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1.
Diagnostics (Basel) ; 13(4)2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36832147

RESUMO

The ectopic pancreas is a benign subepithelial tumor (SET) mostly found incidentally in the stomach and duodenum. Here, we present computed tomography (CT) scans and endoscopic ultrasound (EUS) images from a 71-year-old Taiwanese man newly diagnosed with colonic adenocarcinoma. CT examination revealed a mural nodule in the proximal jejunum, with good enhancement after IV contrast medium administration. Push enteroscopy was performed to localize the lesion and evaluate its nature, and a 1 cm subepithelial lesion was found. The lesion appeared hyperechoic within the submucosal layer of the bowel wall on endoscopic ultrasound examination. A tattoo was performed, and the lesion was removed during the resection of colon cancer. The histopathology confirmed the presence of pancreatic tissue inside. As far as we know, this is the first description in the literature of an endoscopic ultrasound finding of a jejunal ectopic pancreas.

2.
Diagnostics (Basel) ; 12(9)2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-36140524

RESUMO

The efficacy of new generation endoscopic ultrasound-guided biopsy needles has been promising in recent years. Yet, comparing these needles' diagnostic yield and safety to conventional needles is not well-known. Our study aims to compare the adverse events of endoscopic ultrasound-guided tissue acquisition (EUS-TA) with different types of needles, including FNA needles, FNB needles with a Franseen tip and FNB needles with a reverse bevel. Furthermore, we will analyze the risk factors, including tumor vascularity, different needle types, and the underlying disease, which may impact the safety of the procedures. From May 2014 to December 2021, 192 consecutive EUS-TAs were performed on pancreatic and peripancreatic lesions in our hospital using different types of FNA and FNB needles. We retrospectively reviewed the data and identified the risk factors for EUS-TA-related complications. As a result, the hypervascular tumor is a significant risk factor for adverse events in our multivariate analysis, with an odds ratio of 4.96 (95% CI 1.33-18.47), while liver cirrhosis is one of the risk factors for adverse events during EUS-TA, with an odds ratio of 5.3 (95% CI 1.1-25.6). However, the risk of adverse events did not increase using Franseen-tip needles, compared to conventional FNA or FNB needles with a reverse bevel. In conclusion, we must be more cautious in patients with liver cirrhosis and hypervascular tumors, such as pancreatic neuroendocrine tumors, when performing EUS-guided tissue acquisition.

3.
World J Gastroenterol ; 24(44): 5034-5045, 2018 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-30510378

RESUMO

AIM: To explore the risk factors of developing chronic pancreatitis (CP) in patients with acute pancreatitis (AP) and develop a prediction score for CP. METHODS: Using the National Health Insurance Research Database in Taiwan, we obtained large, population-based data of 5971 eligible patients diagnosed with AP from 2000 to 2013. After excluding patients with obstructive pancreatitis and biliary pancreatitis and those with a follow-up period of less than 1 year, we conducted a multivariate analysis using the data of 3739 patients to identify the risk factors of CP and subsequently develop a scoring system that could predict the development of CP in patients with AP. In addition, we validated the scoring system using a validation cohort. RESULTS: Among the study subjects, 142 patients (12.98%) developed CP among patients with RAP. On the other hand, only 32 patients (1.21%) developed CP among patients with only one episode of AP. The multivariate analysis revealed that the presence of recurrent AP (RAP), alcoholism, smoking habit, and age of onset of < 55 years were the four important risk factors for CP. We developed a scoring system (risk score 1 and risk score 2) from the derivation cohort by classifying the patients into low-risk, moderate-risk, and high-risk categories based on similar magnitudes of hazard and validated the performance using another validation cohort. Using the prediction score model, the area under the curve (AUC) [95% confidence interval (CI)] in predicting the 5-year CP incidence in risk score 1 (without the number of AP episodes) was 0.83 (0.79, 0.87), whereas the AUC (95%CI) in risk score 2 (including the number of AP episodes) was 0.84 (0.80, 0.88). This result demonstrated that the risk score 2 has somewhat better prediction performance than risk score 1. However, both of them had similar performance between the derivation and validation cohorts. CONCLUSION: In the study,we identified the risk factors of CP and developed a prediction score model for CP.


Assuntos
Pancreatite Crônica/epidemiologia , Adulto , Idoso , Área Sob a Curva , Estudos de Coortes , Bases de Dados Factuais/estatística & dados numéricos , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Programas Nacionais de Saúde/estatística & dados numéricos , Valor Preditivo dos Testes , Fatores de Risco , Taiwan/epidemiologia
4.
Arthritis Rheumatol ; 69(6): 1325-1336, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28118536

RESUMO

OBJECTIVE: To evaluate proinflammatory cytokines and leukocyte subpopulations in the cerebrospinal fluid (CSF) and blood of patients with neonatal-onset multisystem inflammatory disease (NOMID) after treatment, and to compare inflammatory cytokines in the CSF and blood in 6 patients treated with 2 interleukin-1 (IL-1) blockers-anakinra and canakinumab. METHODS: During routine follow-up visits between December 2011 and October 2013, we immunophenotyped the CSF of 17 pediatric NOMID patients who were treated with anakinra, and analyzed CSF cytokine levels in samples obtained at baseline and at 3-5-year follow-up visits and compared them to samples from healthy controls. RESULTS: CSF levels of IL-6, interferon-γ-inducible 10-kd protein (IP-10/CXCL10), and IL-18 and monocyte and granulocyte counts significantly decreased with anakinra treatment but did not normalize to levels in the controls, even in patients fulfilling criteria for clinical remission. CSF IL-6 and IL-18 levels significantly correlated with measures of blood-brain barrier function, specifically CSF protein (r = 0.75 and r = 0.81, respectively) and albumin quotient (r = 0.79 and r = 0.68, respectively). When patients were treated with canakinumab versus anakinra, median CSF white blood cell counts and IL-6 levels were significantly higher with canakinumab treatment (10.2 cells/mm3 versus 3.7 cells/mm3 and 150.7 pg/ml versus 28.5 pg/ml, respectively) despite similar serum cytokine levels. CONCLUSION: CSF leukocyte subpopulations and cytokine levels significantly improve with optimized IL-1 blocking treatment, but do not normalize. The correlation of CSF IL-6, IP-10/CXCL10, and IL-18 levels with clinical laboratory measures of inflammation and blood-brain barrier function suggests that they may have a role as biomarkers in central nervous system (CNS) inflammation. The difference in inhibition of CSF biomarkers between 2 IL-1 blocking agents, anakinra and canakinumab, suggests differences in efficacy in the intrathecal compartment, with anakinra being more effective. Our data indicate that intrathecal immune responses shape CNS inflammation and should be assessed in addition to blood markers.


Assuntos
Barreira Hematoencefálica/metabolismo , Síndromes Periódicas Associadas à Criopirina/líquido cefalorraquidiano , Citocinas/metabolismo , Meningite Asséptica/líquido cefalorraquidiano , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , Antirreumáticos/uso terapêutico , Biomarcadores/líquido cefalorraquidiano , Pré-Escolar , Síndromes Periódicas Associadas à Criopirina/tratamento farmacológico , Citocinas/líquido cefalorraquidiano , Feminino , Seguimentos , Humanos , Lactente , Recém-Nascido , Proteína Antagonista do Receptor de Interleucina 1/uso terapêutico , Masculino , Meningite Asséptica/tratamento farmacológico , Resultado do Tratamento
5.
Clin Infect Dis ; 64(3): 275-283, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-28011613

RESUMO

BACKGROUND: Cryptococcus can cause meningoencephalitis (CM) among previously healthy non-HIV adults. Spinal arachnoiditis is under-recognized, since diagnosis is difficult with concomitant central nervous system (CNS) pathology. METHODS: We describe 6 cases of spinal arachnoiditis among 26 consecutively recruited CM patients with normal CD4 counts who achieved microbiologic control. We performed detailed neurological exams, cerebrospinal fluid (CSF) immunophenotyping and biomarker analysis before and after adjunctive immunomodulatory intervention with high dose pulse corticosteroids, affording causal inference into pathophysiology. RESULTS: All 6 exhibited severe lower motor neuron involvement in addition to cognitive changes and gait disturbances from meningoencephalitis. Spinal involvement was associated with asymmetric weakness and urinary retention. Diagnostic specificity was improved by MRI imaging which demonstrated lumbar spinal nerve root enhancement and clumping or lesions. Despite negative fungal cultures, CSF inflammatory biomarkers, sCD27 and sCD21, as well as the neuronal damage biomarker, neurofilament light chain (NFL), were elevated compared to healthy donor (HD) controls. Elevations in these biomarkers were associated with clinical symptoms and showed improvement with adjunctive high dose pulse corticosteroids. CONCLUSIONS: These data suggest that a post-infectious spinal arachnoiditis is an important complication of CM in previously healthy individuals, requiring heightened clinician awareness. Despite microbiological control, this syndrome causes significant pathology likely due to increased inflammation and may be amenable to suppressive therapeutics.


Assuntos
Aracnoidite/congênito , Cryptococcus , Encefalite Infecciosa/complicações , Meningite Criptocócica/complicações , Meningoencefalite/complicações , Adulto , Anti-Inflamatórios/uso terapêutico , Aracnoidite/diagnóstico por imagem , Aracnoidite/tratamento farmacológico , Aracnoidite/imunologia , Aracnoidite/microbiologia , Biomarcadores/líquido cefalorraquidiano , Relação CD4-CD8 , Feminino , Humanos , Imunossupressores/uso terapêutico , Encefalite Infecciosa/líquido cefalorraquidiano , Encefalite Infecciosa/tratamento farmacológico , Encefalite Infecciosa/imunologia , Angiografia por Ressonância Magnética , Masculino , Meningite Criptocócica/tratamento farmacológico , Meningite Criptocócica/imunologia , Meningoencefalite/líquido cefalorraquidiano , Meningoencefalite/tratamento farmacológico , Meningoencefalite/imunologia , Metotrexato/uso terapêutico , Metilprednisolona/uso terapêutico , Pessoa de Meia-Idade , Exame Neurológico , Pulsoterapia , Tacrolimo/uso terapêutico , Adulto Jovem
6.
PLoS Pathog ; 11(5): e1004884, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-26020932

RESUMO

The fungus Cryptococcus is a major cause of meningoencephalitis in HIV-infected as well as HIV-uninfected individuals with mortalities in developed countries of 20% and 30%, respectively. In HIV-related disease, defects in T-cell immunity are paramount, whereas there is little understanding of mechanisms of susceptibility in non-HIV related disease, especially that occurring in previously healthy adults. The present description is the first detailed immunological study of non-HIV-infected patients including those with severe central nervous system (s-CNS) disease to 1) identify mechanisms of susceptibility as well as 2) understand mechanisms underlying severe disease. Despite the expectation that, as in HIV, T-cell immunity would be deficient in such patients, cerebrospinal fluid (CSF) immunophenotyping, T-cell activation studies, soluble cytokine mapping and tissue cellular phenotyping demonstrated that patients with s-CNS disease had effective microbiological control, but displayed strong intrathecal expansion and activation of cells of both the innate and adaptive immunity including HLA-DR+ CD4+ and CD8+ cells and NK cells. These expanded CSF T cells were enriched for cryptococcal-antigen specific CD4+ cells and expressed high levels of IFN-γ as well as a lack of elevated CSF levels of typical T-cell specific Th2 cytokines -- IL-4 and IL-13. This inflammatory response was accompanied by elevated levels of CSF NFL, a marker of axonal damage, consistent with ongoing neurological damage. However, while tissue macrophage recruitment to the site of infection was intact, polarization studies of brain biopsy and autopsy specimens demonstrated an M2 macrophage polarization and poor phagocytosis of fungal cells. These studies thus expand the paradigm for cryptococcal disease susceptibility to include a prominent role for macrophage activation defects and suggest a spectrum of disease whereby severe neurological disease is characterized by immune-mediated host cell damage.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Cryptococcus neoformans/imunologia , Células Matadoras Naturais/imunologia , Meningite Criptocócica/imunologia , Células Th1/imunologia , Adulto , Autopsia , Encéfalo/imunologia , Encéfalo/metabolismo , Encéfalo/patologia , Linfócitos T CD4-Positivos/microbiologia , Linfócitos T CD8-Positivos/microbiologia , Estudos de Coortes , Citocinas/metabolismo , Feminino , Citometria de Fluxo , Humanos , Imunofenotipagem , Células Matadoras Naturais/microbiologia , Ativação Linfocitária , Masculino , Meningite Criptocócica/líquido cefalorraquidiano , Meningite Criptocócica/microbiologia , Pessoa de Meia-Idade , Adulto Jovem
7.
Ann Neurol ; 78(1): 3-20, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25808056

RESUMO

OBJECTIVE: The management of complex patients with neuroimmunological diseases is hindered by an inability to reliably measure intrathecal inflammation. Currently implemented laboratory tests developed >40 years ago either are not dynamic or fail to capture low levels of central nervous system (CNS) inflammation. Therefore, we aimed to identify and validate biomarkers of CNS inflammation in 2 blinded, prospectively acquired cohorts of untreated patients with neuroimmunological diseases and embedded controls, with the ultimate goal of developing clinically useful tools. METHODS: Because biomarkers with maximum utility reflect immune phenotypes, we included an assessment of cell specificity in purified primary immune cells. Biomarkers were quantified by optimized electrochemiluminescent immunoassays. RESULTS: Among markers with cell-specific secretion, soluble CD27 is a validated biomarker of intrathecal T-cell activation, with an area under the receiver operating characteristic curve of 0.97. Comparing the quantities of cerebrospinal fluid (CSF) immune cells and their respective cell-specific soluble biomarkers (released by CSF cells as well as their counterparts in CNS tissue) provided invaluable information about stationary CNS immune responses, previously attainable via brain biopsy only. Unexpectedly, progressive and relapsing-remitting multiple sclerosis (MS) patients have comparable numbers of activated intrathecal T and B cells, which are preferentially embedded in CNS tissue in the former group. INTERPRETATION: The cell-specific biomarkers of intrathecal inflammation may improve diagnosis and management of neuroimmunological diseases and provide pharmacodynamic markers for future therapeutic developments in patients with intrathecal inflammation that is not captured by imaging, such as in progressive MS.


Assuntos
Biomarcadores/líquido cefalorraquidiano , Líquido Cefalorraquidiano/citologia , Esclerose Múltipla Crônica Progressiva/líquido cefalorraquidiano , Esclerose Múltipla Recidivante-Remitente/líquido cefalorraquidiano , Adulto , Idoso , Linfócitos B/citologia , Estudos de Casos e Controles , Líquido Cefalorraquidiano/imunologia , Estudos de Coortes , Feminino , Humanos , Inflamação/líquido cefalorraquidiano , Subunidade p40 da Interleucina-12/líquido cefalorraquidiano , Interleucina-8/líquido cefalorraquidiano , Receptores de Lipopolissacarídeos/líquido cefalorraquidiano , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Doenças do Sistema Nervoso/líquido cefalorraquidiano , Estudos Prospectivos , Receptores de Complemento 3d/metabolismo , Linfócitos T/citologia , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/líquido cefalorraquidiano , Adulto Jovem
8.
Plast Reconstr Surg ; 132(2): 251e-262e, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23897353

RESUMO

BACKGROUND: Restoring peripheral nerve function after long gap peripheral nerve damage is challenging. Lithium chloride has demonstrated neuroprotective qualities and therefore shows great potential therapeutic benefit for some neurodegenerative diseases. This study examined the synergistic combination of glial cell line-derived neurotrophic factor and lithium chloride and its effect on peripheral nerve regeneration in a rat sciatic nerve injury model. METHODS: Polycaprolactone conduits with glial cell line-derived neurotrophic factor-loaded double-walled microspheres and local injections of lithium chloride, 1.5 or 2.5 mEq/kg body weight, were examined in a 15-mm rat sciatic nerve defect model. Eighteen Lewis male rats were divided randomly into control, 1.5-, and 2.5-mEq/kg lithium chloride injection groups. As an indicator of recovery, nerve sections were stained with S100, protein gene product 9.5 antibody, and toluidine blue. RESULTS: Nerves stained with S100 and protein gene product 9.5 antibody demonstrated a significantly increased density of Schwann cells and axons in the 2.5-mEq/kg lithium chloride injection-treated groups compared with both the control and 1.5-mEq/kg lithium chloride injection-treated groups (p<0.05). At 6 weeks, histomorphometry revealed a significantly higher fiber density in the middle of the conduit for the 2.5-mEq/kg groups compared with the 1.5-mEq/kg group or the control group. CONCLUSION: Polycaprolactone nerve guides with glial cell line-derived neurotrophic factor-loaded double-walled microspheres and local injections of lithium chloride, 2.5-mEq/kg, represent a potentially viable guiding material for Schwann cell and axon migration and proliferation for the treatment of peripheral nerve regeneration.


Assuntos
Fator Neurotrófico Derivado de Linhagem de Célula Glial/farmacologia , Cloreto de Lítio/farmacologia , Regeneração Nervosa/efeitos dos fármacos , Traumatismos dos Nervos Periféricos/tratamento farmacológico , Nervo Isquiático/efeitos dos fármacos , Animais , Biópsia por Agulha , Modelos Animais de Doenças , Sinergismo Farmacológico , Imuno-Histoquímica , Masculino , Condução Nervosa/efeitos dos fármacos , Traumatismos dos Nervos Periféricos/patologia , Distribuição Aleatória , Ratos , Ratos Endogâmicos Lew , Valores de Referência , Nervo Isquiático/lesões , Nervo Isquiático/patologia , Resultado do Tratamento
9.
Acta Biomater ; 9(2): 5243-50, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23022891

RESUMO

Cell sheet technology has been studied for applications such as bone, ligament and skin regeneration. There has been limited examination of adipose-derived stem cells (ASCs) for cell sheet applications. The specific aim of this study was to evaluate ASC sheet technology for wound healing. ASCs were isolated from discarded human abdominal subcutaneous adipose tissue, and ASC cell sheets were created on the surface of fibrin-grafted culture dishes. In vitro examination consisted of the histochemical characterization of the ASC sheets. In vivo experiments consisted of implanting single-layer cell sheets, triple-layer cell sheets or non-treated control onto a full-thickness wound defect (including epidermis, dermis, and subcutaneous fat) in nude mice for 3 weeks. Cell sheets were easily peeled off from the culture dishes using forceps. The single- and triple-layer ASC sheets showed complete extracellular structure via hematoxylin & eosin staining. In vivo, the injury area was measured 7, 10, 14 and 21 days post-treatment to assess wound recovery. The ASC sheet-treated groups' injury area was significantly smaller than that of the non-treated control group at all time points except day 21. The triple-layer ASC sheet treatment significantly enhanced wound healing compared to the single-layer ASC sheet at 7, 10 and 14 days. The density of blood vessels showed that ASC cell sheet treatment slightly enhanced total vessel proliferation compared to the empty wound injury treatment. Our studies indicate that ASC sheets present a potentially viable matrix for full-thickness defect wound healing in a mouse model. Consequently, our ASC sheet technology represents a substantial advance in developing various types of three-dimensional tissues.


Assuntos
Tecido Adiposo/citologia , Transplante de Células-Tronco , Células-Tronco/citologia , Cicatrização , Adulto , Animais , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Humanos , Imuno-Histoquímica , Camundongos , Camundongos Nus , Pessoa de Meia-Idade
10.
Tissue Eng Part C Methods ; 18(1): 54-61, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-21902468

RESUMO

To further differentiate adipose-derived stem cells (ASCs) into mature adipocytes and create three-dimensional (3D) adipose tissue in vitro, we applied multicompartment hollow fiber-based bioreactor technology with decentral mass exchange for more physiological substrate gradients and integral oxygenation. We hypothesize that a dynamic 3D perfusion in such a bioreactor will result in longer-term culture of human adipocytes in vitro, thus providing metabolically active tissue serving as a diagnostic model for screening drugs to treat diabetes. ASCs were isolated from discarded human abdominal subcutaneous adipose tissue and then inoculated into dynamic 3D culture bioreactors to undergo adipogenic differentiation. Insulin-stimulated glucose uptake from the medium was assessed with and without TNF-alpha. 3D adipose tissue was generated in the 3D-bioreactors. Immunohistochemical staining indicated that 3D-bioreactor culture displayed multiple mature adipocyte markers with more unilocular morphologies as compared with two-dimensional (2D) cultures. Results of real-time polymerase chain reaction showed 3D-bioreactor treatment had more efficient differentiation in fatty acid-binding protein 4 expression. Repeated insulin stimulation resulted in increased glucose uptake, with a return to baseline between testing. Importantly, TNF-alpha inhibited glucose uptake, an indication of the metabolic activity of the tissue. 3D bioreactors allow more mature adipocyte differentiation of ASCs compared with traditional 2D culture and generate adipose tissue in vitro for up to 2 months. Reproducible metabolic activity of the adipose tissue in the bioreactor was demonstrated, which is potentially useful for drug discovery. We present here, to the best of our knowledge for the first time, the development of a coherent 3D high density fat-like tissue consisting of unilocular structure from primary adipose stem cells in vitro.


Assuntos
Adipogenia , Tecido Adiposo/citologia , Reatores Biológicos , Células-Tronco/citologia , Adipócitos/citologia , Adulto , Técnicas de Cultura de Células , Diferenciação Celular , Feminino , Humanos , Imuno-Histoquímica/métodos , Pessoa de Meia-Idade , Oxigênio/química , Perfusão , Fator de Necrose Tumoral alfa/metabolismo
11.
Plast Reconstr Surg ; 129(1): 67-78, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22186500

RESUMO

BACKGROUND: Restoration with sufficient functional recovery after long-gap peripheral nerve damage remains a clinical challenge. In vitro, keratins, which are derived from human hair, enhance activity and gene expression of Schwann cells. The specific aim of the authors' study was to examine keratin gel as conduit filler for peripheral nerve regeneration in a rat sciatic nerve injury model. METHODS: Incorporation of glial cell line-derived, neurotrophic factor, double-walled microspheres into polycaprolactone nerve guides has demonstrated an off-the-shelf product alternative to promote nerve regeneration, and this conduit was filled with keratin gel and examined in a rat 15-mm sciatic nerve defect model. As an indicator of recovery, nerve sections were stained with S100 and protein gene product 9.5 antibody. RESULTS: The keratin-treated groups, compared with both saline and empty polycaprolactone (control) groups (p < 0.05), demonstrated a significantly increased density of Schwann cells and axons. Polycaprolactone-based nerve conduits possess optimal mechanical and degradative properties, rendering the biocompatible conduits potentially useful in peripheral nerve repair. CONCLUSION: From their studies, the authors conclude that polycaprolactone nerve guides with glial cell line-derived, neurotrophic factor-loaded, double-walled microspheres filled with keratin gel represent a potentially viable guiding material for Schwann cell and axon migration and proliferation in the treatment of peripheral nerve regeneration.


Assuntos
Regeneração Nervosa , Traumatismos dos Nervos Periféricos/cirurgia , Nervo Isquiático/lesões , Engenharia Tecidual/métodos , Alicerces Teciduais , Géis , Humanos , Queratinas , Modelos Animais , Músculo Esquelético/patologia , Tamanho do Órgão , Poliésteres , Células de Schwann , Cicatrização/fisiologia
12.
Ann Plast Surg ; 67(2): 147-55, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21712696

RESUMO

Restoration with sufficient functional recovery after long-gap peripheral nerve damage remains a clinical challenge. Silk has shown clinical promise for numerous tissue engineering applications due to its biocompatibility, impressive mechanical properties, and Food and Drug Administration approval. The aim of this study was to evaluate the efficacy of silk fibroin--based nerve guides containing glial cell line-derived neurotrophic factor (GDNF) in a long-gap sized (15 mm) rat sciatic nerve defect model. Four groups of nerve conduits were prepared: (1) silk conduits with empty silk microspheres, (2) silk conduits with GDNF-loaded silk microspheres uniformly distributed in the conduit wall, (3) silk conduits with GDNF-loaded silk microspheres in a controlled manner with the highest GDNF concentration at the distal end, and (4) isograft. After 6 weeks, the nerve grafts were explanted, harvested, and fixed for histologic analysis. Nerve tissue stained with the S-100, and neuroendocrine marker PGP 9.5 antibodies demonstrated a significantly increased density of nerve tissue in the GDNF-treated groups compared with the empty microsphere (control) group (P < 0.05). GDNF-treated animals with a higher concentration of GDNF in the distal portion possessed a significantly higher density of PGP 9.5 protein middle conduit part than comparison to GDNF uniform-treated animals (P < 0.05). Silk-based nerve conduits possess optimal mechanical and degradative properties, rendering them potentially useful in peripheral nerve repair. This study demonstrates that novel, porous silk fibroin--based nerve conduits, infused with GDNF in a controlled manner, represent a potentially viable conduit for Schwann cell migration and proliferation in the regeneration of peripheral nerves.


Assuntos
Fibroínas , Fator Neurotrófico Derivado de Linhagem de Célula Glial/administração & dosagem , Regeneração Tecidual Guiada/métodos , Regeneração Nervosa , Nervo Isquiático/cirurgia , Alicerces Teciduais , Animais , Fibroínas/química , Microesferas , Músculo Esquelético/inervação , Distribuição Aleatória , Ratos , Células de Schwann/fisiologia , Nervo Isquiático/lesões , Nervo Isquiático/fisiologia
14.
Knee Surg Sports Traumatol Arthrosc ; 17(11): 1326-31, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19633829

RESUMO

Osteochondral defects are frequent, painful, debilitating and expensive to treat, often resulting in poor results. The goal of the present study was to synthesize and characterize a novel biocompatible and biodegradable hydrogel comprised of poly(ethylene glycol), gelatin, and genipin, and examine the hydrogel as an injectable biomaterial in combination with a cyanoacrylate-based surgical sealant for cartilage repair. An osteochondral knee defect was generated in 24 rats, then the hydrogel, with or without a surgical sealant, was injected into the defect and followed for 14 days. The results demonstrated that the hydrogel is biocompatible and biodegradable, and that the cyanoacrylate-based surgical sealant is a relatively safe option for maintaining the hydrogel in the defect. This is the first study describing a cyanoacrylate-based surgical sealant in combination with a polymer hydrogel for cartilage repair.


Assuntos
Materiais Biocompatíveis/administração & dosagem , Doenças das Cartilagens/terapia , Hidrogel de Polietilenoglicol-Dimetacrilato/administração & dosagem , Traumatismos do Joelho/terapia , Adesivos Teciduais/administração & dosagem , Animais , Cartilagem Articular/lesões , Modelos Animais de Doenças , Feminino , Injeções Intra-Articulares , Articulação do Joelho , Ratos
15.
Acta Biomater ; 5(5): 1416-24, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19129013

RESUMO

Polyethersulfone (PES) is a nondegradable, biocompatible, synthetic polymer that is commonly utilized as a membrane material for applications such as hemodialysis, ultrafiltration and bioreactor technology. Various studies have shown surface modification to be a valuable tool in the development of nondegradable materials which promote cell adhesion. Cells of interest include adipose-derived stem cells (ASCs). ASCs are multipotent mesenchymal stem cells that are useful for various regenerative medicine applications. In this study, we hypothesized that PES surfaces modified with a peptide sequence based from fibronectin, such as Arg-Gly-Asp (RGD), Arg-Gly-Asp-Ser and Gly-Arg-Gly-Asp-Ser, would increase ASC adhesion compared to unmodified PES surfaces. The synthetic peptides were covalently bonded to amine-modified PES surfaces using 1-ethyl-3-(dimethylaminopropyl) carbodiimide. The surfaces were characterized using a ninhydrin assay and contact angle measurements. The ninhydrin assay confirmed the presence of amine groups on the surface of peptide-treated PES disks. Advancing water contact angles were analyzed to detect changes in the hydrophilicity of the polymer surfaces, and results indicated our PES membranes had excellent hydrophilicity. The attachment and proliferation of human ASCs was assessed and RGD-treated surfaces resulted in a higher number of attached ASCs after 6 and 48 h, as compared to unmodified PES surfaces. Additionally, varying concentrations of the RGD peptide sequence concentration were examined. These results indicate that PES membranes modified with the RGD peptide sequence can be utilized for enhanced ASC attachment in biomedical applications.


Assuntos
Tecido Adiposo/citologia , Peptídeos/química , Polímeros/química , Células-Tronco/citologia , Sulfonas/química , Adulto , Sequência de Aminoácidos , Adesão Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Feminino , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Ninidrina , Oligopeptídeos/química , Oligopeptídeos/farmacologia , Peptídeos/farmacologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/ultraestrutura , Propriedades de Superfície/efeitos dos fármacos
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