RESUMO
In eukaryotes, three-dimensional genome organization is critical for transcriptional regulation of gene expression. Long noncoding RNAs (lncRNAs) can modulate chromatin conformation of spatially related genomic locations within the nucleus. Here, we show that the lncRNA APOLO (AUXIN-REGULATED PROMOTER LOOP) recognizes multiple distant independent loci in the Arabidopsis thaliana genome. We found that APOLO targets are not spatially associated in the nucleus and that APOLO recognizes its targets by short sequence complementarity and the formation of DNA-RNA duplexes (R-loops). The invasion of APOLO to the target DNA decoys the plant Polycomb Repressive Complex 1 component LHP1, modulating local chromatin 3D conformation. APOLO lncRNA coordinates the expression of distal unrelated auxin-responsive genes during lateral root development in Arabidopsis. Hence, R-loop formation and chromatin protein decoy mediate trans action of lncRNAs on distant loci. VIDEO ABSTRACT.
Assuntos
Arabidopsis/metabolismo , Montagem e Desmontagem da Cromatina , Cromatina/metabolismo , Regulação da Expressão Gênica de Plantas , Plantas Geneticamente Modificadas/metabolismo , RNA Longo não Codificante/metabolismo , RNA de Plantas/metabolismo , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Cromatina/genética , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Ácidos Indolacéticos/farmacologia , Modelos Genéticos , Plantas Geneticamente Modificadas/efeitos dos fármacos , Plantas Geneticamente Modificadas/genética , Estruturas R-Loop , RNA Polimerase II/genética , RNA Polimerase II/metabolismo , RNA Longo não Codificante/genética , RNA de Plantas/genética , Relação Estrutura-Atividade , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Human APOBEC3H and homologous single-stranded DNA cytosine deaminases are unique to mammals. These DNA-editing enzymes function in innate immunity by restricting the replication of viruses and transposons. APOBEC3H also contributes to cancer mutagenesis. Here, we address the fundamental nature of RNA in regulating human APOBEC3H activities. APOBEC3H co-purifies with RNA as an inactive protein, and RNase A treatment enables strong DNA deaminase activity. RNA-binding-defective mutants demonstrate clear separation of function by becoming DNA hypermutators. Biochemical and crystallographic data demonstrate a mechanism in which double-stranded RNA mediates enzyme dimerization. Additionally, APOBEC3H separation-of-function mutants show that RNA binding is required for cytoplasmic localization, packaging into HIV-1 particles, and antiviral activity. Overall, these results support a model in which structured RNA negatively regulates the potentially harmful DNA deamination activity of APOBEC3H while, at the same time, positively regulating its antiviral activity.
Assuntos
Aminoidrolases/metabolismo , Dimerização , HIV-1/crescimento & desenvolvimento , Montagem de Vírus/genética , Aminoidrolases/genética , Linhagem Celular Tumoral , Cristalografia por Raios X , Citosina Desaminase/metabolismo , Células HEK293 , Células HeLa , Humanos , Estrutura Secundária de Proteína , RNA/genética , RNA/metabolismo , Proteínas de Ligação a RNA/genética , Ribonuclease Pancreático/metabolismoRESUMO
Duplex sequencing technology has been widely used in the detection of low-frequency mutations in circulating tumor deoxyribonucleic acid (DNA), but how to determine the sequencing depth and other experimental parameters to ensure the stable detection of low-frequency mutations is still an urgent problem to be solved. The mutation detection rules of duplex sequencing constrain not only the number of mutated templates but also the number of mutation-supportive reads corresponding to each forward and reverse strand of the mutated templates. To tackle this problem, we proposed a Depth Estimation model for stable detection of Low-Frequency MUTations in duplex sequencing (DELFMUT), which models the identity correspondence and quantitative relationships between templates and reads using the zero-truncated negative binomial distribution without considering the sequences composed of bases. The results of DELFMUT were verified by real duplex sequencing data. In the case of known mutation frequency and mutation detection rule, DELFMUT can recommend the combinations of DNA input and sequencing depth to guarantee the stable detection of mutations, and it has a great application value in guiding the experimental parameter setting of duplex sequencing technology.
Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Neoplasias , Humanos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Mutação , Neoplasias/genética , Taxa de Mutação , DNARESUMO
Mutations in mitochondrial DNA (mtDNA) contribute to multiple diseases. However, how new mtDNA mutations arise and accumulate with age remains understudied because of the high error rates of current sequencing technologies. Duplex sequencing reduces error rates by several orders of magnitude via independently tagging and analyzing each of the two template DNA strands. Here, using duplex sequencing, we obtained high-quality mtDNA sequences for somatic tissues (liver and skeletal muscle) and single oocytes of 30 unrelated rhesus macaques, from 1 to 23 y of age. Sequencing single oocytes minimized effects of natural selection on germline mutations. In total, we identified 17,637 tissue-specific de novo mutations. Their frequency increased â¼3.5-fold in liver and â¼2.8-fold in muscle over the â¼20 y assessed. Mutation frequency in oocytes increased â¼2.5-fold until the age of 9 y, but did not increase after that, suggesting that oocytes of older animals maintain the quality of their mtDNA. We found the light-strand origin of replication (OriL) to be a hotspot for mutation accumulation with aging in liver. Indeed, the 33-nucleotide-long OriL harbored 12 variant hotspots, 10 of which likely disrupt its hairpin structure and affect replication efficiency. Moreover, in somatic tissues, protein-coding variants were subject to positive selection (potentially mitigating toxic effects of mitochondrial activity), the strength of which increased with the number of macaques harboring variants. Our work illuminates the origins and accumulation of somatic and germline mtDNA mutations with aging in primates and has implications for delayed reproduction in modern human societies.
Assuntos
Envelhecimento , Mitocôndrias , Mutação , Oócitos , Animais , DNA Mitocondrial/genética , DNA Mitocondrial/metabolismo , Humanos , Macaca mulatta/genética , Mitocôndrias/genética , Oócitos/metabolismoRESUMO
Somatic mutations are accumulated in normal human tissues with aging and exposure to carcinogens. If we can accurately count any passenger mutations in any single DNA molecule, since their quantity is much larger than driver mutations, we can sensitively detect mutation accumulation in polyclonal normal tissues. Duplex sequencing, which tags both DNA strands in one DNA molecule, enables accurate count of such mutations, but requires a very large number of sequencing reads for each single sample of human-genome size. Here, we reduced the genome size to 1/90 using the BamHI restriction enzyme and established a cost-effective pipeline. The enzymatically cleaved and optimal sequencing (EcoSeq) method was able to count somatic mutations in a single DNA molecule with a sensitivity of as low as 3 × 10-8 per base pair (bp), as assessed by measuring artificially prepared mutations. Taking advantages of EcoSeq, we analyzed normal peripheral blood cells of pediatric sarcoma patients who received chemotherapy (n = 10) and those who did not (n = 10). The former had a mutation frequency of 31.2 ± 13.4 × 10-8 per base pair while the latter had 9.0 ± 4.5 × 10-8 per base pair (P < 0.001). The increase in mutation frequency was confirmed by analysis of the same patients before and after chemotherapy, and increased mutation frequencies persisted 46 to 64 mo after chemotherapy, indicating that the mutation accumulation constitutes a risk of secondary leukemia. EcoSeq has the potential to reveal accumulation of somatic mutations and exposure to environmental factors in any DNA samples and will contribute to cancer risk estimation.
Assuntos
Análise Mutacional de DNA , Genoma Humano , Sequenciamento de Nucleotídeos em Larga Escala , Taxa de Mutação , Imagem Individual de Molécula , Envelhecimento/genética , Pareamento de Bases , Criança , Análise Mutacional de DNA/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Mutação , Imagem Individual de Molécula/métodosRESUMO
MicroRNAs (MiRNAs) are valuable biomarkers for the diagnosis and prognosis of diseases. The development of reliable assays is an urgent pursuit. We herein fabricate a novel electrochemical sensing strategy based on the conformation transitions of DNA nanostructures and click chemistry. Duplex-specific nuclease (DSN)-catalyzed reaction is first used for the disintegration of the DNA triangular pyramid frustum (DNA TPF). A DNA triangle is formed, which in turn assists strain-promoted alkyne-azide cycloaddition (SPAAC) to localize single-stranded DNA probes (P1). After SPAAC ligation, multiple DNA hairpins are spontaneously folded, and the labeled electrochemical species are dragged near the electrode interface. By recording and analyzing the responses, a highly sensitive electrochemical biosensor is established, which exhibits high sensitivity and reproducibility. Clinical applications have been verified with good stability. This sensing strategy relies on the integration of DNA nanostructures and click chemistry, which may inspire further designs for the development of DNA nanotechnology and applications in clinical chemistry.
Assuntos
Técnicas Biossensoriais , Química Click , DNA , Técnicas Eletroquímicas , Nanoestruturas , Técnicas Biossensoriais/métodos , Nanoestruturas/química , Técnicas Eletroquímicas/métodos , DNA/química , Humanos , Reação de Cicloadição , MicroRNAs/análise , Alcinos/química , Azidas/química , Nanotecnologia/métodos , Conformação de Ácido Nucleico , Sondas de DNA/químicaRESUMO
BACKGROUND: Nuclear introns in Euglenida have been understudied. This study aimed to investigate nuclear introns in Euglenida by identifying a large number of introns in Euglena gracilis (E. gracilis), including cis-spliced conventional and nonconventional introns, as well as trans-spliced outrons. We also examined the sequence characteristics of these introns. RESULTS: A total of 28,337 introns and 11,921 outrons were identified. Conventional and nonconventional introns have distinct splice site features; the former harbour canonical GT/C-AG splice sites, whereas the latter are capable of forming structured motifs with their terminal sequences. We observed that short introns had a preference for canonical GT-AG introns. Notably, conventional introns and outrons in E. gracilis exhibited a distinct cytidine-rich polypyrimidine tract, in contrast to the thymidine-rich tracts observed in other organisms. Furthermore, the SL-RNAs in E. gracilis, as well as in other trans-splicing species, can form a recently discovered motif called the extended U6/5' ss duplex with the respective U6s. We also describe a novel type of alternative splicing pattern in E. gracilis. The tandem repeat sequences of introns in this protist were determined, and their contents were comparable to those in humans. CONCLUSIONS: Our findings highlight the unique features of E. gracilis introns and provide insights into the splicing mechanism of these introns, as well as the genomics and evolution of Euglenida.
Assuntos
Euglena gracilis , Íntrons , Euglena gracilis/genética , Sítios de Splice de RNA , Processamento Alternativo , Splicing de RNARESUMO
OBJECTIVE: Current societal guidelines recommend duplex ultrasound (DUS) surveillance beyond 30 days after carotid endarterectomy (CEA) for patients with risk factors for restenosis or who underwent primary closure. However, the appropriate duration of this surveillance has not yet been identified, and the rate at which DUS surveillance prompts intervention is unknown. Multiple calls for decreasing health care spending that does not provide value, including unnecessary testing, have been made. The purpose of this study was to examine the rate of intervention prompted by surveillance DUS on the ipsilateral or contralateral carotid artery after CEA and determine the value of continued surveillance by determining the rate of DUS-prompted intervention. METHODS: A single-center, retrospective chart review of all patients older than 18 years who had undergone CEA from August 2009 to July 2022 was performed. Patients with at least one postoperative duplex in our Intersocietal Accreditation Council-accredited ultrasound lab were included. Exclusion criteria were patients with incomplete medical charts or patients who underwent a concomitant procedure. The primary end point was return to the operating room for subsequent intervention based on abnormal surveillance DUS findings. Secondary end points were the number of postoperative surveillance duplexes, duration of surveillance, and incidence of perioperative stroke. The study participant data were queried for patients who had a diagnosis of stroke that occurred following their procedure. RESULTS: A total 767 patients, accounting for 771 procedures, were included in this study, which resulted in 2145 ultrasound scans. A total of 40 (5.2%) patients required 44 subsequent interventions that were prompted by DUS surveillance scans. The average number of ultrasound scans per patient was 2.8 (range: 0-14), and the average duration of surveillance was 26.4 months (range: 0-155 months). Of the 767 patients, 669 (87.2%) had a unilateral CEA. A total of 62 of 767 (8.1%) patients had planned endarterectomies on the contralateral side based on initial imaging, not prompted by interval DUS surveillance scans. Of 767 patients, 28 (3.7%) patients who underwent CEA had a subsequent procedure for progression of contralateral disease, which was prompted by duplex surveillance scans. The average duration between index CEA and intervention on contralateral carotid was 29.57 months (range: 3-81 months). A total of 11 patients, accounting for 12 procedures, underwent a subsequent procedure for restenosis of their ipsilateral carotid, prompted by duplex surveillance scans. The average duration between index CEA and reintervention on the ipsilateral carotid was 17.9 months (range: 4-70 months). Three of 767 (0.4%) patients in total were identified as having a perioperative stroke. CONCLUSIONS: The overall rate of ipsilateral reintervention after CEA is low. A small percentage of patients will progress their contralateral disease, ultimately requiring surgical intervention. These data suggest that regular duplex surveillance after CEA is warranted for patients with at least moderate contralateral disease; however, the yield is low for ipsilateral restenosis after 36 months based on this single institution study. Further study is needed to better delineate which patients need follow-up to decrease unnecessary testing while still targeting patients most at risk of restenosis or contralateral progression of disease.
Assuntos
Estenose das Carótidas , Endarterectomia das Carótidas , Acidente Vascular Cerebral , Humanos , Endarterectomia das Carótidas/efeitos adversos , Endarterectomia das Carótidas/métodos , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/cirurgia , Estenose das Carótidas/complicações , Estudos Retrospectivos , Artérias Carótidas , Acidente Vascular Cerebral/etiologia , Fatores de Risco , Ultrassonografia Doppler Dupla , Resultado do TratamentoRESUMO
OBJECTIVE: Superficial femoral artery (SFA) stenting is a common treatment for peripheral artery disease. It is effective in the short term; however, in-stent restenosis (ISR) limits long-term success. Surveillance with duplex ultrasound (DUS) can identify patients who develop ISR leading to early reintervention, but data to support this practice is sparce. The purpose of this study was to evaluate whether surveillance and subsequent reintervention improves outcomes in patients with SFA stents. METHODS: A single-center, retrospective study was performed with patients undergoing SFA stenting between 2005 and 2020 who had a follow-up with DUS. Five groups were identified based on the presence of ISR on DUS (ISR vs no ISR [NISR]), recurrence of symptoms (symptomatic [SX] vs asymptomatic [ASX]), and if any reintervention was performed (reintervention [R] vs no reintervention [NR]): (1) ISR+SX+R; (2) ISR+SX+NR; (3) ISR+ASX+R; (4) ISR+ASX+NR; and (5) NISR+NR. The primary endpoint was amputation-free survival, and the secondary endpoint was patency. Predictors of mortality and surveillance were identified by multivariable logistic regressions and Cox multivariate regression models. Survival curves were presented as Kaplan-Meier plots using log-rank test for subgroup comparison. RESULTS: Two hundred fifty-seven patients were included in the analysis. The indication for intervention was claudication in 28% and chronic limb-threatening ischemia in 72%. A total of 161 patients (63%) underwent reintervention for ISR. Of patients who had restenosis on DUS, those who were symptomatic and did not undergo reintervention (ISR+SX+NR) did the worst, with 50% amputation rate. In contrast, those who were asymptomatic but did undergo reintervention (ISR+ASX+R) had the lowest amputation rate of 13%. Active smoking was a predictor of both loss of patency and amputation (1.72; 95% confidence interval [CI], 1.00-2.98; P = .050; 3.55; 95% CI, 1.53-8.25; P = .003). Post procedure dual antiplatelet therapy had a positive association with limb salvage (hazard ratio [HR], 0.23; 95% CI, 0.09-0.58; P = .001), whereas diabetes (HR, 2.61; 95% CI, 1.21-6.01; P = .019), stent occlusion (HR, 17.0; 95% CI, 5.93-63.1; P < .001), and chronic limb-threatening ischemia presentations (HR, 4.31; 95% CI, 1.86-11.7; P=.002) were negatively associated with limb salvage. CONCLUSIONS: Routine surveillance DUS and subsequent reintervention on ISR after SFA stenting is associated with improved patency and amputation-free survival. Surveillance DUS should be routine for patients after stenting, with reintervention strongly considered if ISR is identified for both symptomatic and asymptomatic.
Assuntos
Artéria Femoral , Doença Arterial Periférica , Humanos , Artéria Femoral/diagnóstico por imagem , Artéria Femoral/cirurgia , Isquemia Crônica Crítica de Membro , Estudos Retrospectivos , Resultado do Tratamento , Fatores de Risco , Grau de Desobstrução Vascular , Stents , Doença Arterial Periférica/diagnóstico por imagem , Doença Arterial Periférica/terapia , Constrição PatológicaRESUMO
OBJECTIVE: Selection criteria for carotid duplex ultrasonography screening (DUS) before coronary artery bypass grafting (CABG) is primarily based on limited observational analysis, and the risks associated with carotid artery stenosis (CAS) detected by this approach to preoperative DUS are uncertain. This study aimed to determine the association of carotid DUS with stroke and mortality among patients undergoing CABG. METHODS: Adult patients with coronary artery disease who underwent isolated CABG or CABG with concomitant valvular or congenital procedure were identified. CHA2DS2-VASc score was assessed before CABG, and patients were recorded as high risk if they had a score of 3 or higher. The primary outcomes were stroke and all-cause mortality. Secondary outcomes included ischemic stroke, non-ischemic stroke, transient ischemic attack, and cardiovascular mortality. RESULTS: Among 8958 patients who underwent CABG, 70.9% (n = 6347) received carotid DUS preoperatively (low-risk, 57.3%; high-risk, 42.7%). In the low-risk cohort, there was no significant difference in the risk of stroke (20.7 per 1000 patient-years for CAS vs 13.1 per 1000 patient-years for no CAS; adjusted hazard ratio [aHR], 1.14; 95% confidence interval [CI], 0.78-1.68) or mortality (20.5 per 1000 patient-years for CAS vs 16.8 per 1000 patient-years for no CAS; aHR, 1.33; 95% CI, 0.97-1.83) at 15 years. In the high-risk cohort, CAS was associated with significantly higher risks of stroke at 30 days (433.2 vs 279.5 per 1000 patient-years; aHR, 1.92; 95% CI, 1.00-3.70) and mortality at 15 years (38.4 vs 32.7 per 1000 patient-years; aHR, 1.25; 95% CI, 1.01-1.57) compared with no CAS. CONCLUSIONS: CAS did not impact the incidence of stroke or mortality in the low-risk cohort who underwent CABG. However, in the high-risk cohort, CAS was associated with a significant increase in the risks of 30-day stroke and 15-year mortality, indicating selective carotid DUS is necessarily recommended for these patients.
Assuntos
Estenose das Carótidas , Ponte de Artéria Coronária , Doença da Artéria Coronariana , Valor Preditivo dos Testes , Acidente Vascular Cerebral , Ultrassonografia Doppler Dupla , Humanos , Masculino , Feminino , Ponte de Artéria Coronária/mortalidade , Ponte de Artéria Coronária/efeitos adversos , Idoso , Medição de Risco , Estenose das Carótidas/diagnóstico por imagem , Estenose das Carótidas/mortalidade , Estenose das Carótidas/complicações , Estenose das Carótidas/cirurgia , Pessoa de Meia-Idade , Fatores de Risco , Estudos Retrospectivos , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/etiologia , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/mortalidade , Doença da Artéria Coronariana/cirurgia , Doença da Artéria Coronariana/complicações , Resultado do Tratamento , Fatores de TempoRESUMO
Nucleic acids, with their unique duplex structure, which is key for information replication, have sparked interest in self-replication's role in life's origins. Early template-based replicators, initially built on short oligonucleotides, expanded to include peptides and synthetic molecules. We explore here the potential of a class of synthetic duplex-forming oligoanilines, as self-replicators. We have recently developed oligoanilines equipped with 2-trifluoromethylphenol-phosphine oxide H-bond base pairs and we investigate whether the imine formed between aniline and aldehyde complementary monomers can self-replicate. Despite lacking a clear sigmoidal kinetic profile, control experiments with a methylated donor and a competitive inhibitor support self-replication. Further investigations with the reduced aniline dimer demonstrate templated synthesis, revealing a characteristic parabolic growth. After showing sequence selective duplex formation, templated synthesis and the emergence of catalytic function, the self-replication behaviour further suggests that the unique properties of nucleic acids can be paralleled by synthetic recognition-encoded molecules.
RESUMO
A guanine-rich oligonucleotide based on a human telomeric sequence but with the first three-nucleotide intervening stretch replaced by a putative 15-nucleotide hairpin-forming sequence shows a pH-dependent folding into different quadruplex-duplex hybrids in a potassium containing buffer. At slightly acidic pH, the quadruplex domain adopts a chair-type conformation. Upon increasing the pH, a transition with a midpoint close to neutral pH to a major and minor (3+1) hybrid topology with either a coaxially stacked or orthogonally oriented duplex stem-loop occurs. NMR-derived high-resolution structures reveal that an adenine protonation is prerequisite for the formation of a non-canonical base quartet, capping the outer G-tetrad at the quadruplex-duplex interface and stabilizing the antiparallel chair conformation in an acidic environment. Being directly associated with interactions at the quadruplex-duplex interface, this unique pH-dependent topological transition is fully reversible. Coupled with a conformation-sensitive optical readout demonstrated as a proof of concept using the fluorescent dye thiazole orange, the present quadruplex-duplex hybrid architecture represents a potentially valuable pH-sensing system responsive in a physiological pH range of 7±1.
Assuntos
Quadruplex G , Concentração de Íons de Hidrogênio , Humanos , Benzotiazóis/química , DNA/química , Oligonucleotídeos/química , Quinolinas/química , Conformação de Ácido Nucleico , Corantes Fluorescentes/química , Telômero/química , Guanina/química , Espectroscopia de Ressonância MagnéticaRESUMO
BACKGROUND: Patients with lower extremity arterial disease (LEAD) frequently require revascularization procedures. Currently used diagnostic methods are insufficient in predicting successful outcomes and focus on macrovascular rather than microvascular state. Several promising modalities to increase diagnostic accuracy are emerging, including maximal systolic acceleration (ACCmax), measured by duplex ultrasound (DUS). For the assessment of tissue perfusion, near-infrared fluorescence (NIR) imaging using indocyanine green (ICG) demonstrates promising results. This study aims to identify the usefulness of combining these two methods for macrovascular and microvascular perfusion assessment to predict successful clinical outcomes. METHODS: A retrospective study was performed collecting preinterventional and postinterventional DUS and ICG NIR fluorescence imaging measurements from LEAD patients undergoing revascularization. The correlation between the preinterventional and postinterventional perfusion parameters, described as the delta (Δ) ACCmax and ΔICG NIR fluorescence parameters, were analyzed. Improvements in perfusion parameters were compared to clinical outcomes, defined as improvement in pain-free walking distance, freedom from rest pain, or tendency toward wound and ulcer healing. RESULTS: A total of 38 patients (42 limbs) were included. ACCmax and ICG NIR fluorescence perfusion parameters improved significantly after revascularization (p<0.001). Patients with a poor clinical outcome had a significantly lower improvement of both parameters after revascularization (p<0.001-0.016). Lack of correlation was found between the delta of ACCmax and ICG NIR fluorescence imaging. Multiple non-congruent improvements of macrovascular parameters (ACCmax) and perfusion (ICG NIR fluorescence) were seen within patients. However, for all patients with a successful clinical outcome, at least one parameter improved. CONCLUSION: Combining ACCmax and ICG NIR fluorescence imaging revealed improvement in at least one parameter within all patients with a successful clinical outcome. This study highlights the potential of assessing both the macrovascular state and tissue perfusion following lower extremity revascularization, as both appear to reflect different aspects of vascularization. CLINICAL IMPACT: Numerous techniques have been developed to assess tissue perfusion to predict clinical outcomes following revascularization in patients with peripheral artery disease. However, none are widely implemented in clinical practice. This study emphasized the importance of employing multiple modalities from different perspectives for more accurate prediction. By focusing on both the macrovascular state and tissue perfusion, clinicians can better guide themselves in their treatment strategies.
RESUMO
BACKGROUND: Natural DNA restriction enzymes bind duplex DNA with high affinity at multiple sites; however, for some of the artificial chemical-based restriction moieties, invasion of the double-strand for efficient cleavage is an obstacle. We have previously reported photo-induced double-duplex invasion (pDDI) using 3-cyanovinylcarbazole (K)-containing probes for both the target strands that photo-crosslink with pyrimidine bases in a sequence-specific manner on both the strands, stabilizing the opened double-strand for cleavage. The drawback of the pDDI was low efficiency due to inter-probe cross-linking, solved by the inclusion of 5-cyano-uridine at -1 position on the complimentary strand with respect to K in both probes. Although this led to reduced inter-probe cross-linking, the pDDI efficiency was still low. RESULTS: Here, we report that inter-probe cross-linking and intra-probe cross-linking of a single probe is also leading to reduced pDDI efficiency. We addressed this problem by designing DDI probes to inhibit both inter-probe and intra-probe cross-linking. CONCLUSION: Based on the new design of pDDI probe with 5-cyano uridine led to a drastic increase in the efficiency of pDDI in (400-mer) double-stranded DNA with only 1 s of photo-irradiation.
Assuntos
Carbazóis , DNA , Reagentes de Ligações Cruzadas , DNA/química , Carbazóis/químicaRESUMO
The frequent mutations in SARS-CoV-2 significantly increase the virus's pathogenicity and transmissibility while also diminishing the effectiveness of vaccines. Consequently, assays capable of rapidly and simultaneously identifying multiple SARS-CoV-2 variants are essential for large-scale applications that aim to monitor the evolution of the virus. In this work, we propose a method combining duplex-specific nuclease (DSN)-assisted cyclic amplification with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) detection, enabling the simultaneous identification of multiple SARS-CoV-2 variants at high-throughput. Due to the high specificity of DSN, single-base mutations can be resolved by the method. With ultra-sensitive detection by MALDI-TOF MS, a limit of detection of 100 pM viral RNA fragment was demonstrated. The assay was used for simultaneous identification and typing of SARS-CoV-2 Alpha, Beta, and Delta variants. The whole assay can be accomplished within 3 h, and the amplification is performed under constant temperature, making the technique simple in operation and efficient. It is also feasible to extend the technique to the detection of many other variants of the virus. We expect that the method can add value to the rapid screening of viral variants and can play an important role in pandemic control.
Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodos , SARS-CoV-2/genética , COVID-19/diagnósticoRESUMO
BACKGROUND: Children frequently undergo routine Doppler-ultrasound (DUS) after liver transplantation (LT) for which they are fasted, but this may cause hunger and discomfort. OBJECTIVE: To determine if DUS measurements, with focus on the portal vein (PV), are affected by prandial changes, and if this affects distress and feasibility of the DUS. MATERIALS AND METHODS: Children were prospectively included to undergo a pre- and postprandial DUS on the same day at 6 months after LT. Pre- and anastomotic PV peak systolic velocity (PSV), and hepatic artery and hepatic vein DUS measurements were obtained. Pre- and postprandial measurements, and relative postprandial change of PV velocity ratio (VR) compared to PV anastomotic PSV, were compared using paired-sample t-tests and intraclass correlation coefficients (ICC). Obscuration by bowel gas, difficulty of DUS, and impact of fasting were assessed using 5-point rating scales. RESULTS: Twenty-eight children (median age 3.5 years, IQR 1.6-10.8) were included; four were subsequently excluded because they were not fasted (N = 2) or withdrew consent for the second DUS (N = 2). Measurements between pre- and postprandial DUS, and relative postprandial change of VR compared to PV anastomotic PSV, were not significantly different (p > .05). Test consistency was good (ICC = 0.69, 95% CI = 0.29-0.67) for PV anastomotic PSV, and excellent (95% CI = 0.61-0.93) for PV VR. Obscuration by bowel gas or ease of DUS did not change after eating (p > .05). The majority (16/28, 57.2%) found fasting difficult, and several (13/28, 46.4%) got upset when fasted. CONCLUSION: Children with an LT do not need to be fasted for routine DUS, which may decrease the burden of the examination.
Assuntos
Transplante de Fígado , Humanos , Criança , Pré-Escolar , Velocidade do Fluxo Sanguíneo , Estudos Retrospectivos , Ultrassonografia Doppler , Jejum , Valor Preditivo dos TestesRESUMO
BACKGROUND: Tuberculosis in cattle is caused by Mycobacterium tuberculosis complex (MTBC) species. Apart from MTBC, different Nontuberculous Mycobacteria (NTM) species have also been isolated from cattle. The presence of NTM infection in bovines makes the diagnosis of bovine tuberculosis (bTB) a cumbersome task. Therefore, a cross sectional study was conducted to isolate and characterize different Mycobacterium spp. from a slaughterhouse situated in Kolkata, a city in the eastern part of India. RESULTS: Out of 258 morbid samples, 98 isolates were found to be positive for bacterial growth, and 35% (n = 34) were positive for Mycobacterium. 94% of Mycobacterial cultural isolates were NTM (n = 32), and the rest (n = 2) were found to be MTBC. Species-level identification of the isolates by hsp65 sequencing revealed that out of 32 isolates, 24 were M. fortuitum, three were M. abscessus, two each were M. chelonae and M. parascrofulaceum, and one was M. novocastrense. A phylogenetic tree with partial hsp65 gene sequences was also constructed to determine the relatedness of the unknown isolates to the reference strains. CONCLUSION: Both NTM species and MTBCs were identified from TB-like lesions in cattle that were slaughtered at the Kolkata abattoir. This discovery may indicate that NTM contributes to the development of lesions in cattle. Also, we recommend implication of more specific diagnostic tests for bTB.
Assuntos
Matadouros , Mycobacterium , Filogenia , Tuberculose Bovina , Animais , Bovinos , Tuberculose Bovina/microbiologia , Tuberculose Bovina/diagnóstico , Índia/epidemiologia , Estudos Transversais , Mycobacterium/isolamento & purificação , Mycobacterium/genética , Mycobacterium/classificação , Chaperonina 60/genética , Micobactérias não Tuberculosas/isolamento & purificação , Micobactérias não Tuberculosas/genética , Micobactérias não Tuberculosas/classificação , Proteínas de Bactérias/genéticaRESUMO
BACKGROUND: Bilateral duplicated kidney and ureter is a rare condition in urology, and it is even rarer for patients to have multiple stones simultaneously. We delineate the diagnostic and therapeutic trajectory of a patient presenting with bilateral duplex kidneys and ureters, characterized by the presence of multiple stones. Notably, the left kidney is a complete duplication, whereas the right kidney exhibits an incomplete duplication. CASE PRESENTATION: A 47-year-old male patient was diagnosed with bilateral duplex kidney and ureter combined with multiple stones. Ureteral flexible lithotripsy and percutaneous nephrolithotomy were performed successively in our hospital. On the postoperative five day, he was discharged from the hospital without apparent discomfort.The double J tube was pulled out one month later, and no stone recurrence was found after 3 months of follow-up. CONCLUSIONS: Bilateral duplicated renal ureteral malformations combined with multiple stones are very rare. Stones can be removed by ureteroscopic lithotripsy or percutaneous nephrolithotripsy and sometimes multiple procedures are required, which should be chosen according to the patient's relevant condition.
Assuntos
Cálculos Renais , Rim , Ureter , Cálculos Ureterais , Humanos , Masculino , Pessoa de Meia-Idade , Ureter/anormalidades , Ureter/diagnóstico por imagem , Rim/anormalidades , Rim/diagnóstico por imagem , Cálculos Ureterais/diagnóstico por imagem , Cálculos Ureterais/complicações , Cálculos Ureterais/terapia , Cálculos Renais/diagnóstico por imagem , Cálculos Renais/cirurgia , Cálculos Renais/complicações , Nefrolitotomia Percutânea , Litotripsia/métodosRESUMO
BACKGROUND: This research investigates the correlation between the severity of internal carotid artery (ICA) stenosis and retinal parameters in patients with proliferative diabetic retinopathy (PDR), aiming to uncover potential risk factors. METHODS: A retrospective analysis of 68 patients (136 eyes) diagnosed with bilateral PDR from January 1, 2017, to December 31, 2021, was conducted. Carotid artery stenosis (CAS) was assessed using neck computed tomography angiography (CTA) and carotid duplex ultrasound (CDUS), with stenosis classified into two groups: normal (group 1) and mild or above (group 2), based on the North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Optical coherence tomography (OCT) and OCT angiography (OCTA) measured several retinal parameters, including sub foveal choroidal thickness (SFCT), retinal nerve fiber layer (RNFL) thickness, ganglion cell-inner plexiform layer (GCIPL) thickness, vessel density (VD), and foveal avascular zone (FAZ) area. Statistical analyses determined correlations between ICA degrees and retinal parameters. RESULTS: This study showed significant differences between groups in total VD, FAZ area, total RNFL thickness, and temporal RNFL thickness, indicating that patients with more severe ICA stenosis had noticeable retinal changes. Other parameters such as hyperlipidemia, total cholesterol levels, and intraocular pressure (IOP) also differed significantly, while no notable differences were observed in SFCT, central VD, average GCIPL, and superior, nasal, and inferior RNFL thickness. CONCLUSION: The study findings highlight retinal changes, such as an increased FAZ area, decreased total VD, and a total and thinner temporal RNFL, which suggest the need for carotid artery evaluation in patients. These findings have important clinical implications for the need for carotid work up in patients with PDR.
Assuntos
Estenose das Carótidas , Diabetes Mellitus , Retinopatia Diabética , Humanos , Retinopatia Diabética/complicações , Retinopatia Diabética/diagnóstico , Estudos Retrospectivos , Tomografia de Coerência Óptica/métodos , Estenose das Carótidas/complicações , Estenose das Carótidas/diagnóstico por imagem , Constrição Patológica , Angiografia , Fatores de Risco , Vasos Retinianos , Angiofluoresceinografia/métodosRESUMO
OBJECTIVES: The current study aims to investigate the value of penile elastography in assessing the fibrotic changes in the corpora cavernosa. PATIENTS AND METHODS: Eighty participants were included in the study. These were divided into two equal groups: a study group (group 1) included patients with ED who did not respond to intracavernosal injection (ICI), and an age-matched control group (group 2) included age-matched subjects with normal erection. All subjects answered an International Index of Erectile Function-5 (IIEF-5) questionnaire. The first group was evaluated by two ICI trials of 1 mL Quadmix, each took place 1 week apart, followed by a color duplex/Doppler ultrasonography (CDDU) scan using also a 1 mL Quadmix. All the above was done a week before the penile shear wave elastography (SWE) scan. It comprised a 12-section scan of both corpora cavernosa. Each corpus was scanned in three different segments (proximal, mid-shaft, and distal), and in both longitudinal and transverse axes. RESULTS: Comparisons of the laboratory data were non-significant, apart from the glycosylated hemoglobin which proved significant (P value <.001) in both groups. Also, the IIEF-5 scores were significantly lower in the study group (P value <.001). Significantly higher SWE readings (indicating higher fibrotic) were found in the study group compared with the control group in almost all of the scanned segments and their combinations (P value <.05). CONCLUSION: SWE can effectively assess the fibrotic changes occurring in the corpora cavernosa. Hence, SWE could be utilized as a modality that helps diagnose patients with ED.