The role of hSWI/SNF complexes in transcriptional activation is well characterized; however, little is known about their function in transcriptional repression. We have previously shown that subunits of the mSin3A/ histone deacetylase 2 (HDAC2) corepressor complex copurify with hSWI/SNF complexes. Here we show that the type II arginine-specific methyltransferase PRMT5, which is involved in cyclin E repression, can be found in association with Brg1 and hBrm-based hSWI/SNF complexes. We also show that hSWI/SNF-associated PRMT5 can methylate hypoacetylated histones H3 and H4 more efficiently than hyperacetylated histones H3 and H4. Protein-protein interaction studies indicate that PRMT5 and mSin3A interact with the same hSWI/ SNF subunits as those targeted by c-Myc. These observations prompted us to examine the expression profile of the c-Myc target genes, carbamoyl-phosphate synthase-aspartate carbamoyltransferase-dihydroorotase (cad) and nucleolin (nuc). We found that cad repression is altered in cells that express inactive Brg1 and in cells treated with the HDAC inhibitor depsipeptide. Using chromatin immunoprecipitation assays, we found that Brg1, mSin3A, HDAC2, and PRMT5 are directly recruited to the cad promoter. These results suggest that hSWI/SNF complexes, through their ability to interact with activator and repressor proteins, control expression of genes involved in cell growth and proliferation.During cell growth and differentiation several genes become either repressed or activated. These variations in expression often correlate with changes in chromatin structure and occur in the context of the cell cycle. Recruitment of the highly related Brg1 and hBrm chromatin remodeling complexes, which can disrupt nucleosome structure and increase accessibility to DNA, has been implicated in transcriptional activation of many inducible genes (21, 41). However, in view of recent findings, which show that subunits of mSin3/histone deacetylase (HDAC) corepressor complexes can be found in association with Brg1 and hBrm chromatin remodelers and that HDACs 1 and 2 are integral components of the NuRD complex, it appears that ATP-dependent chromatin remodeling might also be involved in transcriptional repression (32,51,56,63,65). Consistent with this notion, mutation of yeast SWI2/ SNF2 can lead to gene derepression (28,35,53). Furthermore, Brg1, hBrm, and
To clarify presentations, organisms, and locations of deep neck abscesses in children.Design: Retrospective review.Setting: Tertiary children's hospital. The study population comprised 169 patients younger than 19 years who were surgically treated for deep neck abscesses between 1989 and 1999.Main Outcome Measure: Resolution of abscess.Results: Neck mass (91%), fever (86%), cervical adenopathy (83%), poor oral intake (66%), and neck stiffness (59%) were common in all ages. Patients younger than 4 years, compared with patients 4 years or older, presented with agitation (50% vs 14%), cough (35% vs 14%), drooling (27% vs 12%), lethargy (46% vs 33%), oropharyngeal abnormalities (45% vs 60%), respiratory distress (5% vs 2%), retractions (5% vs 2%), rhinorrhea (53% vs 15%), stridor (4% vs 2%), and trismus (14% vs 53%). Children younger than 1 year were infected with Staphylococcus aureus (79%) vs group A streptococcus (6%). Children 1 year or older were infected with group A streptococcus (29%) vs S aureus (16%). Retropharyngeal or parapharyngeal regions were involved in children 1 year or older (49%) vs younger than 1 year (21%). Anterior or posterior triangles and submandibular or submental regions were involved in 39% and 36%, respectively, of children younger than 1 year vs 30% and 23%, respectively, of children 1 year or older. Retropharyngeal and parapharyngeal abscesses yielded group A streptococcus (34%) vs S aureus (11%). Anterior and posterior triangle abscesses yielded S aureus (35%) vs group A streptococcus (19%), as did submandibular and submental abscesses (42% vs 19%).Conclusions: Abscesses in children younger than 1 year affected anterior or posterior triangles and submandibular or submental regions, yielding S aureus. Abscesses in children 1 year or older affected retropharyngeal or parapharyngeal regions, yielding group A streptococcus.
To determine if temperature-controlled radiofrequency (TCRF) tonsil reduction and adenoidectomy (TCRF&A) and conventional tonsillectomy and adenoidectomy (T&A) are statistically similar in outcome and to compare morbidity between TCRF&A and conventional T&A.
Limited data exist regarding the echogenicity of perineural catheters, but visualization is crucial to ensure accurate placement and efficacy of the subsequent local anesthetic infusion. The objective of this study was to determine the comparative echogenicity of various regional anesthesia catheters. In an in vitro porcine-bovine model, we compared the echogenic qualities of 3 commercially available regional anesthesia catheters and 1 catheter under development to optimize echogenicity. Outcomes included visual echogenicity ranking, image quality, and scanning time, as assessed by 2 blinded investigators. The experimental catheter was found to be more echogenic than 2 of the 3 comparators.
Perioperative anxiety and distress are common in pediatric patients undergoing general anesthesia and increase the risk for immediate and long‐term postoperative complications. This concise review outlines key research and clinically‐relevant scales that measure pediatric perioperative affect. Strengths and weaknesses of each scale are highlighted. A literature review identified 11 articles with the following inclusion criteria: patients less than or equal to 18 years, perioperative anxiety or distress, and original studies with reliability or validity data. Although robust research‐based assessment tools to measure anxiety have been developed, such as the Modified Yale Preoperative Anxiety Scale, they are too complex and time‐consuming to complete by clinicians also providing anesthesia. Clinically‐based anxiety measurement scales tend to be easier to use, however they require further testing before widespread standard utilization. The HRAD ± scale (Happy, Relaxed, Anxious, Distressed, with a yes/no answer to cooperation) may be a promising observational anxiety scale that is efficient and includes an assessment of compliance. Further studies are needed to refine a clinically‐relevant anxiety assessment tool and appraise interventions that reduce perioperative distress.
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