Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
2.
BMC Oral Health ; 23(1): 896, 2023 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-37986066

RESUMO

BACKGROUND: Most studies assessing the sensitivity and specificity of caries detection methods have been performed in vitro using the histological method as the gold standard showing inconsistent values. The aim of this study was to compare the sensitivity and specificity in detecting occlusal caries using the International Caries Detection and Assessment System (ICDAS II) with the radiographic method (RM), while using the Spectra™ Caries Detection System (SCDS) as the reference test. METHODS: One hundred sixty children, ages 7-12 years, participated in the study. Five zones in the occlusal surfaces of 859 primary and 632 first permanent molars were examined visually using ICDAS-II, the RM using bitewing radiographs and SCDS. The descriptive statistics of sensitivity and specificity were calculated and compared. RESULTS: For all molars combined and for primary molars only, the sensitivity of ICDAS II was higher for detecting total caries (p < 0.001), caries in enamel (p < 0.001), and caries in dentin (p = 0.016), but it was not different for detecting caries in the dentin of permanent first molars (p = 0.214), and primary second molars (p = 0.761). The specificity of RM was higher for detecting total caries, caries in enamel for all molars combined and for permanent first molars (p < 0.001). For caries in dentin, the specificity of ICDAS II was higher for all molars combined and for primary molars only (p < 0.001). For total caries in primary molars only, and caries in dentin of permanent first molars only, the specificity was not different (p = 0.156 and p = 0.181 respectively). CONCLUSIONS: The sensitivity and specificity of ICDAS II and RM changes depending on whether the carious lesion compromises the enamel or dentin, and if the caries detection is performed in the primary molars or permanent first molars.


Assuntos
Suscetibilidade à Cárie Dentária , Cárie Dentária , Criança , Humanos , Sensibilidade e Especificidade , Cárie Dentária/diagnóstico por imagem , Cárie Dentária/patologia , Esmalte Dentário/patologia , Dente Molar/diagnóstico por imagem , Dente Molar/patologia , Reprodutibilidade dos Testes , Dentina/diagnóstico por imagem
3.
J Dent Educ ; 87(12): 1746-1753, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37712337

RESUMO

PURPOSE: Gaining knowledge on the extent of digital technology implementation in dental education and the barriers to it will help inform future directions to promote the use of such technology and will enhance dental education. This study aimed to investigate the utilization of digitally fabricated removable prostheses and the potential obstacles to implementing such technology in US dental schools. METHODS: A survey was developed and distributed to the restorative dentistry department chairs and postdoctoral prosthodontic program directors. The survey delivery protocol included follow-up emails 1 week, 3 weeks, and 4 weeks after the initial email. The collected data were analyzed descriptively. RESULTS: The response rate was 85% and 45% for predoctoral and postdoctoral prosthodontic programs, respectively. The results showed that 88.06% of the predoctoral programs and 95.65% of the postdoctoral prosthodontic programs implement digital complete dentures in the curriculum; however, the digital removable partial dentures implementation rate was recorded at 70.77% in predoctoral programs and 61.9% in postdoctoral prosthodontic programs. CONCLUSIONS: Dental schools are challenged by cost, design software limitations, IT and laboratory support, and faculty training. Multifaceted support is instrumental in further implementing digital removable prosthodontics into dental education.


Assuntos
Implantes Dentários , Prostodontia/educação , Inquéritos e Questionários , Currículo , Educação em Odontologia
4.
J World Fed Orthod ; 12(3): 93-104, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37198009

RESUMO

BACKGROUND: This study investigates characteristics of temporary anchorage devices (TADs) use by surveying a sample of international orthodontists. Furthermore, the survey investigates the stability, insertion technique, and failure rate of TADs and professionals' experience in residency, and it also attempts to establish guidelines for its use in everyday practice. METHODS: A 19-question survey was sent to orthodontists worldwide asking opinion-based, case-specific, and placement technique questions regarding TADs. Results were collected from 251 survey respondents. The country/regions of practice and length of time practicing orthodontics were the independent variables. RESULTS: Survey respondents indicated that most orthodontists rarely or sporadically use TADs. Significant differences were also found for TAD utilization purposes, sizes, and placement techniques among different countries/regions and for failure rates (1 or more of the last 6 TADs placed failed-61.6%). A significant difference was found in how many TADs orthodontists placed in residency versus private practice (56% vs. 15%) in relation to how long they have been practicing, but it did not greatly affect the frequency of use, mechanics, or placement technique. CONCLUSIONS: The frequency of TAD use is similar in many different countries and among different age groups. Although the collected responses suggested significant differences among respondents from different countries, the variability of results for TAD use worldwide prevent the establishment of clear guidelines.


Assuntos
Procedimentos de Ancoragem Ortodôntica , Ortodontia , Humanos , Ortodontistas , Inquéritos e Questionários , Prática Privada
5.
J Dent Educ ; 87(5): 669-675, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36646656

RESUMO

PURPOSE/OBJECTIVES: This study investigates the relationship between first-year grades and cumulative grades at the end of dental school to explore trends in academic performance in the predoctoral dental curriculum. The objective of this research is to provide information to inform student support efforts for predoctoral dental programs. METHODS: Academic records for 156 students who completed their first year (D1) of predoctoral dental education in 2015/2016 were reviewed. The analysis reviews outcomes at the end of D1 and the end of the 4-year curriculum. The outcomes of this study are grade point average (GPA) at the end of the 4-year traditional dental school curriculum, grouped as basic science, preclinical, preclinical laboratory, translational, and clinical. Regression analyses were performed for each outcome. A GPA change of 0.5 was employed to demonstrate change, as it represented half a letter grade. RESULT: The analysis found first-year grades to be related to 4-year academic outcomes. For example, a 0.5-grade point score increase in the first-year basic science GPA was associated with a 0.503 increase in basic science GPA. However, a 0.5-grade point increase in first-year annual GPA was associated with a 0.084 increase in the clinical science GPA. First-year annual GPA was the only significant predictor variable for overall 4-year GPA; a 0.5-grade point increase in the first-year annual GPA was associated with a 0.386 increase in overall GPA. CONCLUSION: The results of this study suggest that academic and personal support in the first year of dental school is paramount in supporting student success in predoctoral dental education.


Assuntos
Desempenho Acadêmico , Avaliação Educacional , Humanos , Critérios de Admissão Escolar , Estudantes de Odontologia , Análise de Regressão
6.
Front Microbiol ; 13: 960882, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36187979

RESUMO

Aflatoxin B1 (AFB1) contaminates rice during harvest or storage and causes a considerable risk to human and animal health. In this study, Trametes versicolor AFB1-degrading enzyme (TV-AFB1D) gene recombinantly expressed in engineered E. coli BL21 (DE3) and Saccharomyces cerevisiae. The TV-AFB1D enzymatic characteristics and AFB1 degradation efficiency in contaminated rice were investigated. Results showed that the size of recombinant TV-AFB1D expressing in E. coli BL21 (DE3) and S. cerevisiae was appropriately 77 KDa. The kinetic equation of TV-AFB1D was y = 0.01671x + 1.80756 (R 2 = 0.994, Km = 9.24 mM, and Vmax = 553.23 mM/min). The Kcat and Kcat/Km values of TV-AFB1D were 0.07392 (s-1) and 8 M-1 s-1, respectively. The AFB1 concentration of contaminated rice decreased from 100 µg/ml to 32.6 µg/ml after treatment at 32°C for 5 h under the catabolism of TV-AFB1D. S. cerevisiae engineered strains carrying aldehyde oxidase 1 (AOX1) and Cauliflower mosaic virus 35 S (CaMV 35 S) promoters caused the residual AFB1 contents, respectively, decreased to 3.4 and 2.9 µg/g from the initial AFB1 content of 7.4 µg/g after 24 h of fermentation using AFB1-contaminated rice as substrate. The AFB1 degradation rates of S. cerevisiae engineered strains carrying AOX1 and CaMV promoters were 54 and 61%, respectively. Engineered S. cerevisiae strains integrated with TV-AFB1D expression cassettes were developed to simultaneously degrade AFB1 and produce ethanol using AFB1-contaminated rice as substrate. Thus, TV-AFB1D has significant application potential in the AFB1 decomposition from contaminated agricultural products.

7.
Am J Orthod Dentofacial Orthop ; 162(6): 824-838, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36055883

RESUMO

INTRODUCTION: The objectives of this study were to identify differences between generations of orthodontists in the United States and to evaluate the perspective of each generation on widely debated topics in orthodontics. METHODS: A 22-item Institutional Review Board-approved survey was randomly distributed to orthodontists in the United States and Canada. Participants were asked questions about the use of technology, the future of clear aligner therapy, orthodontic education, student debt, marketing, and corporate orthodontics, among other topics. RESULTS: Significant increase in female orthodontists over generations and a decrease in orthodontic educators were found (P <0.001). Among generations, differences were found regarding the amount of student debt, use of specific diagnostic tools, marketing preferences, and their opinion on the future of clear aligner therapy. Most of the silent generation did not have student debt, whereas millennials reported paying off their debt in 1 year to >20 years and being most heavily burdened by student debt. Younger generations appeared more likely to use cone-beam computed tomography and intraoral imaging, whereas older generations preferred traditional diagnostic tools such as hand-wrist radiographs and alginate impressions. Most of the silent generation indicated not marketing their practices, whereas millennials rely heavily on social media and e-mails for marketing. CONCLUSIONS: Clear distinctions exist between different generations of orthodontists. Issues such as increasing student debt load and a decrease in orthodontic educators over generations should be addressed to preserve the future of the orthodontic specialty.


Assuntos
Ortodontia , Ortodontistas , Feminino , Humanos , Estados Unidos , Ortodontia/educação , Inquéritos e Questionários , Assistência Odontológica , Tomografia Computadorizada de Feixe Cônico
8.
Microb Cell Fact ; 21(1): 160, 2022 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-35964044

RESUMO

BACKGROUND: Saccharomyces cerevisiae generally consumes glucose to produce ethanol accompanied by the main by-products of glycerol, acetic acid, and lactic acid. The minimization of the formation of by-products in S. cerevisiae was an effective way to improve the economic viability of the bioethanol industry. In this study, S. cerevisiae GPD2, FPS1, ADH2, and DLD3 genes were knocked out by the Clustered Regularly Interspaced Short Palindromic Repeats Cas9 (CRISPR-Cas9) approach. The mechanism of gene deletion affecting ethanol metabolism was further elucidated based on metabolic flux and transcriptomics approaches. RESULTS: The engineered S. cerevisiae with gene deletion of GPD2, FPS1, ADH2, and DLD3 was constructed by the CRISPR-Cas9 approach. The ethanol content of engineered S. cerevisiae GPD2 Delta FPS1 Delta ADH2 Delta DLD3 Delta increased by 18.58% with the decrease of glycerol, acetic acid, and lactic acid contents by 22.32, 8.87, and 16.82%, respectively. The metabolic flux analysis indicated that the carbon flux rethanol in engineered strain increased from 60.969 to 63.379. The sequencing-based RNA-Seq transcriptomics represented 472 differential expression genes (DEGs) were identified in engineered S. cerevisiae, in which 195 and 277 genes were significantly up-regulated and down-regulated, respectively. The enriched pathways of up-regulated genes were mainly involved in the energy metabolism of carbohydrates, while the down-regulated genes were mainly enriched in acid metabolic pathways. CONCLUSIONS: The yield of ethanol in engineered S. cerevisiae increased with the decrease of the by-products including glycerol, acetic acid, and lactic acid. The deletion of genes GPD2, FPS1, ADH2, and DLD3 resulted in the redirection of carbon flux.


Assuntos
Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Álcool Desidrogenase/genética , Etanol/metabolismo , Fermentação , Glicerol/metabolismo , Ácido Láctico/metabolismo , Proteínas de Membrana/genética , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Transcriptoma
9.
J Fungi (Basel) ; 8(7)2022 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-35887459

RESUMO

Bioethanol plays an important value in renewable liquid fuel. The excessive accumulation of glycerol and organic acids caused the decrease of ethanol content in the process of industrial ethanol production. In this study, the CRISPR-Cas9 approach was used to construct S. cerevisiae engineering strains by the deletion of GPD2, FPS1, and ADH2 for the improvement of ethanol production. RNA sequencing and transcriptome analysis were used to investigate the effect of gene deletion on gene expression. The results indicated that engineered S. cerevisiae SCGFA by the simultaneous deletion of GPD2, FPS1, and ADH2 produced 23.1 g/L ethanol, which increased by 0.18% in comparison with the wild-type strain with 50 g/L of glucose as substrate. SCGFA strain exhibited the ethanol conversion rate of 0.462 g per g of glucose. In addition, the contents of glycerol, lactic acid, acetic acid, and succinic acid in SCGFA decreased by 22.7, 12.7, 8.1, 19.9, and 20.7% compared with the wild-type strain, respectively. The up-regulated gene enrichment showed glycolysis, fatty acid, and carbon metabolism could affect the ethanol production of SCGFA according to the Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. Therefore, the engineering strain SCGFA had great potential in the production of bioethanol.

10.
J Dent Educ ; 86(6): 706-713, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35020948

RESUMO

PURPOSE: Most students entering dental school have outstanding academic credentials. Despite this, some students face academic difficulties throughout their dental education. The study investigates outcomes at the end of the first-year and the end of the 4-year curriculum. METHODS: This study reviewed data from 177 students in the entering classes of 2015 and 2016. The regression models included 156 students who completed the 4-year curriculum on the traditional timeline. RESULTS: Undergraduate cumulative GPA had a significant association with dental school outcomes in 4-year biomedical science GPA, translational science GPA, and clinical science GPA (increase of 0.31, 0.31, and 0.08 for a one-unit increase in undergraduate GPA). A one-unit increase in DAT was reflected in increased in first-year biomedical science GPA, preclinical science GPA, and cumulative GPA (0.04, 0.06, and 0.10, respectively). Conversely, a one-unit increase in failure or withdrawal from undergraduate courses was associated with decreases in first-year biomedical science GPA, preclinical science GPA, and cumulative GPA (0.08, 0.09, and 0.08, respectively). The only significant relationship for clinical science (patient care) GPA was cumulative undergraduate GPA (0.08 increase per unit). CONCLUSION: The results of this study suggest students who are extremely strong academically in college will be strong throughout dental school and suggest benefits of targeted services for academically at-risk students. Due to the limited association of admission records to clinical grades, the results support holistic admission processes.


Assuntos
Faculdades de Odontologia , Estudantes de Odontologia , Logro , Avaliação Educacional , Humanos , Critérios de Admissão Escolar
11.
J Endod ; 48(2): 208-212.e3, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34780805

RESUMO

INTRODUCTION: Diabetes mellitus (DM) is a complex multisystemic disorder that affects an estimated 21 million Americans. No studies have evaluated the association of DM with the prevalence of each pulpal diagnosis. The objective of this study was to compare the prevalence of each pulp diagnosis including symptomatic irreversible pulpitis (SIP), asymptomatic irreversible pulpitis, reversible pulpitis, normal pulp, and pulp necrosis (PN) in DM patients against a nondiabetic control group. METHODS: A retrospective chart review was approved by Rutgers University Institutional Review Board. The prevalence of the diagnoses SIP, asymptomatic irreversible pulpitis, reversible pulpitis, normal pulp, and PN was calculated from AxiUm (Exan software, Las Vegas, NV) electronic health records at Rutgers School of Dental Medicine. The chi-square test was used to see the relationship between the 2 categoric variables. Second, binary logistic regression analyses were performed for each group. RESULTS: A total of 2979 teeth were diagnosed with a pulp condition between April 2013 and November 2018. The total tooth number of DM patients was 682, whereas the tooth number of nondiabetic patients was 2297. In the subgroup of patients younger than 40 years old, SIP was notably more prevalent in DM patients. In addition, the prevalence of PN in elderly DM patients (60-69 years old) was significantly higher than in the control group. CONCLUSIONS: The prevalence of SIP in DM patients was significantly higher compared with the control group (<40 years old), suggesting the possibility that DM could hypersensitize the subgroup of patients younger than 40 years old to pulpitis pain.


Assuntos
Diabetes Mellitus , Pulpite , Adulto , Idoso , Polpa Dentária , Diabetes Mellitus/epidemiologia , Humanos , Pessoa de Meia-Idade , Prevalência , Pulpite/epidemiologia , Estudos Retrospectivos
12.
Ecol Evol ; 11(18): 12583-12595, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34594522

RESUMO

Geological events, landscape features, and climate fluctuations have shaped the distribution of genetic diversity and evolutionary history in freshwater fish, but little attention has been paid to that around the Gulf of Tonkin; therefore, we investigated the phylogeographic structure of the dwarf snakehead (Channa gachua) on Hainan Island and mainland China, as well as two populations in Vietnam. We attempted to elucidate the origins of freshwater fish in South Hainan by incorporating genetic data from DNA markers on both the mitochondrial cytochrome b gene (cyt b) and the nuclear recombination-activating gene 1 (RAG-1). Mitochondrial phylogenetic analysis identified two major lineages (lineages A and B), which may represent separate species. Divergence data suggested that C. gachua populations diverged between 0.516 and 2.376 myr. The divergence of the two cryptic species is congruent with sea-level rise, which subsequently isolated Hainan from the mainland. During the Pleistocene glaciations, the entire region of the Gulf of Tonkin and the Qiongzhou Strait became part of the coastal plain of the Asian continent, which might have resulted in the current distribution patterns and dispersal routes of C. gachua populations. The formation of three sublineages in lineage A indicated that the Gulf of Tonkin was a geographical barrier between Hainan Island and mainland China but not between Vietnam and Hainan Island. The results of this study may help to elucidate the origins of freshwater fish in South Hainan and the phylogeographic structure of C. gachua.

13.
Microsc Res Tech ; 84(12): 2906-2914, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34196449

RESUMO

Hepatocyte nuclear factor-4α (HNF4α) presents in multiple isoforms generated using alternative promoter (P1 and P2) and splicing. Neither conservation of tissue distribution of HNF4α isoforms, nor presence of alternative promoter usage is known. In this study, to detect the expression of HNF4α in some species of animals, we have applied monoclonal antibodies against P1 (K9218) and P2 (H6939) promoter-driven and P1/P2 promoter-driven H1415 HNF4α for immunohistochemistry and western blot analysis. Antibody K9218 was observed in the hepatocytes, proximal tubules of the kidney, and epithelial cells in the mucosa of the small intestine and colon of rats, chicken, and tortoise, whereas antibody H6939 signal were detected in the stomach, pancreas, bile duct, and pancreatic duct of human and rats. The signal for antibody K9218 was recognized in tissues of a wide range of mammals, bird, reptile, amphibian, and fish as well. Antibody H1415 displayed a positive reaction in hepatocytes and intestinal epithelial cells in chicken and tortoise, whereas the bile duct, mucosal epithelial cells in the stomach, or pancreas in these animals were negative. Western blotting showed the binding of the antibody with HNF4α protein from each animal. The sequence of human HNF4α was 100% identical to murine and rat HNF4α, 88.9% to chicken, 77.8% to Xenopus HNF4α, and 81.5% to medaka. However, the specific part of human and invertebrate Drosophila HNF4 shares only 14.8% sequence identity. This antibody is useful for detecting HNF4α isoforms in a wide range of vertebrates, and suggests many insights into animal evolution.


Assuntos
Fator 4 Nuclear de Hepatócito , Hepatócitos , Animais , Fator 4 Nuclear de Hepatócito/genética , Fator 4 Nuclear de Hepatócito/metabolismo , Imuno-Histoquímica , Camundongos , Regiões Promotoras Genéticas , Ratos , Vertebrados/metabolismo
14.
Toxins (Basel) ; 13(5)2021 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-34068167

RESUMO

Aflatoxins seriously threaten the health of humans and animals due to their potential carcinogenic properties. Enzymatic degradation approach is an effective and environmentally friendly alternative that involves changing the structure of aflatoxins. In this study, Trametes versicolor aflatoxin B1-degrading enzyme gene (TV-AFB1D) was integrated into the genome of Pichia pastoris GS115 by homologous recombination approach. The recombinant TV-AFB1D was expressed in engineering P. pastoris with a size of approximately 77 kDa under the induction of methanol. The maximum activity of TV-AFB1D reached 17.5 U/mL after the induction of 0.8% ethanol (v/v) for 84 h at 28 °C. The AFB1 proportion of 75.9% was degraded using AFB1 standard sample after catalysis for 12 h. In addition, the AFB1 proportion was 48.5% using AFB1-contaminated peanuts after the catalysis for 18 h at 34 °C. The recombinant TV-AFB1D would have good practical application value in AFB1 degradation in food crops. This study provides an alternative degrading enzyme for the degradation of AFB1 in aflatoxin-contaminated grain and feed via enzymatic degradation approach.


Assuntos
Aflatoxina B1/metabolismo , Arachis/química , Polyporaceae/genética , Saccharomycetales/genética , Enzimas/genética , Polyporaceae/enzimologia , Saccharomycetales/enzimologia , Temperatura , Fatores de Tempo
17.
J Clin Pharm Ther ; 46(3): 807-813, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33555057

RESUMO

WHAT IS KNOWN AND OBJECTIVES: Haematological toxicity including thrombocytopenia, anaemia and leucopenia is the main adverse events of linezolid (LZD) therapy. This study aimed to investigate the risk factors for LZD-induced haematological toxicity and define the threshold of plasma trough concentration to minimize the haematological toxicity. METHODS: 145 patients who received LZD for more than 10 days were retrospectively reviewed to determine the incidence of LZD-induced haematological toxicity. Meanwhile, the risk factors of haematological toxicity were confirmed by univariate and multivariate logistic regression analysis. RESULTS AND DISCUSSION: 9 (6.2%) patients developed leucopenia, while 52 (35.9%) and 26 (17.9%) patients developed thrombocytopenia and anaemia, respectively. The estimated glomerular filtration rate (eGFR) <90 ml/min/1.73 m2 (OR, 2.744; 95% CI, 1.117-6.734; p = 0.028) and baseline platelet count <200 × 109 /L (OR, 6.817; 95% CI, 2.870-16.193; p < 0.0001) were found to be significant risk factors for LZD-related thrombocytopenia. Aspartate aminotransferase (AST) >80 U/L (OR, 4.844; 95% CI, 1.207-19.451; p = 0.026) and eGFR <90 ml/min/1.73 m2 (OR, 7.132; 95% CI, 2.088-24.357; p = 0.002) were the risk factors for LZD-related anaemia. However, no significant risk factors were identified for LZD-related leucopenia. Moreover, LZD plasma trough concentration >8 mg/L [OR, 3.047; 95% CI, 1.233-7.539; p = 0.016] could be a predictor for the development of thrombocytopenia and anaemia. WHAT IS NEW AND CONCLUSION: Hepatic and/or renal dysfunction are the risk factors for LZD-related haematological toxicity, while the target plasma trough concentration within 8 mg/L via dose reduction could minimize the haematological toxicity induced by LZD.


Assuntos
Antibacterianos/efeitos adversos , Doenças Hematológicas/induzido quimicamente , Linezolida/efeitos adversos , Adulto , Idoso , Idoso de 80 Anos ou mais , Antibacterianos/sangue , China , Monitoramento de Medicamentos , Feminino , Humanos , Testes de Função Renal , Linezolida/sangue , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Estudos Retrospectivos , Trombocitopenia/induzido quimicamente , Adulto Jovem
18.
Cell Rep ; 34(5): 108703, 2021 02 02.
Artigo em Inglês | MEDLINE | ID: mdl-33535042

RESUMO

Using chromatin conformation capture, we show that an enhancer cluster in the STARD10 type 2 diabetes (T2D) locus forms a defined 3-dimensional (3D) chromatin domain. A 4.1-kb region within this locus, carrying 5 T2D-associated variants, physically interacts with CTCF-binding regions and with an enhancer possessing strong transcriptional activity. Analysis of human islet 3D chromatin interaction maps identifies the FCHSD2 gene as an additional target of the enhancer cluster. CRISPR-Cas9-mediated deletion of the variant region, or of the associated enhancer, from human pancreas-derived EndoC-ßH1 cells impairs glucose-stimulated insulin secretion. Expression of both STARD10 and FCHSD2 is reduced in cells harboring CRISPR deletions, and lower expression of STARD10 and FCHSD2 is associated, the latter nominally, with the possession of risk variant alleles in human islets. Finally, CRISPR-Cas9-mediated loss of STARD10 or FCHSD2, but not ARAP1, impairs regulated insulin secretion. Thus, multiple genes at the STARD10 locus influence ß cell function.


Assuntos
Proteínas de Transporte/metabolismo , Cromatina/metabolismo , Células Secretoras de Insulina/metabolismo , Proteínas de Membrana/metabolismo , Fosfoproteínas/metabolismo , Humanos
19.
Mol Phylogenet Evol ; 153: 106950, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32889137

RESUMO

Cryptic species describe two or more species that had mistakenly been considered to be a single species, a phenomenon that has been found throughout the tree of life. Recognizing cryptic species is key to estimating the real biodiversity of the world and understanding evolutionary processes. Molecular methods present an unprecedented opportunity for biologists to question whether morphologically similar populations are actually cryptic species. The minnow Tanichthys albonubes is a critically endangered freshwater fish and was classified as a second-class state-protected animal in China. Previous studies have revealed highly divergent lineages with similar morphological characters in this species. Herein, we tested for cryptic species across the ranges of all known wild populations of this minnow. Using multilocus molecular (one mitochondrial gene, two nuclear genes and 13 microsatellite loci) and morphological data for 230 individuals from eight populations, we found deep genetic divergence among these populations with subtle morphological disparity. Morphological examination found variance among these populations in the number of branched anal-fin rays. Based on genetic data, we inferred eight monophyletic groups that were well supported by haplotype network and population clustering analyses. Species delimitation methods suggested eight putative species in the T. albonubes complex. Molecular dating suggested that these cryptic species diverged in the period from the Pliocene to the Pleistocene. Based on these findings, we propose the existence of seven cryptic species in the T. albonubes complex. Our results highlight the need for a taxonomic revision of Tanichthys. What is more, the conservation status of and conservation strategies for the T. albonubes complex should be reassessed as soon as possible.


Assuntos
Cyprinidae/classificação , Especiação Genética , Filogenia , Animais , China , Conservação dos Recursos Naturais , Cyprinidae/genética , Genes Mitocondriais/genética , Repetições de Microssatélites/genética , Especificidade da Espécie
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA