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1.
Int J Oral Maxillofac Surg ; 47(12): 1541-1542, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29752203

RESUMO

Retropharyngeal lipoma in a child is an extremely rare pathological entity. The unusual case of a child with a retropharyngeal lipoma presenting with snoring is reported. Retropharyngeal lipoma should be considered in the differential diagnosis of snoring in children.


Assuntos
Lipoma/diagnóstico , Lipoma/cirurgia , Neoplasias Faríngeas/diagnóstico , Neoplasias Faríngeas/cirurgia , Criança , Diagnóstico Diferencial , Endoscopia , Feminino , Humanos , Ronco , Tomografia Computadorizada por Raios X
3.
Transplant Proc ; 49(5): 1142-1149, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28583545

RESUMO

BACKGROUND: In an experimental animal model of islet transplantation, stable induction of insulin-dependent diabetes mellitus (IDDM) and islet isolation from donor pancreas are essential. Total pancreatectomy for IDDM induction and islet procurement in nonhuman primates leads to unwanted loss of exocrine function and may lead to morbidities associated with IDDM. METHODS: IDDM induction with streptozotocin (STZ) is associated with drug toxicity of STZ and necessitates the killing of another animal for islet procurement. In this study, we performed a subtotal pancreatectomy combined with reduced STZ injection to induce IDDM and procure islets in a nonhuman primate model. RESULTS: Twelve cynomolgus monkeys received low-dose STZ injections (60 mg/kg) simultaneously with subtotal pancreatectomy. All monkeys recovered from the procedure without complications. IDDM was induced in the animals. 57,691 ± 16,050 islets were isolated from the resected pancreas and transplanted into other monkeys. CONCLUSIONS: Simultaneous subtotal pancreatectomy and low-dose STZ injection represent an effective and safe method to create an animal model of insulin dependence diabetes, while at the same time providing sufficient amounts of fresh islet cells for allotransplantation without requiring killing of additional animals.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Modelos Animais de Doenças , Transplante das Ilhotas Pancreáticas/métodos , Pancreatectomia/métodos , Animais , Diabetes Mellitus Experimental/cirurgia , Diabetes Mellitus Tipo 1/cirurgia , Macaca fascicularis , Estreptozocina
4.
Osteoporos Int ; 28(4): 1377-1384, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-28188454

RESUMO

This study sought to determine the minimal serum 25-hydroxyvitamin D [25(OH)D] concentration required to maintain bone health in postmenopausal women with low bone mass. A serum 25(OH)D concentration of 20 ng/mL rather than 30 ng/mL was appropriate for bone health. INTRODUCTION: There is no consensus on the minimal serum 25-hydroxyvitamin D [25(OH)D] concentration required to maintain bone health. The aim of this study was to investigate the relationship between 25(OH)D measured via liquid chromatography-mass spectrometry (LC-MS/MS), which is the current gold standard, and biochemical markers of bone turnover, PTH, and bone mineral densitometry (BMD). METHODS: The medical records of 750 postmenopausal women newly diagnosed with osteoporosis or osteopenia at Samsung Medical Center from 2009 to 2014 were investigated. Subjects were divided into four groups according to serum 25(OH)D concentration: <10, 10-20, 20-30, and ≥30 ng/mL. Serum concentrations of bone-specific alkaline phosphatase (BS-ALP), carboxy-terminal cross-linking telopeptide of type 1 collagen (CTx), intact PTH (iPTH), and BMD were compared among the four groups using analysis of covariance. Thresholds of 25(OH)D were then assessed using spline plots and locally weighted regression smoothing (LOESS) plots. RESULTS: 25(OH)D was negatively correlated with serum BS-ALP, CTx, and iPTH. Only femur neck and total femur BMD had significant positive relationships with 25(OH)D. Cutoff values of 11.9 and 9.7 ng/mL were estimated from the spline plots of femur neck and total femur BMD, respectively. For iPTH, the LOESS plot showed a steep decrease to a serum 25(OH)D concentration of about 20 ng/mL, followed by a plateau. CONCLUSIONS: According to this study, a serum 25(OH)D concentration of 20 ng/mL, rather than 30 ng/mL, was appropriate for bone health.


Assuntos
Densidade Óssea/fisiologia , Osteoporose Pós-Menopausa/sangue , Deficiência de Vitamina D/sangue , Vitamina D/análogos & derivados , Idoso , Biomarcadores/sangue , Remodelação Óssea/fisiologia , Cromatografia Líquida/métodos , Feminino , Fêmur/fisiopatologia , Colo do Fêmur/fisiopatologia , Humanos , Pessoa de Meia-Idade , Osteoporose Pós-Menopausa/etiologia , Osteoporose Pós-Menopausa/fisiopatologia , Hormônio Paratireóideo/sangue , Espectrometria de Massas em Tandem/métodos , Vitamina D/sangue , Deficiência de Vitamina D/complicações , Deficiência de Vitamina D/fisiopatologia
5.
Am J Transplant ; 17(2): 365-376, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27376767

RESUMO

We investigated whether serum deprivation induces islet amyloid polypeptide (IAPP) oligomer accumulation and/or a proinflammatory response and, if so, whether the addition of interleukin (IL)-1 receptor antagonist to the culture medium can relieve the proinflammatory response during serum-deprived culture of nonhuman primate (NHP) islets. After culture in medium with and without Ana under serum-deprived culture conditions, IAPP oligomer/amyloid accumulation, in vitro viability, islet function, cytokine secretion, and posttransplantation outcome in streptozotocin-induced diabetic nude mice were determined in islets isolated from heterozygote human IAPP transgenic (hIAPP+/- ) mice and/or NHP islets. Serum deprivation induced accumulation of IAPP oligomer, but not amyloid, in NHP islets. Anakinra (Ana) protected islets from the serum deprivation-induced impairment of in vitro viability and glucose-stimulated insulin secretion and attenuated serum deprivation-induced caspase-1 activation, transcription, and secretion of IL-1ß, IL-6, and tumor necrosis factor-α in hIAPP+/- mice and NHP islets. Supplementation of medium with Ana during serum-deprived culture also improved posttransplantation in vivo outcomes of NHP islets. In conclusion, serum deprivation induced accumulation of IAPP oligomers and proinflammatory responses in cultured isolated islets. Supplementation of the culture medium with Ana attenuated the functional impairment and proinflammatory responses induced by serum deprivation in ex vivo culture of NHP islets.


Assuntos
Antirreumáticos/farmacologia , Meios de Cultura Livres de Soro/toxicidade , Inflamação/prevenção & controle , Proteína Antagonista do Receptor de Interleucina 1/farmacologia , Ilhotas Pancreáticas/efeitos dos fármacos , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Inflamação/induzido quimicamente , Ilhotas Pancreáticas/patologia , Macaca fascicularis , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus
6.
Nutr Metab Cardiovasc Dis ; 27(3): 234-240, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27989511

RESUMO

BACKGROUND AND AIMS: Several cross-sectional studies reported that serum bilirubin concentrations had an inverse association with type 2 diabetes mellitus (T2DM) prevalence. The aim of the current study was to investigate the relationship between percentage change in bilirubin levels (PCB) and incident risk of T2DM using a longitudinal model. METHODS AND RESULTS: 22,084 participants who received regular health check-ups between 2006 and 2012 were enrolled. Multivariable-adjusted Cox regression models were used to determine the hazard ratio (HR) of incident T2DM based on PCB. PCB was determined by subtracting baseline serum bilirubin level (BB) from the bilirubin level at the end of follow-up or a year before the last date of diagnosis, dividing by BB and multiplying by 100. Compared to non-diabetics, BB was lower in the diabetic group at the initial visit. There were 20,098 participants without T2DM at the initial visit; 1253 new cases occurred during follow-up. As PCB increased, T2DM incidence also increased (P < 0.001). After adjusting for confounders, the HR of incident T2DM in the highest PCB quartile was 2.08 (95% confidence interval [CI] 1.76-2.46). This trend remained significant when PCB was analyzed as a continuous variable (HR for 1-SD increment, 1.25; 95% CI 1.19-1.31). Additional analysis comparing the rate of PCB during the follow-up period revealed that the serum bilirubin level of the Incident T2DM group increased before T2DM development and decreased rapidly thereafter compared to others (P < 0.001). CONCLUSIONS: Bilirubin level increment over time is associated with T2DM development.


Assuntos
Bilirrubina/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/epidemiologia , Adulto , Biomarcadores/sangue , Distribuição de Qui-Quadrado , Diabetes Mellitus Tipo 2/diagnóstico , Feminino , Humanos , Incidência , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Valor Preditivo dos Testes , Prevalência , Prognóstico , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Seul/epidemiologia , Fatores de Tempo
7.
J Nanosci Nanotechnol ; 16(2): 1988-92, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27433714

RESUMO

The left- and right-handed helical silica nanostructures were obtained with the aid of organic templates, the formation of the nanostructures might follow a co-operation self-assembly mechanism. The chirality of the organogel self-assemblies was successfully transcribed in to the silica. The helical pitch and pore size of the silica nanotubes sensitively depended on the optical purity of the neutral gelator in the reaction mixtures.

8.
Am J Transplant ; 15(6): 1543-54, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25865268

RESUMO

The spheroid culture method is an effective strategy for ex vivo expansion of an autologous therapeutic cell population. We investigated if cotransplantation of bone marrow-derived spheroids (BM-spheroid) formed using 3D culture of BM-derived mononuclear cells (BM-MNCs) could improve the posttransplant outcome of islet grafts using a mouse syngeneic marginal mass renal subcapsular islet transplantation model. Using green fluorescent protein transgenic (GFP-Tg) mice, the role of the BM-spheroids and the contribution of vessels derived from donors and recipients in grafted areas were assessed by immunohistochemistry. Compared to fresh BM-MNCs and nonspheroid remnant cells (BM-nonspheroid), the BM-spheroids, mainly composed of CXCR4(+) CD14(+) myeloid cells, showed higher angiogenic capacity, such as in vitro self-formed vessel structures; increased expression of angiogenic and chemoattractive factors; and incorporation into new vessel formation in basement membrane matrix plugs. BM-spheroid cotransplantation with islets improved the posttransplant outcomes in terms of glucose tolerance, serum insulin level, and diabetes reversal rate when compared with cotransplantation of BM-nonspheroids. Immunohistochemistry revealed that cotransplantation of the BM-spheroids increased vessel density, area of grafted endocrine and non-endocrine tissue, and ß cell proliferation. In conclusion, cotransplantation of islets and BM-spheroids improved islet function through facilitation of revascularization and an increase in cell proliferation and islet cell mass.


Assuntos
Células da Medula Óssea/citologia , Células da Medula Óssea/fisiologia , Terapia Baseada em Transplante de Células e Tecidos/métodos , Transplante das Ilhotas Pancreáticas/métodos , Ilhotas Pancreáticas/irrigação sanguínea , Células Mieloides/citologia , Células Mieloides/fisiologia , Animais , Glicemia/metabolismo , Comunicação Celular/fisiologia , Proliferação de Células/fisiologia , Transplante de Células/métodos , Células Cultivadas , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/cirurgia , Modelos Animais de Doenças , Sobrevivência de Enxerto/fisiologia , Técnicas In Vitro , Ilhotas Pancreáticas/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Neovascularização Fisiológica/fisiologia , Estreptozocina/efeitos adversos
9.
Diabetes Obes Metab ; 17(6): 599-602, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25580775

RESUMO

We aimed to compare the efficacy and safety of lobeglitazone and pioglitazone as add-ons to metformin in patients with type 2 diabetes. Patients who were inadequately controlled by metformin were randomized and treated once daily with either lobeglitazone (0.5 mg, n = 128) or pioglitazone (15 mg, n = 125) for 24 weeks, with a 28-week extension trial of lobeglitazone treatment in patients who consented. The primary endpoint was the change in glycated haemoglobin (HbA1c) concentration from baseline to week 24. At week 24, the mean change from baseline in HbA1c was -0.74% for the lobeglitazone group and -0.74% for the pioglitazone group, with a mean difference of 0.01% [95% confidence interval (CI) of difference, -0.16 to 0.18]. The effects of lobeglitazone on lipid variables and the adverse events associated with lobeglitazone were similar to those observed with pioglitazone. Lobeglitazone was not inferior to pioglitazone as an add-on to metformin in terms of their efficacy and safety.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Pirimidinas/uso terapêutico , Tiazolidinedionas/uso terapêutico , Idoso , Glicemia/efeitos dos fármacos , Glicemia/metabolismo , Diabetes Mellitus Tipo 2/sangue , Método Duplo-Cego , Quimioterapia Combinada/métodos , Jejum/sangue , Feminino , Hemoglobinas Glicadas/efeitos dos fármacos , Hemoglobinas Glicadas/metabolismo , Humanos , Resistência à Insulina/fisiologia , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Pioglitazona
10.
Diabet Med ; 32(2): 274-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25307609

RESUMO

AIMS: The contribution of glycaemic variability to the microvascular complication of diabetes has not been established. We examined whether there is an independent association between indices of glycaemic variability in continuous glucose monitoring and extent of albuminuria. METHODS: A total of 173 patients with Type 2 diabetes (without insulin therapy, n = 96; with insulin therapy, n = 77) who had unexplained large fluctuations in blood glucose values underwent three-day continuous glucose monitoring. We used a multinomial logistic regression model to determine whether the indices of glycaemic variability independently affected the odds of having a spot urine albumin/creatinine ratio of 30-299 mg/g and ≥ 300 mg/g. RESULTS: Higher standard deviation (P = 0.002), mean of daily differences (P = 0.023) and mean amplitude of glycaemic excursion (P = 0.043) significantly increased the odds of having a urine albumin/creatinine ratio of ≥ 300 mg/g. In multivariable analysis, only higher standard deviation, but not mean amplitude of glycaemic excursion and mean of daily differences, independently increased the odds of having a urine albumin/creatinine ratio of ≥ 300 mg/g (P = 0.025). Coefficient of variation (sd/mean) was not associated with the odds of having a urine albumin/creatinine ratio of 30-299 or ≥ 300 mg/g. CONCLUSIONS: The independent association between standard deviation and the extent of albuminuria was lost when the measures were normalized by mean glucose level. At least in terms of relative measures of glycaemic variability, we failed to demonstrate an independent association between glycaemic variability and albuminuria extent in patients with inadequately controlled Type 2 diabetes.


Assuntos
Albuminúria/prevenção & controle , Glicemia/análise , Diabetes Mellitus Tipo 2/tratamento farmacológico , Nefropatias Diabéticas/prevenção & controle , Resistência a Medicamentos , Rim/efeitos dos fármacos , Insuficiência Renal Crônica/prevenção & controle , Centros Médicos Acadêmicos , Albuminúria/etiologia , Estudos Transversais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/fisiopatologia , Nefropatias Diabéticas/epidemiologia , Feminino , Humanos , Hiperglicemia/prevenção & controle , Hipoglicemia/induzido quimicamente , Hipoglicemia/prevenção & controle , Hipoglicemiantes/efeitos adversos , Hipoglicemiantes/uso terapêutico , Insulina/efeitos adversos , Insulina/uso terapêutico , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Monitorização Ambulatorial , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/epidemiologia , República da Coreia/epidemiologia , Estudos Retrospectivos , Fatores de Risco , Índice de Gravidade de Doença
11.
Diabetes Obes Metab ; 17(5): 511-5, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25523633

RESUMO

We conducted a 24-week, multicentre, double-blind, randomized study with a 28-week extension to compare the efficacy and safety of anagliptin and sitagliptin as an add-on to metformin in patients with type 2 diabetes. Patients inadequately controlled on metformin were randomized to either anagliptin (100 mg twice daily, n = 92) or sitagliptin (100 mg once daily, n = 88). The primary endpoint was the change in glycated haemoglobin (HbA1c) from baseline to week 24. The mean changes in HbA1c were -0.85 ± 0.70% (p < 0.0001) for anagliptin and -0.83 ± 0.61% (p < 0.0001) for sitagliptin, with a mean difference of -0.02% (95% confidence interval of difference, -0.22 to 0.18%). In both groups, the fasting proinsulin : insulin ratio significantly decreased from baseline, with improved insulin secretion. Safety profiles were similar in each group. In conclusion, the non-inferiority of the efficacy of anagliptin to sitagliptin as an add-on therapy was established with regard to efficacy and safety.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Metformina/uso terapêutico , Pirimidinas/uso terapêutico , Fosfato de Sitagliptina/uso terapêutico , Diabetes Mellitus Tipo 2/sangue , Método Duplo-Cego , Quimioterapia Combinada/métodos , Jejum/sangue , Hemoglobinas Glicadas/efeitos dos fármacos , Humanos , Proinsulina/sangue , Proinsulina/metabolismo
12.
Transplant Proc ; 46(5): 1628-32, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24935338

RESUMO

BACKGROUND: Given the fragility of adult porcine islets, reduction of shearing stress in islet purification using histidine-tryptophan-ketoglutarate (HTK) solution and iodixanol could be an effective strategy. We examined the effect of ductal preservation with HTK solution and an islet purification protocol that utilizes HTK solution and iodixanol in adult porcine islet isolation. METHODS: Islets were isolated with a modified Ricordi method using adult Prestige World Genetics (PWG) and Yucatan pigs. The discontinuous density gradient was composed of either HTK solution/iodixanol (n = 23, iodixanol group) or Hank's balanced salt solution (HBSS)/Ficoll (n = 17, Ficoll group). In the iodixanol group, ductal injection of HTK solution was performed before purification. RESULTS: In PWG pigs, significantly higher islet yield after purification (3480 ± 214.2 islet equivalent [IEQ]/g, P = .003) and higher recovery rate (85.45% ± 3.49%, P = .0043) were obtained from the HTK/iodixanol group as compared to the HBSS/Ficoll group (1905 ± 323.2 IEQ/g, and 67.22% ± 4.77%, respectively). Similar results were obtained in Yucatan pigs with greater body weight. CONCLUSION: Ductal preservation and iodixanol-based islet purification using HTK solution improved the yield of adult porcine islet isolation compared to the conventional method using HBSS and Ficoll. The results of this study support the feasibility of an adult porcine islet isolation protocol using HTK solution and iodixanol, which have the favorable physical properties.


Assuntos
Ilhotas Pancreáticas , Soluções para Preservação de Órgãos , Animais , Glucose , Manitol , Cloreto de Potássio , Procaína , Suínos , Porco Miniatura
13.
Diabetes Metab ; 40(4): 272-7, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24630733

RESUMO

AIMS: This study investigated the relationship between markers of overall glucose exposure, postprandial glucose excursions and glycaemic variability in patients with type 2 diabetes mellitus (T2DM). METHODS: A total of 63 patients with T2DM (mean age 56 years) were enrolled. All wore a continuous glucose monitoring system (CGMS) device for 72 h to collect data on markers of overall glucose exposure, postprandial glucose excursions and glycaemic variability parameters. RESULTS: Spearman's correlation analysis revealed significant correlations between all markers of overall glucose exposure and various parameters related to glucose excursions. The percent coefficient of variation (CV) showed the strongest correlation with glycated albumin (r=0.470, P<0.01). In participants with HbA1c levels < 7.5% (n=33), almost all glycaemic markers and glycaemic variability parameters were significantly correlated with each other. Also, all postprandial glucose excursion parameters showed significant correlation with other glycaemic markers, and all markers of overall glucose exposure were significantly related to mean glucose, postprandial glucose excursions and glycaemic variability parameters (except CV). In contrast, in participants with HbA1c levels ≥ 7.5% (n=30), no parameters of postprandial glucose excursions and glycaemic variability were related to any markers of chronic glycaemia. CONCLUSION: Postprandial glucose excursions may explain glycaemic variability and total glucose exposures in well-controlled T2DM patients.


Assuntos
Glicemia/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Glucose/administração & dosagem , Idoso , Biomarcadores/sangue , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/tratamento farmacológico , Carboidratos da Dieta/administração & dosagem , Feminino , Hemoglobinas Glicadas/metabolismo , Produtos Finais de Glicação Avançada , Humanos , Hipoglicemiantes/uso terapêutico , Masculino , Pessoa de Meia-Idade , Período Pós-Prandial/fisiologia , Albumina Sérica/metabolismo , Albumina Sérica Glicada
14.
Am J Transplant ; 13(6): 1429-40, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23601171

RESUMO

Bone marrow-derived early endothelial progenitor cells (BM-EPCs) are a clinical tool for enhancing revascularization. However, the therapeutic efficacy of co-transplantation of BM-EPC with islets has not been investigated. In this study, marginal mass islets were co-transplanted with or without BM-EPCs under the kidney capsules of syngeneic streptozotocin-induced diabetic mice. Using green fluorescent protein transgenic (GFP-Tg) mice as BM-EPC and islet donors or recipients, the role of EPCs in revascularization was assessed for graft morphology, vascular density and fate of EPCs by immunohistochemistry. Islet-EPC co-transplantation improved the outcome of islet transplantation as measured by glucose tolerance, serum insulin level and diabetes reversal rate, compared with transplantation of islets alone. Between groups, the morphology of islet grafts showed significant differences in size and composition of grafted endocrine tissues. Significantly more vessel density derived from donors and recipients was detected with islet-EPC co-transplantation. Abundant GFP-Tg mice-derived BM-EPCs (GFP-EPCs) were observed in or around islet grafts and incorporated into CD31-positive capillaries. Remaining GFP-EPCs expressed VEGF. In conclusion, co-transplantation of islets with BM-EPCs could improve the outcome of marginal mass islet transplantation by promoting revascularization and preserving islet morphology.


Assuntos
Células da Medula Óssea/citologia , Endotélio Vascular/citologia , Sobrevivência de Enxerto/fisiologia , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/irrigação sanguínea , Transplante de Células-Tronco/métodos , Células-Tronco/citologia , Animais , Modelos Animais de Doenças , Células Endoteliais , Masculino , Camundongos , Camundongos Endogâmicos C57BL
15.
Am J Transplant ; 12(5): 1303-12, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22299723

RESUMO

Iron-containing fragmented islets or free iron released from dying cells could confound the interpretation of MRI of iron nanoparticle-labeled islets. Exclusion of small hypointense spots could be a useful strategy to avoid such artifact. We investigated whether this strategy could improve the estimation of functioning islet mass after islet transplantation. Using a rat syngeneic intraportal islet transplantation model, we quantitatively assessed the relationships between total area, number of hypointense spots on MRI that belong to each size quartile and glycemic control of the recipients. The total area of hypointense spots on MRI was greater in the recipients that achieved diabetes reversal (p = 0.002), whereas the total number of hypointense spots was not different (p = 0.757). Exclusion of small hypointense spots improved the association between the number of hypointense spots and the blood glucose level of the recipients (p < 0.001). Ex-vivo imaging and histologic study confirmed that some small hypointense spots represent the phagocytosed free iron. Exclusion of small hypointense spots improved the quantification of the functional islet mass based on islet MRI. This would be a useful principle in the development of an algorithm to estimate functioning islet mass based on islet MRI.


Assuntos
Dextranos , Diabetes Mellitus Experimental/patologia , Diabetes Mellitus Experimental/cirurgia , Transplante das Ilhotas Pancreáticas , Ilhotas Pancreáticas/patologia , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita , Animais , Glicemia/metabolismo , Meios de Contraste , Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/etiologia , Prognóstico , Ratos , Ratos Endogâmicos Lew , Ratos Wistar
16.
FASEB J ; 23(8): 2639-49, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19332646

RESUMO

The receptor for advanced glycation end products (RAGE) is a multiligand cell surface receptor, and amyloid beta peptide (Abeta) is one of the ligands for RAGE. Because RAGE is a transporter of Abeta from the blood to the brain, RAGE is believed to play an important role in Alzheimer's disease (AD) pathogenesis. In the present study, the role of RAGE in Abeta production was examined in the brain tissue of an AD animal model, Tg2576 mice, as well as cultured cells. Because beta-site APP-cleaving enzyme 1 (BACE1), an essential protease for Abeta production, is up-regulated in cells overexpressing RAGE and in RAGE-injected brains of Tg2576 mice, the molecular mechanisms underlying RAGE, BACE1 expression, and Abeta production were examined. Because RAGE stimulates intracellular calcium, nuclear factor of activated T-cells 1 (NFAT1) was examined. NFAT1 was activated following RAGE-induced BACE1 expression followed by Abeta generation. Injection of soluble RAGE (sRAGE), which acts as a competitor with full-length RAGE (fRAGE), into aged Tg2576 mouse brains reduced the levels of plaques, Abeta, BACE1, and the active form of NFAT1 compared with fRAGE-injected Tg2576 mice. Taken together, RAGE stimulates functional BACE1 expression through NFAT1 activation, resulting in more Abeta production and deposition in the brain.


Assuntos
Doença de Alzheimer/metabolismo , Secretases da Proteína Precursora do Amiloide/biossíntese , Peptídeos beta-Amiloides/biossíntese , Ácido Aspártico Endopeptidases/biossíntese , Fatores de Transcrição NFATC/metabolismo , Receptores Imunológicos/metabolismo , Doença de Alzheimer/etiologia , Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/metabolismo , Peptídeos beta-Amiloides/farmacologia , Animais , Sequência de Bases , Sítios de Ligação/genética , Encéfalo/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Humanos , Camundongos , Camundongos Transgênicos , Sondas de Oligonucleotídeos/genética , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Placa Amiloide/metabolismo , Placa Amiloide/patologia , Receptor para Produtos Finais de Glicação Avançada , Receptores Imunológicos/química , Receptores Imunológicos/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Solubilidade
17.
Cell Death Differ ; 15(9): 1375-84, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18421302

RESUMO

According to the amyloid cascade hypothesis, Alzheimer's disease is the consequence of neuronal cell death induced by beta-amyloid (Abeta), which accumulates by abnormal clearance or production. On the other hand, recent studies have shown cell death-induced alteration in amyloid precursor protein (APP) processing, suggesting potential mutual interactions between APP processing and cell death. We have shown previously that the cell death caused by DNA damage-inducing agents (DDIAs) facilitated gamma-secretase activity and Abeta generation in a Bax/Bcl-2-dependent, but caspase-independent manner. Here, we attempted to elucidate the downstream mechanism that modulates gamma-secretase activity in DDIA-treated cells. N-acetyl cysteine, a potent antioxidant, attenuated DDIA-induced enhancement of gamma-secretase activity but failed to rescue cell death. Overexpression of heat shock protein 70, which blocks cytochrome c release from mitochondria, also reduced gamma-secretase activity. Moreover, glutathione depletion significantly facilitated gamma-secretase activity and Abeta generation by enhancing the formation of higher molecular weight gamma-secretase complex before signs of cell death developed. Finally, Abeta treatment, a known inducer of oxidative stress, also increased gamma-secretase activity. Taken together, these results indicate that DDIA-induced gamma-secretase activation is dependent on augmented oxidative stress, and that Abeta and gamma-secretase may activate each other. On the basis of these results, we propose a feed-back loop between oxidative stress and Abeta generation mediated by gamma-secretase activation.


Assuntos
Secretases da Proteína Precursora do Amiloide/metabolismo , Peptídeos beta-Amiloides/metabolismo , Apoptose , Dano ao DNA , Estresse Oxidativo , Peptídeos beta-Amiloides/farmacologia , Animais , Células CHO , Camptotecina/toxicidade , Cricetinae , Cricetulus , Citocromos c/metabolismo , Ativação Enzimática , Etoposídeo/toxicidade , Glutationa/metabolismo , Humanos , Camundongos , Mitocôndrias/metabolismo , Proteínas de Transporte da Membrana Mitocondrial/antagonistas & inibidores , Poro de Transição de Permeabilidade Mitocondrial , Espécies Reativas de Oxigênio/metabolismo
19.
Respir Med ; 98(2): 115-22, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14971873

RESUMO

Vascular endothelial growth factor (VEGF) is a potent, multifunctional cytokine that contributes to angiogenesis and inflammation. Matrix metalloproteinase-9 (MMP-9) is one of the major proteolytic enzymes that degrade various components of the extracellular matrix. Few data are available on the potential relationship between VEGF and MMP-9 in the accumulation of pleural effusion. We examined levels of VEGF and MMP-9 by means of enzyme immunoassay, zymographic analysis, and Western blot analysis in the patients with liver cirrhosis, tuberculosis, or lung cancer. The levels of VEGF and MMP-9 were significantly increased in the pleural fluids and sera of patients with tuberculosis and were even higher in patients with lung cancer compared with the patients with liver cirrhosis. A significant correlation was established between the level of VEGF and the level of MMP-9 in the pleural effusion. These results suggest that overproduction of VEGF and MMP-9 is associated with accumulation of the pleural effusion in tuberculosis and lung cancer. The relationship between VEGF and MMP-9 in the pleural effusion may have a role in the pathogenesis of pleural fluid formation.


Assuntos
Metaloproteinase 9 da Matriz/metabolismo , Derrame Pleural/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Western Blotting , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Cirrose Hepática/complicações , Cirrose Hepática/metabolismo , Neoplasias Pulmonares/complicações , Neoplasias Pulmonares/metabolismo , Masculino , Pessoa de Meia-Idade , Derrame Pleural/complicações , Tuberculose/metabolismo
20.
Clin Exp Allergy ; 34(2): 276-84, 2004 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-14987308

RESUMO

BACKGROUND: Toluene diisocyanate (TDI)-induced asthma is an inflammatory disease of the airways characterized by airway remodelling due, at least in part, to an excess of extracellular matrix deposition in the airway wall. The ratio of matrix metalloproteinase-9 (MMP-9) and its inhibitor, tissue inhibitor of metalloproteinase-1 (TIMP-1) may be a marker of the balance between airway tissue destruction and repair. OBJECTIVE: We determined whether an imbalance of the MMP-9 : TIMP-1 molar ratio is present before and/or after challenge with TDI. METHODS: We used a murine model of TDI-induced asthma to evaluate the MMP-9 and TIMP-1 balance in the lung. RESULTS: The expression of MMP-9 and TIMP-1 mRNAs and proteins in the lungs increased at 7 h after TDI inhalation and continued for up to 72 h. Immunohistochemical and immunocytological analyses in the lungs of TDI-exposed mice revealed increases of immunoreactive MMP-9 and TIMP-1. There were significant correlations between the levels of MMP-9 or TIMP-1 and the number of neutrophils, lymphocytes, or eosinophils. The molar ratio of MMP-9/TIMP-1 significantly decreased at 7 h after TDI inhalation and continued up to 72 h. CONCLUSION: These data suggest that TDI-induced asthma may be associated with an imbalance between MMP-9 and TIMP-1, which could be useful as a marker of airway inflammation and airway remodelling in this disease.


Assuntos
Asma/enzimologia , Pulmão/enzimologia , Metaloproteinase 9 da Matriz/metabolismo , Doenças Profissionais/enzimologia , Inibidor Tecidual de Metaloproteinase-1/metabolismo , Animais , Western Blotting/métodos , Brônquios/enzimologia , Líquido da Lavagem Broncoalveolar/química , Feminino , Immunoblotting/métodos , Imuno-Histoquímica/métodos , Metaloproteinase 9 da Matriz/genética , Camundongos , Camundongos Endogâmicos BALB C , Modelos Animais , RNA Mensageiro/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Solventes , Inibidor Tecidual de Metaloproteinase-1/genética , Tolueno 2,4-Di-Isocianato
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