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1.
Proc Natl Acad Sci U S A ; 120(43): e2221915120, 2023 10 24.
Article in English | MEDLINE | ID: mdl-37844240

ABSTRACT

This article sheds light on how to capture knowledge integration dynamics in college course content, improves and enriches the definition and measurement of interdisciplinarity, and expands the scope of research on the benefits of interdisciplinarity to postcollege outcomes. We distinguish between what higher education institutions claim regarding interdisciplinarity and what they appear to actually do. We focus on the core academic element of student experience-the courses they take, develop a text-based semantic measure of interdisciplinarity in college curriculum, and test its relationship to average earnings of graduates from different types of schools of higher education. We observe that greater exposure to interdisciplinarity-especially for science majors-is associated with increased earnings after college graduation.


Subject(s)
Curriculum , Interdisciplinary Studies , Humans , Universities , Students , Schools
2.
Am J Med Genet A ; 185(7): 2190-2197, 2021 07.
Article in English | MEDLINE | ID: mdl-33931933

ABSTRACT

Spinal muscular atrophy with congenital bone fractures 2 (SMABF2), a type of arthrogryposis multiplex congenita (AMC), is characterized by congenital joint contractures, prenatal fractures of long bones, and respiratory distress and results from biallelic variants in ASCC1. Here, we describe an infant with severe, diffuse hypotonia, congenital contractures, and pulmonary hypoplasia characteristic of SMABF2, with the unique features of cleft palate, small spleen, transverse liver, and pulmonary thromboemboli with chondroid appearance. This infant also had impaired coagulation with diffuse petechiae and ecchymoses which has only been reported in one other infant with AMC. Using trio whole genome sequencing, our proband was identified to have biallelic variants in ASCC1. Using deep next generation sequencing of parental cDNA, we characterized alteration of splicing encoded by the novel, maternally inherited ASCC1 variant (c.297-8 T > G) which provides a mechanism for functional pathogenicity. The paternally inherited ASCC1 variant is a rare nonsense variant (c.466C > T; p.Arg156*) that has been previously identified in one other infant with AMC. This report extends the phenotypic characteristics of ASCC1-associated AMC (SMABF2) and describes a novel intronic variant that partially disrupts RNA splicing.


Subject(s)
Arthrogryposis/genetics , Carrier Proteins/genetics , Muscular Atrophy, Spinal/genetics , Arthrogryposis/diagnostic imaging , Arthrogryposis/physiopathology , Codon, Nonsense/genetics , Female , Humans , Infant, Newborn , Muscular Atrophy, Spinal/diagnostic imaging , Muscular Atrophy, Spinal/physiopathology , Whole Genome Sequencing
3.
MedEdPORTAL ; 17: 11131, 2021 03 25.
Article in English | MEDLINE | ID: mdl-33816792

ABSTRACT

Introduction: The ability to apply knowledge gained in neuroscience coursework to a clinical scenario is found to be difficult by many medical students. Neuroscience is both important for future clinical practice and an area frequently tested on USMLE Step 1 examinations. Methods: Second-year medical students created a peer-led flipped classroom to help first-year students practice applying medical neuroscience course information to clinical situations and demonstrate how that information might be tested in board-style questions. The second-year students designed a series of board-style questions that included explanations for both the correct and incorrect answers. We divided the first-year students (n = 80) into small groups during the flipped classroom sessions, where they were led by second-year medical students in discussion about the questions and clinical situations. Results: Students reported agreement that the session addressed gaps in their knowledge and provided them with useful critical thinking skills for approaching board-style questions (83% and 81% agreed or strongly agreed, respectively). Discussion: The flipped classroom improved student confidence in both applying neuroscience concepts to clinical scenarios and to board-style vignette questions.


Subject(s)
Students, Medical , Test Taking Skills , Humans , Peer Group , Thinking
4.
Rep Pract Oncol Radiother ; 26(6): 883-891, 2021.
Article in English | MEDLINE | ID: mdl-34992859

ABSTRACT

BACKGROUND: This analysis evaluates the impacts of biologically effective dose (BED) and histology on local control (LC) of spinal metastases treated with highly conformal radiotherapy to moderately-escalated doses. MATERIALS AND METHODS: Patients were treated at two institutions from 2010-2020. Treatments with less than 5 Gy per fraction or 8 Gy in 1 fraction were excluded. The dataset was divided into three RPA classes predictive of survival (1). The primary endpoint was LC. RESULTS: 223 patients with 248 treatments met inclusion criteria. Patients had a median Karnofsky Performance Status (KPS ) of 80, and common histologies included breast (29.4%), non-small cell lung cancer (15.7%), and prostate (13.3%). A median 24 Gy was delivered in 3 fractions (BED: 38.4 Gy) to a median planning target volume (PTV) of 37.3 cc. 2-year LC was 75.7%, and 2-year OS was 42.1%. Increased BED was predictive of improved LC for primary prostate cancer (HR = 0.85, 95% CI: 0.74-0.99). Patients with favorable survival (RPA class 1) had improved LC with BED ≥ 40 Gy (p = 0.05), unlike the intermediate and poor survival groups. No grade 3-5 toxicities were reported. CONCLUSIONS: Moderately-escalated treatments were efficacious and well-tolerated. BED ≥ 40 Gy may improve LC, particularly for prostate cancer and patients with favorable survival.

5.
J Radiosurg SBRT ; 7(2): 95-103, 2020.
Article in English | MEDLINE | ID: mdl-33282463

ABSTRACT

Background: This study compares the outcomes of stereotactic body radiation therapy (SBRT) for sacral and thoracolumbar spine metastases. Methods: This analysis considered each sacral spine SBRT treatment at a single institution and a cohort of consecutive thoracolumbar treatments. Results: 28 patients with 35 sacral treatments and 41 patients with 49 thoracolumbar treatments were included. Local control was 63% and 90%, respectively. The sacral cohort contained more lesions with ≥2 vertebrae and epidural and paraspinal involvement. Sacral patients had larger treatment volumes, increased rates of subsequent SBRT, decreased propensity for pain improvement, and decreased local control (p=0.02 on Kaplan-Meier analysis). Multivariate analysis demonstrated that PTV > 50 cc and epidural involvement were correlated with decreased local control. No cases had grade ≥3 toxicity. Conclusion: SBRT for sacral spine metastases is a distinct disease process than metastases to the thoracolumbar spine, resulting in lower rates of local control and pain improvement.

6.
J Neurosurg Spine ; 34(2): 267-276, 2020 Oct 23.
Article in English | MEDLINE | ID: mdl-33096522

ABSTRACT

OBJECTIVE: This study evaluated a large cohort of patients treated with stereotactic body radiation therapy for spinal metastases and investigated predictive factors for local control, local progression-free survival (LPFS), overall survival, and pain response between the different spinal regions. METHODS: The study was undertaken via retrospective review at a single institution. Patients with a tumor metastatic to the spine were included, while patients with benign tumors or primary spinal cord cancers were excluded. Statistical analysis involved univariate analysis, Cox proportional hazards analysis, the Kaplan-Meier method, and machine learning techniques (decision-tree analysis). RESULTS: A total of 165 patients with 190 distinct lesions met all inclusion criteria for the study. Lesions were distributed throughout the cervical (19%), thoracic (43%), lumbar (19%), and sacral (18%) spines. The most common treatment regimen was 24 Gy in 3 fractions (44%). Via the Kaplan-Meier method, the 24-month local control was 80%. Sacral spine lesions demonstrated decreased local control (p = 0.01) and LPFS (p < 0.005) compared with those of the thoracolumbar spine. The cervical spine cases had improved local control (p < 0.005) and LPFS (p < 0.005) compared with the sacral spine and trended toward improvement relative to the thoracolumbar spine. The 36-month local control rates for cervical, thoracolumbar, and sacral tumors were 86%, 73%, and 44%, respectively. Comparably, the 36-month LPFS rates for cervical, thoracolumbar, and sacral tumors were 85%, 67%, and 35%, respectively. A planning target volume (PTV) > 50 cm3 was also predictive of local failure (p = 0.04). Fewer cervical spine cases had disease with PTV > 50 cm3 than the thoracolumbar (p = 5.87 × 10-8) and sacral (p = 3.9 × 10-3) cases. Using decision-tree analysis, the highest-fidelity models for predicting pain-free status and local failure demonstrated the first splits as being cervical and sacral location, respectively. CONCLUSIONS: This study presents a novel risk stratification for local failure and LPFS by spinal region. Patients with metastases to the sacral spine may have decreased local control due to increased PTV, especially with a PTV of > 50 cm3. Multidisciplinary care should be emphasized in these patients, and both surgical intervention and radiotherapy should be strongly considered.

7.
J Neurooncol ; 148(2): 381-388, 2020 Jun.
Article in English | MEDLINE | ID: mdl-32415643

ABSTRACT

INTRODUCTION: Stereotactic radiosurgery (SRS) has shown durable local control for the treatment of metastatic diseasespinal metastases. Multilevel disease or epidural or paraspinal involvement present challenges to achieving local control, and this study aims to analyze treatment outcomes for such lesions. METHODS: Patients treated at a single institution with SRS to the spine from 2010-2018 were retrospectively reviewed. Inclusion criteria required clinical follow-up with either a pain assessment or imaging study. Bulky spine metastasis was defined as consisting of multilevel disease or epidural or paraspinal tumor involvement. RESULTS: 54 patients treated for 62 lesions met inclusion criteria. 42 treatments included at least two vertebrae, and 21 and 31 had paraspinal and epidural involvement, respectively. Treatment regimens had a median 24 Gy in 3 fractions to a volume of 37.75 cm3. Median follow-up was 14.36 months, with 5 instances (8%) of local failure. Median overall survival was 13.32 months. Pain improvement was achieved in 47 treatments (76%), and pain improved with treatment (p < 0.0001). Severe pain (HR = 3.08, p = 0.05), additional bone metastases (HR = 4.82, p = 0.05), and paraspinal involvement (HR = 3.93, p < 0.005) were predictive for worse overall survival. Kaplan-Meier analysis demonstrated that prior chemotherapy (p = 0.03) and additional bone metastases (p = 0.02) were predictive of worse overall survival. Grade < 3 toxicity was observed in 19 cases; no grade ≥ 3 side effects were observed. CONCLUSIONS: SRS can effectively treat bulky metastases to the spine, resulting in improvement of pain with minimal toxicity. Severe pain independently predicts for worse overall survival, indicating that treatment prior to worsening of pain is strongly recommended.


Subject(s)
Radiosurgery , Spinal Neoplasms/radiotherapy , Aged , Female , Humans , Male , Middle Aged , Retrospective Studies , Spinal Neoplasms/diagnosis , Spinal Neoplasms/secondary , Treatment Outcome
8.
Am J Physiol Endocrinol Metab ; 315(6): E1121-E1132, 2018 12 01.
Article in English | MEDLINE | ID: mdl-30226997

ABSTRACT

Gain-of-function (GOF) mutations in the ATP-sensitive potassium (KATP) channels cause neonatal diabetes. Despite the well-established genetic root of the disease, pathways modulating disease severity and treatment effectiveness remain poorly understood. Patient phenotypes can vary from severe diabetes to remission, even in individuals with the same mutation and within the same family, suggesting that subtle modifiers can influence disease outcome. We have tested the underlying mechanism of transient vs. permanent neonatal diabetes in KATP-GOF mice treated for 14 days with glibenclamide. Some KATP-GOF mice show remission of diabetes and enhanced insulin sensitivity long after diabetes treatment has ended, while others maintain severe insulin-resistance. However, insulin sensitivity is not different between the two groups before or during diabetes induction, suggesting that improved sensitivity is a consequence, rather than the cause of, remission, implicating other factors modulating glucose early in diabetes progression. Leptin, glucagon, insulin, and glucagon-like peptide-1 are not different between remitters and nonremitters. However, liver glucose production is significantly reduced before transgene induction in remitter, relative to nonremitter and nontreated, mice. Surprisingly, while subsequent remitter animals exhibited normal serum cytokines, nonremitter mice showed increased cytokines, which paralleled the divergence in blood glucose. Together, these results suggest that systemic inflammation may play a role in the remitting versus non-remitting outcome. Supporting this conclusion, treatment with the anti-inflammatory meloxicam significantly increased the fraction of remitting animals. Beyond neonatal diabetes, the potential for inflammation and glucose production to exacerbate other forms of diabetes from a compensated state to a glucotoxic state should be considered.


Subject(s)
Diabetes Mellitus/metabolism , Glyburide/therapeutic use , Inflammation/metabolism , Insulin Resistance/physiology , Animals , Blood Glucose/metabolism , Cytokines/blood , Diabetes Mellitus/drug therapy , Diabetes Mellitus/genetics , Glucagon/blood , Glucagon-Like Peptide 1/blood , Insulin/blood , Leptin/blood , Mice , Mice, Transgenic , Mutation , Potassium Channels, Inwardly Rectifying/genetics , Potassium Channels, Inwardly Rectifying/metabolism
9.
J Mol Biol ; 426(18): 3095-3107, 2014 Sep 09.
Article in English | MEDLINE | ID: mdl-24976131

ABSTRACT

Intrinsic termination signals for multisubunit bacterial RNA polymerases (RNAPs) encode a GC-rich stem-loop structure followed by a polyuridine [poly(U)] tract, and it has been proposed that steric clash of the stem-loop with the exit pore of the RNAP imposes a shearing force on the RNA in the downstream RNA:DNA hybrid, resulting in misalignment of the active site. The structurally unrelated T7 RNAP terminates at a similar type of signal (TΦ), suggesting a common mechanism for termination. In the absence of a hairpin (passive conditions), T7 RNAP slips efficiently in both homopolymeric A and U tracts, and we have found that replacement of the U tract in TΦ with a slippage-prone A tract still allows efficient termination. Under passive conditions, incorporation of a single G residue following a poly(U) tract (which is the situation during termination at TΦ) results in a "locked" complex that is unable to extend the transcript. Our results support a model in which transmission of the shearing force generated by steric clash of the hairpin with the exit pore is promoted by the presence of a slippery tracts downstream, resulting in alterations in the active site and the formation of a locked complex that represents an early step in the termination pathway.


Subject(s)
Bacteriophage T7/enzymology , DNA-Directed RNA Polymerases/metabolism , Inverted Repeat Sequences/genetics , Terminator Regions, Genetic/genetics , Transcription, Genetic/genetics , Viral Proteins/metabolism , Bacteriophage T7/genetics , DNA/genetics , DNA-Directed RNA Polymerases/genetics , Mitochondria/enzymology , Models, Genetic , Poly A/genetics , Poly U/genetics , RNA/genetics , Templates, Genetic , Transcription Termination, Genetic , Viral Proteins/genetics , Yeasts/enzymology
10.
Mol Cell Biol ; 34(13): 2360-9, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24732805

ABSTRACT

DEAD box proteins have been widely implicated in regulation of gene expression. Here, we show that the yeast Saccharomyces cerevisiae DEAD box protein Mss116p, previously known as a mitochondrial splicing factor, also acts as a transcription factor that modulates the activity of the single-subunit mitochondrial RNA polymerase encoded by RPO41. Binding of Mss116p stabilizes paused mitochondrial RNA polymerase elongation complexes in vitro and favors the posttranslocated state of the enzyme, resulting in a lower concentration of nucleotide substrate required to escape the pause; this mechanism of action is similar to that of elongation factors that enhance the processivity of multisubunit RNA polymerases. In a yeast strain in which the RNA splicing-related functions of Mss116p are dispensable, overexpression of RPO41 or MSS116 increases cell survival from colonies that were exposed to low temperature, suggesting a role for Mss116p in enhancing the efficiency of mitochondrial transcription under stress conditions.


Subject(s)
DEAD-box RNA Helicases/isolation & purification , DNA-Directed RNA Polymerases/metabolism , Mitochondria/enzymology , Mitochondrial Proteins/metabolism , Saccharomyces cerevisiae Proteins/isolation & purification , Saccharomyces cerevisiae Proteins/metabolism , Saccharomyces cerevisiae/enzymology , Transcription, Genetic , Binding Sites/genetics , Cell Survival , DEAD-box RNA Helicases/genetics , DNA-Directed RNA Polymerases/antagonists & inhibitors , DNA-Directed RNA Polymerases/genetics , Escherichia coli/enzymology , Gene Expression Regulation, Fungal , Mitochondria/genetics , Mitochondrial Proteins/antagonists & inhibitors , Mitochondrial Proteins/genetics , Peptide Elongation Factors/genetics , Protein Binding/genetics , RNA/biosynthesis , RNA/genetics , RNA, Fungal/biosynthesis , RNA, Fungal/genetics , RNA, Mitochondrial , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/antagonists & inhibitors , Saccharomyces cerevisiae Proteins/genetics , Stress, Physiological/genetics , Transcription Factors , Transcriptional Activation
11.
J Nanomater ; 20122012.
Article in English | MEDLINE | ID: mdl-24683414

ABSTRACT

This paper details a facile approach for the synthesis of stable and monodisperse silver nanoparticles performed at ambient/low temperature where Allium sativum (garlic) extract functions as the silver salt reducing agent during nanoparticle synthesis as well as the post-synthesis stabilizing ligands. Varying the synthesis conditions provides control of particle size, size-distribution, and kinetics of particle formation. Infrared spectroscopy, energy dispersive x-ray chemical analysis, and high performance liquid chromatography indicated that the carbohydrates present in the garlic extract are the most likely nanoparticle stabilizing chemistry. The synthesized silver nanoparticles also demonstrate potential for biomeical applications, owing to the 1) enhanced stability in biological media, 2) resistance to oxidation by the addition of H2O2, 3) ease and scalability of synthesis, and 4) lack of harsh chemicals required for synthesis. Cytotoxicity assays indicated no decrease in cellular proliferation for vascular smooth muscle cells and 3T3 fibroblasts at a concentration of 25 µg/ml, confirming that garlic extract prepared silver nanoparticles are ideal candidates for future experimentation and implementation into biomedical applications.

12.
Am J Public Health ; 101(4): 596-601, 2011 Apr.
Article in English | MEDLINE | ID: mdl-21389289

ABSTRACT

In homelessness research and policymaking, it seems to be axiomatic that single adults experience 3 temporally based types of homelessness: chronic, episodic, and transitional. We discuss problems with the theorization of this typology and with the research design, data analysis, and time-aggregated conceptualization and measurement of temporality in the empirical work supporting the typology. To address the latter, we suggest a time-patterned approach to temporality and report a 10-group typology that differs significantly from the more familiar 3-group typology. We argue that which approach is used-and how typologies are developed more generally-should be based on theory and the uses to which typologies are put rather than on claims to being more true.


Subject(s)
Ill-Housed Persons/classification , Research , Humans , Policy Making , Public Health , Research Design , Statistics as Topic , United States
13.
Biochemistry ; 49(19): 4018-26, 2010 May 18.
Article in English | MEDLINE | ID: mdl-20387858

ABSTRACT

The existence of histone nonallelic variants has been known for more than 30 years, but only recently have we acquired significant insights into their functions. Nucleosomes containing histone variants are nonrandomly distributed in genomes and may impart different biological functions to the relevant chromatin regions. We have used the model T7 RNA polymerase to transcribe reconstituted nucleosomes containing either canonical human recombinant histones or two histone variants, H2A.Z or H3.3, whose presence has been associated with active transcription. Remarkably, in contrast to canonical and H3.3-containing nucleosomes, H2A.Z-containing nucleosomes were refractive to transcription, with residual levels of transcription determined by the sequence of the underlying DNA template. To our knowledge, this is the first example of a nucleosome that is intrinsically untranscribable.


Subject(s)
Histones/metabolism , Nucleosomes/metabolism , Transcription, Genetic , Animals , Base Sequence , DNA-Directed RNA Polymerases/metabolism , Drosophila/metabolism , Humans , Models, Molecular , Molecular Sequence Data
14.
J Biol Chem ; 285(6): 3957-3964, 2010 Feb 05.
Article in English | MEDLINE | ID: mdl-19920143

ABSTRACT

Transcription of the yeast mitochondrial genome is carried out by an RNA polymerase (Rpo41p) that is related to single subunit bacteriophage RNA polymerases but requires an additional factor (Mtf1p) for initiation. In this work we show that Mtf1p is involved in multiple roles during initiation including discrimination of upstream base pairs in the promoter, initial melting of three to four base pairs around the site of transcript initiation, and suppression of nonspecific initiation. It, thus, appears that Mtf1p is functionally analogous to initiation factors of multisubunit RNA polymerases, such as sigma. Photocross-linking experiments reveal close proximity between Mtf1p and the promoter DNA and show that the C-terminal domain makes contacts with the template strand in the vicinity of the start site. Interestingly, Mtf1p is related to a class of RNA methyltransferases, suggesting an early evolutionary link between RNA synthesis and processing.


Subject(s)
DNA, Mitochondrial/genetics , Mitochondrial Proteins/physiology , Saccharomyces cerevisiae Proteins/physiology , Transcription Factors/physiology , Transcription, Genetic , Base Sequence , DNA, Fungal/chemistry , DNA, Fungal/genetics , DNA, Fungal/metabolism , DNA-Directed RNA Polymerases/genetics , DNA-Directed RNA Polymerases/metabolism , Mitochondrial Proteins/genetics , Mitochondrial Proteins/metabolism , Models, Biological , Mutation , Nucleic Acid Conformation , Promoter Regions, Genetic/genetics , Protein Binding , Saccharomyces cerevisiae/genetics , Saccharomyces cerevisiae Proteins/genetics , Saccharomyces cerevisiae Proteins/metabolism , Transcription Factors/genetics , Transcription Factors/metabolism , Transcription Initiation Site
15.
J Mol Biol ; 391(5): 808-12, 2009 Sep 04.
Article in English | MEDLINE | ID: mdl-19576223

ABSTRACT

Using a template that contains promoters for T3 and T7 RNA polymerases (RNAPs) in opposing orientations, and His-tagged derivatives of these RNAPs that allow immobilization on solid matrices, we have determined that a T7 elongation complex (EC) may be advanced past a halted T3 EC, and that after the collision the halted T3 EC may resume transcription. Since RNAPs moving in opposite directions use two different strands of the DNA as their templates, it seems likely that they manage to pass by one other by temporarily releasing their nontemplate strand while maintaining association with their template strand.


Subject(s)
DNA-Directed RNA Polymerases/metabolism , DNA/genetics , Transcription, Genetic , Viral Proteins/metabolism , Base Sequence , DNA-Directed RNA Polymerases/genetics , Molecular Sequence Data , Viral Proteins/genetics
16.
Yeast ; 26(8): 423-40, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19536766

ABSTRACT

The abundance of mitochondrial (mt) transcripts varies under different conditions, and is thought to depend upon rates of transcription initiation, transcription termination/attenuation and RNA processing/degradation. The requirement to maintain the balance between RNA synthesis and processing may involve coordination between these processes; however, little is known about factors that regulate the activity of mtRNA polymerase (mtRNAP). Recent attempts to identify mtRNAP-protein interactions in yeast by means of a generalized tandem affinity purification (TAP) protocol were not successful, most likely because they involved a C-terminal mtRNAP-TAP fusion (which is incompatible with mtRNAP function) and because of the use of whole-cell solubilization protocols that did not preserve the integrity of mt protein complexes. Based upon the structure of T7 RNAP (to which mtRNAPs show high sequence similarity), we identified positions in yeast mtRNAP that allow insertion of a small affinity tag, confirmed the mature N-terminus, constructed a functional N-terminal TAP-mtRNAP fusion, pulled down associated proteins, and identified them by LC-MS-MS. Among the proteins found in the pull-down were a DEAD-box protein (Mss116p) and an RNA-binding protein (Pet127p). Previous genetic experiments suggested a role for these proteins in linking transcription and RNA degradation, in that a defect in the mt degradadosome could be suppressed by overexpression of either of these proteins or, independently, by mutations in either mtRNAP or its initiation factor Mtf1p. Further, we found that Mss116p inhibits transcription by mtRNAP in vitro in a steady-state reaction. Our results support the hypothesis that Mss116p and Pet127p are involved in modulation of mtRNAP activity.


Subject(s)
Chromatography, Affinity/methods , DNA-Directed RNA Polymerases/isolation & purification , GTP-Binding Proteins/isolation & purification , Mitochondria/enzymology , Mitochondrial Proteins/isolation & purification , Saccharomyces cerevisiae Proteins/isolation & purification , Saccharomyces cerevisiae/enzymology , Amino Acid Sequence , Chromatography, Liquid , GTP-Binding Proteins/metabolism , Mitochondrial Proteins/metabolism , Models, Molecular , Molecular Sequence Data , Protein Structure, Tertiary , RNA/metabolism , RNA, Fungal/metabolism , RNA, Mitochondrial , Saccharomyces cerevisiae Proteins/metabolism , Sequence Homology, Amino Acid , Tandem Mass Spectrometry
17.
BJU Int ; 103(10): 1386-90, 2009 May.
Article in English | MEDLINE | ID: mdl-19154474

ABSTRACT

OBJECTIVE: To compare the efficacy of extracorporeal electromagnetic stimulation (ES) of the pelvic floor for treating stress urinary incontinence (SUI) vs sham ES. PATIENTS AND METHODS: In all, 70 women with urodynamically confirmed SUI were randomized to receive active (35) or sham (35) ES. The NeoControl chair (NeoTonus, Marietta, GA, USA) was used, and treatment consisted of three sessions per week for 6 weeks. data were collected before and after treatment on all women, including a 20-min provocative pad-test with a predetermined bladder volume (primary outcome measure), a 3-day bladder diary and 24 h pad-test. Circumvaginal muscle (CVM) rating score, perineometry using two separate instruments and video-urodynamics were also used, and the Urinary Incontinence Quality of Life Scale (I-QOL) and King's Health Questionnaires. Patients were fully re-evaluated 8 weeks after treatment, and the bladder diary, pad-test and questionnaires were repeated at 6 months. The urotherapist and physician were unaware to which treatment group the patient was assigned. RESULTS: In the overall group of 70 patients there were significant improvements in each of the primary and secondary outcome measures at 8 weeks. There were also significant improvements in primary and secondary outcome measures in the active treatment group when compared with baseline measures. At 8 weeks, there were improvements in the mean (sd) values for the 20-min pad-test, of 39.5 (5.1) vs 19.4 (4.6) g (P < 0.001); the 24-h pad-test, of 24.0 (4.7) vs 10.1 (3.1) g (P < 0.01); the number of pads/day, of 0.9 (0.1) vs 0.6 (0.1) (P < 0.01), the I-QOL score, of 63.7 (2.8) vs 71.2 (3.3) (P < 0.001); and King's Health Questionnaire score, of 9.6 (0.8) vs 6.9 (0.7) (P < 0.001). However, these improvements were not statistically significant when compared with the sham-treatment group. In those patients on active treatment who had a poor pelvic floor contraction at the initial assessment (defined by the CVM score and perineometry), there was a significant reduction (P < 0.05) in the 20-min pad-test leakage when compared with the sham-treatment group. CONCLUSIONS: ES was no more effective overall than sham treatment in this patient group. However, in those women who were unable to generate adequate pelvic floor muscle contractions, there was an objective improvement in provocative pad testing when compared to sham treatment.


Subject(s)
Electric Stimulation Therapy/methods , Magnetic Field Therapy/methods , Muscle Contraction/physiology , Pelvic Floor/physiology , Urinary Incontinence, Stress/therapy , Analysis of Variance , Double-Blind Method , Female , Humans , Incontinence Pads , Middle Aged , Treatment Outcome
18.
J Biol Chem ; 282(31): 22879-86, 2007 Aug 03.
Article in English | MEDLINE | ID: mdl-17548349

ABSTRACT

During the transition from an initiation complex to an elongation complex (EC), T7 RNA polymerase undergoes major conformational changes that involve reorientation of a "core" subdomain as a rigid body and extensive refolding of other elements in the 266 residue N-terminal domain. The pathway and timing of these events is poorly understood. To examine this, we introduced proline residues into regions of the N-terminal domain that become alpha-helical during the reorganization and changed the charge of a key residue that interacts with the RNA:DNA hybrid 5 bp upstream of the active site in the EC but not in the initiation complex. These alterations resulted in a diminished ability to make products >5-7 nt and/or a slow transition through this point. The results indicate that the transition to an EC is a multistep process and that the movement of the core subdomain and reorganization of certain elements in the N-terminal domain commence prior to promoter release (at 8-9 nt).


Subject(s)
DNA-Directed RNA Polymerases/chemistry , Viral Proteins/chemistry , Bacteriophage T7/metabolism , Base Sequence , Binding Sites , DNA/chemistry , Kinetics , Models, Biological , Models, Molecular , Molecular Sequence Data , Mutation , Promoter Regions, Genetic , Protein Structure, Tertiary , RNA/chemistry , Trypsin/chemistry
19.
J Biol Chem ; 282(30): 21578-82, 2007 Jul 27.
Article in English | MEDLINE | ID: mdl-17526498

ABSTRACT

To extend the nascent transcript, RNA polymerases must melt the DNA duplex downstream from the active site to expose the next acceptor base for substrate binding and incorporation. A number of mechanisms have been proposed to account for the manner in which the correct substrate is selected, and these differ in their predictions as to how far the downstream DNA is melted. Using fluorescence quenching experiments, we provide evidence that cellular RNA polymerases from bacteria and yeast melt only one DNA base pair downstream from the active site. These data argue against a model in which multiple NTPs are lined up downstream of the active site.


Subject(s)
Base Pairing , DNA-Directed RNA Polymerases/metabolism , DNA/metabolism , Oligodeoxyribonucleotides/metabolism , Bacteriophage T7/enzymology , Base Sequence , Binding Sites , Molecular Sequence Data , Oligodeoxyribonucleotides/chemistry , Protein Subunits/metabolism , Spectrometry, Fluorescence , Substrate Specificity , Viral Proteins/metabolism
20.
Mol Cell ; 24(2): 257-66, 2006 Oct 20.
Article in English | MEDLINE | ID: mdl-17052459

ABSTRACT

Recent work showed that the single-subunit T7 RNA polymerase (RNAP) can generate misincorporation errors by a mechanism that involves misalignment of the DNA template strand. Here, we show that the same mechanism can produce errors during transcription by the multisubunit yeast RNAP II and bacterial RNAPs. Fluorescence spectroscopy reveals a reorganization of the template strand during this process, and molecular modeling suggests an open space above the polymerase active site that could accommodate a misaligned base. Substrate competition assays indicate that template misalignment, not misincorporation, is the preferred mechanism for substitution errors by cellular RNAPs. Misalignment could account for data previously taken as evidence for additional NTP binding sites downstream of the active site. Analysis of the effects of different template topologies on misincorporation indicates that the duplex DNA immediately downstream of the active site plays an important role in transcription fidelity.


Subject(s)
DNA-Directed RNA Polymerases/chemistry , DNA-Directed RNA Polymerases/genetics , Transcription, Genetic , Viral Proteins/chemistry , Base Sequence , Binding Sites , Binding, Competitive , DNA/chemistry , Escherichia coli/enzymology , Models, Genetic , Molecular Sequence Data , Saccharomyces cerevisiae/enzymology , Spectrometry, Fluorescence , Thermus/enzymology , Time Factors
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