116 research outputs found

    Estimating the Accuracy of Anal Cytology in the Presence of an Imperfect Reference Standard

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    Background: The study aim is to estimate sensitivity and specificity of anal cytology for histologic HSIL in analyses adjusted for the imperfect biopsy reference standard. Methods and Principal Findings: Retrospective cohort study of an anal dysplasia screening program for HIV infected adults. We estimated the prevalence of histologic HSIL by concurrent cytology category and the associated cytology ROC area. Cytology operating characteristics for HSIL were estimated and adjusted for the imperfect reference standard by 3 methodologies. The study cohort included 261 patients with 3 available measures: (1) referral cytology; (2) HRA cytology; and (3) HRA directed biopsy. The prevalence of biopsy HSIL varied according to the concurrent HRA cytology result: 64.5

    RNAstructure: software for RNA secondary structure prediction and analysis

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    <p>Abstract</p> <p>Background</p> <p>To understand an RNA sequence's mechanism of action, the structure must be known. Furthermore, target RNA structure is an important consideration in the design of small interfering RNAs and antisense DNA oligonucleotides. RNA secondary structure prediction, using thermodynamics, can be used to develop hypotheses about the structure of an RNA sequence.</p> <p>Results</p> <p>RNAstructure is a software package for RNA secondary structure prediction and analysis. It uses thermodynamics and utilizes the most recent set of nearest neighbor parameters from the Turner group. It includes methods for secondary structure prediction (using several algorithms), prediction of base pair probabilities, bimolecular structure prediction, and prediction of a structure common to two sequences. This contribution describes new extensions to the package, including a library of C++ classes for incorporation into other programs, a user-friendly graphical user interface written in JAVA, and new Unix-style text interfaces. The original graphical user interface for Microsoft Windows is still maintained.</p> <p>Conclusion</p> <p>The extensions to RNAstructure serve to make RNA secondary structure prediction user-friendly. The package is available for download from the Mathews lab homepage at <url>http://rna.urmc.rochester.edu/RNAstructure.html</url>.</p

    The use of Reamer–irrigator–aspirator in the management of long bone osteomyelitis: an update

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    Purpose: Reamer–irrigator–aspirator (RIA) is an innovative device that its indications have recently been expanded to the management of long bone infections. Methods: In this narrative review, we summarise the most important studies in the field and we present the current open questions pertaining to the use of RIA in the management of osteomyelitis of long bones. Results: The relevant literature is sparse and low quality. Nevertheless, the use of RIA for infected cases has yielded promising outcomes in specialised centres. Technical aspects that merit special attention in osteomyelitis of long bones are its inapplicability in small diameter long bones, the inadequate debridement of wide metaphyseal areas and the potential bleeding sequelae. The use of RIA in open fracture management to reduce infection risk has not gained acceptance. The antibiotic impregnated nails and rods constitute a complimentary strategy for the management of infections. Conclusions: The use of RIA for the management of long bone infections is an innovative and promising strategy. High quality studies are needed to shed light in its efficacy compared to conventional methods of management of osteomyelitis of long bones

    Effects of crystalline glucocorticoid triamcinolone acetonide on cultered human supraspinatus tendon cells

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    Background Rotator cuff tears are a common cause of shoulder pain and impairment. Subacromial glucocorticoid injections are widely used for treatment of epiphenomenons of chronic impingement syndrome with the possible side effects of tendon rupture and impaired tendon healing

    Interaction between Thymidylate Synthase and Its Cognate mRNA in Zebrafish Embryos

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    Thymidylate synthase (TS), which catalyzes the de novo synthesis of dUMP, is an important target for cancer therapy. In this report, the effects of 5-fluorouracil (5-FU) and ZD1694 on the regulation of TS gene expression were evaluated in zebrafish embryos. Our results revealed that the expression of TS was increased by about six-fold when embryos were treated with 1.0 µM 5-FU and there was a greater than 10-fold increase in the TS protein level after treatment with 0.4 µM ZD1694. Northern blot analysis confirmed that expression of TS mRNA was identical in treated or untreated embryos. Gel shift and immunoprecipitation assays revealed that zebrafish TS was specifically bound with its cognate mRNA in vitro and in vivo. We identified a 20 nt RNA sequence, TS:N20, localized to the 5′-UTR of TS mRNA, which corresponded to nt 13–32; TS:N20 bound to the TS protein with an affinity similar to that of the full-length TS mRNA. The MFold program predicted that TS:N20 formed a stable stem-loop structure similar to that of the cis-acting element found in human TS mRNA. Variant RNAs with either a deletion or mutation in the core motif of TS:N20 were unable to bind to the TS protein. In vitro translation experiments, using the rabbit lysate system, confirmed that zebrafish TS mRNA translation was significantly repressed when an excess amount of TS protein was included in the system. Additionally, a TS stability experiment confirmed that treatment of zebrafish embryos with 5-FU could increase the TS stability significantly, and the half life of TS protein was about 2.7 times longer than in untreated embryos. Our study revealed a structural requirement for the interaction of TS RNA with TS protein. These findings also demonstrated that the increase in TS protein induced by 5-FU occurs at the post-transcriptional level and that increased stability and translation efficiency both contributed to the increase in TS protein levels induced by TS inhibitors

    A new interdisciplinary treatment strategy versus usual medical care for the treatment of subacromial impingement syndrome: a randomized controlled trial

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    BACKGROUND: Subacromial impingement syndrome (SIS) is the most frequently recorded shoulder disorder. When conservative treatment of SIS fails, a subacromial decompression is warranted. However, the best moment of referral for surgery is not well defined. Both early and late referrals have disadvantages – unnecessary operations and smaller improvements in shoulder function, respectively. This paper describes the design of a new interdisciplinary treatment strategy for SIS (TRANSIT), which comprises rules to treat SIS in primary care and a well-defined moment of referral for surgery. METHODS/DESIGN: The effectiveness of an arthroscopic subacromial decompression versus usual medical care will be evaluated in a randomized controlled trial (RCT). Patients are eligible for inclusion when experiencing a recurrence of SIS within one year after a first episode of SIS which was successfully treated with a subacromial corticosteroid injection. After inclusion they will receive injection treatment again by their general practitioner. When, after this treatment, there is a second recurrence within a year post-injection, the participants will be randomized to either an arthroscopic subacromial decompression (intervention group) or continuation of usual medical care (control group). The latter will be performed by a general practitioner according to the Dutch National Guidelines for Shoulder Problems. At inclusion, at randomization and three, six and 12 months post-randomization an outcome assessment will take place. The primary outcome measure is the patient-reported Shoulder Disability Questionnaire. The secondary outcome measures include both disease-specific and generic measures, and an economic evaluation. Treatment effects will be compared for all measurement points by using a GLM repeated measures analyses. DISCUSSION: The rationale and design of an RCT comparing arthroscopic subacromial decompression with usual medical care for subacromial impingement syndrome are presented. The results of this study will improve insight into the best moment of referral for surgery for SIS

    Pivotal Role of Inosine Triphosphate Pyrophosphatase in Maintaining Genome Stability and the Prevention of Apoptosis in Human Cells

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    Pure nucleotide precursor pools are a prerequisite for high-fidelity DNA replication and the suppression of mutagenesis and carcinogenesis. ITPases are nucleoside triphosphate pyrophosphatases that clean the precursor pools of the non-canonical triphosphates of inosine and xanthine. The precise role of the human ITPase, encoded by the ITPA gene, is not clearly defined. ITPA is clinically important because a widespread polymorphism, 94C>A, leads to null ITPase activity in erythrocytes and is associated with an adverse reaction to thiopurine drugs. We studied the cellular function of ITPA in HeLa cells using the purine analog 6-N hydroxylaminopurine (HAP), whose triphosphate is also a substrate for ITPA. In this study, we demonstrate that ITPA knockdown sensitizes HeLa cells to HAP-induced DNA breaks and apoptosis. The HAP-induced DNA damage and cytotoxicity observed in ITPA knockdown cells are rescued by an overexpression of the yeast ITPase encoded by the HAM1 gene. We further show that ITPA knockdown results in elevated mutagenesis in response to HAP treatment. Our studies reveal the significance of ITPA in preventing base analog-induced apoptosis, DNA damage and mutagenesis in human cells. This implies that individuals with defective ITPase are predisposed to genome damage by impurities in nucleotide pools, which is drastically augmented by therapy with purine analogs. They are also at an elevated risk for degenerative diseases and cancer

    Attentional control theory in childhood: enhanced attentional capture by non-emotional and emotional distractors in anxiety and depression

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    Attentional control theory (ACT) proposes that anxiety is associated with executive functioning deficits. The theory has been widely investigated in adults. The current study tested whether symptoms of childhood anxiety and depression were associated with experimentally measured attentional control in the context of non-emotional and emotional stimuli. Sixty-one children (mean age = 9.23 years, range = 8.39 - 10.41) reported their trait anxiety and depression symptoms and completed three visual search tasks. The tasks used a variant of an irrelevant singleton paradigm and measured attentional capture by task-irrelevant non-emotional (color) and emotional (facial expressions) distractors. Significant attentional capture by both non-emotional and emotional distractors was observed, and was significantly correlated with trait anxiety and symptoms of depression. The strength of relationship between attentional capture and the symptoms did not differ significantly for non-emotional and emotional distractors. The results suggest that symptoms of childhood anxiety and depression are associated with poorer attentional control both in the presence of emotional and non-emotional stimuli, supporting ACT in younger populations. This attentional deficit in the context of non-emotional information might be as central to childhood internalizing symptoms as attentional biases often observed on tasks investigating processing of emotional stimuli

    Neural expression and post-transcriptional dosage compensation of the steroid metabolic enzyme 17β-HSD type 4

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    <p>Abstract</p> <p>Background</p> <p>Steroids affect many tissues, including the brain. In the zebra finch, the estrogenic steroid estradiol (E<sub>2</sub>) is especially effective at promoting growth of the neural circuit specialized for song. In this species, only the males sing and they have a much larger and more interconnected song circuit than females. Thus, it was surprising that the gene for 17β-hydroxysteroid dehydrogenase type 4 (HSD17B4), an enzyme that converts E<sub>2 </sub>to a less potent estrogen, had been mapped to the Z sex chromosome. As a consequence, it was likely that HSD17B4 was differentially expressed in males (ZZ) and females (ZW) because dosage compensation of Z chromosome genes is incomplete in birds. If a higher abundance of HSD17B4 mRNA in males than females was translated into functional enzyme in the brain, then contrary to expectation, males could produce less E<sub>2 </sub>in their brains than females.</p> <p>Results</p> <p>Here, we used molecular and biochemical techniques to confirm the HSD17B4 Z chromosome location in the zebra finch and to determine that HSD17B4 mRNA and activity were detectable in the early developing and adult brain. As expected, HSD17B4 mRNA expression levels were higher in males compared to females. This provides further evidence of the incomplete Z chromosome inactivation mechanisms in birds. We detected HSD17B4 mRNA in regions that suggested a role for this enzyme in the early organization and adult function of song nuclei. We did not, however, detect significant sex differences in HSD17B4 activity levels in the adult brain.</p> <p>Conclusions</p> <p>Our results demonstrate that the HSD17B4 gene is expressed and active in the zebra finch brain as an E<sub>2 </sub>metabolizing enzyme, but that dosage compensation of this Z-linked gene may occur via post-transcriptional mechanisms.</p
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