groups. These data were confirmed by PCNA and Ki-67 expression, which was significantly increased in the treated groups 24 h and 2 days after liver resection. TGF-beta and HIF mRNA both were upregulated in control animals 3 h after surgery. CONCLUSION: rHuEPO effectively increased liver regeneration in rats after 70% liver resection and enhanced survival after 90% hepatectomy. Thus, rHuEPO may increase the regenerative capacity after major hepatectomy.


Assuntos
Eritropoetina/farmacologia , Hepatectomia , Regeneração Hepática/efeitos dos fármacos , Fígado/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Eritropoetina/administração & dosagem , Humanos , Injeções Intravenosas , Injeções Subcutâneas , Antígeno Ki-67/metabolismo , Fígado/metabolismo , Fígado/patologia , Fígado/cirurgia , Masculino , Índice Mitótico , Modelos Animais , Veia Porta , Antígeno Nuclear de Célula em Proliferação/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Proteínas Recombinantes , Fator de Transcrição STAT3/genética , Fator de Transcrição STAT3/metabolismo , Fatores de Tempo , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
18.
J Gastroenterol Hepatol ; 22(5): 738-48, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17444865

RESUMO

BACKGROUND AND AIM: Poly (ADP-ribose) polymerase (PARP) inhibitors such as 3-aminobenzamide (3-ABA) enhance the in vitro cytotoxicity of DNA mono-functional alkylating agents such as radiation or chemotherapeutic agents. The aim of this study was to test an approach combining the PARP inhibitor 3-ABA with standard gemcitabine therapy in human pancreatic cancer cells. METHODS: Cell viability was determined by proliferation assay (XTT). Cell-cycle analysis (FACS), ELISA (M30 Apoptosense), Western blot for caspase 8 and PARP, and electron microscopy were used to identify apoptosis. Tumor growth and survival was assessed in nude mice by subcutaneously injected Capan-1 cells. In addition, Ki67 staining was performed on tumors for cell proliferation and in vivo apoptosis induction was measured by TUNEL assay and ELISA. RESULTS: Combination therapy of gemcitabine and 3-ABA suppressed tumor cell growth more than gemcitabine alone in XTT, FACS and ELISA analysis. CONCLUSION: This in vivo study demonstrated a significantly reduced tumor weight and increased survival up to 40 days after cell inoculation with combination therapy compared to animals treated with PBS, gemcitabine or 3-ABA alone. Furthermore, TUNEL assay revealed a significant apoptosis induction and reduced proliferation in the combination group.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Benzamidas/farmacologia , Desoxicitidina/análogos & derivados , Inibidores Enzimáticos/farmacologia , Neoplasias Pancreáticas/tratamento farmacológico , Inibidores de Poli(ADP-Ribose) Polimerases , Animais , Antimetabólitos Antineoplásicos/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Apoptose/efeitos dos fármacos , Benzamidas/administração & dosagem , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Separação Celular , Sobrevivência Celular/efeitos dos fármacos , Desoxicitidina/administração & dosagem , Desoxicitidina/farmacologia , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Inibidores Enzimáticos/administração & dosagem , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Marcação In Situ das Extremidades Cortadas , Concentração Inibidora 50 , Camundongos , Camundongos Nus , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/patologia , Poli(ADP-Ribose) Polimerases/metabolismo , Fatores de Tempo , Gencitabina
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