Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 26
Filtrar
2.
Diagnostics (Basel) ; 13(7)2023 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-37046507

RESUMO

Accurate classification of pancreatic cystic lesions (PCLs) is important to facilitate proper treatment and to improve patient outcomes. We utilized the convolutional neural network (CNN) of VGG19 to develop a computer-aided diagnosis (CAD) system in the classification of subtypes of PCLs in endoscopic ultrasound-guided needle-based confocal laser endomicroscopy (nCLE). From a retrospectively collected 22,424 nCLE video frames (50 videos) as the training/validation set and 11,047 nCLE video frames (18 videos) as the test set, we developed and compared the diagnostic performance of three CNNs with distinct methods of designating the region of interest. The diagnostic accuracy for subtypes of PCLs by CNNs with manual, maximal rectangular, and U-Net algorithm-designated ROIs was 100%, 38.9%, and 66.7% on a per-video basis and 88.99%, 73.94%, and 76.12% on a per-frame basis, respectively. Our per-frame analysis suggested differential levels of diagnostic accuracy among the five subtypes of PCLs, where non-mucinous PCLs (serous cystic neoplasm: 93.11%, cystic neuroendocrine tumor: 84.31%, and pseudocyst: 98%) had higher diagnostic accuracy than mucinous PCLs (intraductal papillary mucinous neoplasm: 84.43% and mucinous cystic neoplasm: 86.1%). Our CNN demonstrated superior specificity compared to the state-of-the-art for the classification of mucinous PCLs (IPMN and MCN), with high specificity (94.3% and 92.8%, respectively) but low sensitivity (46% and 45.2%, respectively). This suggests the complimentary role of CNN-enabled CAD systems, especially for clinically suspected mucinous PCLs.

3.
Lab Invest ; 102(9): 1023-1037, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35585132

RESUMO

Irritable bowel syndrome (IBS) is characterized by visceral hypersensitivity (VH) associated with abnormal serotonin/5-hydroxytryptamine (5-HT) metabolism and neurotrophin-dependent mucosal neurite outgrowth. The underlying mechanisms of VH remain poorly understood. We investigated the role of 5-HT7 receptor in mucosal innervation and intestinal hyperalgesia. A high density of mucosal nerve fibres stained for 5-HT7 was observed in colonoscopic biopsy specimens from IBS patients compared with those from healthy controls. Staining of 5-HT3 and 5-HT4 receptors was observed mainly in colonic epithelia with comparable levels between IBS and controls. Visceromotor responses to colorectal distension were evaluated in two mouse models, one postinfectious with Giardia and subjected to water avoidance stress (GW) and the other postinflammatory with trinitrobenzene sulfonic acid-induced colitis (PT). Increased VH was associated with higher mucosal density of 5-HT7-expressing nerve fibres and elevated neurotrophin and neurotrophin receptor levels in the GW and PT mice. The increased VH was inhibited by intraperitoneal injection of SB-269970 (a selective 5-HT7 antagonist). Peroral multiple doses of CYY1005 (a novel 5-HT7 ligand) decreased VH and reduced mucosal density of 5-HT7-expressing nerve fibres in mouse colon. Human neuroblastoma SH-SY5Y cells incubated with bacteria-free mouse colonic supernatant, 5-HT, nerve growth factor, or brain-derived neurotrophic factor exhibited nerve fibre elongation, which was inhibited by 5-HT7 antagonists. Gene silencing of HTR7 also reduced the nerve fibre length. Activation of 5-HT7 upregulated NGF and BDNF gene expression, while stimulation with neurotrophins increased the levels of tryptophan hydroxylase 2 and 5-HT7 in neurons. A positive-feedback loop was observed between serotonin and neurotrophin pathways via 5-HT7 activation to aggravate fibre elongation, whereby 5-HT3 and 5-HT4 had no roles. In conclusion, 5-HT7-dependent mucosal neurite outgrowth contributed to VH. A novel 5-HT7 antagonist could be used as peroral analgesics for IBS-related pain.


Assuntos
Síndrome do Intestino Irritável , Neuroblastoma , Animais , Humanos , Mucosa Intestinal , Camundongos , Crescimento Neuronal , Serotonina
4.
Carcinogenesis ; 42(7): 961-974, 2021 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-34000008

RESUMO

Myosin light chain kinase (MLCK) regulates actinomyosin contraction. Two splice variants of long MLCK are expressed in epithelial cells and divergently regulate gut barrier functions; reduced MLCK levels in human colorectal cancers (CRC) with unclarified significance have been reported. CRC are solid tumors clonally sustained by stem cells highly expressing CD44 and CD133. The aim was to investigate the role of MLCK splice variants in CRC tumorigenesis. We found lower MLCK1/2 and higher CD44 expression in human CRC, but no change in CD133 or LGR5. Large-scale bioinformatics showed an inverse relationship between MYLK and CD44 in human sample gene datasets. A 3-fold increased tumor burden was observed in MLCK(-/-) mice compared with wild-type (WT) mice in a chemical-induced CRC model. Primary tumorspheres derived from the MLCK(-/-) mice displayed larger sizes and higher CD44 transcript levels than those from the WT mice. Bioinformatics revealed binding of TEAD4 (a transcriptional enhancer factor family member in the Hippo pathway) to CD44 promoter, which was confirmed by luciferase reporter assay. Individually expressing MLCK1 and MLCK2 variants in the MLCK-knockout (KO) Caco-2 cells inhibited the nuclear localization of TEAD4 cofactors, VGLL3 and YAP1, respectively, and both variants reduced the CD44 transcription. Accelerated cell cycle transit was observed in the MLCK-KO cells, whereby expression of MLCK1/2 variants counterbalanced the cell hyperproliferation. In conclusion, MLCK1/2 variants are novel tumor suppressors by downregulating the TEAD4/CD44 axis via reducing nuclear translocation of distinct transcriptional coactivators. The reduction of epithelial MLCKs, especially isoform 2, may drive cancer stemness and tumorigenesis.


Assuntos
Processamento Alternativo , Biomarcadores Tumorais/metabolismo , Neoplasias do Colo/patologia , Proteínas de Ligação a DNA/metabolismo , Regulação Neoplásica da Expressão Gênica , Receptores de Hialuronatos/metabolismo , Proteínas Musculares/metabolismo , Quinase de Cadeia Leve de Miosina/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Apoptose , Biomarcadores Tumorais/genética , Ciclo Celular , Movimento Celular , Proliferação de Células , Neoplasias do Colo/genética , Neoplasias do Colo/metabolismo , Proteínas de Ligação a DNA/genética , Humanos , Receptores de Hialuronatos/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas Musculares/genética , Quinase de Cadeia Leve de Miosina/genética , Fosforilação , Prognóstico , Taxa de Sobrevida , Fatores de Transcrição de Domínio TEA , Fatores de Transcrição/genética , Células Tumorais Cultivadas , Proteínas de Sinalização YAP
5.
Front Oncol ; 9: 1282, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31824857

RESUMO

Reprogrammed glucose metabolism and increased glycolysis have been implicated in tumor chemoresistance. The aim was to investigate the distinct roles of the glucose metabolites pyruvate and ATP in chemoresistance mechanisms, including cell death and proliferation. Our data showed higher glucose transporters in colorectal cancer (CRC) from non-responsive patients than those responsive to chemotherapy. Human CRC cell lines exposed to 5-fluorouracil (5-FU) displayed elevated cell viability and larger tumors in xenograft mouse models if cultured in high-glucose medium. Glucose conferred resistance to 5-FU-induced necroptosis via pyruvate scavenging of mitochondrial free radicals, whereas ATP replenishment had no effect on cell death. Glucose attenuated the 5-FU-induced G0/G1 shift but not the S phase arrest. Opposing effects were observed by glucose metabolites; ATP increased while pyruvate decreased the G0/G1 shift. Lastly, 5-FU-induced tumor spheroid destruction was prevented by glucose and pyruvate, but not by ATP. Our finding argues against ATP as the main effector for glucose-mediated chemoresistance and supports a key role of glycolytic pyruvate as an antioxidant for dual modes of action: necroptosis reduction and a cell cycle shift to a quiescent state.

6.
Gastrointest Endosc ; 87(5): 1339-1344, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29225083

RESUMO

BACKGROUND AND AIMS: Magnifying narrow-band imaging (M-NBI) is important in the diagnosis of early gastric cancers (EGCs) but requires expertise to master. We developed a computer-aided diagnosis (CADx) system to assist endoscopists in identifying and delineating EGCs. METHODS: We retrospectively collected and randomly selected 66 EGC M-NBI images and 60 non-cancer M-NBI images into a training set and 61 EGC M-NBI images and 20 non-cancer M-NBI images into a test set. After preprocessing and partition, we determined 8 gray-level co-occurrence matrix (GLCM) features for each partitioned 40 × 40 pixel block and calculated a coefficient of variation of 8 GLCM feature vectors. We then trained a support vector machine (SVMLv1) based on variation vectors from the training set and examined in the test set. Furthermore, we collected 2 determined P and Q GLCM feature vectors from cancerous image blocks containing irregular microvessels from the training set, and we trained another SVM (SVMLv2) to delineate cancerous blocks, which were compared with expert-delineated areas for area concordance. RESULTS: The diagnostic performance revealed accuracy of 96.3%, precision (positive predictive value [PPV]) of 98.3%, recall (sensitivity) of 96.7%, and specificity of 95%, at a rate of 0.41 ± 0.01 seconds per image. The performance of area concordance, on a block basis, demonstrated accuracy of 73.8% ± 10.9%, precision (PPV) of 75.3% ± 20.9%, recall (sensitivity) of 65.5% ± 19.9%, and specificity of 80.8% ± 17.1%, at a rate of 0.49 ± 0.04 seconds per image. CONCLUSIONS: This pilot study demonstrates that our CADx system has great potential in real-time diagnosis and delineation of EGCs in M-NBI images.


Assuntos
Diagnóstico por Computador/métodos , Gastroscopia/métodos , Processamento de Imagem Assistida por Computador/métodos , Imagem de Banda Estreita/métodos , Neoplasias Gástricas/diagnóstico por imagem , Idoso , Estudos de Casos e Controles , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
7.
Dig Dis Sci ; 62(6): 1498-1510, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28144894

RESUMO

BACKGROUND: Intestinal ischemia/reperfusion (I/R) causes barrier impairment and bacterial influx. Protection against I/R injury in sterile organs by hypoxic preconditioning (HPC) had been attributed to erythropoietic and angiogenic responses. Our previous study showed attenuation of intestinal I/R injury by HPC for 21 days in a neutrophil-dependent manner. AIM: To investigate the underlying mechanisms of neutrophil priming by HPC, and explore whether adoptive transfer of primed neutrophils is sufficient to ameliorate intestinal I/R injury. METHODS: Rats raised in normoxia (NM) and HPC for 3 or 7 days were subjected to sham operation or superior mesenteric artery occlusion for I/R challenge. Neutrophils isolated from rats raised in NM or HPC for 21 days were intravenously injected into naïve controls prior to I/R. RESULTS: Similar to the protective effect of HPC-21d, I/R-induced mucosal damage was attenuated by HPC-7d but not by HPC-3d. Naïve rats reconstituted with neutrophils of HPC-21d rats showed increase in intestinal phagocytic infiltration and myeloperoxidase activity, and barrier protection against I/R insult. Elevated free radical production, and higher bactericidal and phagocytic activity were observed in HPC neutrophils compared to NM controls. Moreover, increased serum levels of tumor necrosis factor α (TNFα) and cytokine-induced neutrophil chemoattractant-1 (CINC-1) were seen in HPC rats. Naïve neutrophils incubated with HPC serum or recombinant TNFα, but not CINC-1, exhibited heightened respiratory burst and bactericidal activity. Lastly, neutrophil priming effect was abolished by neutralization of TNFα in HPC serum. CONCLUSIONS: TNFα-primed neutrophils by HPC act as effectors cells for enhancing barrier integrity under gut ischemia.


Assuntos
Translocação Bacteriana , Mucosa Intestinal/irrigação sanguínea , Precondicionamento Isquêmico , Neutrófilos/fisiologia , Neutrófilos/transplante , Traumatismo por Reperfusão/prevenção & controle , Fator de Necrose Tumoral alfa/sangue , Animais , Atividade Bactericida do Sangue , Células Cultivadas , Quimiocina CXCL1/sangue , Quimiocina CXCL1/farmacologia , Radicais Livres/metabolismo , Mucosa Intestinal/patologia , Intestinos/irrigação sanguínea , Intestinos/microbiologia , Masculino , Ativação de Neutrófilo , Fagocitose , Ratos , Ratos Wistar , Proteínas Recombinantes/farmacologia , Traumatismo por Reperfusão/patologia , Explosão Respiratória/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
8.
J Physiol ; 595(2): 505-521, 2017 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-27121603

RESUMO

KEY POINTS: Intestinal ischaemia causes epithelial death and crypt dysfunction, leading to barrier defects and gut bacteria-derived septic complications. Enteral glucose protects against ischaemic injury; however, the roles played by glucose metabolites such as pyruvate and ATP on epithelial death and crypt dysfunction remain elusive. A novel form of necrotic death that involves the assembly and phosphorylation of receptor interacting protein kinase 1/3 complex was found in ischaemic enterocytes. Pyruvate suppressed epithelial cell death in an ATP-independent manner and failed to maintain crypt function. Conversely, replenishment of ATP partly restored crypt proliferation but had no effect on epithelial necroptosis in ischaemic gut. Our data argue against the traditional view of ATP as the main cytoprotective factor by glucose metabolism, and indicate a novel anti-necroptotic role of glycolytic pyruvate under ischaemic stress. ABSTRACT: Mesenteric ischaemia/reperfusion induces epithelial death in both forms of apoptosis and necrosis, leading to villus denudation and gut barrier damage. It remains unclear whether programmed cell necrosis [i.e. receptor-interacting protein kinase (RIP)-dependent necroptosis] is involved in ischaemic injury. Previous studies have demonstrated that enteral glucose uptake by sodium-glucose transporter 1 ameliorated ischaemia/reperfusion-induced epithelial injury, partly via anti-apoptotic signalling and maintenance of crypt proliferation. Glucose metabolism is generally assumed to be cytoprotective; however, the roles played by glucose metabolites (e.g. pyruvate and ATP) on epithelial cell death and crypt dysfunction remain elusive. The present study aimed to investigate the cytoprotective effects exerted by distinct glycolytic metabolites in ischaemic gut. Wistar rats subjected to mesenteric ischaemia were enterally instilled glucose, pyruvate or liposomal ATP. The results showed that intestinal ischaemia caused RIP1-dependent epithelial necroptosis and villus destruction accompanied by a reduction in crypt proliferation. Enteral glucose uptake decreased epithelial cell death and increased crypt proliferation, and ameliorated mucosal histological damage. Instillation of cell-permeable pyruvate suppressed epithelial cell death in an ATP-independent manner and improved the villus morphology but failed to maintain crypt function. Conversely, the administration of liposomal ATP partly restored crypt proliferation but did not reduce epithelial necroptosis and histopathological injury. Lastly, glucose and pyruvate attenuated mucosal-to-serosal macromolecular flux and prevented enteric bacterial translocation upon blood reperfusion. In conclusion, glucose metabolites protect against ischaemic injury through distinct modes and sites, including inhibition of epithelial necroptosis by pyruvate and the promotion of crypt proliferation by ATP.


Assuntos
Trifosfato de Adenosina/metabolismo , Enterócitos/metabolismo , Enterócitos/patologia , Glucose/metabolismo , Ácido Pirúvico/metabolismo , Traumatismo por Reperfusão/metabolismo , Traumatismo por Reperfusão/patologia , Animais , Apoptose , Enterócitos/ultraestrutura , Jejuno/metabolismo , Jejuno/patologia , Jejuno/ultraestrutura , Fígado/microbiologia , Masculino , Microscopia Eletrônica de Transmissão , Necrose , Proteínas Serina-Treonina Quinases/metabolismo , Ratos Wistar , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Baço/microbiologia
9.
Mol Cell Oncol ; 3(1): e1029064, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27308544

RESUMO

Gut microbiota and lipopolysaccharide (LPS) signaling have been associated with colon cancer development. Our recent findings demonstrated that LPS receptor subunits expressed on colonocytes have antagonistic roles in cell death and tumorigenesis: epithelial toll-like receptor 4 (TLR4) confers resistance to the apoptosis induced by its co-receptor CD14 and contributes to epithelial transition to cancer.

10.
Cancer Res ; 76(16): 4684-95, 2016 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-27328732

RESUMO

Colorectal carcinogenesis is affected by overexpression of the lipopolysaccharide (LPS) receptors CD14 and TLR4, which antagonize each other by affecting epithelial cell proliferation and apoptosis. Eritoran is an investigational drug for sepsis treatment that resembles the lipid A moiety of LPS and therefore acts as a TLR4 inhibitor. In the present study, we explored the potential therapeutic uses and mechanisms of action of eritoran in reducing colon cancer progression. Eritoran administration via intracolonic, intragastric, or intravenous routes significantly reduced tumor burden in a chemically induced mouse model of colorectal carcinoma. Decreased proliferation and increased apoptosis were observed in mouse tumor cells after eritoran treatment. In vitro cultures of mouse primary tumor spheroids and human cancer cell lines displayed increased cell proliferation and cell-cycle progression following LPS challenge. This effect was inhibited by eritoran and by silencing CD14 or TLR4. In contrast, apoptosis induced by eritoran was eliminated by silencing CD14 or protein kinase Cζ (PKCζ) but not TLR4. Lastly, LPS and eritoran caused hyperphosphorylation of PKCζ in a CD14-dependent and TLR4-independent manner. Blocking PKCζ activation by a Src kinase inhibitor and a PKCζ-pseudosubstrate prevented eritoran-induced apoptosis. In summary, our work offers a preclinical proof of concept for the exploration of eritoran as a clinical treatment, with a mechanistic rationale to reposition this drug to improve the management of colorectal cancer. Cancer Res; 76(16); 4684-95. ©2016 AACR.


Assuntos
Antineoplásicos/farmacologia , Neoplasias Colorretais/patologia , Dissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Fosfatos Açúcares/farmacologia , Receptor 4 Toll-Like/metabolismo , Animais , Apoptose/efeitos dos fármacos , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Modelos Animais de Doenças , Imunofluorescência , Humanos , Marcação In Situ das Extremidades Cortadas , Receptores de Lipopolissacarídeos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C
11.
J Gastroenterol Hepatol ; 31(9): 1594-603, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26773283

RESUMO

BACKGROUND AND AIM: Irritable bowel syndrome is characterized by abdominal pain and altered bowel habits and may occur following stressful events or infectious gastroenteritis such as giardiasis. Recent findings revealed a link between cholecystokinin (CCK), neurotrophin synthesis, and intestinal hyperalgesia. The aim was to investigate the role of CCK in visceral hypersensitivity using mouse models challenged with a bout of infection with Giardia lamblia or psychological stress, either alone or in combination. METHODS: Abdominal pain was evaluated by visceromoter response to colorectal distension. Nerve fibers in intestinal tissues were stained using immunohistochemistry (PGP9.5). Human neuroblastoma SH-SY5Y cells incubated with bacterial-free mouse gut supernatant or recombinant CCK-8S were assessed for neurite outgrowth and nerve growth factor (NGF) production. RESULTS: Intestinal hypersensitivity was induced by either stress or Giardia infection, and a trend of increased pain was seen following dual stimuli. Increased CCK levels and PGP9.5 immunoreactivity were found in colonic mucosa of mice following stress and/or infection. Inhibitors to the CCK-A receptor (L-364718) or CCK-B receptor (L-365260) blocked visceral hypersensitivity caused by stress, but not when induced by giardiasis. Nerve fiber elongation and NGF synthesis were observed in SH-SY5Y cells after incubation with colonic supernatants from mice given the dual stimuli, or after treatment with CCK-8S. Increased nerve fiber length by colonic supernatant and CCK-8S was attenuated by L-365260 or neutralizing anti-NGF. CONCLUSIONS: This new model successfully recapitulates intestinal hypernociception induced by stress or Giardia. Colonic CCK contributes to visceral hypersensitivity caused by stress, but not by Giardia, partly via NGF-dependent neurite outgrowth.


Assuntos
Colecistocinina/fisiologia , Colo/metabolismo , Hiperalgesia/metabolismo , Crescimento Neuronal/fisiologia , Dor Abdominal/etiologia , Dor Abdominal/metabolismo , Dor Abdominal/patologia , Animais , Células Cultivadas , Colecistocinina/farmacologia , Técnicas de Cocultura , Colo/inervação , Meios de Cultivo Condicionados , Dilatação , Giardia lamblia , Giardíase/complicações , Humanos , Hiperalgesia/etiologia , Hiperalgesia/patologia , Mucosa Intestinal/inervação , Mucosa Intestinal/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Fibras Nervosas/efeitos dos fármacos , Fibras Nervosas/patologia , Fator de Crescimento Neural/antagonistas & inibidores , Fator de Crescimento Neural/metabolismo , Crescimento Neuronal/efeitos dos fármacos , Proteínas Recombinantes/farmacologia , Estresse Psicológico/complicações
12.
Artigo em Inglês | MEDLINE | ID: mdl-24110716

RESUMO

Gastric cancer is the fourth common cancer and the second major cause of cancer death worldwide. Early detection of gastric cancer by endoscopy surveillance is actively investigated to improve patient survival, especially using the newly developed magnifying narrow-band imaging endoscopy in the stomach. However, meticulous examination of the aforementioned images is both time and experience demanding and interpretation could be variable among different doctors, which hindered its widespread application. In this study, we developed a new image analysis system by adopting local binary pattern and vector quantization to perform pattern comparison between known training abnormal images and testing images of magnifying narrow band endoscopy images in the stomach. Our preliminary results demonstrated promising potential for automatically labeled region of interest for endoscopy doctors to focus on abnormal lesions for subsequent targeted biopsy, with the rates of recall 0.46-1.00 and precision 0.39-0.87.


Assuntos
Diagnóstico por Computador/métodos , Endoscopia/métodos , Neoplasias Gástricas/diagnóstico , Biópsia , Detecção Precoce de Câncer , Estudos de Viabilidade , Humanos
13.
Lab Invest ; 92(5): 783-96, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22370946

RESUMO

Intestinal ischemia/reperfusion (I/R) induces mucosal barrier dysfunction and bacterial translocation (BT). Neutrophil-derived oxidative free radicals have been incriminated in the pathogenesis of ischemic injury in various organs, but their role in the bacteria-containing intestinal tract is debatable. Primed neutrophils are characterized by a faster and higher respiratory burst activity associated with more robust bactericidal effects on exposure to a second stimulus. Hypoxic preconditioning (HPC) attenuates ischemic injury in brain, heart, lung and kidney; no reports were found in the gut. Our aim is to investigate whether neutrophil priming by HPC protects against intestinal I/R-induced barrier damage and bacterial influx. Rats were raised in normoxia (NM) or kept in a hypobaric hypoxic chamber (380 Torr) 17 h/day for 3 weeks for HPC, followed by sham operation or intestinal I/R. Gut permeability was determined by using an ex vivo macromolecular flux assay and an in vivo magnetic resonance imaging-based method. Liver and spleen homogenates were plated for bacterial culturing. Rats raised in HPC showed diminished levels of BT, and partially improved mucosal histopathology and epithelial barrier function compared with the NM groups after intestinal I/R. Augmented cytokine-induced neutrophil chemoattractant (CINC)-1 and -3 levels and myeloperoxidase activity correlated with enhanced infiltration of neutrophils in intestines of HPC-I/R compared with NM-I/R rats. HPC alone caused blood neutrophil priming, as shown by elevated production of superoxide and hydrogen peroxide on stimulation, increased membrane translocation of cytosolic p47(phox) and p67(phox), as well as augmented bacterial-killing and phagocytotic activities. Neutrophil depletion reversed the mucosal protection by HPC, and aggravated intestinal leakiness and BT following I/R. In conclusion, neutrophil priming by HPC protects against I/R-induced BT via direct antimicrobial activity by oxidative respiratory bursts and through promotion of epithelial barrier integrity for luminal confinement of enteric bacteria.


Assuntos
Translocação Bacteriana/fisiologia , Hipóxia/metabolismo , Mucosa Intestinal/metabolismo , Intestinos/microbiologia , Neutrófilos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Traumatismo por Reperfusão/microbiologia , Animais , Membrana Celular/metabolismo , Células Cultivadas , Quimiocina CXCL1/análise , Quimiocina CXCL1/metabolismo , Quimiocina CXCL2/análise , Quimiocina CXCL2/metabolismo , Mucosa Intestinal/microbiologia , Mucosa Intestinal/fisiopatologia , Intestinos/fisiopatologia , Fígado/citologia , Fígado/metabolismo , Masculino , Permeabilidade , Peroxidase/análise , Peroxidase/metabolismo , Ratos , Ratos Wistar , Traumatismo por Reperfusão/imunologia , Traumatismo por Reperfusão/fisiopatologia , Baço/citologia , Baço/metabolismo
14.
Pancreas ; 40(2): 200-5, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21404457

RESUMO

OBJECTIVES: To clarify the clinical and pathophysiological characteristics of autoimmune pancreatitis (AIP) in Asia. METHODS: A retrospective, actual situation survey of AIP diagnosed by Asian criteria was conducted in 10 centers of Japan, Korea, Taiwan, China, and India. RESULTS: A total of 327 AIP cases (258 male and 69 female subjects; average age, 60.0 years) were enrolled. Obstructive jaundice was the most frequent initial symptom (46%-74%), followed by weight loss (4%-51%) and abdominal pain (19%-44%). Diffuse swelling of the pancreas was frequent in Japan (64%) and Korea (81%), but segmental swelling of the pancreas was more frequent in Taiwan (70%) and China (72%) (P < 0.01). Serum immunoglobulin G4 levels were elevated in 58%-100% of cases in Japan, Korea, and Taiwan. Pathologically, almost all AIPs in Asia were lymphoplasmacytic sclerosing pancreatitis. Sclerosing cholangitis was the most frequent extrapancreatic lesion (60%-81%). Steroid therapy was a major and effective therapeutic strategy in Japan, Korea, and Taiwan. However, the rate of resection or bypass operation was higher in Taiwan (40%) and China (72%) (P < 0.01). CONCLUSIONS: Features of AIP are fundamentally similar in Japan, Korea, Taiwan, and China. Knowledge of emerging AIP should be more widespread in Asia to avoid unnecessary operation.


Assuntos
Povo Asiático , Doenças Autoimunes/diagnóstico , Indicadores Básicos de Saúde , Pancreatite/diagnóstico , Ásia/epidemiologia , Autoanticorpos/sangue , Doenças Autoimunes/etnologia , Doenças Autoimunes/fisiopatologia , Doenças Autoimunes/terapia , Biomarcadores/sangue , Biópsia , Feminino , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Pancreatectomia , Pancreatite/etnologia , Valor Preditivo dos Testes , Estudos Retrospectivos , Esteroides/uso terapêutico , Tomografia Computadorizada por Raios X , Resultado do Tratamento
15.
Lab Invest ; 91(2): 294-309, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20975661

RESUMO

Intestinal ischemia/reperfusion (I/R) causes mucosal barrier damage and bacterial translocation (BT), leading to septic complications. Previous in vitro studies showed that activation of sodium/glucose transporter 1 (SGLT1) prevented the epithelial apoptosis and permeability rise induced by microbial products. Our aim was to investigate whether luminal glucose uptake by SGLT1 protects against ischemia-induced epithelial cell death and barrier dysfunction, and to explore the glucose-mediated cellular survival pathways in vivo. Rat jejunum was luminally instilled with either vehicle, a pancaspase inhibitor ZVAD, or glucose prior to I/R challenge (occlusion of the superior mesenteric artery for 20 min and reperfusion for 60 min). Histopathology and apoptosis in the jejunum were examined by TUNEL staining and caspase-3 cleavage. Intestinal permeability was evaluated using in vivo assays measuring luminal-to-blood passage of fluorescein-dextran and portal drainage of enterally administered gadodiamide by magnetic resonance imaging. BT was determined by culturing liver and spleen homogenates. Immunofluorescent analysis and kinase assay were used to study PI3K/Akt signaling pathways. Intestinal I/R caused enterocyte apoptosis and villous destruction. Intestinal infusion with ZVAD decreased the I/R-triggered gut permeability rise and BT, suggesting that the barrier damage was partly dependent on cell apoptosis. Enteral instillation of glucose attenuated the epithelial apoptosis, barrier damage, and mucosal inflammation caused by I/R. Phloridzin (a SGLT1 inhibitor) reduced the protective effect of glucose in a dose-dependent manner. Enteral glucose increased the mucosal Akt kinase activity as evidenced by the augmented phosphorylation of exogenous GSK3. Enhanced membrane translocation and phosphorylation of Akt in epithelial cells were associated with elevated phosphorylation of mTOR, Bad, and FoxO1/3a following glucose uptake. Inhibition of PI3K/Akt signaling by LY294002 and wortmannin partially blocked the glucose-mediated rescue of cell apoptosis and barrier damage. In conclusion, SGLT1 glucose uptake alleviated I/R-induced barrier dysfunction and BT, partly by inhibiting epithelial apoptosis via activation of PI3K/Akt signaling.


Assuntos
Glucose/metabolismo , Mucosa Intestinal/patologia , Proteína Oncogênica v-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Traumatismo por Reperfusão/metabolismo , Transdução de Sinais/fisiologia , Transportador 1 de Glucose-Sódio/metabolismo , Animais , Apoptose/fisiologia , Caspase 3/metabolismo , Imunofluorescência , Gadolínio DTPA , Marcação In Situ das Extremidades Cortadas , Jejuno/citologia , Jejuno/patologia , Imageamento por Ressonância Magnética , Masculino , Permeabilidade , Florizina/farmacologia , Fosforilação , Ratos , Ratos Wistar , Traumatismo por Reperfusão/patologia , Transportador 1 de Glucose-Sódio/antagonistas & inibidores
17.
J Clin Gastroenterol ; 44(5): e96-100, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20216431

RESUMO

OBJECTIVE: Ischemic colitis (IC) spans a broad spectrum from self-limiting illness to intestinal gangrene and mortality. Prognostic factors specifically for nonpostoperative IC were not fully characterized. We aim to focus on nonpostoperative IC in patients with renal dysfunction and try to identify prognostic factors for adverse outcomes. METHODS: We conducted a retrospective analysis at a university-affiliated tertiary medical center in Taiwan. From January 2003 to August 2008, 25 men and 52 women (mean age: 66 y) had colonoscopic biopsy-proven IC without prior culprit surgery. We estimated glomerular filtration rate with simplified Modification of Diet in Renal Disease equation. Nine patients with glomerular filtration rate below 30 mL per minute per 1.73 m were classified as renal dysfunction group (including 7 dialysis patients). Adverse outcomes were defined as need for surgery and mortality. Predictors for adverse outcomes were captured by univariate and multivariate analysis. Research ethical committee approved the study protocol. RESULTS: Patients with renal dysfunction more often had: diabetes mellitus (56% vs. 16%, P=0.02), prolonged symptoms (6.8 d vs. 3.5 d, P=0.01), lower hemoglobin (11.1 g/dL vs. 13.4 g/dL, P=0.01), and more often right colonic involvement (56% vs. 19%, P=0.03). Renal dysfunction patients also had longer hospitalization days (median 15 d vs. 4 d, P=0.045). However, there was no statistical significance in the rate of either surgery or mortality between these 2 groups (P>0.05). Univariate analysis showed that renal dysfunction, sex, emergency department referral, presentation with abdominal pain were significant for adverse outcome (P<0.1). Multivariate analysis revealed that male sex conveyed 9.5-fold risk (P=0.01) and renal dysfunction conveyed 8.5-fold risk (P=0.03) for adverse outcomes. CONCLUSIONS: Nonpostoperative IC patients with concurrent renal dysfunction had distinct clinical profiles. Multivariate analysis showed that male patients had 9.5-fold and renal dysfunction patients had 8.5-fold increased risk for adverse outcomes. Although IC is often self-limited, our data warrants special attention and aggressive therapy in treating these patients.


Assuntos
Dor Abdominal/etiologia , Colite Isquêmica/patologia , Nefropatias/complicações , Centros Médicos Acadêmicos , Adulto , Idoso , Idoso de 80 Anos ou mais , Colite Isquêmica/etiologia , Colite Isquêmica/mortalidade , Diabetes Mellitus/fisiopatologia , Feminino , Taxa de Filtração Glomerular , Hemoglobinas/metabolismo , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Estudos Retrospectivos , Fatores de Risco , Fatores Sexuais , Taiwan , Adulto Jovem
19.
Nephrol Dial Transplant ; 23(3): 1005-10, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18042613

RESUMO

BACKGROUND: The peritoneum is subject to alterations in the life-long course of peritoneal dialysis (PD). Studies of the parietal peritoneum by non-invasive ultrasonography in PD patients are limited. We hypothesize that a prolonged PD duration is associated with a thicker peritoneum on ultrasonography and alterations in Doppler indexes of mesenteric vessels. METHODS: We recruited two groups of patients, 18 who had >7 years of PD and 18 who had <12 months of PD. We excluded patients with active peritonitis, history of major abdominal surgery, cirrhosis or malignancy. We measured the sonographic thickness of the parietal peritoneum and Doppler indexes of mesenteric vessels by trans-abdominal ultrasonography at two PD units in Taiwan. RESULTS: We found no significant difference between two groups of PD patients in peritoneal thickness and in Doppler indexes. However, our univariate and multivariate analysis indicated that peritoneal thickness is associated with peritoneal transport characteristics (dialysate/plasma creatinine) but not with age, duration of dialysis, body height, body weight or Doppler index. The peritoneum is significantly thicker in rapid transporters than in slow transporters (RUQ: 0.59 +/- 0.40 mm versus 0.27 +/- 0.29 mm, P = 0.01; LUQ: 0.60 +/- 0.40 mm versus 0.27 +/- 0.32 mm, P = 0.016; LQ: 1.07 +/- 0.85 mm versus 0.48 +/- 0.53 mm, P = 0.026). In addition, rapid transporters have a marginally lower Doppler resistive index of the superior mesenteric artery (0.87 +/- 0.08 versus 0.90 +/- 0.10, P = 0.028). CONCLUSIONS: Our data showed that peritoneal thickening is not inevitable in long-term PD patients. Sonographic thickness in the parietal peritoneum is associated with transport characteristics. Rapid transporters have a significantly thicker peritoneum. The Doppler index of mesenteric vessels had no association with PD duration or transport characteristics. Trans-abdominal ultrasonography is non-invasive and useful in evaluating peritoneal characteristics of PD patients.


Assuntos
Falência Renal Crônica/terapia , Artérias Mesentéricas/diagnóstico por imagem , Veias Mesentéricas/diagnóstico por imagem , Diálise Peritoneal/efeitos adversos , Peritônio/diagnóstico por imagem , Peritônio/metabolismo , Adulto , Idoso , Transporte Biológico/fisiologia , Biópsia , Creatinina/sangue , Estudos Transversais , Feminino , Humanos , Falência Renal Crônica/diagnóstico por imagem , Falência Renal Crônica/patologia , Modelos Lineares , Masculino , Artérias Mesentéricas/patologia , Veias Mesentéricas/patologia , Pessoa de Meia-Idade , Análise Multivariada , Peritônio/anatomia & histologia , Peritônio/patologia , Taiwan , Fatores de Tempo , Ultrassonografia
20.
J Formos Med Assoc ; 106(11): 961-4, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18063519

RESUMO

Primary gastric angiosarcoma is a rare gastric tumor. Previously reported cases are limited and usually symptomatic. Preoperative diagnosis is difficult and should be differentiated from adenocarcinoma or gastrointestinal stromal tumor. We report a 55-year-old man with primary gastric angiosarcoma presenting as an asymptomatic gastric submucosal tumor. Abdominal ultrasonography showed a heteroechogenic tumor with several notably anechoic portions between the stomach and the gallbladder. Computed tomography showed that the tumor originated from the stomach, and upper gastrointestinal endoscopy showed a large gastric submucosal tumor at the lower body. Laparotomy was performed and a purple circumscribed tumor measuring 8.5 x 5.0 x 4.0 cm was found on the serosal aspect of the lower body. The tumor was soft and spongy with areas of hemorrhagic pools on section. Microscopically, the tumor was composed of proliferative neoplastic spindle to epithelioid cells. The neoplastic cells infiltrated and dissected the smooth muscle as vessel-forming architectures. On immunohistochemical study, the tumor cells were positive for CD34. These findings confirmed a diagnosis of primary gastric angiosarcoma. The patient has been well during the 11-month postoperative follow-up.


Assuntos
Hemangiossarcoma/patologia , Neoplasias Gástricas/patologia , Mucosa Gástrica/patologia , Humanos , Achados Incidentais , Masculino , Pessoa de Meia-Idade
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA