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1.
J Pediatr Surg ; 55(2): 245-248, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761454

RESUMO

BACKGROUND: Plication of diaphragm (DP) for eventration (DE) can be done using thoracic or abdominal approaches. The purpose of our study was to compare outcomes between these approaches based on our experience and on systematic literature review. METHODS: Retrospective records of children <16 years who underwent DP (single-center, 2004-2018) were recorded and analyzed. Systematic review and meta-analysis of related studies was undertaken. Data are reported as median (range). RESULTS: Eighty-nine cases were identified in thoracic (Congenital = 5, Acquired = 84) and 13 (Congenital = 10, Acquired = 3) in abdominal group aged 5.88 (0.36-184.44) and 10.0 (0.12-181.8) months. Improvement in diaphragm level post-DP was significantly higher in abdominal [2(0-4)] than chest [1.5(0-5)] group (p = 0.04). On Cox regression analysis, there was a non-significant trend to a longer time to extubation in the chest group (Hazard ratio (HR) = 0.539[0.208-1.395], p = 0.203). Patients operated transthoracically left intensive care unit after a significantly longer time (HR = 0.339[0.119-0.966], p = 0.043). Patients operated transabdominally tended to be fed later, although this was not significant (HR = 1.801[0.762-4.253], p = 0.043). On Kaplan-Meier analysis, there was a non-significant trend to a lower rate of recurrence in the abdominal group (HR = 0.3196[0.061-1.675], p = 0.1876). In the meta-analysis including three published studies as well as our data (total n = 181, Thoracic = 139, Abdominal = 42), no difference was found in the incidence of recurrence amongst the 2 groups (RD = -0.04, 95%CI = -0.25, 0.18, p = 0.74). CONCLUSION: This is one of the largest reports on outcomes of children undergoing DP for DE. There is no significant difference in recurrence rate, even though all recurrences in our series (15.7%) were in the acquired cases operated using a thoracic approach. TYPE OF STUDY: Treatment Retrospective Comparative Study. LEVEL OF EVIDENCE: Level III.


Assuntos
Abdome/cirurgia , Diafragma/cirurgia , Eventração Diafragmática/cirurgia , Procedimentos Cirúrgicos Torácicos , Adolescente , Criança , Pré-Escolar , Eventração Diafragmática/epidemiologia , Humanos , Lactente , Recém-Nascido , Recidiva , Estudos Retrospectivos , Procedimentos Cirúrgicos Torácicos/efeitos adversos , Procedimentos Cirúrgicos Torácicos/métodos , Procedimentos Cirúrgicos Torácicos/estatística & dados numéricos , Resultado do Tratamento
2.
Pediatr Blood Cancer ; 66(2): e27502, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30393993

RESUMO

BACKGROUND/OBJECTIVES: Central database registrations are widely used tools for assessment of clinical results, but their reliability is subject to debate. The aim of this study is to evaluate the reliability of central database registration for Wilms tumor (WT) nephrectomy-related complications. DESIGN/METHODS: All Dutch patients undergoing WT nephrectomy according to the International Society of Paediatric Oncology (SIOP) 2001 protocol between 2001 and 2013 were evaluated. Results from the central database were analyzed and compared with data found via individual medical records analysis (gold standard). RESULTS: A total of 179 patients were included. Fourteen (7.8%) patients with a total of 17 complications were identified in the central database. The medical records revealed that 33 (18.4%) of patients had undergone a total of 41 complications (P < 0.001). Operative complications were similar between the groups (P = 0.157). Eleven short-term complications were noted in the central database versus 27 in the medical records (P = 0.059). Significantly more long-term complications, namely, adhesive small-bowel obstruction, were noted from the medical records compared with the central database (7 vs 1, respectively, P < 0.001). Postoperative chemotherapy was significantly delayed by on average 6 days (P < 0.0001) in patients with complications. No significant effect of complications on event-free survival, overall survival, or the relapse rate was recorded. CONCLUSION: Central database registrations underestimate the incidence of surgery-related complications after WT nephrectomy and need to be regarded with caution.


Assuntos
Registros Hospitalares , Neoplasias Renais/cirurgia , Complicações Pós-Operatórias/epidemiologia , Sistema de Registros , Tumor de Wilms/cirurgia , Adolescente , Criança , Pré-Escolar , Bases de Dados Factuais , Feminino , Humanos , Incidência , Lactente , Masculino , Nefrectomia/efeitos adversos , Estudos Retrospectivos
3.
Pancreas ; 46(9): 1091-1097, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28902777

RESUMO

The aim of this study was to compare operative versus nonoperative management of blunt pancreatic trauma in children. A systematic literature search was performed. Studies including children with blunt pancreatic injuries classified according to the American Association for the Surgery of Trauma classification were included. The primary outcome was pseudocyst formation. After screening 526 studies, 23 studies with 928 patients were included. Sufficient data were available for 674 patients (73%). Of 309 patients with grade I or II injuries, 258 (83%) were initially managed nonoperatively with a 96% success rate. Of 365 patients with grade III, IV, or V injuries, nonoperative management was initially chosen for 167 patients (46%) with an 89% success rate. Pseudocysts occurred in 18% of patients managed nonoperatively versus 4% of patients managed operatively (P < 0.01), of whom 65% were treated nonoperatively. Hospitalization was 20.5 days after nonoperative versus 15.1 days after operative management (nonparametric t test, P = 0.41). Blunt pancreatic trauma in children can be managed nonoperatively in the majority of patients with grade I or II injuries and in about half of the patients with grade III to V injuries. Although pseudocysts are more common after nonoperative management, two thirds can be managed nonoperatively.


Assuntos
Tomada de Decisões , Pâncreas/lesões , Pâncreas/cirurgia , Ferimentos não Penetrantes/cirurgia , Criança , Feminino , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Avaliação de Resultados em Cuidados de Saúde/métodos , Avaliação de Resultados em Cuidados de Saúde/estatística & dados numéricos , Índices de Gravidade do Trauma , Ferimentos não Penetrantes/patologia
4.
Ann Otol Rhinol Laryngol ; 126(1): 6-8, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27821414

RESUMO

BACKGROUND/PURPOSE: During repair of esophageal atresia with distal tracheo-esophageal fistula, air leakage through the fistula during mechanical ventilation can cause respiratory demise. METHODS: From February 2012 until November 2014, all patients with esophageal atresia and distal tracheo-esophageal fistula were subjected to preoperative tracheobronchoscopy. Relatively distal fistulas were cannulated with a Fogarty catheter and blocked by insufflation (video illustration). Relatively proximal distal fistulas were sealed by precise placement of a cuffed ventilation tube. RESULTS: Nine of 12 patients received Fogarty balloon placement. The fistula of the remaining 3 patients were sealed by careful tube placement. No complications related to tracheobronchoscopy or Fogarty placement were noted. All procedures were uneventful. CONCLUSIONS: Preoperative tracheobronchoscopy to evaluate the usefulness of Fogarty balloon insertion or correct tube placement for distal tracheo-esophageal fistula is a safe and easy to perform procedure that can avoid complications in type C esophageal atresia repair.


Assuntos
Broncoscopia , Cateterismo , Atresia Esofágica/terapia , Fístula Traqueoesofágica/terapia , Feminino , Humanos , Recém-Nascido , Insuflação , Cuidados Pré-Operatórios
5.
Ned Tijdschr Geneeskd ; 159: A8911, 2015.
Artigo em Holandês | MEDLINE | ID: mdl-26443112

RESUMO

In children with no prior history of abdominal surgery and no signs of intussusception or incarcerated inguinal hernia, mechanical ileus may have a congenital cause such as malrotation with volvulus or a persistent omphalomesenteric duct. Acquired causes include sigmoid volvulus. We present two cases of mechanical ileus in children. The first case involved a 6-year-old boy who presented with acute abdominal pain and vomiting. An emergency laparotomy was performed, with resection of the omphalomesenteric duct. Recovery was uneventful. The other case concerned a 9-year-old boy who presented with increasing abdominal pain, bilious vomiting and general clinical deterioration. An emergency laparotomy was performed, revealing malrotation with volvulus and intestinal ischaemia. Children with no prior abdominal history who present with symptoms that may be caused by mechanical obstruction should be managed with a view to surgery and without delay, in order to prevent a catastrophic outcome resulting from a congenital or acquired mechanical obstruction.


Assuntos
Íleus/etiologia , Obstrução Intestinal/etiologia , Volvo Intestinal/complicações , Divertículo Ileal/complicações , Dor Abdominal/diagnóstico , Dor Abdominal/etiologia , Criança , Hérnia Inguinal/cirurgia , Humanos , Íleus/diagnóstico , Íleus/cirurgia , Obstrução Intestinal/diagnóstico , Obstrução Intestinal/cirurgia , Volvo Intestinal/diagnóstico , Volvo Intestinal/cirurgia , Intussuscepção , Laparotomia , Masculino , Divertículo Ileal/diagnóstico , Divertículo Ileal/cirurgia , Vômito/diagnóstico , Vômito/etiologia
6.
J Pediatr Surg ; 47(8): 1611-3, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22901927

RESUMO

Congenital esophageal stenosis combined with H-type tracheoesophageal fistula is a rare clinical entity that is often not diagnosed until months or sometimes many years after birth. We present a case of a boy who presented both these entities and was treated by thoracoscopy.


Assuntos
Estenose Esofágica/cirurgia , Toracoscopia/métodos , Fístula Traqueoesofágica/cirurgia , Broncoscopia , Dilatação/instrumentação , Dilatação/métodos , Dispneia/etiologia , Estenose Esofágica/complicações , Estenose Esofágica/congênito , Estenose Esofágica/diagnóstico por imagem , Estenose Esofágica/terapia , Esofagoscopia , Humanos , Recém-Nascido , Masculino , Radiografia , Fístula Traqueoesofágica/complicações , Fístula Traqueoesofágica/congênito
7.
Cell Transplant ; 19(6): 783-9, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20573304

RESUMO

Elimination of galactose-α(1,3)galactose (Gal) expression in pig organs has been previously shown to prevent hyperacute xenograft rejection. However, naturally present antibodies to non-Gal epitopes activate endothelial cells, leading to acute humoral xenograft rejection. Still, it is unknown whether xenogeneic pig liver sinusoidal endothelial cells (LSECs) from α(1,3)galactosyltransferase (GalT)-deficient pigs are damaged by antibody and complement-mediated mechanisms. The present study examined the xeno-antibody response of LSECs from GalT-deficient and wild pigs. Isolated LSEC from wild-type and GalT pigs were expose to human and baboon sera; IgM and IgG binding was analyzed by flow cytometry. Complement activation (C3a and CH50) was quantified in vitro from serum-exposed LSEC cultures using Enzyme-Linked ImmunoSorbent assay (ELISA). Levels of complement-activated cytotoxicity (CAC) were also determined by a fluorescent Live-Dead Assay and by the quantification of LDH release. IgM binding to GalT knockout (KO) LSECs was significantly lower (80% human and 87% baboon) compare to wild-type pig LSEC. IgG binding was low in all groups. Moreover, complement activation (C3a and CH50) levels released following exposure to human or baboon sera were importantly reduced (42% human and 52% baboon), CAC in GalT KO LSECs was reduced by 60% in human serum and by 72% in baboon serum when compared to wild-type LSECs, and LDH release levels were reduced by 37% and 57%, respectively. LSECs from GalT KO pigs exhibit a significant protection to humoral-induced cell damage compared to LSECs from wild pigs when exposed to human serum. Although insufficient to inhibit xenogeneic reactivity completely, transgenic GalT KO expression on pig livers might contribute to a successful application of clinical xenotransplantation in combination with other protective strategies.


Assuntos
Células Endoteliais/enzimologia , Células Endoteliais/imunologia , Galactosiltransferases/deficiência , Galactosiltransferases/imunologia , Fígado/citologia , Animais , Ativação do Complemento/imunologia , Complemento C3a/imunologia , Citotoxicidade Imunológica , Humanos , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Papio/sangue , Papio/imunologia , Suínos
8.
Hepatology ; 47(5): 1437-45, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18393287

RESUMO

UNLABELLED: Hepatitis C virus (HCV) infects over 3% of the world population and is the leading cause of chronic liver disease worldwide. HCV has long been known to associate with circulating lipoproteins, and its interactions with the cholesterol and lipid pathways have been recently described. In this work, we demonstrate that HCV is actively secreted by infected cells through a Golgi-dependent mechanism while bound to very low density lipoprotein (vLDL). Silencing apolipoprotein B (ApoB) messenger RNA in infected cells causes a 70% reduction in the secretion of both ApoB-100 and HCV. More importantly, we demonstrate that the grapefruit flavonoid naringenin, previously shown to inhibit vLDL secretion both in vivo and in vitro, inhibits the microsomal triglyceride transfer protein activity as well as the transcription of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase and acyl-coenzyme A:cholesterol acyltransferase 2 in infected cells. Stimulation with naringenin reduces HCV secretion in infected cells by 80%. Moreover, we find that naringenin is effective at concentrations that are an order of magnitude below the toxic threshold in primary human hepatocytes and in mice. CONCLUSION: These results suggest a novel therapeutic approach for the treatment of HCV infection.


Assuntos
Apolipoproteínas B/fisiologia , Flavanonas/farmacologia , Inativação Gênica , Hepacivirus/fisiologia , Apolipoproteínas B/genética , Carcinoma Hepatocelular/virologia , Linhagem Celular Tumoral , Sobrevivência Celular , Citrus paradisi , Primers do DNA , Ensaio de Imunoadsorção Enzimática , Hepacivirus/efeitos dos fármacos , Hepacivirus/patogenicidade , Humanos , Neoplasias Hepáticas/virologia , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Proteínas do Core Viral/análise
9.
Hepatology ; 47(5): 1634-43, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18395843

RESUMO

UNLABELLED: Orthotopic liver transplantation is the only proven effective treatment for fulminant hepatic failure (FHF), but its use is limited because of organ donor shortage, associated high costs, and the requirement for lifelong immunosuppression. FHF is usually accompanied by massive hepatocellular death with compensatory liver regeneration that fails to meet the cellular losses. Therefore, therapy aimed at inhibiting cell death and stimulating endogenous repair pathways could offer major benefits in the treatment of FHF. Recent studies have demonstrated that mesenchymal stem cell (MSC) therapy can prevent parenchymal cell loss and promote tissue repair in models of myocardial infarction, acute kidney failure, and stroke through the action of trophic secreted molecules. In this study, we investigated whether MSC therapy can protect the acutely injured liver and stimulate regeneration. In a D-galactosamine-induced rat model of acute liver injury, we show that systemic infusion of MSC-conditioned medium (MSC-CM) provides a significant survival benefit and prevents the release of liver injury biomarkers. Furthermore, MSC-CM therapy resulted in a 90% reduction of apoptotic hepatocellular death and a three-fold increment in the number of proliferating hepatocytes. This was accompanied by a dramatic increase in the expression levels of 10 genes known to be up-regulated during hepatocyte replication. Direct antiapoptotic and promitotic effects of MSC-CM on hepatocytes were demonstrated using in vitro assays. CONCLUSION: These data provide the first clear evidence that MSC-CM therapy provides trophic support to the injured liver by inhibiting hepatocellular death and stimulating regeneration, potentially creating new avenues for the treatment of FHF.


Assuntos
Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/fisiopatologia , Carcinoma Hepatocelular/cirurgia , Falência Hepática/cirurgia , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/fisiopatologia , Neoplasias Hepáticas/cirurgia , Regeneração Hepática/fisiologia , Transplante de Células-Tronco Mesenquimais , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Morte Celular , Humanos , Testes de Função Hepática , Masculino , Células-Tronco Mesenquimais , Ratos , Ratos Sprague-Dawley , Transplante Heterólogo
10.
Stem Cells ; 26(2): 474-84, 2008 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-18065398

RESUMO

Embryonic stem cell-derived endoderm is critical for the development of cellular therapies for the treatment of disease such as diabetes, liver cirrhosis, or pulmonary emphysema. Here, we describe a novel approach to induce endoderm from mouse embryonic stem (mES) cells using fibronectin-coated collagen gels. This technique results in a homogeneous endoderm-like cell population, demonstrating endoderm-specific gene and protein expression, which remains committed following in vivo transplantation. In this system, activin, normally an endoderm inducer, caused an 80% decrease in the Foxa2-positive endoderm fraction, whereas follistatin increased the Foxa2-positive endoderm fraction to 78%. Our work suggests that activin delays the induction of endoderm through its transient precursors, the epiblast and mesendoderm. Long-term differentiation displays a twofold reduction in hepatic gene expression and threefold reduction in hepatic protein expression of activin-treated cells compared with follistatin-treated cells. Moreover, subcutaneous transplantation of activin-treated cells in a syngeneic mouse generated a heterogeneous teratoma-like mass, suggesting that these were a more primitive population. In contrast, follistatin-treated cells resulted in an encapsulated epithelial-like mass, suggesting that these cells remained committed to the endoderm lineage. In conclusion, we demonstrate a novel technique to induce the direct differentiation of endoderm from mES cells without cell sorting. In addition, our work suggests a new role for activin in induction of the precursors to endoderm and a new endoderm-enrichment technique using follistatin.


Assuntos
Ativinas/farmacologia , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/efeitos dos fármacos , Endoderma/citologia , Endoderma/efeitos dos fármacos , Animais , Sequência de Bases , Técnicas de Cultura de Células , Diferenciação Celular , Colágeno , Meios de Cultura Livres de Soro , Primers do DNA/genética , Indução Embrionária/efeitos dos fármacos , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias/transplante , Endoderma/metabolismo , Feminino , Folistatina/farmacologia , Géis , Expressão Gênica/efeitos dos fármacos , Camadas Germinativas/citologia , Camadas Germinativas/efeitos dos fármacos , Camadas Germinativas/metabolismo , Cinética , Mesoderma/citologia , Mesoderma/efeitos dos fármacos , Mesoderma/metabolismo , Camundongos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
11.
Biochem Biophys Res Commun ; 363(2): 247-52, 2007 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-17869217

RESUMO

Bone marrow-derived mesenchymal stem cells (MSCs) have been reported to prevent the development of liver fibrosis in a number of pre-clinical studies. Marked changes in liver histopathology and serological markers of liver function have been observed without a clear understanding of the therapeutic mechanism by which stem cells act. We sought to determine if MSCs could modulate the activity of resident liver cells, specifically hepatic stellate cells (SCs) by paracrine mechanisms using indirect cocultures. Indirect coculture of MSCs and activated SCs led to a significant decrease in collagen deposition and proliferation, while inducing apoptosis of activated SCs. The molecular mechanisms underlying the modulation of SC activity by MSCs were examined. IL-6 secretion from activated SCs induced IL-10 secretion from MSCs, suggesting a dynamic response of MSCs to the SCs in the microenvironment. Blockade of MSC-derived IL-10 and TNF-alpha abolished the inhibitory effects of MSCs on SC proliferation and collagen synthesis. In addition, release of HGF by MSCs was responsible for the marked induction of apoptosis in SCs as determined by antibody-neutralization studies. These findings demonstrate that MSCs can modulate the function of activated SCs via paracrine mechanisms provide a plausible explanation for the protective role of MSCs in liver inflammation and fibrosis, which may also be relevant to other models of tissue fibrosis.


Assuntos
Comunicação Celular/imunologia , Citocinas/imunologia , Hepatócitos/imunologia , Fatores Imunológicos/imunologia , Células-Tronco Mesenquimais/imunologia , Comunicação Parácrina/imunologia , Animais , Células Cultivadas , Feminino , Humanos , Modelos Imunológicos , Ratos , Ratos Endogâmicos Lew
12.
PLoS One ; 2(9): e941, 2007 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-17895982

RESUMO

Modulation of the immune system may be a viable alternative in the treatment of fulminant hepatic failure (FHF) and can potentially eliminate the need for donor hepatocytes for cellular therapies. Multipotent bone marrow-derived mesenchymal stem cells (MSCs) have been shown to inhibit the function of various immune cells by undefined paracrine mediators in vitro. Yet, the therapeutic potential of MSC-derived molecules has not been tested in immunological conditions in vivo. Herein, we report that the administration of MSC-derived molecules in two clinically relevant forms-intravenous bolus of conditioned medium (MSC-CM) or extracorporeal perfusion with a bioreactor containing MSCs (MSC-EB)-can provide a significant survival benefit in rats undergoing FHF. We observed a cell mass-dependent reduction in mortality that was abolished at high cell numbers indicating a therapeutic window. Histopathological analysis of liver tissue after MSC-CM treatment showed dramatic reduction of panlobular leukocytic infiltrates, hepatocellular death and bile duct duplication. Furthermore, we demonstrate using computed tomography of adoptively transferred leukocytes that MSC-CM functionally diverts immune cells from the injured organ indicating that altered leukocyte migration by MSC-CM therapy may account for the absence of immune cells in liver tissue. Preliminary analysis of the MSC secretome using a protein array screen revealed a large fraction of chemotactic cytokines, or chemokines. When MSC-CM was fractionated based on heparin binding affinity, a known ligand for all chemokines, only the heparin-bound eluent reversed FHF indicating that the active components of MSC-CM reside in this fraction. These data provide the first experimental evidence of the medicinal use of MSC-derived molecules in the treatment of an inflammatory condition and support the role of chemokines and altered leukocyte migration as a novel therapeutic modality for FHF.


Assuntos
Meios de Cultivo Condicionados/farmacologia , Falência Hepática Aguda/tratamento farmacológico , Células-Tronco Mesenquimais/metabolismo , Transferência Adotiva/métodos , Animais , Morte Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Células Cultivadas , Quimiocinas/metabolismo , Meios de Cultivo Condicionados/metabolismo , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/patologia , Humanos , Leucócitos/citologia , Leucócitos/efeitos dos fármacos , Leucócitos/metabolismo , Falência Hepática Aguda/patologia , Falência Hepática Aguda/terapia , Masculino , Células-Tronco Mesenquimais/citologia , Camundongos , Células NIH 3T3 , Análise Serial de Proteínas , Ratos , Ratos Sprague-Dawley
13.
Tissue Eng ; 13(10): 2465-73, 2007 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17665999

RESUMO

The isolation of undifferentiated adult stem/progenitor cells remains a challenging task primarily due to the rare quantity of these cells in biological samples and the lack of unique markers. Herein, we report a relatively straightforward method for isolation of human mesenchymal stem cells (MSCs) based on their unusual resistance to osmotic lysis, which we term "osmotic selection" (OS). MSCs can remarkably withstand significant exposure to hypotonic conditions (> 30 min) with only a reversible impairment in cell proliferation and with no loss of stem cell potential after exposure. Comparison of MSCs to other circulating nonhematopoietic cells revealed a time regime, by which purification of these cells would be attainable without considerable cell loss. OS showed a 50-fold enrichment of fibroblast colony-forming units from umbilical cord blood samples when compared to commonly employed techniques. After upstream processing, isolated cells using OS were immunophenotyped to be CD14-, CD34-, CD45-, CD44+, CD105+, and CD106+, and displayed multipotent differentiation. Preliminary investigations to determine mechanisms responsible for osmolytic resistance revealed MSCs to have an ineffective volume of 59%, with the ability to double cell volume at infinite dilution. Disruption of filamentous actin polymerization by cytochalasin D sensitized MSCs to osmotic lysis, which suggests a cytoskeletal element involved in osmolytic resistance.


Assuntos
Separação Celular/métodos , Sangue Fetal/citologia , Análise de Injeção de Fluxo/métodos , Células-Tronco Mesenquimais/citologia , Células Cultivadas , Humanos , Osmose
14.
Tissue Eng ; 12(10): 2965-73, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-17518664

RESUMO

Fetal hepatocytes (FHEPs) are a potential source of highly proliferative transplantable cells but express low levels of liver-specific functions. We hypothesized that the microenvironment of adult hepatocytes (AHEPs) may upregulate these functions. Primary FHEPs were seeded on top of collagen-sandwiched AHEPs directly or separated by a porous transwell membrane insert. In direct co-cultures, albumin (ALB) secretion, urea synthesis, and cytochrome P450 (CytP450) activity were all approximately 2 times as high as the sum of the corresponding monocultures. Using a transwell porous insert led to similar results, suggesting a major role for soluble factors. When AHEPs and FHEPs were separated after co-culture, they both initially showed significantly higher ALB secretion than control monocultures, whereas urea synthesis was significantly lower for the FHEPs only. Functions of previously co-cultured FHEPs normalized over the course of a week, but AHEP function remained high even after separation. In conclusion, co-culturing AHEPs with FHEPs increases expression of liver-specific functions in both cell types. The effect on FHEPs, but not AHEPs, was reversible. Unraveling the underlying mechanisms and optimizing this phenomenon will be useful in making fetal liver cells a potential cell source for hepatic tissue-engineering applications.


Assuntos
Envelhecimento/patologia , Envelhecimento/fisiologia , Técnicas de Cocultura/métodos , Hepatócitos/citologia , Hepatócitos/fisiologia , Engenharia Tecidual/métodos , Animais , Células Cultivadas , Feminino , Testes de Função Hepática , Ratos , Ratos Endogâmicos Lew
15.
Ann Surg Oncol ; 12(8): 597-608, 2005 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16021534

RESUMO

BACKGROUND: It has been suggested that performing a sentinel node biopsy (SNB) in patients with cutaneous melanoma increases the incidence of in-transit metastasis (ITM). METHODS: ITM rates for 2018 patients with primary melanomas > or =1.0 mm thick treated at a single institution between 1991 and 2000 according to 3 protocols were compared: wide local excision (WLE) only (n = 1035), WLE plus SNB (n = 754), and WLE plus elective lymph node dissection (n = 229). RESULTS: The incidence of ITM for the three protocols was 4.9%, 3.6%, and 5.7%, respectively (not significant), and as a first site of recurrent disease the incidence was 2.5%, 2.4%, and 4.4%, respectively (not significant). The subset of patients who were node positive after SNB and after elective lymph node dissection also had similar ITM rates (10.8% and 7.1%, respectively; P = .11). On multivariate analysis, primary tumor thickness and patient age predicted ITM as a first recurrence, but type of treatment did not. Patients who underwent WLE only and who had a subsequent therapeutic lymph node dissection (n = 149) had an ITM rate of 24.2%, compared with 10.8% in patients with a tumor-positive sentinel node treated with immediate dissection (n = 102; P = .03). CONCLUSIONS: Performing an SNB in patients with melanoma treated by WLE does not increase the incidence of ITM.


Assuntos
Melanoma/patologia , Inoculação de Neoplasia , Biópsia de Linfonodo Sentinela , Neoplasias Cutâneas/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Feminino , Humanos , Excisão de Linfonodo , Metástase Linfática , Masculino , Melanoma/mortalidade , Pessoa de Meia-Idade , Biópsia de Linfonodo Sentinela/efeitos adversos , Neoplasias Cutâneas/mortalidade , Análise de Sobrevida
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