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CIViC (Clinical Interpretation of Variants in Cancer; civicdb.org) is a crowd-sourced, public domain knowledgebase composed of literature-derived evidence characterizing the clinical utility of cancer variants. As clinical sequencing becomes more prevalent in cancer management, the need for cancer variant interpretation has grown beyond the capability of any single institution. CIViC contains peer-reviewed, published literature curated and expertly-moderated into structured data units (Evidence Items) that can be accessed globally and in real time, reducing barriers to clinical variant knowledge sharing. We have extended CIViC's functionality to support emergent variant interpretation guidelines, increase interoperability with other variant resources, and promote widespread dissemination of structured curated data. To support the full breadth of variant interpretation from basic to translational, including integration of somatic and germline variant knowledge and inference of drug response, we have enabled curation of three new Evidence Types (Predisposing, Oncogenic and Functional). The growing CIViC knowledgebase has over 300 contributors and distributes clinically-relevant cancer variant data currently representing >3200 variants in >470 genes from >3100 publications.
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Variación Genética , Neoplasias , Humanos , Neoplasias/genética , Bases del Conocimiento , Secuenciación de Nucleótidos de Alto RendimientoRESUMEN
BACKGROUND: Miscarriage is a frustrating complication of pregnancy that is common among women of reproductive age. Insufficient decidualization which not only impairs embryo implantation but disturbs fetomaternal immune-tolerance, has been widely regarded as a major cause of miscarriage; however, the underlying mechanisms resulting in decidual impairment are largely unknown. METHODS: With informed consent, decidual tissue from patients with spontaneous abortion or normal pregnant women was collected to detect the expression profile of UCHL1. Human endometrial stromal cells (HESCs) were used to explore the roles of UCHL1 in decidualization and dNK modulation, as well as the mechanisms involved. C57/BL6 female mice (7-10 weeks old) were used to construct pregnancy model or artificially induced decidualization model to evaluate the effect of UCHL1 on mice decidualization and pregnancy outcome. RESULTS: The Ubiquitin C-terminal hydrolase L1 (UCHL1), as a deubiquitinating enzyme, was significantly downregulated in decidua from patients with miscarriage, along with impaired decidualization and decreased dNKs. Blockage of UCHL1 led to insufficient decidualization and resultant decreased expression of cytokines CXCL12, IL-15, TGF-ß which were critical for generation of decidual NK cells (dNKs), whereas UCHL1 overexpression enhanced decidualization accompanied by increase in dNKs. Mechanistically, the promotion of UCHL1 on decidualization was dependent on its deubiquitinating activity, and intervention of UCHL1 inhibited the activation of JAK2/STAT3 signaling pathway, resulting in aberrant decidualization and decreased production of cytokines associated with dNKs modulation. Furthermore, we found that inhibition of UCHL1 also disrupted the decidualization in mice and eventually caused adverse pregnancy outcome. CONCLUSIONS: UCHL1 plays significant roles in decidualization and dNKs modulation during pregnancy in both humans and mice. Its deficiency indicates a poor pregnancy outcome due to defective decidualization, making UCHL1 a potential target for the diagnosis and treatment of miscarriage.
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Aborto Espontáneo , Decidua , Células Asesinas Naturales , Ratones Endogámicos C57BL , Ubiquitina Tiolesterasa , Ubiquitina Tiolesterasa/metabolismo , Ubiquitina Tiolesterasa/deficiencia , Femenino , Decidua/metabolismo , Animales , Embarazo , Aborto Espontáneo/metabolismo , Humanos , Células Asesinas Naturales/metabolismo , Células Asesinas Naturales/inmunología , Adulto , Ratones , Células del Estroma/metabolismo , Transducción de SeñalRESUMEN
PURPOSE: Clinical next-generation sequencing is an effective approach for identifying pathogenic sequence variants that are medically actionable for participants and families but are not associated with the participant's primary diagnosis. These variants are called secondary findings (SFs). According to the literature, there is no report of the types and frequencies of SFs in a large pediatric cohort that includes substantial African-American participants. We sought to investigate the types (including American College of Medical Genetics and Genomics [ACMG] and non-ACMG-recommended gene lists), frequencies, and rates of SFs, as well as the effects of SF disclosure on the participants and families of a large pediatric cohort at the Center for Applied Genomics at The Children's Hospital of Philadelphia. METHODS: We systematically identified pathogenic (P) and likely pathogenic (LP) variants in established disease-causing genes, adhering to ACMG v3.2 secondary finding guidelines and beyond. For non-ACMG SFs, akin to incidental findings in clinical settings, we utilized a set of criteria focusing on pediatric onset, high penetrance, moderate to severe phenotypes, and the clinical actionability of the variants. This criteria-based approach was applied rather than using a fixed gene list to ensure that the variants identified are likely to affect participant health significantly. To identify and categorize these variants, we used a clinical-grade variant classification standard per ACMG/AMP recommendations; additionally, we conducted a detailed literature search to ensure a comprehensive exploration of potential SFs relevant to pediatric participants. RESULTS: We report a distinctive distribution of 1464 P/LP SF variants in 16,713 participants. There were 427 unique variants in ACMG genes and 265 in non-ACMG genes. The most frequently mutated genes among the ACMG and non-ACMG gene lists were TTR(41.6%) and CHEK2 (7.16%), respectively. Overall, variants of possible medical importance were found in 8.76% of participants in both ACMG (5.81%) and non-ACMG (2.95%) genes. CONCLUSION: Our study revealed that 8.76% of a large, multiethnic pediatric cohort carried actionable secondary genetic findings, with 5.81% in ACMG genes and 2.95% in non-ACMG genes. These findings emphasize the importance of including diverse populations in genetic research to ensure that all groups benefit from early identification of disease risks. Our results provide a foundation for expanding the ACMG gene list and improving clinical care through early interventions.
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Root growth and development depend on continuous cell division and differentiation in root tips. In these processes, reactive oxygen species (ROS) play a critical role as signaling molecules. However, few ROS signaling regulators have been identified. In this study, we found knockdown of a syntaxin gene, SYNTAXIN OF PLANTS81 in Arabidopsis thaliana (AtSYP81) resulted in a severe reduction in root meristem activity and disruption of root stem cell niche (SCN) identity. Subsequently, we found AtSYP81 was highly expressed in roots and localized on the endoplasmic reticulum (ER). Interestingly, the reduced expression of AtSYP81 conferred a decreased number of peroxisomes in root meristem cells, raising a possibility that AtSYP81 regulates root development through peroxisome-mediated ROS production. Further transcriptome analysis revealed that class III peroxidases, which are responsible for intracellular ROS homeostasis, showed significantly changed expression in the atsyp81 mutants and AtSYP81 overexpression lines, adding evidence of the regulatory role of AtSYP81 in ROS signaling. Accordingly, rescuing the decreased ROS level via applying ROS donors effectively restored the defects in root meristem activity and SCN identity in the atsyp81 mutants. APETALA2 (AP2) transcription factors PLETHORA1 and 2 (PLT1 and PLT2) were then established as the downstream effectors in this pathway, while potential crosstalk between ROS signaling and auxin signaling was also indicated. Taken together, our findings suggest that AtSYP81 regulates root meristem activity and maintains root SCN identity by controlling peroxisome- and peroxidase-mediated ROS homeostasis, thus both broadening and deepening our understanding of the biological roles of SNARE proteins and ROS signaling.
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Proteínas de Arabidopsis , Arabidopsis , Meristema/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Raíces de Plantas/metabolismo , Proteínas Qa-SNARE/metabolismo , Nicho de Células Madre/genética , Factores de Transcripción/metabolismo , Arabidopsis/metabolismo , Regulación de la Expresión Génica de las Plantas , Ácidos Indolacéticos/metabolismoRESUMEN
The bromodomain adjacent to zinc finger 2B (BAZ2B) gene encodes a chromatin remodeling protein that has been shown to perform a variety of regulatory functions. It has been proposed that loss of BAZ2B function is associated with neurodevelopmental phenotypes, and some recurrent structural birth defects and dysmorphic features have been documented among individuals carrying heterozygous loss-of-function BAZ2B variants. However, additional evidence is needed to confirm that these phenotypes are attributable to BAZ2B deficiency. Here, we report 10 unrelated individuals with heterozygous deletions, stop-gain, frameshift, missense, splice junction, indel, and start-loss variants affecting BAZ2B. These included a paternal intragenic deletion and a maternal frameshift variant that were inherited from mildly affected or asymptomatic parents. The analysis of molecular and clinical data from this cohort, and that of individuals previously reported, suggests that BAZ2B haploinsufficiency causes an autosomal dominant neurodevelopmental syndrome that is incompletely penetrant. The phenotypes most commonly seen in association with loss of BAZ2B function include developmental delay, intellectual disability, autism spectrum disorder, speech delay-with some affected individuals being non-verbal-behavioral abnormalities, seizures, vision-related issues, congenital heart defects, poor fetal growth, and an indistinct pattern of dysmorphic features in which epicanthal folds and small ears are particularly common.
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Trastorno del Espectro Autista , Discapacidad Intelectual , Trastornos del Neurodesarrollo , Factores Generales de Transcripción , Humanos , Discapacidad Intelectual/genética , Factores de Transcripción/genética , Fenotipo , Dedos de Zinc , Trastornos del Neurodesarrollo/genética , Proteínas que Contienen Bromodominio , Factores Generales de Transcripción/genéticaRESUMEN
Antimicrobial resistance (AMR) is a great threat to animal and public health. Here, we conducted a surveillance of Escherichia coli isolated from healthy chickens during 2009-2014 to identify the characteristics of AMR. A total of 351 (95.64%) E. coli isolates were obtained from 367 healthy chicken fecal samples collected from 6 farms located in Shandong Province, China. The susceptibility to 10 antimicrobials, the prevalence of antibiotic resistance genes (ARGs), phylogenetic clustering, and multilocus sequence typing were evaluated. The isolates exhibited high resistant rates (>95%) to ampicillin, cefotaxime, ciprofloxacin, ceftiofur, and enrofloxacin. The most prevalent ARGs were blaCTX-M (36.36%), aac(6')-Ib-cr (30.79%), qnrS (29.62%), oqxAB (27%), mcr-1 (15.83%), blaTEM (9.09%), qnrC (3.52%), qnrD (0.88%), and qepA (0.29%). Phylogenetic clustering analysis indicated that the most prevalent group was group D (37.89%), followed by group B1 (34.76%), A (24.22%), and B2 (3.13%). Fifty-seven sequence types (STs) were identified among the 124 blaCTX-M-positive strains, and the dominant STs were ST354 (13.71%), ST117 (5.65%), ST155, ST2309, and ST2505 (4.84% each). There was a significant association between 17 pairs of AMR phenotypes, 14 pairs of ARGs, and 11 pairs of AMR-ARGs. The strongest association was found between ST602 and qnrC (odds ratios: 22.2). This study implied that E. coli isolated from healthy chickens could potentially serve as a reservoir of AMR and ARGs, and significant associations exist among AMR, ARGs, phylogenetic groups, and STs. Our study highlighted the need for routine surveillance of AMR in healthy chickens, and promoting appropriate antibiotic use and implementing regular monitoring of resistance in broilers are crucial for fostering the development of the poultry industry and safeguarding public health.
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The ability to quickly identify specific serotypes of Shiga toxin-producing Escherichia coli (STEC) could facilitate the monitoring and control of STEC pathogens. In this study, we identified the receptors and receptor-binding proteins (RBPs) of three novel phages (pO91, pO103, and pO111) isolated from hospital wastewater. Recombinant versions of these RBPs (pO91-ORF43, pO103-ORF42, and pO111-ORF8) fused to a fluorescent reporter protein were then constructed. Both fluorescence microscopy and transmission electron microscopy showed that all three recombinant RBPs were bound to the bacterial surface. Indirect enzyme-linked immunosorbent assay was used to verify that each recombinant RBP bound specifically to E. coli O91, O103, or O111, but not to any of the 83 strains of E. coli with different O-antigens, nor to 10 other bacterial species that were tested. The recombinant RBPs adsorbed to their respective host bacteria within 10 min of incubation. The minimum concentration of bacteria required for detection by the recombinant RBPs was 33 colony-forming units (CFU)/mL (range: 3.3 × 10 to 3.3 × 108 CFU/mL). Furthermore, each recombinant RBP was also able to detect bacteria in lettuce, chicken breast meat, and infected mice, indicating that their usage will facilitate the detection of STEC and may help to reduce the spread of STEC-related infections and diseases.
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Bacteriófagos , Infecciones por Escherichia coli , Proteínas de Escherichia coli , Escherichia coli Shiga-Toxigénica , Animales , Ratones , Toxina Shiga/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Infecciones por Escherichia coli/microbiología , Proteínas Portadoras/metabolismo , Bacteriófagos/genética , Bacteriófagos/metabolismoRESUMEN
The Repeat Expansion Diseases, a large group of human diseases that includes the fragile X-related disorders (FXDs) and Huntington's disease (HD), all result from expansion of a disease-specific microsatellite via a mechanism that is not fully understood. We have previously shown that mismatch repair (MMR) proteins are required for expansion in a mouse model of the FXDs, but that the FANCD2 and FANCI associated nuclease 1 (FAN1), a component of the Fanconi anemia (FA) DNA repair pathway, is protective. FAN1's nuclease activity has been reported to be dispensable for protection against expansion in an HD cell model. However, we show here that in a FXD mouse model a point mutation in the nuclease domain of FAN1 has the same effect on expansion as a null mutation. Furthermore, we show that FAN1 and another nuclease, EXO1, have an additive effect in protecting against MSH3-dependent expansions. Lastly, we show that the loss of FANCD2, a vital component of the Fanconi anemia DNA repair pathway, has no effect on expansions. Thus, FAN1 protects against MSH3-dependent expansions without diverting the expansion intermediates into the canonical FA pathway and this protection depends on FAN1 having an intact nuclease domain.
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Dominio Catalítico , Endodesoxirribonucleasas/metabolismo , Exodesoxirribonucleasas/metabolismo , Enzimas Multifuncionales/metabolismo , Expansión de Repetición de Trinucleótido , Animales , Enzimas Reparadoras del ADN/metabolismo , Endodesoxirribonucleasas/química , Endodesoxirribonucleasas/genética , Exodesoxirribonucleasas/química , Exodesoxirribonucleasas/genética , Proteína del Grupo de Complementación D2 de la Anemia de Fanconi/genética , Proteína del Grupo de Complementación D2 de la Anemia de Fanconi/metabolismo , Ratones , Ratones Endogámicos C57BL , Enzimas Multifuncionales/química , Enzimas Multifuncionales/genética , Proteína 3 Homóloga de MutS/metabolismo , Mutación PuntualRESUMEN
Expansion of a CGG-repeat tract in the 5' untranslated region of the FMR1 gene causes the fragile X-related disorders (FXDs; aka the FMR1 disorders). The expansion mechanism is likely shared by the 35+ other diseases resulting from expansion of a disease-specific microsatellite, but many steps in this process are unknown. We have shown previously that expansion is dependent upon functional mismatch repair proteins, including an absolute requirement for MutLγ, one of the three MutL heterodimeric complexes found in mammalian cells. We demonstrate here that both MutLα and MutLß, the two other MutL complexes present in mammalian cells, are also required for most, if not all, expansions in a mouse embryonic stem cell model of the FXDs. A role for MutLα and MutLß is consistent with human GWA studies implicating these complexes as modifiers of expansion risk in other Repeat Expansion Diseases. The requirement for all three complexes suggests a novel model in which these complexes co-operate to generate expansions. It also suggests that the PMS1 subunit of MutLß may be a reasonable therapeutic target in those diseases in which somatic expansion is an important disease modifier.
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Síndrome del Cromosoma X Frágil/genética , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto/genética , Proteínas MutL/genética , Expansión de Repetición de Trinucleótido/genética , Animales , Línea Celular , Reparación de la Incompatibilidad de ADN , Modelos Animales de Enfermedad , Células Madre Embrionarias , Técnicas de Inactivación de Genes , Humanos , Ratones , Endonucleasa PMS2 de Reparación del Emparejamiento Incorrecto/metabolismo , Proteínas MutL/metabolismoRESUMEN
In the reference interferometer demodulation scheme, it's difficult to guarantee in practice that both interferometers have the same optical path length difference (OPD), which makes the phase modulation depth different in different interferometers with the same laser modulation. The random shift of phase modulation depth also affects the demodulation results. An improved phase-generated carrier (PGC) technique is proposed based on an auxiliary reference interferometer and the ellipse fitting algorithm (EFA). The technique ensures the correct fitting of the EFA for small amplitude signals by introducing a sinusoidal signal as an additional phase modulation. The combination of the reference interferometer and EFA can eliminate the effect of different phase modulation depths of the two interferometers caused by different OPDs, the non-linear distortion caused by phase modulation depth shifts, and improve the accuracy of the demodulation results. The experiment results are consistent with the theoretical analysis, and the method extends the application of the EFA in the reference interferometer phase demodulation technique.
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Coffin-Siris syndrome (CSS) is an autosomal dominant neurodevelopmental syndrome that can present with a variety of structural birth defects. Pathogenic variants in 12 genes have been shown to cause CSS. Most of these genes encode proteins that are a part of the mammalian switch/sucrose non-fermentable (mSWI/SNF; BAF) complex. An association between genes that cause CSS and congenital diaphragmatic hernia (CDH) has been suggested based on case reports and the analysis of CSS and CDH cohorts. Here, we describe an unpublished individual with CSS and CDH, and we report additional clinical information on four published cases. Data from these individuals, and a review of the literature, provide evidence that deleterious variants in ARID1B, ARID1A, SMARCB1, SMARCA4, SMARCE1, ARID2, DPF2, and SMARCC2, which are associated with CSS types 1-8, respectively, are associated with the development of CDH. This suggests that additional genetic testing to identify a separate cause of CDH in an individual with CSS may be unwarranted, and that comprehensive genetic testing for individuals with non-isolated CDH should include an evaluation of CSS-related genes. These data also suggest that the mSWI/SNF (BAF) complex may play an important role in diaphragm development.
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Anomalías Múltiples , Deformidades Congénitas de la Mano , Hernias Diafragmáticas Congénitas , Discapacidad Intelectual , Micrognatismo , Anomalías Múltiples/diagnóstico , Anomalías Múltiples/genética , Proteínas Cromosómicas no Histona , ADN Helicasas/genética , Proteínas de Unión al ADN/genética , Cara/anomalías , Deformidades Congénitas de la Mano/complicaciones , Deformidades Congénitas de la Mano/diagnóstico , Deformidades Congénitas de la Mano/genética , Hernias Diafragmáticas Congénitas/genética , Hernias Diafragmáticas Congénitas/patología , Humanos , Discapacidad Intelectual/patología , Micrognatismo/genética , Micrognatismo/patología , Cuello/anomalías , Proteínas Nucleares/genética , Factores de Transcripción/genéticaRESUMEN
Congenital diaphragmatic hernia (CDH) can occur in isolation or in conjunction with other birth defects (CDH+). A molecular etiology can only be identified in a subset of CDH cases. This is due, in part, to an incomplete understanding of the genes that contribute to diaphragm development. Here, we used clinical and molecular data from 36 individuals with CDH+ who are cataloged in the DECIPHER database to identify genes that may play a role in diaphragm development and to discover new phenotypic expansions. Among this group, we identified individuals who carried putatively deleterious sequence or copy number variants affecting CREBBP, SMARCA4, UBA2, and USP9X. The role of these genes in diaphragm development was supported by their expression in the developing mouse diaphragm, their similarity to known CDH genes using data from a previously published and validated machine learning algorithm, and/or the presence of CDH in other individuals with their associated genetic disorders. Our results demonstrate how data from DECIPHER, and other public databases, can be used to identify new phenotypic expansions and suggest that CREBBP, SMARCA4, UBA2, and USP9X play a role in diaphragm development.
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Hernias Diafragmáticas Congénitas , Animales , Variaciones en el Número de Copia de ADN , Diafragma , Hernias Diafragmáticas Congénitas/genética , RatonesRESUMEN
Esophageal atresia/tracheoesophageal fistula (EA/TEF) is a life-threatening birth defect that often occurs with other major birth defects (EA/TEF+). Despite advances in genetic testing, a molecular diagnosis can only be made in a minority of EA/TEF+ cases. Here, we analyzed clinical exome sequencing data and data from the DECIPHER database to determine the efficacy of exome sequencing in cases of EA/TEF+ and to identify phenotypic expansions involving EA/TEF. Among 67 individuals with EA/TEF+ referred for clinical exome sequencing, a definitive or probable diagnosis was made in 11 cases for an efficacy rate of 16% (11/67). This efficacy rate is significantly lower than that reported for other major birth defects, suggesting that polygenic, multifactorial, epigenetic, and/or environmental factors may play a particularly important role in EA/TEF pathogenesis. Our cohort included individuals with pathogenic or likely pathogenic variants that affect TCF4 and its downstream target NRXN1, and FANCA, FANCB, and FANCC, which are associated with Fanconi anemia. These cases, previously published case reports, and comparisons to other EA/TEF genes made using a machine learning algorithm, provide evidence in support of a potential pathogenic role for these genes in the development of EA/TEF.
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Atresia Esofágica , Fístula Traqueoesofágica , Humanos , Fístula Traqueoesofágica/diagnóstico , Fístula Traqueoesofágica/genética , Fístula Traqueoesofágica/complicaciones , Atresia Esofágica/diagnóstico , Atresia Esofágica/genética , Atresia Esofágica/complicaciones , Exoma/genética , Secuenciación del ExomaRESUMEN
A highly sensitive temperature and strain sensor based on an antiresonant hollow core fiber (ARHCF) probe with the Vernier effect is proposed and experimentally demonstrated. The ARHCF probe is used as a reference interferometer by sandwiching an ARHCF, which is insensitive to temperature, strain, and refractive index, between a single-mode fiber (SMF) and a polarization-maintaining fiber (PMF). The polarization mode interferometer (PMI), fabricated by splicing a section of PMF with a fiber polarizer at a 45-degree angle, works as a sensing interferometer. The Vernier effect is introduced by connecting the reference interferometer and the PMI in parallel. The experimental results show that by introducing the Vernier effect, the temperature sensitivity is improved from -1.68 to -15.7nm/∘C and the strain sensitivity is improved from 5.09 to 47.65 pm/µÎµ. The magnification is consistent with the theoretical results. The reference segment of the proposed sensor is not affected by ambient factors, which provides a new strategy and idea for the development of multiparameter sensors based on the Vernier effect.
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Streptococcus suis is an important zoonotic pathogen that poses a serious threat to the pig industry and human health. The massive use of macrolides has led to the emergence of resistance in S. suis, and S. suis is suspected to be a reservoir of antimicrobial resistance genes. The mechanism to macrolide resistance in S. suis is mainly due to ermB and mefA. In this study, loop-mediated isothermal amplification (LAMP) methods were developed to detect ermB and mefA genes in S. suis through turbidimetry detection. The sensitivity and specificity of the LAMP reactions were determined. All results of LAMP and polymerase chain reaction (PCR) assay were compared to determine whether LAMP method was accurate and reliable. The results showed that all 100 nonstreptococcus clinical isolates tested negative, indicating the high specificity of LAMP assays. The detection limit of LAMP assay was 1 fg per reaction, and 102-104-fold lower than those of conventional PCR methods. Evaluation of the performance of the LAMP assay in S. suis clinical strains revealed a good consistency between LAMP and PCR assays. In conclusion, LAMP assays are specific, sensitive, and rapid methods to detect ermB and mefA in S. suis.
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Streptococcus suis , Porcinos , Humanos , Animales , Streptococcus suis/genética , Antibacterianos/farmacología , Macrólidos , Farmacorresistencia Bacteriana , Técnicas de Amplificación de Ácido Nucleico/métodos , Sensibilidad y EspecificidadRESUMEN
To limit the spread of severe acute respiratory syndrome coronavirus 2, the government of China has been monitoring infected travelers and minimizing cold-chain contamination. However, other factors might contribute to recurring outbreaks. We analyze the role of undocumented migrants as potential transmitters of severe acute respiratory syndrome coronavirus 2 in China.
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COVID-19 , Migrantes , China/epidemiología , Brotes de Enfermedades , Humanos , SARS-CoV-2RESUMEN
The nuclear factor I (NFI) family of transcription factors play an important role in normal development of multiple organs. Three NFI family members are highly expressed in the brain, and deletions or sequence variants in two of these, NFIA and NFIX, have been associated with intellectual disability (ID) and brain malformations. NFIB, however, has not previously been implicated in human disease. Here, we present a cohort of 18 individuals with mild ID and behavioral issues who are haploinsufficient for NFIB. Ten individuals harbored overlapping microdeletions of the chromosomal 9p23-p22.2 region, ranging in size from 225 kb to 4.3 Mb. Five additional subjects had point sequence variations creating a premature termination codon, and three subjects harbored single-nucleotide variations resulting in an inactive protein as determined using an in vitro reporter assay. All individuals presented with additional variable neurodevelopmental phenotypes, including muscular hypotonia, motor and speech delay, attention deficit disorder, autism spectrum disorder, and behavioral abnormalities. While structural brain anomalies, including dysgenesis of corpus callosum, were variable, individuals most frequently presented with macrocephaly. To determine whether macrocephaly could be a functional consequence of NFIB disruption, we analyzed a cortex-specific Nfib conditional knockout mouse model, which is postnatally viable. Utilizing magnetic resonance imaging and histology, we demonstrate that Nfib conditional knockout mice have enlargement of the cerebral cortex but preservation of overall brain structure and interhemispheric connectivity. Based on our findings, we propose that haploinsufficiency of NFIB causes ID with macrocephaly.
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Haploinsuficiencia/genética , Discapacidad Intelectual/genética , Megalencefalia/genética , Factores de Transcripción NFI/genética , Adolescente , Adulto , Animales , Corteza Cerebral/patología , Niño , Preescolar , Codón sin Sentido/genética , Estudios de Cohortes , Cuerpo Calloso/patología , Femenino , Humanos , Masculino , Ratones , Ratones Noqueados , Polimorfismo de Nucleótido Simple/genética , Adulto JovenRESUMEN
The Fragile X-related disorders (FXDs) are Repeat Expansion Diseases resulting from an expansion of a CGG-repeat tract at the 5' end of the FMR1 gene. The mechanism responsible for this unusual mutation is not fully understood. We have previously shown that mismatch repair (MMR) complexes, MSH2/MSH3 (MutSß) and MSH2/MSH6 (MutSα), together with Polß, a DNA polymerase important for base excision repair (BER), are important for expansions in a mouse model of these disorders. Here we show that MLH1/MLH3 (MutLγ), a protein complex that can act downstream of MutSß in MMR, is also required for all germ line and somatic expansions. However, exonuclease I (EXO1), which acts downstream of MutL proteins in MMR, is not required. In fact, a null mutation in Exo1 results in more extensive germ line and somatic expansions than is seen in Exo1+/+ animals. Furthermore, mice homozygous for a point mutation (D173A) in Exo1 that eliminates its nuclease activity but retains its native conformation, shows a level of expansion that is intermediate between Exo1+/+ and Exo1-/- animals. Thus, our data suggests that expansion of the FX repeat in this mouse model occurs via a MutLγ-dependent, EXO1-independent pathway, with EXO1 protecting against expansion both in a nuclease-dependent and a nuclease-independent manner. Our data thus have implications for the expansion mechanism and add to our understanding of the genetic factors that may be modifiers of expansion risk in humans.
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Enzimas Reparadoras del ADN/genética , Exodesoxirribonucleasas/genética , Síndrome del Cromosoma X Frágil/genética , Proteínas MutL/genética , Animales , Reparación de la Incompatibilidad de ADN/genética , Reparación de la Incompatibilidad de ADN/fisiología , Reparación del ADN , Enzimas Reparadoras del ADN/fisiología , Modelos Animales de Enfermedad , Exodesoxirribonucleasas/fisiología , Proteína de la Discapacidad Intelectual del Síndrome del Cromosoma X Frágil/genética , Inestabilidad Genómica , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Homólogo 1 de la Proteína MutL/metabolismo , Proteínas MutL/metabolismo , Mutación , Expansión de Repetición de Trinucleótido/genéticaRESUMEN
Streptococcus suis remains a serious threat to the worldwide swine industry and human health. In this study, rapid assays for the detection of three common virulence-related factors (mrp, epf, and sly) were developed, evaluated, and applied. Loop-mediated isothermal amplification (LAMP) primers were designed using Primer Explorer V5 software. The sensitivity and specificity of the LAMP assays were determined based on sample turbidity. For all three genes, LAMP assays were performed at 62°C with a reaction time of 60 min. The detection limit of conventional polymerase chain reaction (PCR) was 1 ng/µL, 10 pg/µL, and 100 fg/µL for the epf, sly, and mrp genes, respectively. For the LAMP assays, the detection limits were 10 pg/µL, 10 fg/µL, and 100 fg/µL for epf, sly, and mrp, respectively, representing sensitivities 100-1000 times higher than those of the PCR assay. Furthermore, when the LAMP assays were applied to clinical strains, the results were consistent with those of the PCR assay, confirming the LAMP assays as rapid and reliable detection techniques. In conclusion, the LAMP assays described in this study have the potential to become standard methods to detect the virulence factors mrp, epf, and sly. To the best of our knowledge, this is the first study to report the application of LAMP to detect the mrp, epf, and sly genes.
Asunto(s)
Proteínas Bacterianas/análisis , Técnicas de Diagnóstico Molecular/estadística & datos numéricos , Técnicas de Amplificación de Ácido Nucleico/estadística & datos numéricos , Streptococcus suis/genética , Enfermedades de los Porcinos/microbiología , Factores de Virulencia/genética , Animales , Antígenos Bacterianos/análisis , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Amplificación de Ácido Nucleico/métodos , Reacción en Cadena de la Polimerasa , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , PorcinosRESUMEN
Fragile X-related disorders (FXDs), also known as FMR1 disorders, are examples of repeat expansion diseases (REDs), clinical conditions that arise from an increase in the number of repeats in a disease-specific microsatellite. In the case of FXDs, the repeat unit is CGG/CCG and the repeat tract is located in the 5' UTR of the X-linked FMR1 gene. Expansion can result in neurodegeneration, ovarian dysfunction, or intellectual disability depending on the number of repeats in the expanded allele. A growing body of evidence suggests that the mutational mechanisms responsible for many REDs share several common features. It is also increasingly apparent that in some of these diseases the pathologic consequences of expansion may arise in similar ways. It has long been known that many of the disease-associated repeats form unusual DNA and RNA structures. This review will focus on what is known about these structures, the proteins with which they interact, and how they may be related to the causative mutation and disease pathology in the FMR1 disorders.