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2.
J Pediatr Urol ; 15(4): 382.e1-382.e8, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31104999

RESUMO

INTRODUCTION: A potential determinant of successful bladder closures in patients with classic bladder exstrophy (CBE) is the postoperative pelvic immobilization technique. This study investigates the success rates of primary and secondary bladder closures based on various immobilization techniques from a high-volume exstrophy center. METHODS: A prospectively maintained institutional exstrophy-epispadias complex database of 1336 patients was reviewed for patients with CBE who have undergone primary or secondary closures between 1975 and 2018 and subsequently had a known method of pelvic immobilization. Patients were divided into two groups: primary and secondary closures. Associations between closure outcomes and immobilization techniques were determined. RESULTS: A total of 476 patients with primary closures and 101 patients with secondary closures met the inclusion criteria. In total, 343 (72.1%) primary closures were successful. As shown in the table, the success rates of primary closures were highest in patients immobilized with modified Buck's and Bryant's traction (95.0% and 79.3%, respectively) and lowest in those with spica cast (49.6%). A propensity score-adjusted logistic regression (adjusting for osteotomy status, period of closure, location of closure, and closure type) revealed that modified Buck's traction had a 5.60 (95% confidence interval 1.74-23.1, p = 0.008) greater odds of success compared to spica casting during the primary closure. For the secondary closure group, there were 92 (92.1%) successful secondary closures. Success rates were highest in modified Buck's traction (97.3%) and lowest with spica casting (66.7%). DISCUSSION: This study confirms previous findings of better outcomes when patients are immobilized with external fixation and Buck's traction after adjusting for potential confounding factors. Immobilization with modified Buck's or Bryant's traction yielded significantly higher primary closure success rates when compared to spica casting. It is the authors' belief that despite a longer hospital length of stay, external fixation with Buck's traction provides the best chance of a successful closure and, thus, a financially responsible method to care for these children in the postoperative period. CONCLUSIONS: Success rates for primary closures were highest when using modified Buck's traction with external fixation and lowest for spica casts. Similarly, for secondary closures, the best outcomes were achieved using modified Buck's traction with external fixation and the lowest success rates were associated with spica casts.


Assuntos
Extrofia Vesical/cirurgia , Moldes Cirúrgicos , Imobilização/métodos , Procedimentos de Cirurgia Plástica/métodos , Procedimentos Cirúrgicos Urológicos/métodos , Fatores Etários , Análise de Variância , Baltimore , Extrofia Vesical/diagnóstico , Estudos de Coortes , Bases de Dados Factuais , Feminino , Seguimentos , Hospitais Universitários , Humanos , Lactente , Modelos Logísticos , Masculino , Osteotomia , Pelve , Cuidados Pós-Operatórios/métodos , Gravidez , Pontuação de Propensão , Estudos Retrospectivos , Medição de Risco , Fatores Sexuais , Tração/métodos , Resultado do Tratamento
3.
J Pediatr Urol ; 14(5): 430.e1-430.e6, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29914824

RESUMO

BACKGROUND: Primary bladder closure of classic bladder exstrophy (CBE) is a major operation that occasionally requires intraoperative or postoperative (within 72 h) blood transfusions. OBJECTIVE: This study reported perioperative transfusion rates, risk factors for transfusion, and outcomes from a high-volume exstrophy center in primary bladder closure of CBE patients. STUDY DESIGN: A prospectively maintained, institutional exstrophy-epispadias complex database of 1305 patients was reviewed for primary CBE closures performed at the authors' institution (Johns Hopkins Hospital) between 1993 and 2017. Patient and surgical factors were analyzed to determine transfusion rates, risk factors for transfusions, and outcomes. Patients were subdivided into two groups based upon the time of closure: neonatal and delayed closure. RESULTS: A total of 116 patients had a primary bladder closure during 1993-2017. Seventy-three patients were closed in the neonatal period, and 43 were delayed closures. In total, 64 (55%) patients received perioperative transfusions. No transfusion reactions were observed. Twenty-five transfusions were in the neonatal closure group, yielding a transfusion rate of 34%. In comparison, 39 patients were transfused in the delayed closure group, giving a transfusion rate of 91%. Pelvic osteotomy, delayed bladder closure, higher estimated blood loss (EBL), larger pubic diastasis, and longer operative time were all associated with blood transfusion. In multivariable logistic regression, pelvic osteotomy (OR 5.4; 95% CI 1.3-22.8; P < 0.001), higher EBL-to-weight ratio (OR 1.3; 95% CI 1.1-1.6; P = 0.029), and more recent years of primary closure (OR 1.1; 95% CI 1.0-1.2; P = 0.018) remained independent predictors of receiving a transfusion (Summary Table). No adverse transfusion reactions or complications were observed. DISCUSSION: This was the first study from a single high-volume exstrophy center to explore factors that contribute to perioperative blood transfusions. Pelvic osteotomy as a risk factor was unsurprising, as the osteotomy may bleed both during and immediately after closure. However, it is important to use osteotomy for successful closure, despite the increased transfusion risk. The risks accompanying contemporary transfusions are minimal and osteotomies are imperative for successful bladder closure. CONCLUSIONS: More than half of CBE patients undergoing primary closure at a single institution received perioperative blood transfusions. While there was an association between transfusions and osteotomy, delayed primary closure, larger diastasis, increased operative time, and increased length of stay, only the use of pelvic osteotomy, higher EBL-to-weight ratio, and recent year of closure independently increased the odds of receiving a transfusion on multivariate analysis.


Assuntos
Extrofia Vesical/cirurgia , Transfusão de Sangue/estatística & dados numéricos , Feminino , Previsões , Humanos , Recém-Nascido , Masculino , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
4.
J Pediatr Urol ; 14(3): 268.e1-268.e5, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29534861

RESUMO

INTRODUCTION: Endoscopic injection of a bulking agent is a common first-line approach to the treatment of vesicoureteral reflux (VUR). While early outcomes are comparable to open ureteroneocystotomy, 5-25% of children will eventually develop recurrent reflux necessitating repeat injections or open ureteral reimplantation. OBJECTIVE: To determine whether prior endoscopic injection of a bulking agent impacts outcomes of subsequent open ureteral reimplantation. STUDY DESIGN: Using a retrospective cohort design, radiographic and clinical outcomes of open ureteral reimplantation were compared between patients with and without prior endoscopic correction of reflux. Surgical and hospitalization data were also compared between groups and a cost comparison was performed to assess differences in healthcare costs between the two cohorts. Units of analysis included total ureters or total patients. For certain variables, subanalysis of unilateral versus bilateral reimplantation was included. RESULTS: A total of 258 patients underwent open reimplantation for VUR between 2007 and 2016 by five pediatric urologists. Final analysis (see Summary Table) included 192 patients with pre-operative and postoperative voiding cystourethrogram (VCUG) and follow-up data at a median 4.95 months. Among 317 reimplanted refluxing ureters, radiographic resolution was reached in 26/27 (96.3%) patients with and 279/290 (96.2%) without prior endoscopic treatment (P = 0.981). Clinical success was achieved in 17/17 (100%) patients with and 174/175 (99.4%) without prior endoscopic treatment (P = 0.755). There were no statistically significant differences between duration of surgery or length of hospital stay. There were no statistically significant differences between total charges, total costs, and operating room (OR) costs between groups. DISCUSSION: This study indicated that prior endoscopic injection of a bulking agent did not impact the outcomes or costs of subsequent open ureteroneocystotomy. While prior studies have demonstrated tissue changes associated with injection of a bulking agent, these did not seem to significantly impact the difficulty of later open surgery or the success rates compared to patients who proceeded directly to open correction of reflux. CONCLUSION: Open ureteral reimplantation for recurrent VUR after failed endoscopic injection of a bulking agent was safe and effective, with comparable outcomes and costs to open surgery in patients without prior endoscopic correction.


Assuntos
Custos Hospitalares , Reimplante/métodos , Ureter/cirurgia , Procedimentos Cirúrgicos Urológicos/métodos , Refluxo Vesicoureteral/cirurgia , Adolescente , Criança , Pré-Escolar , Custos e Análise de Custo , Cistografia , Cistoscopia , Feminino , Seguimentos , Humanos , Lactente , Masculino , Reimplante/economia , Estudos Retrospectivos , Procedimentos Cirúrgicos Urológicos/economia , Refluxo Vesicoureteral/diagnóstico , Refluxo Vesicoureteral/economia , Adulto Jovem
5.
Br J Dermatol ; 170(4): 907-13, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24641194

RESUMO

BACKGROUND: The aetiology and exact incidence of infantile haemangiomas (IHs) are unknown. Prior studies have noted immunohistochemical and biological characteristics shared by IHs and placental tissue. OBJECTIVES: We investigated the possible association between placental anomalies and the development of IHs, as well as the demographic characteristics and other risk factors for IHs. PATIENTS AND METHODS: Pregnant women (n = 578) were prospectively enrolled and their offspring followed for 9 months. Placental evaluations were performed and demographic data collected on all mother-infant pairs. RESULTS: We evaluated 594 infants: 34 haemangiomas [either IH or congenital (CH)] were identified in 29 infants, yielding an incidence of 4·5% for IH (27 infants) and 0·3% for CH (two infants). Placental anomalies were noted in almost 35% of haemangioma-related pregnancies, approximately twice the incidence noted in pregnancies with unaffected infants (P = 0·025). Other risk factors for IH included prematurity (P = 0·016) and low birth weight (P = 0·028). All IHs were present by 3 months of age, and cessation of growth had occurred in all by 9 months of age. Most occurred on the trunk. Of note, 20% of identified IHs were abortive or telangiectatic in nature, small focal lesions that did not proliferate beyond 3 months of age. Only one IH required intervention. CONCLUSIONS: This is the first prospective American study to document the incidence of IHs in infants followed from birth to early infancy. The association with placental anomalies was statistically significant. The overall incidence mirrors prior estimates, but the need for treatment was lower than previously reported.


Assuntos
Hemangioma/etiologia , Doenças Placentárias , Adolescente , Adulto , California/epidemiologia , Feminino , Hemangioma/epidemiologia , Humanos , Incidência , Lactente , Masculino , Idade Materna , Pessoa de Meia-Idade , Gravidez , Estudos Prospectivos , Fatores de Risco , Adulto Jovem
7.
J Fam Hist ; 34(2): 224-37, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19618558

RESUMO

Building on Davis (1963) and subsequent work, we propose a conceptual framework that provides a guide for the organization of empirical demographic research. Our approach is based on the notion that changes in nuptiality, fertility, and migration are not objectives in and of themselves, but means for reducing welfare gaps - defined as the gaps between actual welfare and that which could be attained with altered demographic and/or other behavior. We clarify theoretical issues concerning three levels of analysis. At the highest level, societal change leads to welfare gaps for families and/or individuals. In turn, behavioral adjustments are made to reduce these gaps. Finally, demographic responses at the community level result when large numbers of families and/or individuals adjust behavior in a particular manner. We consider and exemplify relationships among demographic and other responses in historical, agricultural contexts.


Assuntos
Demografia , Emigrantes e Imigrantes , Fertilidade , Casamento , Opinião Pública , Mudança Social , Responsabilidade Social , Sociedades , Emigrantes e Imigrantes/educação , Emigrantes e Imigrantes/história , Emigrantes e Imigrantes/legislação & jurisprudência , Emigrantes e Imigrantes/psicologia , Emigração e Imigração/história , Emigração e Imigração/legislação & jurisprudência , Características da Família/etnologia , Fertilidade/fisiologia , História do Século XX , Humanos , Casamento/etnologia , Casamento/história , Casamento/legislação & jurisprudência , Casamento/psicologia , Dinâmica Populacional , Saúde Pública/economia , Saúde Pública/educação , Saúde Pública/história , Saúde Pública/legislação & jurisprudência , Mudança Social/história , Condições Sociais/economia , Condições Sociais/história , Condições Sociais/legislação & jurisprudência , Valores Sociais/etnologia , Seguridade Social/economia , Seguridade Social/etnologia , Seguridade Social/história , Seguridade Social/legislação & jurisprudência , Seguridade Social/psicologia , Sociedades/economia , Sociedades/história , Migrantes/educação , Migrantes/história , Migrantes/legislação & jurisprudência , Migrantes/psicologia , Saúde da Mulher/economia , Saúde da Mulher/etnologia , Saúde da Mulher/história , Saúde da Mulher/legislação & jurisprudência
8.
J Am Coll Cardiol ; 38(1): 56-63, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11451296

RESUMO

OBJECTIVES: We developed a prognostic strategy for quantifying the long-term risk of coronary heart disease (CHD) events in survivors of acute coronary syndromes (ACS). BACKGROUND: Strategies for quantifying long-term risk of CHD events have generally been confined to primary prevention settings. The Long-term Intervention with Pravastatin in Ischemic Disease (LIPID) study, which demonstrated that pravastatin reduces CHD events in ACS survivors with a broad range of cholesterol levels, enabled assessment of long-term prognosis in a secondary prevention setting. METHODS: Based on outcomes in 8,557 patients in the LIPID study, a multivariate risk factor model was developed for prediction of CHD death or nonfatal myocardial infarction. Prognostic indexes were developed based on the model, and low-, medium-, high- and very high-risk groups were defined by categorizing the prognostic indexes. RESULTS: In addition to pravastatin treatment, the independently significant risk factors included: total and high density lipoprotein cholesterol, age, gender, smoking status, qualifying ACS, prior coronary revascularization, diabetes mellitus, hypertension and prior stroke. Pravastatin reduced coronary event rates in each risk level, and the relative risk reduction did not vary significantly between risk levels. The predicted five-year coronary event rates ranged from 5% to 19% for those assigned pravastatin and from 6.4% to 23.6% for those assigned placebo. CONCLUSIONS: Long-term prognosis of ACS survivors varied substantially according to conventional risk factor profile. Pravastatin reduced coronary risk within all risk levels; however, absolute risk remained high in treated patients with unfavorable profiles. Our risk stratification strategy enables identification of ACS survivors who remain at very high risk despite statin therapy.


Assuntos
Angina Instável/tratamento farmacológico , Anticolesterolemiantes/uso terapêutico , Doença das Coronárias/epidemiologia , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Infarto do Miocárdio/tratamento farmacológico , Pravastatina/uso terapêutico , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco , Fatores de Risco , Síndrome
9.
Hum Pathol ; 32(4): 396-400, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11331956

RESUMO

Nr-CAM is a member of the immunoglobulin superfamily of neural cell-adhesion molecules initially thought to be expressed mainly in the brain. Here we show the presence of Nr-CAM protein in normal human pancreas and characterize its expression in hyperplastic and neoplastic human pancreatic tissue. Nr-CAM is expressed on the cell surface in normal pancreatic acini with enhanced staining at cell-cell junctions, and weak or no surface staining is seen on normal ductal cells. Nr-CAM expression is markedly up-regulated in intraductal hyperplasia. Expression was well maintained in well or moderately differentiated carcinoma but was reduced or absent from most poorly differentiated tumors. In addition, 4 of 4 human pancreatic adenocarcinoma cell lines tested demonstrated little or no Nr-CAM expression. This differential regulation of Nr-CAM expression suggests that it may be involved in the pathogenesis and invasive/metastatic behavior of pancreatic cancers. HUM PATHOL 32:396-400.


Assuntos
Moléculas de Adesão Celular/biossíntese , Pâncreas/metabolismo , Neoplasias Pancreáticas/metabolismo , Biomarcadores Tumorais , Regulação Neoplásica da Expressão Gênica , Humanos , Hiperplasia , Pâncreas/patologia , Neoplasias Pancreáticas/patologia
10.
J Neurosurg ; 94(4): 596-604, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11302658

RESUMO

OBJECT: A variant of C6 glioma cells, C6R-G/H cells express hygromycin phosphotransferase (HPT) and appear to have reduced tumorigenicity in the embryonic brain. The goal of this study was to investigate their reduced capacity to generate tumors in the adult rat brain. METHODS: Cell lines were implanted into rat brains and tumorigenesis was evaluated. After 3 weeks, all rats with C6 cells showed signs of neurological disease, whereas rats with C6R-G/H cells did not and were either killed then or allowed to survive until later. Histological studies were performed to analyze tumor size, malignancy, angiogenesis, and cell proliferation. Cells isolated from rat brain tumors were analyzed for mutation to HPT by testing their sensitivity to hygromycin. CONCLUSIONS: The results indicate that HPT suppresses tumor formation. Three weeks after implantation, only 44% of animals implanted with C6R-G/H cells developed tumors, whereas all animals that received C6 glioma cells developed high-grade gliomas. The C6R-G/H cells filled a 20-fold smaller maximal cross-sectional area than the C6 cells, and exhibited less malignant characteristics, including reduced angiogenesis, mitosis, and cell proliferation. Similar results were obtained in the brain of nude rats, indicating that the immune system did not play a significant role in suppressing tumor growth. The combination of green fluorescent protein (GFP) and HPT was more effective in suppressing tumorigenesis than either plasmid by itself, indicating that the GFP may protect against inactivation of the HPT. Interestingly. hygromycin resistance was lost in tumor cells that were recovered from a group of animals in which C6R-G/H cells formed tumors, confirming the correlation of HPT with reduced tumorigenicity.


Assuntos
Neoplasias Encefálicas/prevenção & controle , Cinamatos , Glioma/prevenção & controle , Fosfotransferases (Aceptor do Grupo Álcool)/farmacologia , Animais , Neoplasias Encefálicas/patologia , Neoplasias Encefálicas/fisiopatologia , Divisão Celular/efeitos dos fármacos , Resistência a Medicamentos , Feminino , Genes Supressores de Tumor , Glioma/patologia , Glioma/fisiopatologia , Rejeição de Enxerto , Proteínas de Fluorescência Verde , Higromicina B/análogos & derivados , Higromicina B/farmacologia , Proteínas Luminescentes/genética , Proteínas Luminescentes/farmacologia , Mitose/efeitos dos fármacos , Mutação/fisiologia , Transplante de Neoplasias , Neovascularização Patológica , Fenótipo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Ratos , Ratos Endogâmicos WKY , Ratos Nus , Proteínas Recombinantes de Fusão/farmacologia , Transfecção , Células Tumorais Cultivadas
11.
Exp Neurol ; 168(2): 310-22, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11259119

RESUMO

C6-R is a cell line derived from C6 glioma cells that exhibits key properties of radial glia including the ability to support neuronal migration in culture. To explore its potential use in promoting neuronal migration in vivo, we analyzed the behavior of C6-R cells in the intact and injured adult rat CNS. At 6-11 days postimplantation at the splenium of the corpus callosum, green fluorescent protein-labeled C6-R cells were observed primarily in either the corpus callosum or the hippocampus in the brain, and in the spinal cord they migrated more extensively in the white matter than in the grey matter. To determine whether C6-R cells retain their ability to promote neuronal migration in vivo, they were coinjected with labeled neurons into adult brain. When rat embryonic neurons were coimplanted with C6-R cells, the neurons and C6-R cells comigrated through a much larger volume than neurons alone or neurons coimplanted with fibroblasts. In brains preinjured with ibotenic acid, C6-R cells as well as coimplanted neurons distributed widely within the lesion site and migrated into adjacent brain tissue, while transplants with neurons alone were restricted primarily to the lesion site. The results suggest that radial glial cell lines can serve as a scaffold for neuronal migration that may facilitate development of experimental models for neural transplantation and regeneration.


Assuntos
Movimento Celular/fisiologia , Corpo Caloso/fisiologia , Glioma/fisiopatologia , Hipocampo/fisiologia , Neuroglia/fisiologia , Neurônios/fisiologia , Medula Espinal/fisiologia , Animais , Corpo Caloso/transplante , Embrião de Mamíferos , Feminino , Fibroblastos/fisiologia , Fibroblastos/transplante , Glioma/patologia , Hipocampo/transplante , Camundongos , Regeneração Nervosa/fisiologia , Neuroglia/transplante , Neurônios/transplante , Gravidez , Ratos , Ratos Long-Evans , Ratos Sprague-Dawley , Medula Espinal/transplante , Células Tumorais Cultivadas
12.
Pediatr Neurosurg ; 33(1): 49-55, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11025423

RESUMO

We have conducted studies designed to help elucidate the molecular mechanisms involved in brain tumor invasion and angiogenesis, which are critical in the growth of malignant tumors of the central nervous system. A variety of molecular factors have been implicated in these processes. Here we focus on three that are of particular importance in the progression of brain tumors. Angiopoietins are involved in the regulation of vascular development. Hypoxia inducible factor-1 is a transcription factor that up-regulates genes, including genes encoding vascular endothelial growth factor under hypoxic conditions. Focal adhesion kinase is associated with infiltration of tumor cells and angiogenesis.


Assuntos
Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/patologia , Proteínas de Ligação a DNA/metabolismo , Fatores de Crescimento Endotelial/metabolismo , Glioma/irrigação sanguínea , Glioma/patologia , Neovascularização Patológica , Proteínas Nucleares/metabolismo , Proteínas Tirosina Quinases/metabolismo , Fatores de Transcrição , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Proteínas de Ligação a DNA/genética , Fatores de Crescimento Endotelial/genética , Endotélio Vascular/metabolismo , Quinase 1 de Adesão Focal , Proteína-Tirosina Quinases de Adesão Focal , Glioma/genética , Glioma/metabolismo , Humanos , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia , Imuno-Histoquímica , Hibridização In Situ , Glicoproteínas de Membrana/genética , Glicoproteínas de Membrana/metabolismo , Invasividade Neoplásica , Neovascularização Patológica/genética , Neovascularização Patológica/patologia , Proteínas Nucleares/genética , Proteínas Tirosina Quinases/genética , RNA Mensageiro/genética , Regulação para Cima/genética
13.
J Neurobiol ; 42(3): 287-302, 2000 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-10645969

RESUMO

Mammalian L1 and avian Ng-CAM are homologous neural cell adhesion molecules (CAMs) that promote neurite outgrowth and cell adhesion in most neurons. Previous attempts to map these activities to discrete regions in the CAMs have suggested the involvement of a variety of different domains. However, these studies mainly used bacterially expressed proteins that were much less active on a molar basis than the native molecules. To define regions that are critical for maximal neurite outgrowth, we constructed and tested a panel of eukaryotically expressed proteins containing various extracellular segments of human L1 (hL1) or Ng-CAM. Our results indicate that Ig domains 1-4 of hL1 are critical for homophilic binding and neurite outgrowth; however this segment is less potent than the entire extracellular region. Optimal neurite outgrowth activity was seen with proteins containing all six Ig domains of hL1 or Ng-CAM. The adhesive properties of hL1 fragments correlated tightly with their neurite outgrowth activities, suggesting that these two processes are closely linked. These results suggest that Ig domains 1-4 form a structural cassette responsible for hL1 homophilic binding, while Ig domains 1-6 represent a functional region for optimal promotion of neurite outgrowth in vitro and possibly in vivo.


Assuntos
Glicoproteínas de Membrana/química , Glicoproteínas de Membrana/fisiologia , Moléculas de Adesão de Célula Nervosa/química , Moléculas de Adesão de Célula Nervosa/fisiologia , Neuritos/fisiologia , Neurônios/fisiologia , Animais , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Linhagem Celular , Humanos , Complexo Antígeno L1 Leucocitário , Mamíferos , Modelos Moleculares , Neuritos/efeitos dos fármacos , Neurônios/efeitos dos fármacos , Neurônios/ultraestrutura , Conformação Proteica , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Transfecção
14.
J Neurooncol ; 43(2): 109-14, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10533722

RESUMO

Angiogenesis is a crucial process in inflammatory reactions as well as in tumor implantation and growth. Tumors with high rates of invasion and recurrence such as gliomas, are specially dependent on neovascularization. This suggests that inhibition of angiogenesis might reduce the growth of these tumors. Thalidomide has been previously shown to inhibit angiogenesis induced by basic fibroblast growth factor in vivo, using the rabbit corneal micropocket assay. Therefore, the effect of thalidomide and a thalidomide analogue (cc-1069) on the proliferation in vitro of endothelial and glioma cells was tested. We observed a decrease in endothelial cell proliferation in cultures treated with thalidomide or the thalidomide analogue cc-1069. The analogue inhibited endothelial cell proliferation more efficiently than thalidomide. The inhibition occurred in association with a marked decrease in the activity of the nuclear factor SP1 and a moderate inhibition of NF-kappaB activation in nuclear extracts of endothelial cells. The drugs did not impair cell viability. There was no effect of thalidomide or the thalidomide analogue on the proliferation of the glioma cell line (U251) in vitro.


Assuntos
Endotélio Vascular/efeitos dos fármacos , Talidomida/análogos & derivados , Talidomida/farmacologia , Animais , Divisão Celular/efeitos dos fármacos , Córnea/irrigação sanguínea , Endotélio Vascular/citologia , Endotélio Vascular/metabolismo , Fator 2 de Crescimento de Fibroblastos/farmacologia , Glioma , Humanos , NF-kappa B/metabolismo , Neovascularização Patológica/prevenção & controle , Coelhos , Fator de Transcrição Sp1/metabolismo , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/biossíntese , Veias Umbilicais
15.
Exp Neurol ; 159(2): 391-400, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10506510

RESUMO

Angiopoietin-1 (Ang-1) and its naturally occurring antagonist angiopoietin-2 (Ang-2) are novel ligands that regulate tyrosine phosphorylation of the Tie2/Tek receptor on endothelial cells. Proper regulation of Tie2/Tek is absolutely required for normal vascular development, seemingly by regulating vascular remodeling and endothelial cell interactions with supporting pericytes/smooth muscle cells. We investigated the expression of Ang-1 and Ang-2 in human astrocytomas by in situ hybridization and compared them to the distribution of pericytes/smooth muscle cells by immunohistochemistry for alpha-smooth muscle actin (SMA). Ang-1 mRNA was localized in tumor cells and Ang-2 mRNA was detected in endothelial cells of hyperplastic and nonhyperplastic tumor vessels. Ang-2 was also expressed in partially sclerotic vessels and in vascular channels surrounded by tumor cells in brain adjacent to the tumor. Neither Ang-1 nor Ang-2 was detected in normal brain. Dynamic changes in SMA expression during glioma tumorigenesis appear to progress from fragmentation in early vascular hyperplasia to subsequent reassociation and enhanced expression in later stages of vascular proliferation in hyperplastic complexes in high-grade gliomas. All these vessels displaying dynamic changes in SMA immunoreactivity also expressed Ang-2 mRNA. Moreover, SMA immunoreactive intratumoral vascular channels lacking morphological evidence of hyperplasia also showed upregulation of Ang-2. These results suggest that angiopoietins are involved in the early stage of vascular activation and in advanced angiogenesis, and they identify Ang-2 as an early marker of glioma-induced neovascularization. The association between Ang-2 expression and alterations in SMA immunoreactivity suggests a role for Ang-2 in tumor-associated activation of pericytes/smooth muscle cells.


Assuntos
Astrocitoma/irrigação sanguínea , Astrocitoma/genética , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/genética , Encéfalo/metabolismo , Regulação Neoplásica da Expressão Gênica , Neovascularização Patológica , Proteínas/genética , Angiopoietina-1 , Angiopoietina-2 , Biomarcadores , Inibidores Enzimáticos , Glioblastoma/irrigação sanguínea , Glioblastoma/genética , Humanos , Hibridização In Situ , Glicoproteínas de Membrana/genética , Valores de Referência , Transcrição Gênica
18.
J Fam Hist ; 24(4): 493-533, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11623954

RESUMO

Fifty years have passed since the post-World War II development of demography as an academic field. During this time, one of the central focuses of research has been the study of demographic and fertility transitions. The authors review a selection of research developments and analytic issues that have appeared in the literature. After presenting, in roughly chronological order, the general development of this research work, they raise questions concerning theory and methodology. In doing so, they argue that some research directions have been overemphasized to the neglect of others.


Assuntos
Demografia , Dinâmica Populacional , Pesquisa/história , História do Século XX , Teoria de Sistemas
19.
J Neurobiol ; 37(2): 291-304, 1998 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-9805274

RESUMO

Rat C6 glioma is a cell line that has been used extensively as a model of astroglia. Although this cell line retains many of the properties of developing glia, it does not resemble morphologically the specialized form of glia found embryonically, the radial glia. In experiments designed to study a mutant form of receptor protein tyrosine phosphatase beta, we isolated a subclone of C6 called C6-R which, like radial glia, assumes a highly polarized radial-like morphology in culture. C6-R cells and, to a somewhat lesser extent, C6 cells, express cytoskeletal proteins found in developing astroglia including glial fibrillary acidic protein and RC1. As seen with radial glia, cerebellar granule cell bodies and neurites migrated along radial processes of C6-R cells in culture. Morphological analysis of dye-labeled cells injected into the developing forebrain revealed that a large fraction (approximately 60%) of the C6-R cells in the cortex assumed a radial orientation and about half of these (approximately 30%) made contact with the pial surface. In contrast, the parental C6 cells generally formed aggregates and only displayed a radial alignment when associated with blood vessels. These results suggest that we have generated a stable cell line from C6 glioma which has adopted certain key features of radial glia, including the ability to promote neuronal migration in culture and integrate radially in vivo in response to local cues. This cell line may be particularly useful for studying receptors on radial glia that mediate neuronal migration.


Assuntos
Neuroglia/citologia , Animais , Movimento Celular , Sobrevivência Celular/fisiologia , Cerebelo/citologia , Células Clonais , Glioma/patologia , Fenótipo , Ratos , Células Tumorais Cultivadas
20.
Neurosurgery ; 41(5): 1052-9, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9361058

RESUMO

OBJECTIVE: Tenascin-C (TN) is an extracellular matrix glycoprotein with a characteristic six-armed structure. The aim of this study was to determine whether the concentration of TN in the cyst fluid of brain tumors can be used as a marker for angiogenesis and glioma grade. METHODS: We investigated the expression of TN in the cyst wall and cyst fluid of human brain tumors by immunohistochemistry, immunoprecipitation, and immunoblotting. The tumors included 12 astrocytomas (5 glioblastoma multiforme tumors, 1 anaplastic astrocytoma, 1 low-grade astrocytoma, 4 juvenile pilocytic astrocytomas, and 1 mixed glioma), 2 dysembryoplastic neuroepithelial tumors, 3 craniopharyngiomas, 2 ependymomas, 2 metastatic carcinomas, 3 arachnoid cysts, 1 glial ependymal cyst, and 1 inflammatory cyst. RESULTS: We detected no expression of TN in the cyst fluids of the ependymomas, craniopharyngiomas, and nonpilocytic low-grade astrocytoma. By contrast, TN was detected in the cyst fluids of all the other tumors. Results of quantitative immunoblotting using a PhosphorImager unit (Molecular Dynamics, Sunnyvale, CA) revealed that, on average, a 5-fold higher signal was observed in the glioblastoma multiforme tumors as compared with the anaplastic astrocytoma, and a 10-fold higher signal as compared with the mixed glioma, juvenile pilocytic astrocytomas, and dysembryoplastic neuroepithelial tumors. Results of TN immunohistochemistry in the astrocytomas correlated with glioma grade, with stronger staining of the hyperplastic vessels and tumor cells being observed in higher grade gliomas. No TN immunoreactivity was detected in the walls of the ependymomas, arachnoid cysts, and glial ependymal cyst that lack hyperplastic vessels, and minimal TN immunoreactivity was observed in the perivascular gliotic rim of the craniopharyngiomas. No TN was detected in the cyst fluid of these cystic processes. CONCLUSION: The presence of TN in and around the hyperplastic vessels and tumor cells present in the cyst walls of astrocytomas and its deposition in the intratumoral cyst fluid in which angiogenic factors have been detected further suggests a role for TN as an angiogenic modulator. These preliminary results suggest that immunodetection of TN in the tumor cyst fluid may indicate tumor type and grade.


Assuntos
Encefalopatias/patologia , Neoplasias Encefálicas/irrigação sanguínea , Neoplasias Encefálicas/patologia , Cistos/patologia , Glioma/irrigação sanguínea , Glioma/patologia , Neovascularização Patológica , Tenascina/análise , Adolescente , Adulto , Astrocitoma/irrigação sanguínea , Astrocitoma/patologia , Astrocitoma/cirurgia , Biomarcadores , Encefalopatias/cirurgia , Neoplasias Encefálicas/cirurgia , Criança , Pré-Escolar , Cistos/cirurgia , Feminino , Glioma/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade
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