Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
J Endod ; 50(7): 1011-1016, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38642733

RESUMO

INTRODUCTION: The purpose of this study was to evaluate the effect of side flattening of cutting flutes on the cyclic resistance and torsional resistance of nickel-titanium files. METHODS: Both novel flattened Platinum V.EU (PL) and standard nonflattened CC Premium V.EU (CC) rotaries were tested. For cyclic fatigue tests, all the files were rotated in an artificial root canal with a curvature of 45° and a radius of 6.06 mm at 300 rpm (n = 15 in each group). The number of cycles to failure (NCF) was calculated. For torsional tests, the files were rotated at 2 rpm clockwise until fracture occurred. The maximum torque value at fracture was measured and the toughness and distortion angle were computed. Subsequently, 5 fragments were randomly selected in each experiment, the cross-section and longitudinal direction of the fragments were photographed using a scanning electron microscope. An unpaired t-test was performed at a significance level of 95%. RESULTS: There was a statistically significant difference in NCF between CC and PL (P < .05). CC showed higher NCF than PL. There was no statistically significant difference between CC and PL with regards to the parameters related to torsional resistance (distortion angle, ultimate strength, and toughness) (P > .05). CONCLUSION: Within the limitations of this study, side flattening of the file did not improve cyclic resistance or torsional resistance of the files. As side flattening may reduce a file's cyclic resistance, such files should be used with caution in clinical practice.


Assuntos
Falha de Equipamento , Níquel , Preparo de Canal Radicular , Titânio , Torção Mecânica , Preparo de Canal Radicular/instrumentação , Teste de Materiais , Desenho de Equipamento , Torque , Microscopia Eletrônica de Varredura , Instrumentos Odontológicos , Ligas Dentárias/química
2.
N Engl J Med ; 389(19): 1741-1752, 2023 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-37937776

RESUMO

BACKGROUND: In 2021, the American College of Medical Genetics and Genomics (ACMG) recommended reporting actionable genotypes in 73 genes associated with diseases for which preventive or therapeutic measures are available. Evaluations of the association of actionable genotypes in these genes with life span are currently lacking. METHODS: We assessed the prevalence of coding and splice variants in genes on the ACMG Secondary Findings, version 3.0 (ACMG SF v3.0), list in the genomes of 57,933 Icelanders. We assigned pathogenicity to all reviewed variants using reported evidence in the ClinVar database, the frequency of variants, and their associations with disease to create a manually curated set of actionable genotypes (variants). We assessed the relationship between these genotypes and life span and further examined the specific causes of death among carriers. RESULTS: Through manual curation of 4405 sequence variants in the ACMG SF v3.0 genes, we identified 235 actionable genotypes in 53 genes. Of the 57,933 participants, 2306 (4.0%) carried at least one actionable genotype. We found shorter median survival among persons carrying actionable genotypes than among noncarriers. Specifically, we found that carrying an actionable genotype in a cancer gene was associated with survival that was 3 years shorter than that among noncarriers, with causes of death among carriers attributed primarily to cancer-related conditions. Furthermore, we found evidence of association between carrying an actionable genotype in certain genes in the cardiovascular disease group and a reduced life span. CONCLUSIONS: On the basis of the ACMG SF v3.0 guidelines, we found that approximately 1 in 25 Icelanders carried an actionable genotype and that carrying such a genotype was associated with a reduced life span. (Funded by deCODE Genetics-Amgen.).


Assuntos
Doença , Genômica , Longevidade , Humanos , Alelos , Testes Genéticos , Variação Genética , Genótipo , Islândia/epidemiologia , Longevidade/genética , Doença/genética , Doenças Cardiovasculares/genética , Neoplasias/genética
3.
Arterioscler Thromb Vasc Biol ; 41(10): 2616-2628, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34407635

RESUMO

Objective: Familial hypercholesterolemia (FH) is traditionally defined as a monogenic disease characterized by severely elevated LDL-C (low-density lipoprotein cholesterol) levels. In practice, FH is commonly a clinical diagnosis without confirmation of a causative mutation. In this study, we sought to characterize and compare monogenic and clinically defined FH in a large sample of Icelanders. Approach and Results: We whole-genome sequenced 49 962 Icelanders and imputed the identified variants into an overall sample of 166 281 chip-genotyped Icelanders. We identified 20 FH mutations in LDLR, APOB, and PCSK9 with combined prevalence of 1 in 836. Monogenic FH was associated with severely elevated LDL-C levels and increased risk of premature coronary disease, aortic valve stenosis, and high burden of coronary atherosclerosis. We used a modified version of the Dutch Lipid Clinic Network criteria to screen for the clinical FH phenotype among living adult participants (N=79 058). Clinical FH was found in 2.2% of participants, of whom only 5.2% had monogenic FH. Mutation-negative clinical FH has a strong polygenic basis. Both individuals with monogenic FH and individuals with mutation-negative clinical FH were markedly undertreated with cholesterol-lowering medications and only a minority attained an LDL-C target of <2.6 mmol/L (<100 mg/dL; 11.0% and 24.9%, respectively) or <1.8 mmol/L (<70 mg/dL; 0.0% and 5.2%, respectively), as recommended for primary prevention by European Society of Cardiology/European Atherosclerosis Society cholesterol guidelines. Conclusions: Clinically defined FH is a relatively common phenotype that is explained by monogenic FH in only a minority of cases. Both monogenic and clinical FH confer high cardiovascular risk but are markedly undertreated.


Assuntos
Apolipoproteína B-100/genética , Doenças Cardiovasculares/genética , Hiperlipoproteinemia Tipo II/genética , Lipídeos/sangue , Mutação , Pró-Proteína Convertase 9/genética , Receptores de LDL/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/etnologia , Doenças Cardiovasculares/terapia , Feminino , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Inibidores de Hidroximetilglutaril-CoA Redutases/uso terapêutico , Hiperlipoproteinemia Tipo II/diagnóstico , Hiperlipoproteinemia Tipo II/tratamento farmacológico , Hiperlipoproteinemia Tipo II/etnologia , Islândia/epidemiologia , Masculino , Pessoa de Meia-Idade , Fenótipo , Prevalência , Prognóstico , Medição de Risco , Fatores de Risco , Adulto Jovem
4.
Cancer Res ; 81(8): 1954-1964, 2021 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-33602785

RESUMO

The success of genome-wide association studies (GWAS) in identifying common, low-penetrance variant-cancer associations for the past decade is undisputed. However, discovering additional high-penetrance cancer mutations in unknown cancer predisposing genes requires detection of variant-cancer association of ultra-rare coding variants. Consequently, large-scale next-generation sequence data with associated phenotype information are needed. Here, we used genotype data on 166,281 Icelanders, of which, 49,708 were whole-genome sequenced and 408,595 individuals from the UK Biobank, of which, 41,147 were whole-exome sequenced, to test for association between loss-of-function burden in autosomal genes and basal cell carcinoma (BCC), the most common cancer in Caucasians. A total of 25,205 BCC cases and 683,058 controls were tested. Rare germline loss-of-function variants in PTPN14 conferred substantial risks of BCC (OR, 8.0; P = 1.9 × 10-12), with a quarter of carriers getting BCC before age 70 and over half in their lifetime. Furthermore, common variants at the PTPN14 locus were associated with BCC, suggesting PTPN14 as a new, high-impact BCC predisposition gene. A follow-up investigation of 24 cancers and three benign tumor types showed that PTPN14 loss-of-function variants are associated with high risk of cervical cancer (OR, 12.7, P = 1.6 × 10-4) and low age at diagnosis. Our findings, using power-increasing methods with high-quality rare variant genotypes, highlight future prospects for new discoveries on carcinogenesis. SIGNIFICANCE: This study identifies the tumor-suppressor gene PTPN14 as a high-impact BCC predisposition gene and indicates that inactivation of PTPN14 by germline sequence variants may also lead to increased risk of cervical cancer.


Assuntos
Carcinoma Basocelular/genética , Mutação com Perda de Função , Penetrância , Proteínas Tirosina Fosfatases não Receptoras/genética , Neoplasias Cutâneas/genética , Neoplasias do Colo do Útero/genética , Fatores Etários , Carcinoma Basocelular/epidemiologia , Estudos de Casos e Controles , Feminino , Frequência do Gene , Genes Supressores de Tumor , Predisposição Genética para Doença , Testes Genéticos , Estudo de Associação Genômica Ampla , Genótipo , Mutação em Linhagem Germinativa , Humanos , Islândia/epidemiologia , Masculino , Razão de Chances , Neoplasias Cutâneas/epidemiologia , Bancos de Tecidos/estatística & dados numéricos , Reino Unido/epidemiologia , Neoplasias do Colo do Útero/epidemiologia , Sequenciamento do Exoma/estatística & dados numéricos , Sequenciamento Completo do Genoma/estatística & dados numéricos
5.
Circ Genom Precis Med ; 14(1): e003029, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33315477

RESUMO

BACKGROUND: Loss-of-function mutations in the LDL (low-density lipoprotein) receptor gene (LDLR) cause elevated levels of LDL cholesterol and premature cardiovascular disease. To date, a gain-of-function mutation in LDLR with a large effect on LDL cholesterol levels has not been described. Here, we searched for sequence variants in LDLR that have a large effect on LDL cholesterol levels. METHODS: We analyzed whole-genome sequencing data from 43 202 Icelanders. Single-nucleotide polymorphisms and structural variants including deletions, insertions, and duplications were genotyped using whole-genome sequencing-based data. LDL cholesterol associations were carried out in a sample of >100 000 Icelanders with genetic information (imputed or whole-genome sequencing). Molecular analyses were performed using RNA sequencing and protein expression assays in Epstein-Barr virus-transformed lymphocytes. RESULTS: We discovered a 2.5-kb deletion (del2.5) overlapping the 3' untranslated region of LDLR in 7 heterozygous carriers from a single family. Mean level of LDL cholesterol was 74% lower in del2.5 carriers than in 101 851 noncarriers, a difference of 2.48 mmol/L (96 mg/dL; P=8.4×10-8). Del2.5 results in production of an alternative mRNA isoform with a truncated 3' untranslated region. The truncation leads to a loss of target sites for microRNAs known to repress translation of LDLR. In Epstein-Barr virus-transformed lymphocytes derived from del2.5 carriers, expression of alternative mRNA isoform was 1.84-fold higher than the wild-type isoform (P=0.0013), and there was 1.79-fold higher surface expression of the LDL receptor than in noncarriers (P=0.0086). We did not find a highly penetrant detrimental impact of lifelong very low levels of LDL cholesterol due to del2.5 on health of the carriers. CONCLUSIONS: Del2.5 is the first reported gain-of-function mutation in LDLR causing a large reduction in LDL cholesterol. These data point to a role for alternative polyadenylation of LDLR mRNA as a potent regulator of LDL receptor expression in humans.


Assuntos
LDL-Colesterol/sangue , Receptores de LDL/genética , Regiões 3' não Traduzidas , Processamento Alternativo , Mutação com Ganho de Função , Deleção de Genes , Vetores Genéticos/genética , Vetores Genéticos/metabolismo , Herpesvirus Humano 4/genética , Heterozigoto , Humanos , Hiperlipoproteinemia Tipo II/genética , Hiperlipoproteinemia Tipo II/patologia , Islândia , Linfócitos/citologia , Linfócitos/metabolismo , MicroRNAs/metabolismo , Linhagem , Isoformas de Proteínas/genética , RNA Mensageiro/metabolismo
6.
Nature ; 584(7822): 619-623, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32581359

RESUMO

Autoimmune thyroid disease is the most common autoimmune disease and is highly heritable1. Here, by using a genome-wide association study of 30,234 cases and 725,172 controls from Iceland and the UK Biobank, we find 99 sequence variants at 93 loci, of which 84 variants are previously unreported2-7. A low-frequency (1.36%) intronic variant in FLT3 (rs76428106-C) has the largest effect on risk of autoimmune thyroid disease (odds ratio (OR) = 1.46, P = 2.37 × 10-24). rs76428106-C is also associated with systemic lupus erythematosus (OR = 1.90, P = 6.46 × 10-4), rheumatoid factor and/or anti-CCP-positive rheumatoid arthritis (OR = 1.41, P = 4.31 × 10-4) and coeliac disease (OR = 1.62, P = 1.20 × 10-4). FLT3 encodes fms-related tyrosine kinase 3, a receptor that regulates haematopoietic progenitor and dendritic cells. RNA sequencing revealed that rs76428106-C generates a cryptic splice site, which introduces a stop codon in 30% of transcripts that are predicted to encode a truncated protein, which lacks its tyrosine kinase domains. Each copy of rs76428106-C doubles the plasma levels of the FTL3 ligand. Activating somatic mutations in FLT3 are associated with acute myeloid leukaemia8 with a poor prognosis and rs76428106-C also predisposes individuals to acute myeloid leukaemia (OR = 1.90, P = 5.40 × 10-3). Thus, a predicted loss-of-function germline mutation in FLT3 causes a reduction in full-length FLT3, with a compensatory increase in the levels of its ligand and an increased disease risk, similar to that of a gain-of-function mutation.


Assuntos
Códon sem Sentido/genética , Predisposição Genética para Doença/genética , Ligantes , Mutação , Tireoidite Autoimune/genética , Tirosina Quinase 3 Semelhante a fms/genética , Tirosina Quinase 3 Semelhante a fms/metabolismo , Alelos , Doenças Autoimunes/genética , Bases de Dados Factuais , Estudo de Associação Genômica Ampla , Mutação em Linhagem Germinativa , Humanos , Islândia , Íntrons/genética , Leucemia Mieloide Aguda , Mutação com Perda de Função , Sítios de Splice de RNA/genética , Reino Unido
7.
N Engl J Med ; 382(24): 2302-2315, 2020 06 11.
Artigo em Inglês | MEDLINE | ID: mdl-32289214

RESUMO

BACKGROUND: During the current worldwide pandemic, coronavirus disease 2019 (Covid-19) was first diagnosed in Iceland at the end of February. However, data are limited on how SARS-CoV-2, the virus that causes Covid-19, enters and spreads in a population. METHODS: We targeted testing to persons living in Iceland who were at high risk for infection (mainly those who were symptomatic, had recently traveled to high-risk countries, or had contact with infected persons). We also carried out population screening using two strategies: issuing an open invitation to 10,797 persons and sending random invitations to 2283 persons. We sequenced SARS-CoV-2 from 643 samples. RESULTS: As of April 4, a total of 1221 of 9199 persons (13.3%) who were recruited for targeted testing had positive results for infection with SARS-CoV-2. Of those tested in the general population, 87 (0.8%) in the open-invitation screening and 13 (0.6%) in the random-population screening tested positive for the virus. In total, 6% of the population was screened. Most persons in the targeted-testing group who received positive tests early in the study had recently traveled internationally, in contrast to those who tested positive later in the study. Children under 10 years of age were less likely to receive a positive result than were persons 10 years of age or older, with percentages of 6.7% and 13.7%, respectively, for targeted testing; in the population screening, no child under 10 years of age had a positive result, as compared with 0.8% of those 10 years of age or older. Fewer females than males received positive results both in targeted testing (11.0% vs. 16.7%) and in population screening (0.6% vs. 0.9%). The haplotypes of the sequenced SARS-CoV-2 viruses were diverse and changed over time. The percentage of infected participants that was determined through population screening remained stable for the 20-day duration of screening. CONCLUSIONS: In a population-based study in Iceland, children under 10 years of age and females had a lower incidence of SARS-CoV-2 infection than adolescents or adults and males. The proportion of infected persons identified through population screening did not change substantially during the screening period, which was consistent with a beneficial effect of containment efforts. (Funded by deCODE Genetics-Amgen.).


Assuntos
Infecções por Coronavirus/epidemiologia , Monitoramento Epidemiológico , Pneumonia Viral/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Betacoronavirus/genética , COVID-19 , Criança , Pré-Escolar , Busca de Comunicante , Feminino , Haplótipos , Humanos , Islândia/epidemiologia , Lactente , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Pandemias , SARS-CoV-2 , Viagem , Adulto Jovem
8.
Commun Biol ; 3(1): 129, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32184442

RESUMO

Pelvic organ prolapse (POP) is a downward descent of one or more of the pelvic organs, resulting in a protrusion of the vaginal wall and/or uterus. We performed a genome-wide association study of POP using data from Iceland and the UK Biobank, a total of 15,010 cases with hospital-based diagnosis code and 340,734 female controls, and found eight sequence variants at seven loci associating with POP (P < 5 × 10-8); seven common (minor allele frequency >5%) and one with minor allele frequency of 4.87%. Some of the variants associating with POP also associated with traits of similar pathophysiology. Of these, rs3820282, which may alter the estrogen-based regulation of WNT4, also associates with leiomyoma of uterus, gestational duration and endometriosis. Rs3791675 at EFEMP1, a gene involved in connective tissue homeostasis, also associates with hernias and carpal tunnel syndrome. Our results highlight the role of connective tissue metabolism and estrogen exposure in the etiology of POP.


Assuntos
Proteínas da Matriz Extracelular/genética , Loci Gênicos , Polimorfismo de Nucleotídeo Único , Prolapso Uterino/genética , Proteína Wnt4/genética , Índice de Massa Corporal , Estudos de Casos e Controles , Comorbidade , Feminino , Frequência do Gene , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Humanos , Islândia/epidemiologia , Fenótipo , Medição de Risco , Fatores de Risco , Reino Unido/epidemiologia , Prolapso Uterino/diagnóstico , Prolapso Uterino/epidemiologia
9.
Materials (Basel) ; 12(3)2019 Feb 05.
Artigo em Inglês | MEDLINE | ID: mdl-30764565

RESUMO

This study compared the torque generation during canal shaping with a nickel-titanium endodontic instrument according to the extent of glide-path establishment. Seventy-five simulated S-shaped canal blocks were divided into five groups (n = 15) according to the number of repetitive insertions to the working length using a One G glide-path instrument: groups with 5, 10, 15, and 20 insertions as well as group Z without glide-path establishment. When the tip of the One G file reached the working length, the file was moved back and forth repetitively at the working length for the designated number of times for each group. The instrumentation procedure with HyFlex EDM had 15 pecking strokes. During instrumentation, the generated torque was transmitted to a customized data acquisition module and collected using customized software. Data were computed to determine the maximum torque and total stress. The maximum screw-in forces were statistically analyzed using one-way analysis of variance and Tukey's post hoc comparison test with a significance level of 95%. While the maximum stress did not have significant differences among the five groups (p > 0.05), groups with more than 10 repetitive insertions generated lower total stress during instrumentation than did the group with 5 insertions and group Z (p < 0.05). Under the limitations of this study, repetitive insertions of glide-path establishment files at the working length reduced stress generation during the shaping using nickel-titanium instruments.

10.
Nat Commun ; 9(1): 4447, 2018 10 25.
Artigo em Inglês | MEDLINE | ID: mdl-30361506

RESUMO

Mutations in genes encoding subunits of the phagocyte NADPH oxidase complex are recognized to cause chronic granulomatous disease (CGD), a severe primary immunodeficiency. Here we describe how deficiency of CYBC1, a previously uncharacterized protein in humans (C17orf62), leads to reduced expression of NADPH oxidase's main subunit (gp91phox) and results in CGD. Analyzing two brothers diagnosed with CGD we identify a homozygous loss-of-function mutation, p.Tyr2Ter, in CYBC1. Imputation of p.Tyr2Ter into 155K chip-genotyped Icelanders reveals six additional homozygotes, all with signs of CGD, manifesting as colitis, rare infections, or a severely impaired PMA-induced neutrophil oxidative burst. Homozygosity for p.Tyr2Ter consequently associates with inflammatory bowel disease (IBD) in Iceland (P = 8.3 × 10-8; OR = 67.6), as well as reduced height (P = 3.3 × 10-4; -8.5 cm). Overall, we find that CYBC1 deficiency results in CGD characterized by colitis and a distinct profile of infections indicative of macrophage dysfunction.


Assuntos
Doença Granulomatosa Crônica/genética , Mutação com Perda de Função/genética , Criança , Colite/genética , Colite/patologia , Citocromos b/metabolismo , Feminino , Homozigoto , Humanos , Masculino , Linhagem , Explosão Respiratória
11.
J Cell Mol Med ; 22(12): 6068-6076, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30324682

RESUMO

Two familial forms of colorectal cancer (CRC), Lynch syndrome (LS) and familial adenomatous polyposis (FAP), are caused by rare mutations in DNA mismatch repair genes (MLH1, MSH2, MSH6, PMS2) and the genes APC and MUTYH, respectively. No information is available on the presence of high-risk CRC mutations in the Romanian population. We performed whole-genome sequencing of 61 Romanian CRC cases with a family history of cancer and/or early onset of disease, focusing the analysis on candidate variants in the LS and FAP genes. The frequencies of all candidate variants were assessed in a cohort of 688 CRC cases and 4567 controls. Immunohistochemical (IHC) staining for MLH1, MSH2, MSH6, and PMS2 was performed on tumour tissue. We identified 11 candidate variants in 11 cases; six variants in MLH1, one in MSH6, one in PMS2, and three in APC. Combining information on the predicted impact of the variants on the proteins, IHC results and previous reports, we found three novel pathogenic variants (MLH1:p.Lys84ThrfsTer4, MLH1:p.Ala586CysfsTer7, PMS2:p.Arg211ThrfsTer38), and two novel variants that are unlikely to be pathogenic. Also, we confirmed three previously published pathogenic LS variants and suggest to reclassify a previously reported variant of uncertain significance to pathogenic (MLH1:c.1559-1G>C).


Assuntos
Polipose Adenomatosa do Colo/genética , Neoplasias Colorretais Hereditárias sem Polipose/genética , Reparo de Erro de Pareamento de DNA/genética , Predisposição Genética para Doença , Polipose Adenomatosa do Colo/epidemiologia , Polipose Adenomatosa do Colo/patologia , Adulto , Idoso , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Neoplasias Colorretais Hereditárias sem Polipose/patologia , DNA Glicosilases/genética , Metilação de DNA/genética , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Proteína 1 Homóloga a MutL/genética , Proteína 2 Homóloga a MutS/genética , Mutação , Fatores de Risco , Romênia/epidemiologia
12.
J Natl Cancer Inst ; 110(9): 967-974, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29767749

RESUMO

Background: Most pathogenic mutations in the BRCA2 gene carry a high risk of hereditary breast and ovarian cancer (HBOC). However, a stop-gain mutation, K3326* (rs11571833), confers risk of lung cancer and cancers of the upper-aero-digestive tract but only a modest risk of breast or ovarian cancer. The Icelandic population provides an opportunity for comprehensive characterization of the cancer risk profiles of K3326* and HBOC mutations because a single mutation, BRCA2 999del5, is responsible for almost all BRCA2-related HBOC in the population. Methods: Genotype information on 43 641 cancer patients and 370 971 control subjects from Iceland, the Netherlands, and the United States was used to assess the cancer risk profiles of K3326* and BRCA2 999del5. BRCA2 expression was assessed using RNAseq data from blood (n = 2233), as well as 52 tissues reported in the GTEx database. Results: The cancer risks associated with K3326* are fundamentally different from those associated with 999del5. We report for the first time an association between K3326* and small cell lung cancer (odds ratio [OR] = 2.06, 95% confidence interval [CI] = 1.35 to 3.16) and squamous cell carcinoma of the skin (OR = 1.69, 95% CI = 1.26 to 2.26). Individuals homozygous for K3326* reach old age and have children. Unlike BRCA2 999del5, the K3326* allele does not affect the level of BRCA2 transcripts, and the allele is expressed to the same extent as the wild-type allele. Conclusions: K3326* associates primarily with cancers that have strong environmental genotoxic risk factors. Expression of the K3326* allele suggests that a variant protein may be made that retains the DNA repair capabilities important to hormone-responsive tissues but may be less efficient in responding to genotoxic stress.


Assuntos
Carcinoma de Células Escamosas/genética , Genes BRCA2 , Predisposição Genética para Doença , Neoplasias Pulmonares/genética , Neoplasias Cutâneas/genética , Carcinoma de Pequenas Células do Pulmão/genética , Alelos , Genótipo , Humanos , Islândia/epidemiologia , Mutação , Países Baixos/epidemiologia , Razão de Chances , Polimorfismo de Nucleotídeo Único , Estados Unidos/epidemiologia
13.
J Endod ; 43(10): 1688-1691, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28720286

RESUMO

INTRODUCTION: The aim of this study was to evaluate the effect of different pecking depth on the stress generated by the screw-in forces of a rotating endodontic file in simulated canals. METHODS: Twenty simulated resin blocks with a J-shaped curvature were used. Twenty OneG files (MicroMega, Besançon, France) were assigned for a screw-in test depending on the pecking depth in 2 groups (n = 10). The files were operated at 300 rpm, and the up and down speed was controlled at 1 mm/s stroke velocity and a 10-millisecond dwell time using a customized device. The distances (pecking depth) for the pecking motion were 2 mm or 4 mm for each group; "6 mm forward and 4 mm backward" and "6 mm forward and 2 mm backward" movements were applied, respectively, for the 2 pecking groups. During the operation, the positive and negative apical loads were recorded at a rate of 50 Hz using customized software attached to the device. The maximum negative apical load (screw-in force [SF]) was recorded, and the total energy during pecking motion until the file reached the working length (cumulative screw-in forces [CSFs]) was computed. The data were analyzed using an independent t test at a significance level of 95%. RESULTS: No significant difference in SF was found between the 2 groups of pecking depths. However, the longer pecking depth (4-mm group) showed a significantly larger CSF compared with the shorter pecking depth group (P < .05). CONCLUSIONS: The shorter pecking depth may generate lower overall stresses for the root dentin as well as the instrument.


Assuntos
Instrumentos Odontológicos , Dentina/lesões , Análise de Falha de Equipamento , Preparo de Canal Radicular/instrumentação , Estresse Mecânico , Cavidade Pulpar/cirurgia , Desenho de Equipamento , Falha de Equipamento , Níquel , Distribuição Aleatória , Preparo de Canal Radicular/métodos , Titânio , Torção Mecânica
14.
Nat Genet ; 49(8): 1182-1191, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28628107

RESUMO

Immunoglobulins are the effector molecules of the adaptive humoral immune system. In a genome-wide association study of 19,219 individuals, we found 38 new variants and replicated 5 known variants associating with IgA, IgG or IgM levels or with composite immunoglobulin traits, accounted for by 32 loci. Variants at these loci also affect the risk of autoimmune diseases and blood malignancies and influence blood cell development. Notable associations include a rare variant at RUNX3 decreasing IgA levels by shifting isoform proportions (rs188468174[C>T]: P = 8.3 × 10-55, ß = -0.90 s.d.), a rare in-frame deletion in FCGR2B abolishing IgG binding to the encoded receptor (p.Asn106del: P = 4.2 × 10-8, ß = 1.03 s.d.), four IGH locus variants influencing class switching, and ten new associations with the HLA region. Our results provide new insight into the regulation of humoral immunity.


Assuntos
Variação Genética , Imunoglobulinas/genética , Estudos de Coortes , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Hematopoese/genética , Humanos , Islândia , Imunidade Humoral/genética , Switching de Imunoglobulina/genética , Isotipos de Imunoglobulinas/genética , Masculino , Polimorfismo de Nucleotídeo Único , Suécia
15.
Nat Commun ; 8: 14755, 2017 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-28466842

RESUMO

Lynch syndrome, caused by germline mutations in the mismatch repair genes, is associated with increased cancer risk. Here using a large whole-genome sequencing data bank, cancer registry and colorectal tumour bank we determine the prevalence of Lynch syndrome, associated cancer risks and pathogenicity of several variants in the Icelandic population. We use colorectal cancer samples from 1,182 patients diagnosed between 2000-2009. One-hundred and thirty-two (11.2%) tumours are mismatch repair deficient per immunohistochemistry. Twenty-one (1.8%) have Lynch syndrome while 106 (9.0%) have somatic hypermethylation or mutations in the mismatch repair genes. The population prevalence of Lynch syndrome is 0.442%. We discover a translocation disrupting MLH1 and three mutations in MSH6 and PMS2 that increase endometrial, colorectal, brain and ovarian cancer risk. We find thirteen mismatch repair variants of uncertain significance that are not associated with cancer risk. We find that founder mutations in MSH6 and PMS2 prevail in Iceland unlike most other populations.


Assuntos
Neoplasias Colorretais Hereditárias sem Polipose/genética , Proteínas de Ligação a DNA/genética , Efeito Fundador , Mutação em Linhagem Germinativa , Endonuclease PMS2 de Reparo de Erro de Pareamento/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Pareamento Incorreto de Bases , Neoplasias Colorretais Hereditárias sem Polipose/epidemiologia , Feminino , Predisposição Genética para Doença , Humanos , Islândia/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência
16.
Blood ; 130(6): 742-752, 2017 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-28483762

RESUMO

Clonal hematopoiesis (CH) arises when a substantial proportion of mature blood cells is derived from a single dominant hematopoietic stem cell lineage. Somatic mutations in candidate driver (CD) genes are thought to be responsible for at least some cases of CH. Using whole-genome sequencing of 11 262 Icelanders, we found 1403 cases of CH by using barcodes of mosaic somatic mutations in peripheral blood, whether or not they have a mutation in a CD gene. We find that CH is very common in the elderly, trending toward inevitability. We show that somatic mutations in TET2, DNMT3A, ASXL1, and PPM1D are associated with CH at high significance. However, known CD mutations were evident in only a fraction of CH cases. Nevertheless, the highly prevalent CH we detect associates with increased mortality rates, risk for hematological malignancy, smoking behavior, telomere length, Y-chromosome loss, and other phenotypic characteristics. Modeling suggests some CH cases could arise in the absence of CD mutations as a result of neutral drift acting on a small population of active hematopoietic stem cells. Finally, we find a germline deletion in intron 3 of the telomerase reverse transcriptase (TERT) gene that predisposes to CH (rs34002450; P = 7.4 × 10-12; odds ratio, 1.37).


Assuntos
DNA (Citosina-5-)-Metiltransferases/genética , Proteínas de Ligação a DNA/genética , Hematopoese , Células-Tronco Hematopoéticas/citologia , Mutação , Proteína Fosfatase 2C/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Células Clonais , DNA Metiltransferase 3A , Dioxigenases , Feminino , Neoplasias Hematológicas/epidemiologia , Neoplasias Hematológicas/genética , Células-Tronco Hematopoéticas/metabolismo , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco
17.
J Endod ; 43(3): 443-446, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28104322

RESUMO

INTRODUCTION: The purpose of this study was to evaluate differences in torsional resistance using up-regulated speed of rotational spindle. METHODS: Three NiTi rotary instrument systems were selected in this study: K3XF (SybronEndo, Glendora, CA), BLX (B&L Biotech, Ansan, Korea), and OneShape (MicroMega, Besançon, France). The tip size and taper for all files were #25 and 0.06. Experimental groups (n = 10/group) were assigned to 2-, 60-, 350-, and 600-rpm groups by the rotational speed of spindle. Forty new files were used for each test. The file tip of 5-mm length was secured between brass plates. While keeping the file straight, it was rotated clockwise at a constant rotational speed until fracture occurred. The parameters of torsional resistance, torsional load (Ncm), and distortion angle (°) were measured using an AEndoS-k (DMJ System, Busan, Korea), and the toughness until fracture was computed from these data. The 1-way analysis of variance test was used to analyze the torsional resistance at a significance level of 95%. All fractured fragments were observed under a scanning electron microscope to evaluate the topographic features of the fractured surfaces. RESULTS: No significant difference in torsional resistance was found among groups when they were compared for ultimate strength at the maximum torque, fracture angle, and toughness. Scanning electron microscopic examination of the fractured cross-sectional surfaces revealed typical features of torsional fractures, concentric abrasion marks, and fibrous dimples from the torsional center. CONCLUSIONS: Under the conditions of the study, the torsional resistances of the rotary instruments were not affected by the rotational speed.


Assuntos
Teste de Materiais , Preparo de Canal Radicular/instrumentação , Rotação , Torção Mecânica , Falha de Equipamento , Níquel , Titânio
18.
Nat Commun ; 7: 12350, 2016 07 25.
Artigo em Inglês | MEDLINE | ID: mdl-27453397

RESUMO

We conducted a genome-wide association scan (GWAS) of endometriosis using 25.5 million sequence variants detected through whole-genome sequencing (WGS) of 8,453 Icelanders and imputed into 1,840 cases and 129,016 control women, followed by testing of associated variants in Danish samples. Here we report the discovery of a new endometriosis susceptibility locus on 4q12 (rs17773813[G], OR=1.28; P=3.8 × 10(-11)), upstream of KDR encoding vascular endothelial growth factor receptor 2 (VEGFR2). The variant correlates with disease severity (P=0.0046) when moderate/severe endometriosis cases are tested against minimal/mild cases. We further report association of rs519664[T] in TTC39B on 9p22 with endometriosis (P=4.8 × 10(-10); OR=1.29). The involvement of KDR in endometriosis risk highlights the importance of the VEGF pathway in the pathogenesis of the disease.


Assuntos
Endometriose/genética , Predisposição Genética para Doença , Lipoproteínas HDL/genética , Proteínas de Neoplasias/genética , Polimorfismo de Nucleotídeo Único/genética , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/genética , Cromossomos Humanos Par 17/genética , Feminino , Loci Gênicos , Estudo de Associação Genômica Ampla , Humanos
19.
Hum Mol Genet ; 25(5): 1008-18, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26740556

RESUMO

Transcriptional and splicing anomalies have been observed in intron 8 of the CASP8 gene (encoding procaspase-8) in association with cutaneous basal-cell carcinoma (BCC) and linked to a germline SNP rs700635. Here, we show that the rs700635[C] allele, which is associated with increased risk of BCC and breast cancer, is protective against prostate cancer [odds ratio (OR) = 0.91, P = 1.0 × 10(-6)]. rs700635[C] is also associated with failures to correctly splice out CASP8 intron 8 in breast and prostate tumours and in corresponding normal tissues. Investigation of rs700635[C] carriers revealed that they have a human-specific short interspersed element-variable number of tandem repeat-Alu (SINE-VNTR-Alu), subfamily-E retrotransposon (SVA-E) inserted into CASP8 intron 8. The SVA-E shows evidence of prior activity, because it has transduced some CASP8 sequences during subsequent retrotransposition events. Whole-genome sequence (WGS) data were used to tag the SVA-E with a surrogate SNP rs1035142[T] (r(2) = 0.999), which showed associations with both the splicing anomalies (P = 6.5 × 10(-32)) and with protection against prostate cancer (OR = 0.91, P = 3.8 × 10(-7)).


Assuntos
Neoplasias da Mama/genética , Carcinoma Basocelular/genética , Caspase 8/genética , Neoplasias da Próstata/genética , Splicing de RNA , Retroelementos , Neoplasias Cutâneas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Alelos , Sequência de Bases , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Carcinoma Basocelular/metabolismo , Carcinoma Basocelular/patologia , Caspase 8/metabolismo , Feminino , Estudo de Associação Genômica Ampla , Humanos , Íntrons , Masculino , Pessoa de Meia-Idade , Dados de Sequência Molecular , Razão de Chances , Polimorfismo de Nucleotídeo Único , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Neoplasias da Próstata/prevenção & controle , Fatores de Proteção , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia
20.
N Y State Dent J ; 81(5): 52-6, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26521329

RESUMO

This article demonstrates a methodological approach to diagnosing a periapical radiolucency that could not be diagnosed using only basic clinical and radiographic findings. The patient was a 59-year-old Hispanic female with a small tender mass on the lower gingiva associated with tooth #25. Radiographic appearance demonstrated a well-defined radiolucent lesion at the apices of the mandibular incisors. The patient had no significant medical history. Cone-beam computed tomography (CBCT) showed bony expansion of the buccal plate. Differential diagnosis included non-endodontic unilocular radiolucent lesions in the anterior mandibular region. Biopsy findings were consistent with periapical cemento-osseous dysplasia (PCOD). In conclusion, clinical appearance of PCOD varies from non-expansile and asymptomatic to being expansile and sometimes symptomatic. In the latter cases, it may be necessary to use additional diagnostic tools to confirm the diagnosis.


Assuntos
Cementoma/diagnóstico por imagem , Incisivo/diagnóstico por imagem , Neoplasias Mandibulares/diagnóstico por imagem , Doenças Periapicais/diagnóstico por imagem , Biópsia/métodos , Tomografia Computadorizada de Feixe Cônico/métodos , Diagnóstico Diferencial , Feminino , Humanos , Pessoa de Meia-Idade , Cisto Radicular/diagnóstico por imagem , Ápice Dentário/diagnóstico por imagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA