RESUMO
Most eukaryotic promoter regions are divergently transcribed. As the RNA polymerase II pre-initiation complex (PIC) is intrinsically asymmetric and responsible for transcription in a single direction, it is unknown how divergent transcription arises. Here, the Saccharomyces cerevisiae Mediator complexed with a PIC (Med-PIC) was assembled on a divergent promoter and analyzed by cryoelectron microscopy. The structure reveals two distinct Med-PICs forming a dimer through the Mediator tail module, induced by a homodimeric activator protein localized near the dimerization interface. The tail dimer is associated with â¼80-bp upstream DNA, such that two flanking core promoter regions are positioned and oriented in a suitable form for PIC assembly in opposite directions. Also, cryoelectron tomography visualized the progress of the PIC assembly on the two core promoter regions, providing direct evidence for the role of the Med-PIC dimer in divergent transcription.
Assuntos
RNA Polimerase II , Proteínas de Saccharomyces cerevisiae , RNA Polimerase II/metabolismo , Microscopia Crioeletrônica , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Regiões Promotoras Genéticas , Transcrição Gênica , Complexo Mediador/genética , Iniciação da Transcrição GenéticaRESUMO
The multisubunit Mediator, comprising â¼30 distinct proteins, plays an essential role in gene expression regulation by acting as a bridge between DNA-binding transcription factors and the RNA polymerase II (RNAPII) transcription machinery. Efforts to uncover the Mediator mechanism have been hindered by a poor understanding of its structure, subunit organization, and conformational rearrangements. By overcoming biochemical and image analysis hurdles, we obtained accurate EM structures of yeast and human Mediators. Subunit localization experiments, docking of partial X-ray structures, and biochemical analyses resulted in comprehensive mapping of yeast Mediator subunits and a complete reinterpretation of our previous Mediator organization model. Large-scale Mediator rearrangements depend on changes at the interfaces between previously described Mediator modules, which appear to be facilitated by factors conducive to transcription initiation. Conservation across eukaryotes of Mediator structure, subunit organization, and RNA polymerase II interaction suggest conservation of fundamental aspects of the Mediator mechanism.
Assuntos
Complexo Mediador/química , Complexo Mediador/ultraestrutura , Microscopia Crioeletrônica , Células HeLa , Humanos , Complexo Mediador/metabolismo , Modelos Moleculares , Mapeamento de Interação de Proteínas , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
The mechanistic understanding of nascent RNAs in transcriptional control remains limited. Here, by a high sensitivity method methylation-inscribed nascent transcripts sequencing (MINT-seq), we characterized the landscapes of N6-methyladenosine (m6A) on nascent RNAs. We uncover heavy but selective m6A deposition on nascent RNAs produced by transcription regulatory elements, including promoter upstream antisense RNAs and enhancer RNAs (eRNAs), which positively correlates with their length, inclusion of m6A motif, and RNA abundances. m6A-eRNAs mark highly active enhancers, where they recruit nuclear m6A reader YTHDC1 to phase separate into liquid-like condensates, in a manner dependent on its C terminus intrinsically disordered region and arginine residues. The m6A-eRNA/YTHDC1 condensate co-mixes with and facilitates the formation of BRD4 coactivator condensate. Consequently, YTHDC1 depletion diminished BRD4 condensate and its recruitment to enhancers, resulting in inhibited enhancer and gene activation. We propose that chemical modifications of eRNAs together with reader proteins play broad roles in enhancer activation and gene transcriptional control.
Assuntos
Adenosina/análogos & derivados , Proteínas de Ciclo Celular/genética , Proteínas do Tecido Nervoso/genética , Fatores de Processamento de RNA/genética , RNA/genética , Fatores de Transcrição/genética , Adenosina/genética , Elementos Facilitadores Genéticos/genética , Regulação da Expressão Gênica/genética , Humanos , Metilação , Elementos Reguladores de Transcrição/genética , Ativação Transcricional/genéticaRESUMO
The RB1 gene is frequently mutated in human cancers but its role in tumorigenesis remains incompletely defined. Using an induced pluripotent stem cell (iPSC) model of hereditary retinoblastoma (RB), we report that the spliceosome is an up-regulated target responding to oncogenic stress in RB1-mutant cells. By investigating transcriptomes and genome occupancies in RB iPSCderived osteoblasts (OBs), we discover that both E2F3a, which mediates spliceosomal gene expression, and pRB, which antagonizes E2F3a, coregulate more than one-third of spliceosomal genes by cobinding to their promoters or enhancers. Pharmacological inhibition of the spliceosome in RB1-mutant cells leads to global intron retention, decreased cell proliferation, and impaired tumorigenesis. Tumor specimen studies and genome-wide TCGA (The Cancer Genome Atlas) expression profile analyses support the clinical relevance of pRB and E2F3a in modulating spliceosomal gene expression in multiple cancer types including osteosarcoma (OS). High levels of pRB/E2F3aregulated spliceosomal genes are associated with poor OS patient survival. Collectively, these findings reveal an undiscovered connection between pRB, E2F3a, the spliceosome, and tumorigenesis, pointing to the spliceosomal machinery as a potentially widespread therapeutic vulnerability of pRB-deficient cancers.
Assuntos
Neoplasias Ósseas , Carcinogênese , Fator de Transcrição E2F3 , Regulação Neoplásica da Expressão Gênica , Células-Tronco Pluripotentes Induzidas , Osteossarcoma , Proteínas de Ligação a Retinoblastoma , Spliceossomos , Ubiquitina-Proteína Ligases , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Carcinogênese/genética , Fator de Transcrição E2F3/genética , Fator de Transcrição E2F3/metabolismo , Genes do Retinoblastoma , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Mutação , Osteossarcoma/genética , Osteossarcoma/patologia , Neoplasias da Retina/genética , Retinoblastoma/genética , Proteínas de Ligação a Retinoblastoma/genética , Proteínas de Ligação a Retinoblastoma/metabolismo , Spliceossomos/genética , Spliceossomos/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
AIMS: To identify the trajectories of body mass index (BMI) and waist circumference (WC), and assess the associations of BMI trajectory, WC trajectory, or the two combined, with type 2 diabetes mellitus (T2DM) risk in Chinese adults. MATERIALS AND METHODS: This study was based on a prospective project-the Prediction for Atherosclerotic Cardiovascular Disease Risk in China (China-PAR). A total of 54 434 participants (39.21% men) who were measured on at least two occasions were included. Three slowly increasing trajectory patterns were identified for BMI, and four for WC, by latent mixed modelling. A nine-category variable was derived by combining the WC trajectory (low, moderate, moderate-high/high) and the BMI trajectory (low, moderate, high). Logistic regression models were applied to estimate the odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: The risk of developing T2DM increased with elevated BMI or WC trajectory levels (all ptrend <0.001). The risks were 2.85 (2.59-3.14) for high BMI trajectory and 4.34 (3.78-4.99) for high WC trajectory versus low trajectory groups, respectively. The association was more pronounced among younger individuals (pinteraction <0.001). In the joint analysis, compared to participants with low WC and BMI trajectory, those with moderate-high/high WC combined with high BMI trajectory had the highest risk of T2DM (OR 3.96, 95% CI 3.48-4.50); even those who maintained moderate-high/high WC but low BMI trajectory showed a higher T2DM risk (OR 3.00, 95% CI 2.31-3.91). CONCLUSIONS: This study suggests that simultaneous dynamic and continuous monitoring of BMI and WC may contribute more than single measurements to predicting T2DM risk and determining preventive strategies.
Assuntos
Diabetes Mellitus Tipo 2 , Adulto , Masculino , Humanos , Feminino , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/epidemiologia , Fatores de Risco , Índice de Massa Corporal , Circunferência da Cintura , Estudos Prospectivos , China/epidemiologiaRESUMO
Disturbances in chondrocyte extracellular matrix (ECM) metabolism in osteoarthritis (OA) are a major cause of OA and potentially lead to personal disability, placing a huge burden on society. Chondrocyte apoptosis and ECM catabolism have a major role in the OA process. Firstly, bioinformatics analysis was performed to screen differentially expressed genes (DEGs) in OA, and serine palmitoyltransferase subunit 2 (SPTLC2) was chosen, which had high-level expression in the OA cartilage tissues and OA chondrocytes. Overexpression and knockdown of SPTLC2 were achieved in OA chondrocytes and normal chondrocytes respectively to study the effect of SPTLC2 upon ECM metabolism of chondrocytes. Cell viability and apoptosis were measured using MTT and flow cytometry analyses; SPTLC2 overexpression enhanced the OA chondrocyte viability and decreased apoptotic rate. In addition, Western blot detection of ECM-related factors (Collagen I, Collage II, MMP-1, MMP-3, and MMP-13) revealed that SPTLC2 overexpression promoted the expression of collagens (Collagen I and Collage II) and suppressed matrix metalloproteinase (MMP-1, MMP-3, and MMP-13) level. In contrast, SPTLC2 knockdown in normal chondrocytes showed opposite effects on cell viability, apoptosis, and ECM degeneration. The articular cartilage of OA rats was transfected with lentivirus overexpressing SPTLC2; HE and Safranin-O fast green demonstrated that SPTLC2 overexpression could alleviate chondrocyte injuries and slow down the development of OA. In conclusion, SPTLC2 plays a role in OA and may be a potential target gene for the treatment of OA.
Assuntos
Cartilagem Articular , Osteoartrite , Ratos , Animais , Condrócitos/metabolismo , Metaloproteinase 13 da Matriz/genética , Metaloproteinase 1 da Matriz/metabolismo , Metaloproteinase 3 da Matriz/genética , Osteoartrite/genética , Osteoartrite/metabolismo , Matriz Extracelular/metabolismo , Cartilagem Articular/metabolismo , Apoptose/genéticaRESUMO
BACKGROUND: Aberrant DNA methylation is a vital molecular alteration commonly detected in type I endometrial cancers (EC), and tet methylcytosine dioxygenase 2 (TET2) and 5-hydroxymethylcytosine (5hmC) play significant roles in DNA demethylation. However, little is known about the function and correlation of TET2 and 5hmC co-expressed in EC. This study intended to investigate the clinical significance of TET2 and 5hmC in EC. METHODS: The levels of TET2 and 5hmC were detected in 326 endometrial tissues by immumohistochemistry, and the correlation of their level was detected by Pearson analysis. The association between the levels of TET2 and 5hmC and clinicopathologic characteristics was analyzed. Prognostic value of TET2 and 5hmC was explored by Kaplan-Meier analysis. The Cox proportional hazard regression model was used for univariate and multivariate analyses. RESULTS: Based on the analysis results, TET2 protein level was positively correlated with 5hmC level in EC tissues (r = 0.801, P < 0.001). TET2+5hmC+ (high TET2 and high 5hmC) association was significantly associated with well differentiation, myometrial invasion, negative lymph node metastasis, and tumor stage in EC. Association of TET2 and 5hmC was confirmed as a prognostic factor (HR = 2.843, 95%CI = 1.226-3.605, P = 0.007) for EC patients, and EC patients with TET2-5hmC- level had poor overall survival. CONCLUSIONS: In summary, the association of TET2 and 5hmC was downregulated in EC tissues, and may be a potential poor prognostic indicator for EC patients. Combined detection of TET2 and 5hmC may be valuable for the diagnosis and prognosis of EC.
Assuntos
5-Metilcitosina , Carcinoma Endometrioide , Dioxigenases , Neoplasias do Endométrio , Feminino , Humanos , 5-Metilcitosina/análogos & derivados , Carcinoma Endometrioide/genética , Relevância Clínica , Dioxigenases/genética , Dioxigenases/metabolismo , Metilação de DNA , Proteínas de Ligação a DNARESUMO
PURPOSE: This study aimed to explore the relationships between lumbar lordosis (LL) correction and improvement of postoperative global sagittal alignment and to establish corresponding linear regressions to predict the change in global tilt (GT) based on the corrected LL following adult spinal deformity (ASD) surgery. METHODS: A total of 240 ASD patients who underwent lumbar correction were enrolled in this multicentre study. The following sagittal parameters were measured pre- and postoperatively: thoracic kyphosis (TK), LL, upper and lower LL (ULL and LLL), pelvic tilt (PT), sagittal vertical axis (SVA) and GT. The correlations among the changes in GT (â³GT), SVA (â³SVA), PT (â³PT), TK (â³TK), LL (â³LL), ULL (â³ULL) and LLL (â³LLL) were assessed, and linear regressions were conducted to predict â³GT, â³SVA, â³PT and â³TK from â³LL, â³ULL and â³LLL. RESULTS: â³LL was statistically correlated with â³GT (r = 0.798, P < 0.001), â³SVA (r = 0.678, P < 0.001), â³PT (r = 0.662, P < 0.001) and â³TK (r = - 0.545, P < 0.001), and the outcomes of the linear regressions are: â³GT = 3.18 + 0.69 × â³LL (R2 = 0.636), â³SVA = 4.78 + 2.57 × â³LL (R2 = 0.459), â³PT = 2.57 + 0.34 × â³LL (R2 = 0.439), â³TK = 7.06-0.43 × â³LL (R2 = 0.297). In addition, â³LLL had more correlations with â³GT, â³SVA and â³PT, while â³ULL had more correlations with â³TK. CONCLUSION: Surgical correction of LL could contribute to the restoration of global sagittal morphology following ASD surgery. These models were established to predict the changes in sagittal parameters, in particular â³GT, determined by â³LL, which has not been previously done and may help to customize a more precise correction plan for ASD patients.
Assuntos
Cifose , Lordose , Piperidinas , Adulto , Animais , Humanos , Lordose/diagnóstico por imagem , Lordose/cirurgia , Cifose/diagnóstico por imagem , Cifose/cirurgia , Catecóis , Modelos LinearesRESUMO
BACKGROUND: For patients with multilevel degenerative cervical myelopathy, laminectomy and posterior cervical fusions (PCF) with instrumentation are widely accepted techniques for symptom relief. However, hardware failure is not rare and results in neck pain or even permanent neurological lesions. There are no in-depth studies of hardware-related complications following laminectomy and PCF with instrumentation. METHODS: The present study was a retrospective, single centre, observational study. Patients who underwent laminectomy and PCF with instrumentation in a single institution between January 2019 and January 2021 were included. Patients were divided into hardware failure and no hardware failure group according to whether there was a hardware failure. Data, including sex, age, screw density, end vertebra (C7 or T1), cervical sagittal alignment parameters (C2-C7 cervical lordosis, C2-C7 sagittal vertical axis, T1 slope, Cervical lordosis correction), regional Hounsfield units (HU) of the screw trajectory and osteoporosis status, were collected and compared between the two groups. RESULTS: We analysed the clinical data of 56 patients in total. The mean overall follow-up duration was 20.6 months (range, 12-30 months). Patients were divided into the hardware failure group (n = 14) and no hardware failure group (n = 42). There were no significant differences in the general information (age, sex, follow-up period) of patients between the two groups. The differences in fusion rate, fixation levels, and screw density between the two groups were not statistically significant (p > 0.05). The failure rate of fixation ending at T1 was lower than that at C7 (9% vs. 36.3%) (p = 0.019). The regional HU values of the pedicle screw (PS) and lateral mass screw (LMS) in the failure group were lower than those in the no failure group (PS: 267 ± 45 vs. 368 ± 43, p = 0.001; LMS: 308 ± 53 vs. 412 ± 41, p = 0.001). The sagittal alignment parameters did not show significant differences between the two groups before surgery or at the final follow-up (p > 0.05). The hardware failure rate in patients without osteoporosis was lower than that in patients with osteoporosis (14.3% vs. 57.1%) (p = 0.001). CONCLUSIONS: Osteoporosis, fixation ending at C7, and low regional HU value of the screw trajectory were the independent risk factors of hardware failure after laminectomy and PCF. Future studies should illuminate if preventive measures targeting these factors can help reduce hardware failure and identified more risk factors, and perform long-term follow-up.
Assuntos
Lordose , Osteoporose , Parafusos Pediculares , Fusão Vertebral , Humanos , Laminectomia/efeitos adversos , Laminectomia/métodos , Lordose/diagnóstico por imagem , Lordose/etiologia , Lordose/cirurgia , Estudos Retrospectivos , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Vértebras Cervicais/patologia , Fusão Vertebral/efeitos adversos , Fusão Vertebral/métodos , Parafusos Pediculares/efeitos adversos , Osteoporose/complicaçõesRESUMO
BACKGROUND: Intervertebral disc degeneration and sarcopenia are both age-related diseases without effective treatments. Their comorbidities may worsen the prognosis, and further studies on interaction and therapy are needed. The purpose of the study was to investigate the prevalence of sarcopenia in intervertebral disc degeneration, and to compare the characteristics of intervertebral disc degeneration with and without sarcopenia and effects of interferential current. METHODS: One hundred twenty disc degeneration patients were included from 2021 to 2022 in a single institute. Medical records, examination results and radiological reports were reviewed. Patients with sarcopenia were screened and grouped according to Asian Working Group for Sarcopenia 2019. VAS, ODI, SARC-F, SMI, gait speed (GS), grip strength, disc Pfirrmann grading, standard cross-sectional area (SCSA), degree of fatty infiltration (DFF), and nerve conduction velocity (NCV) were assessed before and after treatment. RESULTS: The prevalence of sarcopenia in intervertebral disc degeneration was 28.3%. The difference of VAS, ODI, disc Pfirrmann grading, SCSA, DFF and NCV between two groups were significant before intervention (P < 0.05), SCSA and DFF were related to the degree of disc degeneration. The improvement of SMI, GS, grip strength, VAS, SARC-F and ODI in intervertebral disc degeneration with sarcopenia group was significant after intervention, as well as SMI, GS, grip strength, VAS and ODI in those without sarcopenia (P < 0.05). The improvement of grip strength, GS, ODI and SARC-F in intervertebral disc degeneration with sarcopenia group were greater than the one without sarcopenia (P < 0.05), whereas there was no significance in improvement degree of other indicators between the two groups (P > 0.05). CONCLUSION: The prevalence of sarcopenia was high in intervertebral disc degeneration, and paravertebral muscles degeneration correlated with the degree of disc degeneration. Compared to those without sarcopenia, intervertebral disc degeneration patients with sarcopenia have more severe pain, poorer mobility and neurological function. Interferential current is effective in intervertebral disc degeneration patients and sarcopenia patients.
Assuntos
Degeneração do Disco Intervertebral , Disco Intervertebral , Sarcopenia , Humanos , Idoso , Degeneração do Disco Intervertebral/diagnóstico por imagem , Degeneração do Disco Intervertebral/epidemiologia , Estudos Retrospectivos , Sarcopenia/diagnóstico por imagem , Sarcopenia/epidemiologia , Vértebras Lombares , Resultado do TratamentoRESUMO
BACKGROUND: To find out if three-dimensional printing (3DP) off-the-shelf (OTS) prosthesis is superior to titanium mesh cages in anterior cervical corpectomy and fusion (ACCF) when treating single-segment degenerative cervical spondylotic myelopathy (DCSM). METHODS: DCSM patients underwent ACCF from January 2016 to January 2019 in a single center were included. Patients were divided into the 3DP group (28) and the TMC group (23). The hospital stays, operation time, intraoperative blood loss, and the cost of hospitalization were compared. The Japanese Orthopedic Association (JOA) scores and Neck Disability Index (NDI) were recorded pre-operatively, 1 day, 3, 6, 12, and 24 months post-operatively. Radiological data was measured to evaluate fusion, subsidence, and cervical lordosis. Patients were sent with SF-36 to assess their health-related quality of life (HRQoL). RESULTS: The differences in operative time, intraoperative blood loss, and hospital stay were not statistically significant between groups (p > 0.05). Postoperative dysphagia occurred in 2 cases in the 3DP group and 3 cases in the TMC group, which all relieved one week later. The difference in improvement of JOA and NDI between the two groups was not statistically significant (p > 0.05). No hardware failure was found and bony fusion was achieved in all cases except one in the 3DP group. The difference in cervical lordosis (CL), fused segmental angle (FSA), mean vertebral height (MVH), and subsidence rates between groups at each follow-up time point was not statistically significant and the results of the SF-36 were similar (p > 0.05). The total cost was higher in the 3DP group with its higher graft cost (p < 0.05). CONCLUSION: In treating single-segment DCSM with ACCF, both 3DP OTS prosthesis and TMC achieved satisfactory outcomes. However, the more costly 3DP OTS prosthesis was not able to reduce subsidence as it claimed.
Assuntos
Membros Artificiais , Lordose , Doenças da Medula Espinal , Fusão Vertebral , Humanos , Perda Sanguínea Cirúrgica , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Lordose/cirurgia , Impressão Tridimensional , Qualidade de Vida , Doenças da Medula Espinal/cirurgia , Fusão Vertebral/efeitos adversos , Fusão Vertebral/métodos , Telas Cirúrgicas , Titânio , Resultado do TratamentoRESUMO
Eukaryotes share a conserved messenger RNA (mRNA) decay pathway in which bulk mRNA is degraded by exoribonucleases. In addition, it has become clear that more specialized mRNA decay pathways are initiated by endonucleolytic cleavage at particular sites. The transfer RNA (tRNA) splicing endonuclease (TSEN) has been studied for its ability to remove introns from pre-tRNAs. More recently it has been shown that single amino acid mutations in TSEN cause pontocerebellar hypoplasia. Other recent studies indicate that TSEN has other functions, but the nature of these functions has remained obscure. Here we show that yeast TSEN cleaves a specific subset of mRNAs that encode mitochondrial proteins, and that the cleavage sites are in part determined by their sequence. This provides an explanation for the counterintuitive mitochondrial localization of yeast TSEN. To identify these mRNA target sites, we developed a "comPARE" (comparative parallel analysis of RNA ends) bioinformatic approach that should be easily implemented and widely applicable to the study of endoribonucleases. The similarity of tRNA endonuclease-initiated decay to regulated IRE1-dependent decay of mRNA suggests that mRNA specificity by colocalization may be an important determinant for the degradation of localized mRNAs in a variety of eukaryotic cells.
Assuntos
Endorribonucleases , Splicing de RNA/genética , Estabilidade de RNA/genética , RNA Fúngico , RNA Mensageiro , RNA de Transferência , Proteínas de Saccharomyces cerevisiae , Saccharomyces cerevisiae , Endorribonucleases/genética , Endorribonucleases/metabolismo , RNA Fúngico/genética , RNA Fúngico/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Transferência/genética , RNA de Transferência/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismoRESUMO
INTRODUCTION: Vertebral augmentation, including percutaneous vertebroplasty (PVP) or kyphoplasty (PKP), is the current least invasive surgical option and has been widely used to treat the painful osteoporotic vertebral compression fractures (OVCF). However, the postoperative infections could be life-threatening, even though they rarely occur. Our studies aim to clarify the causation and outcomes of spinal infections following augmentation and meanwhile to identify the risk factors. METHODS: A retrospective study was conducted on patients with OVCF who underwent PVP or PKP, and were subsequently admitted to our institution with postoperative spinal infection between January 2010 and December 2022. A total of 33 patients were finally included. RESULTS: The rate of spinal infection after augmentation in our single institute was 0.05% (2/3893). In addition to these 2 patients, the remaining 31 were referred from other hospitals. All 33 patients exhibited elevated inflammatory parameters, 14 patients presented with fever, and 9 patients experienced neurological deficits. Additionally, 29 patients had comorbidity and risk factors. Pathogens were identified in 26 patients, while only 7 patients were examined as culture negative. 27 patients underwent revision surgery and 6 patients only received conservative therapy. Anterior surgery was performed in 2 patients, while posterior surgery was performed in 20 patients. A combined anterior-posterior surgery was performed in 5 patients. At the final follow-up, 18 patients had unrestricted mobility, 10 patients required assistance from crutches or a walker for ambulation, 4 patients needed a wheelchair, and 1 patients died after revision surgery. CONCLUSIONS: Spinal infection after vertebral augmentation is rare, but it cannot be ignored. Surgeons should make every effort to detect the potential preoperative spondylitis or discitis. Once postoperative spinal infection is confirmed, a prompt intravenous antibiotic therapy is warranted. If medication therapy fails, revision surgery involving debridement and spinal reconstruction should be considered.
Assuntos
Fraturas por Compressão , Cifoplastia , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Vertebroplastia , Humanos , Vertebroplastia/efeitos adversos , Fraturas por Compressão/etiologia , Fraturas por Compressão/cirurgia , Fraturas da Coluna Vertebral/cirurgia , Fraturas da Coluna Vertebral/complicações , Estudos Retrospectivos , Coluna Vertebral , Cifoplastia/efeitos adversos , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/induzido quimicamente , Fraturas por Osteoporose/cirurgia , Resultado do Tratamento , Cimentos Ósseos/uso terapêuticoRESUMO
The conserved Mediator co-activator complex has an essential role in the regulation of RNA polymerase II transcription in all eukaryotes. Understanding the structure and interactions of Mediator is crucial for determining how the complex influences transcription initiation and conveys regulatory information to the basal transcription machinery. Here we present a 4.4 Å resolution cryo-electron microscopy map of Schizosaccharomyces pombe Mediator in which conserved Mediator subunits are individually resolved. The essential Med14 subunit works as a central backbone that connects the Mediator head, middle and tail modules. Comparison with a 7.8 Å resolution cryo-electron microscopy map of a Mediator-RNA polymerase II holoenzyme reveals that changes in the structure of Med14 facilitate a large-scale Mediator rearrangement that is essential for holoenzyme formation. Our study suggests that access to different conformations and crosstalk between structural elements are essential for the Mediator regulation mechanism, and could explain the capacity of the complex to integrate multiple regulatory signals.
Assuntos
Complexo Mediador/química , Complexo Mediador/metabolismo , RNA Polimerase II/química , RNA Polimerase II/ultraestrutura , Sítios de Ligação , Microscopia Crioeletrônica , Holoenzimas/química , Holoenzimas/metabolismo , Holoenzimas/ultraestrutura , Complexo Mediador/ultraestrutura , Modelos Moleculares , Ligação Proteica , Conformação Proteica , Subunidades Proteicas/química , Subunidades Proteicas/metabolismo , RNA Polimerase II/metabolismo , Schizosaccharomyces , Proteínas de Schizosaccharomyces pombe/química , Proteínas de Schizosaccharomyces pombe/metabolismo , Proteínas de Schizosaccharomyces pombe/ultraestrutura , Relação Estrutura-AtividadeRESUMO
BACKGROUND: The Surviving Sepsis Campaign Guidelines recommend stress ulcer prophylaxis (SUP) for patients with sepsis who have gastrointestinal (GI) bleeding risks; however, the effect of SUP has not been specially studied in these patients. AIMS: To determine the effects of SUP versus no prophylaxis on patient-important outcomes in critically ill adult patients with sepsis who have risk factors for GI bleeding. METHODS: This retrospective cohort study utilised data from the Medical Information Mart for Intensive Care III database. We compared those who received SUP with proton-pump inhibitors or histamine-2 receptor antagonists for ≥3 days with those who received no prophylaxis. Propensity score matching (PSM) was conducted to make comparisons between groups with similar distributions of study variables. The primary outcome was inhospital mortality. RESULTS: A total of 7744 patients were included in the analysis, with 1088 (14.0%) in the non-SUP group and 6656 (86.0%) in the SUP group. A 1:1 PSM created 866 patients in each cohort. No significant differences were noted between the two groups with regard to inhospital mortality (22.3% vs 20.4%; P = 0.379), GI bleeding (4.7% vs 6.4%; P = 0.172), pneumonia (38.9% vs 36.6%; P = 0.346), Clostridium difficile infection (CDI) (6.4% vs 8.9%; P = 0.0.057) or intensive care unit (ICU) length of stay (LOS) (4.2 days vs 4.6 days; P = 0.394). CONCLUSIONS: Among critically ill, septic, adult patients at risk for GI bleeding, SUP showed no effect on hospital mortality, the rate of GI bleeding, pneumonia, CDI and ICU LOS.
Assuntos
Infecções por Clostridium , Úlcera Péptica , Pneumonia , Sepse , Humanos , Adulto , Estado Terminal , Estudos Retrospectivos , Úlcera/induzido quimicamente , Úlcera/complicações , Úlcera/tratamento farmacológico , Úlcera Péptica/prevenção & controle , Hemorragia Gastrointestinal/epidemiologia , Hemorragia Gastrointestinal/prevenção & controle , Hemorragia Gastrointestinal/induzido quimicamente , Inibidores da Bomba de Prótons/uso terapêutico , Sepse/complicações , Sepse/epidemiologia , Unidades de Terapia Intensiva , Infecções por Clostridium/tratamento farmacológico , Pneumonia/tratamento farmacológicoRESUMO
OBJECT: To investigate the stability and cost-effectiveness of the three-dimensional-printed (3DP) off-the-shelf (OTS) prosthesis in the reconstruction of the anterior column of the thoracic/lumbar spine after tumor resection. METHODS: Thirty-five patients (26 with primary malignant tumors and nine with metastatic malignant tumors) who underwent tumor resection and anterior column reconstruction between January 2014 and January 2019 were included in a single institute. Patients were divided into the 3DP OTS prosthesis (3DP) group (n = 14) and the titanium mesh cage (TMC) group (n = 21) by the type of implant. The operation time, intraoperative blood loss, hospital stay, history of radiotherapy, surgical level and total cost were collected and compared between the two groups. Mechanical complications and radiological parameters including mean vertebral height, subsidence, fixation failure(nonunion, migration, screw loosening, rod breakage) rate were recorded at preoperation, 1 week, 3 months, 6 months, 12 months after surgery then at 1 year interval or stop until the end of survival. The follow-up patients were also sent with short form-36 to assess their health-related quality of life (HRQoL) and questions about the current condition of their disease. RESULTS: The mean overall follow-up was 24.6 months. Of the 35 patients involved, six patients died and six were lost to follow-up. The differences between the two groups in operative time, intraoperative blood loss, and hospital stay were not statistically significant (p > 0.05). The differences in fixation failure and the subsidence rate between the two groups were not statistical significant (p > 0.05). The difference of subsidence rate between the cases with and without osteoporosis, cases with and without radiotherapy was statistically significant within each group (p < 0.05). However, the difference of subsidence rate between the surgical level above or below T10 was not statistically significant (p > 0.05). The response rate of the questionnaire among the survived patients was 100% (23/23 patients). The results of the Short Form- (SF-)36 between the two groups were similar (p > 0.05). The total cost was higher in the 3DP group (p < 0.05) with its higher graft cost (p < 0.05), but the differences in internal fixation cost and other cost were not statistically significant between groups (p > 0.05). CONCLUSION: Compared to TMC, the 3DP OTS prosthesis achieved similar clinical and radiological results in spinal anterior spinal column reconstruction of thoracic/lumbar spinal tumor resection. However, the 3DP OTS prosthesis was more expansive than TMC.
Assuntos
Fusão Vertebral , Neoplasias da Coluna Vertebral , Humanos , Estudos Retrospectivos , Titânio , Neoplasias da Coluna Vertebral/diagnóstico por imagem , Neoplasias da Coluna Vertebral/cirurgia , Resultado do Tratamento , Perda Sanguínea Cirúrgica , Telas Cirúrgicas , Qualidade de Vida , Fusão Vertebral/métodos , Parafusos Ósseos , Vértebras Lombares/cirurgia , Impressão TridimensionalRESUMO
PURPOSE: The aims of this study were to explore the correlations between thoracic kyphosis (TK) and lumbar lordosis (LL) parameters and to build corresponding linear regressions to predict TK morphology and the thoracolumbar inflection point (IP) determined by individual LL parameters in asymptomatic adults. METHODS: A total of 280 adult healthy volunteers were recruited, and full-spine X-rays were performed for each subject in a standing posture. The following sagittal parameters were measured: cumulative TK, LL, proximal LL (PLL), the apices of TK (TKA) and LL (LLA), the IP and the distance from the plumb line of the thoracic apex (TAPL) and the lumbar apex (LAPL) to the gravity line. The correlations between TK and LL parameters were analyzed, and the corresponding linear regressions were conducted. RESULTS: Extensive variations existed in TK alignment, including angular and morphological parameters. In addition, there were statistical correlations of all cumulative TK angles with LL (r values from - 0.173 to - 0.708) and PLL (r values from - 0.206 to - 0.803), TKA and IP with LLA (rs = 0.359 and 0.582, respectively) and TAPL with LAPL (rs = 0.335). The common predictive formulas employed in ASD surgery could include T10-L1 = - 3.6-0.2*LL (R2 = 0.201), T4-L1 = 3.4-0.5*LL (R2 = 0.457), TKA = - 10.3 + 1.1*LLA (R2 = 0.180) and IP = - 12.7 + 1.6*LLA (R2 = 0.330). CONCLUSION: There were intimate associations between TK and LL parameters in asymptomatic adults. Moreover, predictive models for thoracic alignment, particularly cumulative TK, based on LL parameters were proposed, which could better delineate anatomical relationships, guide thoracic construction during adult spinal deformity surgery and may help preventing proximal junctional failure.
RESUMO
Context: The high resistance rate and high recurrence rate of progesterone only as a treatment for endometrial cancer (EC) limit its clinical application. Metformin (MET) may have antitumor ability. Combining MET and medroxyprogesterone acetate (MPA) may strengthen their inhibitory effects on proliferation of EC cells, but MET's mechanisms remain unclear. Objective: The study intended to identify the specific molecular mechanism that MET combined with MPA uses against EC progression. Design: The research team performed a controlled animal study. Setting: The study took place at Xuzhou Medical University in Xuzhou, China. Animals: The animals were16 female non-obese diabetic-severe combined immunodeficient (NOD-SCID) nude mice, about 12 to 16 g in weight. Interventions: The research team divided randomly, the mice into four groups and induced EC in all groups, four in each group: (1) The control group which received received normal saline, (2) the MPA group, which received 100 mg/kg of MPA; (3) the MET group, which received metformin at the rate of 200 mg/kg, each gavage volume was 0.1ml; (4) the MET+MPA group, which received 100 mg/kg of MPA and 200 mg/kg of MET. Outcome measures: The research team: (1) used a CCK-8 kit, an EdU assay, and a flow-cytometry assay to measure cancer-cell proliferation, count, and viability; determine the cell cycle; and measure apoptosis; (2) performed a Western blot analysis to determine the expression of the PR, CD133, pAkt, totalAkt, p-mTOR, and totalTOR antibodies; and (3) determined the size and volume of tumors in vivo and used immunohistochemical staining to determine expression of the Ki67 protein. Results: The MET+MPA group had a significantly lower number of cancer cells than the MET or MDA groups (both P < .001). That group also had significantly more stagnated cancer cells in the G0/G1 phase and significantly fewer cancer cells in the S phase or G2/M phase control, MET, or MPA groups (all P < .01). The MET+MPA group's PCNA and Ki-67 protein expression was significantly lower than that of the MET and MPA group. The EDU assay yielded similar results. Additionally, the MET+MPA group had significantly higher PR expression than that of to MET or MPA group (both P < .001). The MET and MPA groups' expression of CD133, p-Akt, and p-mTOR were significantly lower than those of the control group, while the MET+MPA group's levels were significantly lower than those of the MET and MPA groups. In-vivo experiments revealed that the MET and MPA groups did show decreased tumor size and volume. The MET+MPA group had tumor weights that were significantly lower and tumor volumes were significantly smaller than those of the MET and MPA groups (all P < .001). Immunohistochemical analysis revealed that the MET+MPA group's levels of the Ki-67 antigen were significantly lower than those of the MET and MPA groups. Conclusions: MET inhibited the proliferation of EC cells by increasing MPA-sensitivity, which was dependent on the inhibition of the CD133 expression and the Akt/mTOR pathway. In addition, if MET acts as an effective progestin sensitizer, it certainly offers promising therapeutic prospects for patients with early-stage EC or overgrown endometrium who have fertility requirements.
Assuntos
Neoplasias do Endométrio , Metformina , Humanos , Feminino , Animais , Camundongos , Acetato de Medroxiprogesterona/farmacologia , Acetato de Medroxiprogesterona/uso terapêutico , Metformina/farmacologia , Metformina/uso terapêutico , Camundongos Nus , Proteínas Proto-Oncogênicas c-akt/farmacologia , Proteínas Proto-Oncogênicas c-akt/uso terapêutico , Receptores de Progesterona/metabolismo , Receptores de Progesterona/uso terapêutico , Camundongos Endogâmicos NOD , Camundongos SCID , Neoplasias do Endométrio/tratamento farmacológico , Neoplasias do Endométrio/metabolismo , Neoplasias do Endométrio/patologia , Proliferação de Células , Serina-Treonina Quinases TOR/metabolismo , Serina-Treonina Quinases TOR/farmacologia , Serina-Treonina Quinases TOR/uso terapêutico , Apoptose , Linhagem Celular TumoralRESUMO
Glioblastoma (GBM), the most common subtype of malignant gliomas, is characterized by aggressive infiltration, high malignancy, and poor prognosis. The frustrating anti-GBM outcome of conventional therapeutics is due to the immunosuppressive milieu, in addition to the formidable obstacle of the blood-brain barrier (BBB). Combination therapy with an immune checkpoint blockade (ICB) has emerged as a critical component in the treatment of GBM. Here, we report an engineered macrophage-membrane-coated nanoplatform with enhanced programmed cell death-1 (PD-1) expression (PD-1-MM@PLGA/RAPA). Using both in vitro and in vivo GBM models, we demonstrate that PD-1-MM@PLGA/RAPA can efficiently traverse across the BBB in response to the tumor microenvironment (TME) recruitment with nanoparticles accumulating at the tumor site. Furthermore, we show a boosted immune response as a result of enhancing CD8+ cytotoxic T-lymphocyte (CTL) infiltration. Together we provide a new nanoplatform for enhancing ICB in combination with conventional chemotherapy for GBM and many other cancers.