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1.
Adv Mater ; : e2311313, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38483292

RESUMO

Conventional gas plasma treatments are crucial for functionalizing materials in biomedical applications, but have limitations hindering their broader use. These methods require exposure to reactive media under vacuum conditions, rendering them unsuitable for substrates that demand aqueous environments, such as proteins and hydrogels. In addition, complex geometries are difficult to treat, necessitating extensive customization for each material and shape. To address these constraints, an innovative approach employing plasma polymer nanoparticles (PPN) as a versatile functionalization tool is proposed. PPN share similarities with traditional plasma polymer coatings (PPC) but offer unique advantages: compatibility with aqueous systems, the ability to modify complex geometries, and availability as off-the-shelf products. Robust immobilization of PPN on various substrates, including synthetic polymers, proteins, and complex hydrogel structures is demonstrated in this study. This results in substantial improvements in surface hydrophilicity. Materials functionalization with arginylglycylaspartic acid (RGD)-loaded PPN significantly enhances cell attachment, spreading, and substrate coverage on inert scaffolds compared to passive RGD coatings. Improved adhesion to complex geometries and subsequent differentiation following growth factor exposure is also demonstrated. This research introduces a novel substrate functionalization approach that mimics the outcomes of plasma coating technology but vastly expands its applicability, promising advancements in biomedical materials and devices.

2.
Sci Rep ; 14(1): 7028, 2024 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-38528062

RESUMO

Accurate indel calling plays an important role in precision medicine. A benchmarking indel set is essential for thoroughly evaluating the indel calling performance of bioinformatics pipelines. A reference sample with a set of known-positive variants was developed in the FDA-led Sequencing Quality Control Phase 2 (SEQC2) project, but the known indels in the known-positive set were limited. This project sought to provide an enriched set of known indels that would be more translationally relevant by focusing on additional cancer related regions. A thorough manual review process completed by 42 reviewers, two advisors, and a judging panel of three researchers significantly enriched the known indel set by an additional 516 indels. The extended benchmarking indel set has a large range of variant allele frequencies (VAFs), with 87% of them having a VAF below 20% in reference Sample A. The reference Sample A and the indel set can be used for comprehensive benchmarking of indel calling across a wider range of VAF values in the lower range. Indel length was also variable, but the majority were under 10 base pairs (bps). Most of the indels were within coding regions, with the remainder in the gene regulatory regions. Although high confidence can be derived from the robust study design and meticulous human review, this extensive indel set has not undergone orthogonal validation. The extended benchmarking indel set, along with the indels in the previously published known-positive set, was the truth set used to benchmark indel calling pipelines in a community challenge hosted on the precisionFDA platform. This benchmarking indel set and reference samples can be utilized for a comprehensive evaluation of indel calling pipelines. Additionally, the insights and solutions obtained during the manual review process can aid in improving the performance of these pipelines.


Assuntos
Benchmarking , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Biologia Computacional , Controle de Qualidade , Mutação INDEL , Polimorfismo de Nucleotídeo Único
3.
Breast Cancer ; 29(3): 487-497, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35025065

RESUMO

BACKGROUND: In breast cancer (BC), overexpression of HER2 on the primary tumor (PT) is determined by immunohistochemistry (IHC) or fluorescence in situ hybridization (FISH) to stratify samples as negative, equivocal and positive to identify patients (pts) for anti-HER2 therapy. CAP/ASCO guidelines recommend FISH for analyzing HER2/neu (ERBB2) gene amplification and for resolving equivocal HER2 IHC results. However, pre-analytical and analytical aspects are often confounded by sample related limitations and tumor heterogeneity and HER2 expression may differ between the PT and circulating tumor cells (CTCs), the precursors of metastasis. We used a validation cohort of BC patients to establish a new DEPArray™-PT-HER2-FISH workflow for further application in a development cohort, characterized as PT-HER2-negative but CTC-HER2/neu-positive, to identify patients with PT-HER2 amplified cells not detected by routine pathology. METHODS: 50 µm FFPE tumor curls from the validation cohort (n = 49) and the development cohort (n = 25) underwent cutting, deparaffinization and antigen retrieval followed by dissociation into a single-cell suspension. After staining for cytokeratin, vimentin, DAPI and separation via DEPArray™, single cells were processed for HER2-FISH analysis to assess the number of chromosome 17 and HER2 loci signals for comparison, either with available IHC or conventional tissue section FISH. CTC-HER2/neu status was determined using the AdnaTest BreastCancer (QIAGEN, Hilden, Germany). RESULTS: Applying CAP/ASCO guidelines for HER2 evaluation of single PT cells, the comparison of routine pathology and DEPArray™-HER2-FISH analysis resulted in a concordance rate of 81.6% (40/49 pts) in the validation cohort and 84% (21/25 pts) in the development cohort, respectively. In the latter one, 4/25 patients had single HER2-positive tumor cells with 2/25 BC patients proven to be HER2-positive, despite being HER2-negative in routine pathology. The two other patients showed an equivocal HER2 status in the DEPArray™-HER2-FISH workflow but a negative result in routine pathology. Whereas all four patients with discordant HER2 results had already died, 17/21 patients with concordant HER2 results are still alive. CONCLUSIONS: The DEPArray™ system allows pure tumor cell recovery for subsequent HER2/neu FISH analysis and is highly concordant with conventional pathology. For PT-HER2-negative patients, harboring HER2/neu-positive CTCs, this approach might allow caregivers to more effectively offer anti-HER2 treatment.


Assuntos
Neoplasias da Mama , Carcinoma , Biomarcadores Tumorais/genética , Neoplasias da Mama/patologia , Feminino , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente/métodos , Receptor ErbB-2/metabolismo , Fluxo de Trabalho
4.
JAMA Netw Open ; 4(12): e2140568, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34935924

RESUMO

Importance: Obesity, diabetes, and hypertension are common comorbidities in patients with severe COVID-19, yet little is known about the risk of acute respiratory distress syndrome (ARDS) or death in patients with COVID-19 and metabolic syndrome. Objective: To determine whether metabolic syndrome is associated with an increased risk of ARDS and death from COVID-19. Design, Setting, and Participants: This multicenter cohort study used data from the Society of Critical Care Medicine Discovery Viral Respiratory Illness Universal Study collected from 181 hospitals across 26 countries from February 15, 2020, to February 18, 2021. Outcomes were compared between patients with metabolic syndrome (defined as ≥3 of the following criteria: obesity, prediabetes or diabetes, hypertension, and dyslipidemia) and a control population without metabolic syndrome. Participants included adult patients hospitalized for COVID-19 during the study period who had a completed discharge status. Data were analyzed from February 22 to October 5, 2021. Exposures: Exposures were SARS-CoV-2 infection, metabolic syndrome, obesity, prediabetes or diabetes, hypertension, and/or dyslipidemia. Main Outcomes and Measures: The primary outcome was in-hospital mortality. Secondary outcomes included ARDS, intensive care unit (ICU) admission, need for invasive mechanical ventilation, and length of stay (LOS). Results: Among 46 441 patients hospitalized with COVID-19, 29 040 patients (mean [SD] age, 61.2 [17.8] years; 13 059 [45.0%] women and 15713 [54.1%] men; 6797 Black patients [23.4%], 5325 Hispanic patients [18.3%], and 16 507 White patients [57.8%]) met inclusion criteria. A total of 5069 patients (17.5%) with metabolic syndrome were compared with 23 971 control patients (82.5%) without metabolic syndrome. In adjusted analyses, metabolic syndrome was associated with increased risk of ICU admission (adjusted odds ratio [aOR], 1.32 [95% CI, 1.14-1.53]), invasive mechanical ventilation (aOR, 1.45 [95% CI, 1.28-1.65]), ARDS (aOR, 1.36 [95% CI, 1.12-1.66]), and mortality (aOR, 1.19 [95% CI, 1.08-1.31]) and prolonged hospital LOS (median [IQR], 8.0 [4.2-15.8] days vs 6.8 [3.4-13.0] days; P < .001) and ICU LOS (median [IQR], 7.0 [2.8-15.0] days vs 6.4 [2.7-13.0] days; P < .001). Each additional metabolic syndrome criterion was associated with increased risk of ARDS in an additive fashion (1 criterion: 1147 patients with ARDS [10.4%]; P = .83; 2 criteria: 1191 patients with ARDS [15.3%]; P < .001; 3 criteria: 817 patients with ARDS [19.3%]; P < .001; 4 criteria: 203 patients with ARDS [24.3%]; P < .001). Conclusions and Relevance: These findings suggest that metabolic syndrome was associated with increased risks of ARDS and death in patients hospitalized with COVID-19. The association with ARDS was cumulative for each metabolic syndrome criteria present.


Assuntos
COVID-19/epidemiologia , COVID-19/mortalidade , Hospitalização , Síndrome Metabólica/epidemiologia , Síndrome do Desconforto Respiratório/epidemiologia , Adulto , COVID-19/terapia , Comorbidade , Cuidados Críticos , Feminino , Mortalidade Hospitalar , Humanos , Tempo de Internação , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Respiração Artificial , Fatores de Risco , SARS-CoV-2
5.
BMC Cancer ; 20(1): 945, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33004033

RESUMO

BACKGROUND: Circulating tumor (ct) DNA assays performed in clinical laboratories provide tumor biomarker testing support for biopharmaceutical clinical trials. Yet it is neither practical nor economically feasible for many of these clinical laboratories to internally develop their own liquid biopsy assay. Commercially available ctDNA kits are a potential solution for laboratories seeking to incorporate liquid biopsy into their test menus. However, the scarcity of characterized patient samples and cost of purchasing validation reference standards creates a barrier to entry. In the current study, we evaluated the analytical performance of the AVENIO ctDNA liquid biopsy platform (Roche Sequencing Solutions) for use in our clinical laboratory. METHOD: Intra-laboratory performance evaluation of AVENIO ctDNA Targeted, Expanded, and Surveillance kits (Research Use Only) was performed according to College of American Pathologists (CAP) guidelines for the validation of targeted next generation sequencing assays using purchased reference standards, de-identified human plasma cell-free (cf) DNA samples, and contrived samples derived from commercially purchased normal and cancer human plasma. All samples were sequenced at read depths relevant to clinical settings using the NextSeq High Output kit (Illumina). RESULTS: At the clinically relevant read depth, Avenio ctDNA kits demonstrated 100% sensitivity in detecting single nucleotide variants (SNVs) at ≥0.5% allele frequency (AF) and 50% sensitivity in detecting SNVs at 0.1% AF using 20-40 ng sample input amount. The assay integrated seamlessly into our laboratory's NGS workflow with input DNA mass, target allele frequency (TAF), multiplexing, and number of reads optimized to support a high-throughput assay appropriate for biopharmaceutical trials. CONCLUSIONS: Our study demonstrates that AVENIO ctDNA liquid biopsy platform provides a viable alternative for efficient incorporation of liquid biopsy assays into the clinical laboratory for detecting somatic alterations as low as 0.5%. Accurate detection of variants lower than 0.5% could potentially be achieved by deeper sequencing when clinically indicated and economically feasible.


Assuntos
Biomarcadores Tumorais/sangue , DNA Tumoral Circulante/sangue , Sequenciamento de Nucleotídeos em Larga Escala , Neoplasias/sangue , Ácidos Nucleicos Livres/sangue , Ácidos Nucleicos Livres/genética , DNA Tumoral Circulante/genética , Humanos , Biópsia Líquida , Mutação/genética , Neoplasias/genética
6.
JCI Insight ; 4(5)2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30702443

RESUMO

Molecular profiling of prostate cancer with liquid biopsies, such as circulating tumor cells (CTCs) and cell-free nucleic acid analysis, yields informative yet distinct data sets. Additional insights may be gained by simultaneously interrogating multiple liquid biopsy components to construct a more comprehensive molecular disease profile. We conducted an initial proof-of-principle study aimed at piloting this multiparametric approach. Peripheral blood samples from men with metastatic castrate-resistant prostate cancer were analyzed simultaneously for CTC enumeration, single-cell copy number variations, CTC DNA and matched cell-free DNA mutations, and plasma cell-free RNA levels of androgen receptor (AR) and AR splice variant (ARV7). In addition, liquid biopsies were compared with matched tumor profiles when available, and a second liquid biopsy was drawn and analyzed at disease progression in a subset of patients. In this manner, multiparametric liquid biopsy profiles were successfully generated for each patient and time point, demonstrating the feasibility of this approach and highlighting shared as well as unique cancer-relevant alterations. With further refinement and validation in large cohorts, multiparametric liquid biopsies can optimally integrate disparate but clinically informative data sets and maximize their utility for molecularly directed, real-time patient management.


Assuntos
Biópsia Líquida/métodos , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologia , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Ácidos Nucleicos Livres/sangue , Variações do Número de Cópias de DNA , Progressão da Doença , Perfilação da Expressão Gênica , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Células Neoplásicas Circulantes , Neoplasias da Próstata/genética , Receptores Androgênicos/sangue , Receptores Androgênicos/genética
7.
J Abnorm Child Psychol ; 47(6): 1065-1074, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30547314

RESUMO

Adolescents with depression disorders have higher rates of substance use. In order to advance contextually relevant mental health interventions, basic research is needed to test social ecological mechanisms hypothesized to influence adolescent depression and substance use. Accordingly, we conducted growth curve modeling with a sample of 248 urban adolescents to determine if depression's effect on substance use was dependent upon peer network health (sum of peer risk and protective behaviors) and activity space risk (likelihood of high-risk behaviors at routine locations). Results showed that peer network health moderated the effects of depression on substance use, but this effect was not altered by activity space risk. These findings suggest the importance of peer network health relative to depression and substance use, particularly for young adolescents.


Assuntos
Comportamento do Adolescente , Depressão/epidemiologia , Grupo Associado , Características de Residência/estatística & dados numéricos , Comportamento Social , Transtornos Relacionados ao Uso de Substâncias/epidemiologia , Adolescente , Comorbidade , Feminino , Seguimentos , Humanos , Masculino , Fatores de Proteção
8.
J Subst Abuse Treat ; 93: 15-18, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30126536

RESUMO

OBJECTIVE: This study collected in-depth treatment satisfaction and effectiveness data to provide insight into the mechanisms of behavior change and to identify aspects of a text message- delivered treatment for cannabis use disorder that could be improved. METHODS: Data were collected via a web-based survey from 30 young adults (ages 18-25) who were recent participants in a randomized controlled trial of Peer Network Counseling-txt (PNC- txt), a text message treatment for cannabis use disorder. The survey assessed reactions to the text-delivered treatment, changes in cannabis use, reactions to the peer-focused components, and feedback about improvements to the treatment. RESULTS: Nearly all (93%) respondents found PNC-txt to be helpful to their treatment. The majority of the sample (63%) reported that PNC-txt heightened awareness of their cannabis use, and 40% reported a better understanding of problematic use. Fifty percent reported that they use less cannabis than they did prior to the intervention. Seventy percent of respondents stated that it was helpful to answer questions about their close friend group and nearly one- quarter of participants decreased the amount of time spent with "unhealthy" friends. Approximately 85% indicated that thinking about their peer network helped them meet goals of stopping, reducing, or better managing their cannabis use. CONCLUSIONS: These findings provide insight into the acceptability of the text-delivered treatment platform and potential mechanisms of behavior change for PNC-txt. The participants provided positive feedback about the treatment and indicated that it helped reduce their cannabis use. Given the acceptability and promising efficacy of PNC-txt, continued research is warranted, particularly with adolescents and with larger samples.


Assuntos
Abuso de Maconha/reabilitação , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Satisfação do Paciente , Envio de Mensagens de Texto , Adolescente , Adulto , Aconselhamento/métodos , Feminino , Humanos , Masculino , Fumar Maconha/epidemiologia , Fumar Maconha/prevenção & controle , Grupo Associado , Inquéritos e Questionários , Adulto Jovem
9.
J Mol Diagn ; 20(3): 279-288, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29471114

RESUMO

Cancer genome copy number alterations (CNAs) assist clinicians in selecting targeted therapeutics. Solid tumor CNAs are most commonly evaluated in formalin-fixed, paraffin-embedded (FFPE) tissue by fluorescence in situ hybridization. Although fluorescence in situ hybridization is a sensitive and specific assay for interrogating preselected genomic regions, it provides no information about coexisting clinically significant copy number changes. Chromosomal microarray analysis is an alternative DNA-based method for interrogating genome-wide CNAs in solid tumors. However, DNA extracted from FFPE tumor tissue produces an essential, yet problematic, sample type. The College of American Pathologists/American Society of Clinical Oncology guidelines for optimal tumor tissue handling, published in 2007 for breast cancer and in 2016 for gastroesophageal adenocarcinomas, are lacking for other solid tumors. Thus, cold ischemia times are seldom monitored in non-breast cancer and non-gastroesophageal adenocarcinomas, and all tumor biospecimens are affected by chemical fixation. Although intended to preserve specimens for long-term storage, formalin fixation causes loss of genetic information through DNA damage. Herein, we describe a reference size matching, whole-genome amplification, and fluorescent labeling method for FFPE-derived DNA designed to improve chromosomal microarray results from suboptimal nucleic acids and salvage highly degraded samples. With this technological advance, whole-genome copy number analysis of tumor DNA can be reliably performed in the clinical laboratory for a wide variety of tissue conditions and tumor types.


Assuntos
Cromossomos Humanos/genética , Variações do Número de Cópias de DNA/genética , Corantes Fluorescentes/química , Genoma Humano , Análise em Microsséries/normas , Neoplasias/genética , Inclusão em Parafina/métodos , Fixação de Tecidos/métodos , Linhagem Celular , DNA/genética , Formaldeído , Deleção de Genes , Dosagem de Genes , Humanos , PTEN Fosfo-Hidrolase/genética , Controle de Qualidade , Receptor ErbB-2/genética , Padrões de Referência
10.
Front Oncol ; 3: 240, 2013 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-24062990

RESUMO

The phosphatase and tensin homolog gene (PTEN) on chromosome 10q23.3 is a negative regulator of the PIK3/Akt survival pathway and is the most frequently deleted tumor suppressor gene in prostate cancer. Monoallelic loss of PTEN is present in up to 60% of localized prostate cancers and complete loss of PTEN in prostate cancer is linked to metastasis and androgen-independent progression. Studies on the genomic status of PTEN in prostate cancer initially used a two-color fluorescence in situ hybridization (FISH) assay for PTEN copy number detection in formalin fixed paraffin embedded tissue preparations. More recently, a four-color FISH assay containing two additional control probes flanking the PTEN locus with a lower false-positive rate was reported. Combined with the detection of other critical genomic biomarkers for prostate cancer such as ERG, androgen receptor, and MYC, the evaluation of PTEN genomic status has proven to be invaluable for patient stratification and management. Although less frequent than allelic deletions, point mutations in the gene and epigenetic silencing are also known to contribute to loss of PTEN function, and ultimately to prostate cancer initiation. Overall, it is clear that PTEN is a powerful biomarker for prostate cancer. Used as a companion diagnostic for emerging therapeutic drugs, FISH analysis of PTEN is promisingly moving human prostate cancer closer to more effective cancer management and therapies.

11.
Per Med ; 9(5): 485-496, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29768776

RESUMO

Therapeutics harnessing the power of personalized medicine have the potential to revolutionize healthcare. Companion diagnostics are critical to this goal and are increasingly relied upon to ensure the effective, safe development and use of a personalized therapeutic. Companion diagnostics are the focus of several recent regulatory guidance documents; the drug-diagnostic codevelopment process has become increasingly relevant and necessary. Despite this, the promise of companion diagnostics has not been fully realized and there are multiple difficulties that still need resolution. The path to codevelop a successful companion diagnostic with its complementary drug is complex, fragmented and fraught with several challenges. In this article, we discuss the logistic, strategic business, regulatory and financial challenges involved in drug-companion diagnostic codevelopment.

12.
Diagn Pathol ; 6: 76, 2011 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-21834951

RESUMO

BACKGROUND: The accuracy of melanoma diagnosis continues to challenge the pathology community, even today with sophisticated histopathologic techniques. Melanocytic lesions exhibit significant morphological heterogeneity. While the majority of biopsies can be classified as benign (nevus) or malignant (melanoma) using well-established histopathologic criteria, there exists a cohort for which the prediction of clinical behaviour and invasive or metastatic potential is difficult if not impossible to ascertain on the basis of morphological features alone. Multiple studies have shown that there is significant disagreement between pathologists and even expert dermatopathologists in the diagnosis of this subgroup of difficult melanocytic lesions. METHODS: A four probe FISH assay was utilized to analyse a cohort of 500 samples including 157 nevus, 176 dysplastic nevus and 167 melanoma specimens. RESULTS: Review of the lesions determined the assay identified genetic abnormalities in a total of 83.8% of melanomas, and 1.9% of nevus without atypia, while genetic abnormalities were identified in 6.3%, 6.7%, and 10.3% of nevus identified with mild, moderate and severe atypia, respectively. CONCLUSIONS: Based on this study, inheritable genetic damage/instability identified by FISH testing is a hallmark of a progressive malignant process, and a valuable diagnostic tool for the identification of high risk lesions.


Assuntos
Síndrome do Nevo Displásico/diagnóstico , Hibridização in Situ Fluorescente , Melanoma/diagnóstico , Nevo/diagnóstico , Neoplasias Cutâneas/diagnóstico , Biópsia , Diagnóstico Diferencial , Síndrome do Nevo Displásico/genética , Síndrome do Nevo Displásico/terapia , Predisposição Genética para Doença , Instabilidade Genômica , Hereditariedade , Humanos , Melanoma/genética , Melanoma/terapia , Nevo/genética , Nevo/terapia , Fenótipo , Valor Preditivo dos Testes , Prognóstico , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/terapia
13.
Cancer Genet Cytogenet ; 160(1): 76-8, 2005 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-15949575

RESUMO

Pericentric inversion of the heterochromatic region of chromosome 9 [inv(9)] is a common heteromorphism in the general population. It is presumed familial as there are no reports of de novo inv(9) chromosomes in constitutional karyotypes. We report 2 cases of acquired inv(9) chromosomes; 1 patient with acute myeloid leukemia, 46,XY,inv(9)(p11q13)[11]/46,XY[9], and a second with severe anemia, 46,XX,inv(9)(p11q13)[14]/46,XX[6]. The acquired nature of the inv(9) was confirmed by constitutional karyotyping and/or molecular analysis. The inv(9) in these patients may be a de novo inversion that cytogenetically mimics the constitutional inv(9) heteromorphism. Alternatively, it may be the result of neocentromere activation in 9q due to epigenetic events associated with the disease in these patients that results in a metacentric chromosome similarly mimicking the constitutional inv(9). One previous report of an acquired inv(9) was in a patient with essential thrombocythemia. The differences in clinical presentation may represent different underlying mechanisms generating the inv(9). The significance of an acquired inv(9) is unknown and will require reporting of additional cases.


Assuntos
Inversão Cromossômica , Cromossomos Humanos Par 9 , Idoso , Anemia/genética , Feminino , Humanos , Cariotipagem , Leucemia Mieloide Aguda/genética , Masculino
14.
Hum Mutat ; 21(6): 645-8, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12754712

RESUMO

Uniparental disomy of chromosome 7 (UPD7) is associated with abnormal phenotypic effects because of inappropriate expression of imprinted genes on chromosome 7. Based on the differential methylation of the promoter region of the imprinted PEG1/MEST locus at 7q32, we designed a multiplex methylation PCR (mPCR) assay to rapidly distinguish UPD7 from biparental inheritance of chromosome 7. Primers were designed to produce different sized PCR amplicons based on the parent of origin-specific methylation at this locus; electrophoresis of PCR amplicons showed a 189-bp product from the methylated maternal allele and a 109-bp product from the unmethylated paternal allele. This mPCR assay correctly predicted the chromosome 7 imprinting status in normal control and UPD7 samples. Previous assays for UPD7 required genotyping of the proband and parents, or separate maternal- and paternal-specific mPCR reactions. The advantage of this assay is that parental samples are not required and that amplification of both alleles in the same reaction is simpler and provides an internal control. This multiplex mPCR assay will be useful in screening for UPD7 in patients with Silver-Russell syndrome (SRS; also Russell-Sliver syndrome, RSS), primordial growth retardation, and in patients with supernumerary marker chromosomes or chromosome rearrangements of chromosome 7 origin.


Assuntos
Cromossomos Humanos Par 7/genética , Metilação de DNA , Testes Genéticos/métodos , Reação em Cadeia da Polimerase/métodos , Dissomia Uniparental/genética , Alelos , Linhagem Celular , Primers do DNA , Feminino , Impressão Genômica/genética , Humanos , Masculino , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Proteínas/genética
15.
Plasmid ; 49(2): 160-8, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12726769

RESUMO

Brevibacterium linens has commercial significance in the dairy industry and potential application in the production of bacteriocins and carotenoids. Strain development of these industrially significant organisms would be facilitated by the use of vectors, yet few are available. In this study we report the isolation of four novel plasmids from the Gram-positive coryneform B. linens, and determine the first complete nucleotide sequence of a native plasmid of B. linens. The cryptic plasmid pLIM is 7610 bp in length, and belongs to a subfamily of theta replicating ColE2-related plasmids. Initial investigation suggests that replication in pLIM requires two replicases, a primase (RepA) and a DNA binding protein (RepB), encoded by a single operon repAB. The origin of replication is located upstream of repAB transcription.


Assuntos
Brevibacterium/genética , DNA Helicases , Proteínas de Ligação a DNA , Plasmídeos/genética , Transativadores , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Sequência de Bases , Replicação do DNA , Dados de Sequência Molecular , Fases de Leitura Aberta/genética , Plasmídeos/isolamento & purificação , Proteínas/genética , Origem de Replicação , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
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