246 research outputs found
High-resolution Ultrasonography in Superficial Soft Tissue Tumors
Surgical removal and clinical follow-up of soft tissue masses are easily managed in clinical practice but are dependent on the experience of the clinician. Occasionally, however, a patient is referred from a local clinician to our clinic with an inoperable mass following a surgical procedure. We consider it important to fully understand the nature of the mass prior to surgery, thus avoiding unnecessary surgery in some cases. High-resolution ultrasonography has been widely applied in the musculoskeletal system over the past two decades and is very useful in evaluating the nature of superficial soft tissue masses. It enables the differentiation of benign and malignant masses and the detection of many different types of histology in superficial soft tissue masses. The purpose of this review is to demonstrate the characteristic findings of high-resolution ultrasonography and color Doppler ultrasonography in superficial soft tissue tumors
Ultrasonography-guided Percutaneous Interventional Procedures of the Spleen
Since the introduction of real-time ultrasonography (US) to the medicine in late 1970s, the unique benefit of the real-time cross-sectional imaging has made US one of the most widely used imaging modalities to guide interventional procedures. Among the intra-abdominal solid organs, the spleen is the least common solid organ considered for interventional procedures. Although splenic puncture for splenoportography was performed as early as the 1950s and has had a low complication rate, traditionally a direct splenic puncture is still avoided due to the risk of hemorrhage or laceration. US-guided percutaneous drainage of splenic abscesses has been used as a safe alternative procedure for more than 20 years, however, only a few series reporting such an interventional procedure have been published. This review describes briefly the usefulness, technique, safety, and the outcome of US-guided interventional procedures of the spleen
Intraosseous Lipoma of the Proximal Radius with Extraosseous Extension: A Case Report
Examination of lipomatous tumors with ultrasound (US) is generally limited to the soft tissue component of the mass and cortical contours of the involved bone. We report a patient with an intraosseous lipoma of the proximal radius with extra-osseous extension. US showed a heterogeneous hyperechoic mass lesion (3.5 × 3.0 cm in size) at the radial aspect of the left elbow, with bony cortex interruption. The lesion was associated with increased marginal color flow signals on color Doppler US study. Atypical lipoma or low-grade liposarcoma was diagnosed. The pathologic examination of the lesion demonstrated an abnormal collection of mature adipose tissue consistent with lipoma
Genome-wide transcription-coupled repair in Escherichia coli is mediated by the Mfd translocase
In transcription-coupled repair (TCR), nucleotide excision repair occurs most rapidly in the template strand of actively transcribed genes. TCR has been observed in a limited set of genes directly assayed in Escherichia coli cells. In vitro, Mfd translocase performs reactions necessary to mediate TCR: It removes RNA polymerase blocked by a template strand lesion and rapidly delivers repair enzymes to the lesion. This study applied excision repair sequencing methodology to map the location of repair sites in different E. coli strains. Results showed that Mfd-dependent TCR is widespread in the E. coli genome. Results with UvrD helicase demonstrated its role in basal repair, but no overall role in TCR
Experiential learning of HIV self-test among student nurses: A qualitative study
Background: There is increasing demand for HIV self-tests, and nurses play an important role in counselling and assisting in the testing process. Traditional lecture-based nursing education has not typically focused on self-testing procedures, and there is little understanding of clients' experiences of self-testing. Objectives: To understand the experiential learning (EL)of student nurses during the process of self-testing for HIV. Design: This study used a qualitative design. Settings: A college in northern Taiwan. Participants: We recruited a purposive sample of 30 nursing students. Methods: The OraQuick self-test was used as the self-testing tool in this study. After participants used the OraQuick self-test, they underwent a semi-structured interview during the post-test counselling period. All interview data were subjected to line-by-line content analysis. Results: We extracted nine themes of nursing students' experiences during experiential learning of HIV self-test. In the pre-test stage, they recalled possible risk behaviors for HIV infection, decided to complete the self-test alone or asked for significant others to accompany them, and endured emotional fluctuations immediately prior to the test. When waiting for the test results, they felt isolated from the outside world. Some participants also began questioning the accuracy and safety of the test, and either viewed the results immediately or later on. In the post-test stage, some participants reported being uncertain about the results. Participants reported a greater understanding of the personal impact of testing and revealed their needs for support. Some identified a sense of loss and linked this to the rapid and direct delivery of test results. Conclusions: Our results can be used to guide HIV-related education courses and prevention programs. Experiential learning has the potential to improve HIV pre and post-test counselling, as nurses develop both clinical knowledge and personal insight of the testing process
Mammalian Period represses and de-represses transcription by displacing CLOCK–BMAL1 from promoters in a Cryptochrome-dependent manner
The mammalian circadian clock is controlled by a transcription-translation feedback loop consisting of transcriptional activators circadian locomotor output cycles kaput (CLOCK)–brain and muscle Arnt-like protein-1 (BMAL1), which function as a complex at E/E'-box elements, and repressors Cryptochrome 1 (CRY1)/CRY2 and PER1/PER2. CRYs repress upon binding as CRY–CLOCK–BMAL1–E-box complexes. Period proteins (PERs) repress by removing the heterotrimeric complexes from the E-box. We report here that in the Cry1 promoter, the CRY1–CLOCK–BMAL1–E-box complex represses a transcriptional activator acting in cis, and removal of the heterotrimeric complex by PER2 de-represses the transcriptional activator. ChIP-seq and RNA-seq experiments identified other genes also de-repressed by PER2. These data clarify the role of PER2 and reveal the level of complexity in regulation of Cry1 and other circadian-controlled genes
Human genome-wide repair map of DNA damage caused by the cigarette smoke carcinogen benzo[a]pyrene
Benzo[a]pyrene (BaP) is a widespread potent carcinogen found in food, coal tar, cigarette smoke, and industrial smoke. Cigarette smoking is the leading cause of lung cancer, and the mutagenesis in smoking-associated lung cancer is determined by multiple factors, including nucleotide excision repair. We have developed a general method for genome-wide mapping of nucleotide excision repair at single-nucleotide resolution and applied it to generate repair maps of UV- and BaP-induced DNA damage in human. Results show a novel sequence specificity of BaP diol epoxide-deoxyguanosine repair. This general method can be used to study repair of all types of DNA damages that undergo nucleotide excision repair
Gene Model 129 ( Gm129 ) Encodes a Novel Transcriptional Repressor That Modulates Circadian Gene Expression
The mammalian circadian clock is a molecular oscillator composed of a feedback loop that involves transcriptional activators CLOCK and BMAL1, and repressors Cryptochrome (CRY) and Period (PER). Here we show that a direct CLOCK·BMAL1 target gene, Gm129, is a novel regulator of the feedback loop. ChIP analysis revealed that the CLOCK·BMAL1·CRY1 complex strongly occupies the promoter region of Gm129. Both mRNA and protein levels of GM129 exhibit high amplitude circadian oscillations in mouse liver, and Gm129 gene encodes a nuclear-localized protein that directly interacts with BMAL1 and represses CLOCK·BMAL1 activity. In vitro and in vivo protein-DNA interaction results demonstrate that, like CRY1, GM129 functions as a repressor by binding to the CLOCK·BMAL1 complex on DNA. Although Gm129−/− or Cry1−/−Gm129−/− mice retain a robust circadian rhythm, the peaks of Nr1d1 and Dbp mRNAs in liver exhibit a significant phase delay compared with control. Our results suggest that, in addition to CRYs and PERs, the GM129 protein contributes to the transcriptional feedback loop by modulating CLOCK·BMAL1 activity as a transcriptional repressor
Formation of Arabidopsis Cryptochrome 2 Photobodies in Mammalian Nuclei: APPLICATION AS AN OPTOGENETIC DNA DAMAGE CHECKPOINT SWITCH
Nuclear bodies are discrete suborganelle structures that perform specialized functions in eukaryotic cells. In plant cells, light can induce de novo formation of nuclear bodies called photobodies (PBs) composed of the photosensory pigments, phytochrome (PHY) or cryptochrome (CRY). The mechanisms of formation, the exact compositions, and the functions of plant PBs are not known. Here, we have expressed Arabidopsis CRY2 (AtCRY2) in mammalian cells and analyzed its fate after blue light exposure to understand the requirements for PB formation, the functions of PBs, and their potential use in cell biology. We found that light efficiently induces AtCRY2-PB formation in mammalian cells, indicating that, other than AtCRY2, no plant-specific proteins or nucleic acids are required for AtCRY2-PB formation. Irradiation of AtCRY2 led to its degradation; however, degradation was not dependent upon photobody formation. Furthermore, we found that AtCRY2 photobody formation is associated with light-stimulated interaction with mammalian COP1 E3 ligase. Finally, we demonstrate that by fusing AtCRY2 to the TopBP1 DNA damage checkpoint protein, light-induced AtCRY2 PBs can be used to activate DNA damage signaling pathway in the absence of DNA damage
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