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1.
Proc Natl Acad Sci U S A ; 117(43): 26946-26954, 2020 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-33028676

RESUMO

Remdesivir is a broad-spectrum antiviral nucleotide prodrug that has been clinically evaluated in Ebola virus patients and recently received emergency use authorization (EUA) for treatment of COVID-19. With approvals from the Federal Select Agent Program and the Centers for Disease Control and Prevention's Institutional Biosecurity Board, we characterized the resistance profile of remdesivir by serially passaging Ebola virus under remdesivir selection; we generated lineages with low-level reduced susceptibility to remdesivir after 35 passages. We found that a single amino acid substitution, F548S, in the Ebola virus polymerase conferred low-level reduced susceptibility to remdesivir. The F548 residue is highly conserved in filoviruses but should be subject to specific surveillance among novel filoviruses, in newly emerging variants in ongoing outbreaks, and also in Ebola virus patients undergoing remdesivir therapy. Homology modeling suggests that the Ebola virus polymerase F548 residue lies in the F-motif of the polymerase active site, a region that was previously identified as susceptible to resistance mutations in coronaviruses. Our data suggest that molecular surveillance of this region of the polymerase in remdesivir-treated COVID-19 patients is also warranted.


Assuntos
Monofosfato de Adenosina/análogos & derivados , Alanina/análogos & derivados , Antivirais/farmacologia , Betacoronavirus/enzimologia , Ebolavirus/enzimologia , RNA Polimerase Dependente de RNA/química , Proteínas não Estruturais Virais/química , Monofosfato de Adenosina/farmacologia , Alanina/farmacologia , Betacoronavirus/química , Linhagem Celular , Tolerância a Medicamentos/genética , Ebolavirus/efeitos dos fármacos , Ebolavirus/genética , Humanos , Modelos Moleculares , Mutação , RNA Polimerase Dependente de RNA/genética , SARS-CoV-2 , Proteínas não Estruturais Virais/genética , Replicação Viral/efeitos dos fármacos
2.
J Infect Dis ; 219(11): 1716-1721, 2019 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-30590775

RESUMO

Although bats are increasingly being recognized as natural reservoir hosts of emerging zoonotic viruses, little is known about how they control and clear virus infection in the absence of clinical disease. Here, we test >50 convalescent sera from Egyptian rousette bats (ERBs) experimentally primed or prime-boosted with Marburg virus, Ebola virus, or Sosuga virus for the presence of virus-specific neutralizing antibodies, using infectious reporter viruses. After serum neutralization testing, we conclude that antibody-mediated virus neutralization does not contribute significantly to the control and clearance of Marburg virus, Ebola virus, or Sosuga virus infection in ERBs.


Assuntos
Quirópteros/virologia , Ebolavirus/imunologia , Doença pelo Vírus Ebola/imunologia , Doença do Vírus de Marburg/imunologia , Marburgvirus/imunologia , Paramyxoviridae/imunologia , Animais , Anticorpos Antivirais/imunologia , Convalescença , Reservatórios de Doenças/virologia , Egito/epidemiologia , Doença pelo Vírus Ebola/virologia , Humanos , Imunidade Humoral , Doença do Vírus de Marburg/virologia , Testes de Neutralização
3.
Depress Anxiety ; 36(6): 552-564, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30958911

RESUMO

Hoarding disorder is present in 2-6% of the population and can have an immense impact on the lives of patients and their families. Before its inclusion the Diagnostic and Statistical Manual of Mental Disorders, 5th edition, pathological hoarding was often characterized as a symptom of obsessive-compulsive disorder, and several different diagnostic assessment methods were used to identify and characterize it. Although the age of onset of pathological hoarding is an important epidemiological measure, as clarifying the age of onset of hoarding symptoms may allow for early identification and implementation of evidence-based treatments before symptoms become clinically significant, the typical age of onset of hoarding is still uncertain. To that end, this study is a systematic review and meta-analysis of research published in English between the years 1900 and 2016 containing information on age of onset of hoarding symptoms. Twenty-five studies met inclusion criteria. The mean age of onset of hoarding symptoms across studies was 16.7 years old, with evidence of a bimodal distribution of onset. The authors conclude by discussing practice implications for early identification and treatment.


Assuntos
Transtorno de Acumulação/epidemiologia , Adolescente , Distribuição por Idade , Idade de Início , Transtorno de Acumulação/diagnóstico , Transtorno de Acumulação/terapia , Humanos , Incerteza
4.
Emerg Infect Dis ; 24(5): 898-901, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29664366

RESUMO

A virus isolated from a sick horse from India in 2008 was confirmed by next-generation sequencing analysis to be equine encephalosis virus (EEV). EEV in India is concerning because several species of Culicoides midge, which play a major role in EEV natural maintenance and transmission, are present in this country.


Assuntos
Doenças dos Cavalos/virologia , Orbivirus/isolamento & purificação , Infecções por Reoviridae/veterinária , Animais , Ceratopogonidae/virologia , Doenças dos Cavalos/epidemiologia , Cavalos , Índia/epidemiologia , Orbivirus/genética , Filogenia , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/virologia
5.
J Gen Virol ; 99(8): 991-1000, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29939123

RESUMO

In 1954, a virus named Wad Medani virus (WMV) was isolated from Hyalomma marginatum ticks from Maharashtra State, India. In 1963, another virus was isolated from Sturnia pagodarum birds in Tamil Nadu, India, and named Kammavanpettai virus (KVPTV) based on the site of its isolation. Originally these virus isolates could not be identified with conventional methods. Here we describe next-generation sequencing studies leading to the determination of their complete genome sequences, and identification of both virus isolates as orbiviruses (family Reoviridae). Sequencing data showed that KVPTV has an AT-rich genome, whereas the genome of WMV is GC-rich. The size of the KVPTV genome is 18 234 nucleotides encoding proteins ranging 238-1290 amino acids (aa) in length. Similarly, the size of the WMV genome is 16 941 nucleotides encoding proteins ranging 214-1305 amino acids in length. Phylogenetic analysis of the VP1 gene, along with the capsid genes VP5 and VP7, revealed that KVPTV is likely a novel mosquito-borne virus and WMV is a tick-borne orbivirus. This study focuses on the phylogenetic comparison of these newly identified orbiviruses with mosquito-, tick- and Culicoides-borne orbiviruses isolated in India and other countries.


Assuntos
Culicidae/virologia , Mosquitos Vetores/virologia , Infecções por Reoviridae/transmissão , Reoviridae/genética , Animais , Genoma Viral , Índia , Camundongos , Filogenia
6.
J Infect Dis ; 214(suppl 3): S258-S262, 2016 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-27587631

RESUMO

During the Ebola virus outbreak of 2013-2016, the Viral Special Pathogens Branch field laboratory in Sierra Leone tested approximately 26 000 specimens between August 2014 and October 2015. Analysis of the B2M endogenous control Ct values showed its utility in monitoring specimen quality, comparing results with different specimen types, and interpretation of results. For live patients, blood is the most sensitive specimen type and oral swabs have little diagnostic utility. However, swabs are highly sensitive for diagnostic testing of corpses.


Assuntos
Surtos de Doenças , Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/diagnóstico , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Serviços de Laboratório Clínico , Ebolavirus/genética , Doença pelo Vírus Ebola/epidemiologia , Doença pelo Vírus Ebola/virologia , Humanos , Laboratórios , Reação em Cadeia da Polimerase em Tempo Real/métodos , Sensibilidade e Especificidade , Serra Leoa/epidemiologia
7.
J Infect Dis ; 212 Suppl 2: S350-8, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26232439

RESUMO

In August 2014, the Viral Special Pathogens Branch of the US Centers for Disease Control and Prevention established a field laboratory in Sierra Leone in response to the ongoing Ebola virus outbreak. Through March 2015, this laboratory tested >12 000 specimens from throughout Sierra Leone. We describe the organization and procedures of the laboratory located in Bo, Sierra Leone.


Assuntos
Ebolavirus/isolamento & purificação , Doença pelo Vírus Ebola/diagnóstico , Doença pelo Vírus Ebola/virologia , Centers for Disease Control and Prevention, U.S. , Surtos de Doenças , Epidemias , Humanos , Laboratórios , Serra Leoa/epidemiologia , Estados Unidos
9.
Emerg Infect Dis ; 20(2): 240-7, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24447605

RESUMO

We investigated the extent of lymphocytic choriomeningitis virus (LCMV) infection in employees and rodents at 3 commercial breeding facilities. Of 97 employees tested, 31 (32%) had IgM and/or IgG to LCMV, and aseptic meningitis was diagnosed in 4 employees. Of 1,820 rodents tested in 1 facility, 382 (21%) mice (Mus musculus) had detectable IgG, and 13 (0.7%) were positive by reverse transcription PCR; LCMV was isolated from 8. Rats (Rattus norvegicus) were not found to be infected. S-segment RNA sequence was similar to strains previously isolated in North America. Contact by wild mice with colony mice was the likely source for LCMV, and shipments of infected mice among facilities spread the infection. The breeding colonies were depopulated to prevent further human infections. Future outbreaks can be prevented with monitoring and management, and employees should be made aware of LCMV risks and prevention.


Assuntos
Criação de Animais Domésticos , Surtos de Doenças , Coriomeningite Linfocítica/veterinária , Vírus da Coriomeningite Linfocítica/classificação , Meningite Asséptica/epidemiologia , Exposição Ocupacional , RNA Viral/classificação , Adulto , Animais , Anticorpos Antivirais/sangue , Feminino , Humanos , Imunoglobulina G/sangue , Imunoglobulina M/sangue , Coriomeningite Linfocítica/epidemiologia , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Vírus da Coriomeningite Linfocítica/genética , Masculino , Meningite Asséptica/imunologia , Meningite Asséptica/virologia , Camundongos , Filogenia , RNA Viral/genética , Ratos , Sorotipagem , Estados Unidos/epidemiologia
11.
Anal Verbal Behav ; 39(1): 118-145, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37397137

RESUMO

Children with autism spectrum disorder (ASD) may struggle with verbal behavior related to recall in various contexts. However, relatively little research has evaluated methods for improving recall among this population, and even fewer from a verbal behavior perspective. One socially important set of skills that relies upon a behavioral repertoire of recall is applied reading skills, such as reading comprehension and story recall. Valentino et al. (2015) designed an intervention package to teach children with ASD to recall short stories and conceptualized the behavior as an intraverbal chain. The present study replicated and extended that study with three school-aged children with ASD using a multiple baseline design across stories. For some participants and some stories, story recall was mastered under less intensive intervention conditions than in the previous study. When it was necessary to implement the full intervention package, the effects largely replicated previous research. Improvements in recall were correlated with increases in correct answers to comprehension questions. These data have important implications for clinicians and educators providing reading and recall interventions to children with ASD. Results also have theoretical implications for verbal behavior accounts of memory and recall, and suggest several possible avenues for future research. Supplementary Information: The online version contains supplementary material available at 10.1007/s40616-023-00183-2.

12.
Pediatr Blood Cancer ; 59(4): 642-7, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22147414

RESUMO

BACKGROUND: More effective therapy for children with high-risk neuroblastoma is desperately needed. Preclinical studies have shown that neuroblastoma tumor growth can be inhibited by agents that block angiogenesis. We hypothesized that drugs which target both neuroblastoma cells and tumor angiogenesis would have potent anti-tumor activity. In this study we tested the effects of sorafenib, a multi-kinase inhibitor, on neuroblastoma cell proliferation and signaling, and in mice with subcutaneous human neuroblastoma xenografts or orthotopic adrenal tumors. PROCEDURE: Mice with subcutaneous neuroblastoma xenografts or orthotopic adrenal tumors were treated with sorafenib, and tumor growth rates were measured. Blood vessel architecture and vascular density were evaluated histologically in treated and control neuroblastoma tumors. The in vitro effects of sorafenib on neuroblastoma proliferation, cell cycle, and signaling were also evaluated. RESULTS: Sorafenib inhibited tumor growth in mice with subcutaneous and orthotopic adrenal tumors. Decreased numbers of cycling neuroblastoma cells and tumor blood vessels were seen in treated versus control tumors, and the blood vessels in the treated tumors had more normal architecture. Sorafenib treatment also decreased neuroblastoma cell proliferation, attenuated ERK signaling, and enhanced G(1) /G(0) cell cycle arrest in vitro. CONCLUSIONS: Our results demonstrate that sorafenib inhibits the growth of neuroblastoma tumors by targeting both neuroblastoma cells and tumor blood vessels. Single agent sorafenib should be evaluated in future phase II neuroblastoma studies.


Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Benzenossulfonatos/farmacologia , Proliferação de Células/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Neuroblastoma/patologia , Inibidores de Proteínas Quinases/farmacologia , Piridinas/farmacologia , Animais , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Feminino , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neovascularização Patológica/patologia , Neuroblastoma/irrigação sanguínea , Neuroblastoma/fisiopatologia , Niacinamida/análogos & derivados , Compostos de Fenilureia , Sorafenibe
13.
J Appl Behav Anal ; 55(4): 1280-1293, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35818937

RESUMO

Visual inspection is the traditional method behavior analysts use to interpret functional-analysis results. Limitations of visual inspection include lack of standardized rules, subjectivity, and inconsistent interrater reliability (Fisch, 1998). To address these limitations, researchers have developed, evaluated, and refined structured criteria to aid interpretation of functional analyses of destructive behavior (Hagopian et al., 1997; Roane et al., 2013; Saini et al., 2018). The current study applied the structured criteria Saini et al. (2018) described to functional analyses of inappropriate mealtime behavior. We assessed its predictive validity and evaluated its efficiency relative to 3 post hoc visual inspection procedures. Validity metrics were lower than those in Saini et al. however, ongoing visual inspection increased the efficiency of functional analyses by more than 30%. We discuss these findings relative to the procedural differences between functional analyses of destructive behavior and inappropriate mealtime behavior.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos , Comportamento Problema , Humanos , Refeições , Reprodutibilidade dos Testes
14.
Pediatr Blood Cancer ; 56(1): 164-7, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20860039

RESUMO

The quinoxaline anti-tumor agent (R+)XK469 mediates its effects by topoisomerase IIB inhibition. This report describes a 14-year old with relapsed neuroblastoma who experienced disease stabilization for 14 months while receiving (R+)XK469 monotherapy. Due to this favorable response, laboratory studies were undertaken to determine efficacy in the preclinical setting. (R+)XK469 inhibited proliferation, caused G(2) cell cycle arrest of neuroblastoma cells in vitro, and inhibited growth of neuroblastoma xenograft tumors. These preclinical results, coupled with the favorable clinical response, demonstrate that (R+)XK469 and similar anti-tumor agents may be effective in the treatment of high-risk neuroblastoma and warrant further testing.


Assuntos
Proliferação de Células/efeitos dos fármacos , Neuroblastoma/tratamento farmacológico , Quinoxalinas/farmacologia , Adolescente , Antineoplásicos/farmacologia , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Evolução Fatal , Humanos , Metástase Neoplásica , Neuroblastoma/patologia , Quinoxalinas/uso terapêutico , Resultado do Tratamento , Ensaios Antitumorais Modelo de Xenoenxerto
15.
Mol Cancer ; 9: 138, 2010 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-20525313

RESUMO

BACKGROUND: New, more effective strategies are needed to treat highly aggressive neuroblastoma. Our laboratory has previously shown that full-length Secreted Protein Acidic and Rich in Cysteine (SPARC) and a SPARC peptide corresponding to the follistatin domain of the protein (FS-E) potently block angiogenesis and inhibit the growth of neuroblastoma tumors in preclinical models. Peptide FS-E is structurally complex and difficult to produce, limiting its potential as a therapeutic in the clinic. RESULTS: In this study, we synthesized two smaller and structurally more simple SPARC peptides, FSEN and FSEC, that respectively correspond to the N-and C-terminal loops of peptide FS-E. We show that both peptides FSEN and FSEC have anti-angiogenic activity in vitro and in vivo, although FSEC is more potent. Peptide FSEC also significantly inhibited the growth of neuroblastoma xenografts. Histologic examination demonstrated characteristic features of tumor angiogenesis with structurally abnormal, tortuous blood vessels in control neuroblastoma xenografts. In contrast, the blood vessels observed in tumors, treated with SPARC peptides, were thin walled and structurally more normal. Using a novel method to quantitatively assess blood vessel abnormality we demonstrated that both SPARC peptides induced changes in blood vessel architecture that are consistent with blood vessel normalization. CONCLUSION: Our results demonstrate that SPARC peptide FSEC has potent anti-angiogenic and anti-tumorigenic effects in neuroblastoma. Its simple structure and ease of production indicate that it may have clinical utility in the treatment of high-risk neuroblastoma and other types of pediatric and adult cancers, which depend on angiogenesis.


Assuntos
Inibidores da Angiogênese/farmacologia , Neuroblastoma/tratamento farmacológico , Osteonectina/farmacologia , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Progressão da Doença , Células Endoteliais/efeitos dos fármacos , Imunofluorescência , Humanos , Camundongos , Camundongos Nus , Neovascularização Patológica/tratamento farmacológico , Neuroblastoma/irrigação sanguínea , Peptídeos , Ensaios Antitumorais Modelo de Xenoenxerto
16.
BMC Cancer ; 10: 286, 2010 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-20546602

RESUMO

BACKGROUND: Epigenetic aberrations and a CpG island methylator phenotype have been shown to be associated with poor outcomes in children with neuroblastoma (NB). Seven cancer related genes (THBS-1, CASP8, HIN-1, TIG-1, BLU, SPARC, and HIC-1) that have been shown to have epigenetic changes in adult cancers and play important roles in the regulation of angiogenesis, tumor growth, and apoptosis were analyzed to investigate the role epigenetic alterations play in determining NB phenotype. METHODS: Two NB cell lines (tumorigenic LA1-55n and non-tumorigenic LA1-5s) that differ in their ability to form colonies in soft agar and tumors in nude mice were used. Quantitative RNA expression analyses were performed on seven genes in LA1-5s, LA1-55n and 5-Aza-dC treated LA1-55n NB cell lines. The methylation status around THBS-1, HIN-1, TIG-1 and CASP8 promoters was examined using methylation specific PCR. Chromatin immunoprecipitation assay was used to examine histone modifications along the THBS-1 promoter. Luciferase assay was used to determine THBS-1 promoter activity. Cell proliferation assay was used to examine the effect of 5-Aza-dC on NB cell growth. The soft agar assay was used to determine the tumorigenicity. RESULTS: Promoter methylation values for THBS-1, HIN-1, TIG-1, and CASP8 were higher in LA1-55n cells compared to LA1-5s cells. Consistent with the promoter methylation status, lower levels of gene expression were detected in the LA1-55n cells. Histone marks associated with repressive chromatin states (H3K9Me3, H3K27Me3, and H3K4Me3) were identified in the THBS-1 promoter region in the LA1-55n cells, but not the LA1-5s cells. In contrast, the three histone codes associated with an active chromatin state (acetyl H3, acetyl H4, and H3K4Me3) were present in the THBS-1 promoter region in LA1-5s cells, but not the LA1-55n cells, suggesting that an accessible chromatin structure is important for THBS-1 expression. We also show that 5-Aza-dC treatment of LA1-55n cells alters the DNA methylation status and the histone code in the THBS-1 promoter modifies cell morphology, and inhibits their ability to form colonies in soft agar. CONCLUSION: Our results suggest that epigenetic aberrations contribute to NB phenotype, and that tumorigenic properties can be inhibited by reversing the epigenetic changes with 5-Aza-dC.


Assuntos
Epigênese Genética , Regulação Neoplásica da Expressão Gênica , Neuroblastoma/genética , Acetilação , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Forma Celular , Imunoprecipitação da Cromatina , Metilação de DNA , Metilases de Modificação do DNA/antagonistas & inibidores , Metilases de Modificação do DNA/metabolismo , Decitabina , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Epigênese Genética/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Genótipo , Inibidores de Histona Desacetilases/farmacologia , Histonas/metabolismo , Humanos , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Fenótipo , Reação em Cadeia da Polimerase , Regiões Promotoras Genéticas , Trombospondina 1/genética , Transfecção , Ácido Valproico/farmacologia
17.
Virus Res ; 277: 197836, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31821842

RESUMO

Three genome sequences of Buffalopox virus (BPVX) were retrieved from a human and two buffaloes scab samples. Phylogenomic analysis of the BPXV indicates that it shares a most recent common ancestor with Lister and closely related vaccine strains when compared to potential wild-type VACV strains (like Horsepox virus).


Assuntos
Búfalos/virologia , Genoma Viral , Filogenia , Vaccinia virus/classificação , Animais , Chlorocebus aethiops , DNA Viral/genética , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Índia , Vaccinia virus/isolamento & purificação , Células Vero , Proteínas Virais/genética , Zoonoses/virologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-32561250

RESUMO

OBJECTIVE: The aim of this study was to assess the influence of clinical cues on risk assessment of cancer-associated mucosal abnormalities. STUDY DESIGN: We differentiated lesions with a low risk from those with a high risk for premalignancy or malignancy by using 4 cues: (1) color, (2) location, (3) induration, and (4) pain on exploration. Combinations of color and location were presented through 8 photographs, with induration and pain status variably presented in the standardized history and physical findings. This created 16 clinical scenarios (vignettes) that were permutations of the 4 cues. Three questions assessed the extent to which each cue was used in obtaining a clinical impression as to whether a lesion was benign, premalignant, or malignant. RESULTS: Completed vignette questionnaires were obtained from 130 of 228 invited dentists, (two-thirds males; 79% white; mean age 52 years; average weekly hours of practice 33 hours). Only 40% of the responding dentists had statistically significant decision policies to assign a clinical diagnosis of a lesion as benign, premalignant, or malignant. Lesion location and color were the 2 dominant cues. As a cue, induration was used as a cue by more of the respondents in determining a clinical diagnosis of malignancy, and pain was infrequently used as a cue. CONCLUSIONS: Many dentists do not to have a decision strategy for the clinical diagnosis and risk stratification of oral potentially malignant lesions.


Assuntos
Neoplasias Bucais , Lesões Pré-Cancerosas , Sinais (Psicologia) , Odontólogos , Detecção Precoce de Câncer , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/diagnóstico , Inquéritos e Questionários
19.
Mod Pathol ; 22(7): 950-8, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19407854

RESUMO

Stromal cells have a central function in the regulation of tumor angiogenesis. Recent studies have shown that stromal myofibroblasts (cancer-associated fibroblasts) actively promote tumor growth and enhance tumor angiogenesis in many types of adult carcinomas. To evaluate the function cancer-associated fibroblasts have in neuroblastoma angiogenesis and investigate their relationship to stromal Schwann cells, we quantified cancer-associated fibroblasts in 60 primary neuroblastoma tumors and in a novel neuroblastoma xenograft model in which murine Schwann cells were induced to infiltrate into the tumor stroma. Tumor sections were examined for presence of microvascular proliferation, a hallmark of tumor angiogenesis. Cancer-associated fibroblasts were characterized by positive immunostaining for alpha-smooth muscle actin (alpha-SMA) and were distinguished from pericytes by staining negatively for high-molecular-weight caldesmon. alpha-SMA-positive cells were quantified and their number was defined as high when >1.0% of the area was positive. Associations between high cancer-associated fibroblast number, microvascular proliferation and established prognosticators were analyzed. High numbers of cancer-associated fibroblasts were associated with Schwannian stroma-poor histopathology and microvascular proliferation. Thirty-seven (80%) of the 46 Schwannian stroma-poor tumors had high numbers of cancer-associated fibroblasts in the tumor stroma compared to only 2 (14%) of the 14 Schwannian stroma-rich/dominant tumors (P<0.001). Thirty-three (89%) of 37 tumors with microvascular proliferation had high numbers of cancer-associated fibroblasts compared to 9 (40%) of 22 tumors without microvascular proliferation (P<0.001). In the xenografts with infiltrating Schwann cells (n=10), the number of cancer-associated fibroblasts per mm(2) was approximately sevenfold less than in the control xenografts without stromal Schwann cells (n=9) (mean of 51+/-30 vs 368+/-105, respectively; P<0.001). Thus, cancer-associated fibroblasts were inversely associated with presence of Schwann cells, suggesting that Schwann cells may prevent the activation of fibroblasts. A deeper understanding of the function cancer-associated fibroblasts have in neuroblastoma angiogenesis may guide future development of stroma-directed therapeutic strategies.


Assuntos
Fibroblastos/patologia , Neovascularização Patológica/patologia , Neuroblastoma/patologia , Células de Schwann/patologia , Células Estromais/patologia , Actinas/metabolismo , Animais , Biomarcadores/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Modelos Animais de Doenças , Feminino , Fibroblastos/metabolismo , Humanos , Lactente , Masculino , Camundongos , Camundongos Nus , Transplante de Neoplasias , Neuroblastoma/irrigação sanguínea , Neuroblastoma/mortalidade , Pericitos/metabolismo , Pericitos/patologia , Nervo Isquiático/patologia , Nervo Isquiático/cirurgia
20.
Lancet Infect Dis ; 19(9): 1023-1032, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31300330

RESUMO

BACKGROUND: The ongoing Ebola virus outbreak in the Ituri and North Kivu Provinces of the Democratic Republic of the Congo, which began in July, 2018, is the second largest ever recorded. Despite civil unrest, outbreak control measures and the administration of experimental therapies and a vaccine have been initiated. The aim of this study was to test the efficacy of candidate therapies and diagnostic tests with the outbreak strain Ituri Ebola virus. Lacking a virus isolate from this outbreak, a recombinant Ituri Ebola virus was compared with a similarly engineered Makona virus from the 2013-16 outbreak. METHODS: Using Ebola virus sequences provided by organisations in DR Congo and a reverse genetics system, we generated an authentic Ebola virus from the ongoing outbreak in Ituri and North Kivu provinces. To relate this virus to other Ebola viruses in DR Congo, we did a phylogenetic analysis of representative complete Ebola virus genome sequences from previous outbreaks. We evaluated experimental therapies being tested in clinical trials in DR Congo, including remdesivir and ZMapp monoclonal antibodies, for their ability to inhibit the growth of infectious Ituri Ebola virus in cell culture. We also tested diagnostic assays for detection of the Ituri Ebola virus sequence. FINDINGS: The phylogenetic analysis of whole-genome sequences from each Ebola virus outbreak suggests there are at least two Ebola virus strains in DR Congo, which have independently crossed into the human population. The Ituri Ebola strain initially grew slower than the Makona strain, yet reached similar mean yields of 3 × 107 50% tissue culture infectious dose by 72 h infection in Huh-7 cells. Ituri Ebola virus was similar to Makona in its susceptibility to inhibition by remdesivir and to neutralisation by monoclonal antibodies from ZMapp and other monoclonal antibodies. Remdesivir inhibited Ituri Ebola virus at a 50% effective concentration (EC50) of 12nM (with a selectivity index of 303) and Makona Ebola virus at 13nM (with a selectivity index of 279). The Zmapp monoclonal antibodies 2G4 and 4G7 neutralised Ituri Ebola virus with a mean EC50 of 0·24 µg/mL and 0·48 µg/mL, and Makona Ebola virus with a mean EC50 of 0·45 µg/mL and 0·2 µg/mL. The Xpert Ebola and US Centers for Disease Control and Prevention real-time RT-qPCR diagnostic assays detected Ituri and Makona Ebola virus sequences with similar sensitivities and efficiencies, despite primer site binding mismatches in the Ituri Ebola virus. INTERPRETATION: Our findings provide a rationale for the continued testing of investigational therapies, confirm the effectiveness of the diagnostic assays used in the region, and establish a paradigm for the use of reverse genetics to inform response activities in an outbreak. FUNDING: US Centers for Disease Control and Prevention.


Assuntos
Antivirais/farmacologia , DNA Viral/análise , Surtos de Doenças , Ebolavirus/efeitos dos fármacos , Ebolavirus/genética , Doença pelo Vírus Ebola/epidemiologia , Monofosfato de Adenosina/análogos & derivados , Monofosfato de Adenosina/farmacologia , Alanina/análogos & derivados , Alanina/farmacologia , Amiodarona/farmacologia , Antiarrítmicos/farmacologia , Anticorpos Monoclonais/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , Linhagem Celular , República Democrática do Congo/epidemiologia , Humanos , Filogenia , Ribavirina/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Tamoxifeno/farmacologia , Toremifeno/farmacologia , Verapamil/farmacologia , Cultura de Vírus , Sequenciamento Completo do Genoma
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