830 research outputs found
One hour observation of patients after image-guided percutaneous renal mass biopsy
BACKGROUND: Imaging-guided percutaneous biopsy of renal masses is regarded as safe and is widely used for histopathology diagnosis before treatment. Recommended observation time after tumour biopsy varies in international guidelines and the literature is sparse.PURPOSE: To assess the effect of a 1-h post-biopsy observation time of percutaneous image-guided renal mass biopsy.MATERIAL AND METHODS: This was a single-centre retrospective study. During January 2015 to September 2019, a total of 484 patients underwent renal mass biopsies. 4-h-observation-group: 178 patients and 1-h-observation-group 306 patients. All records were retrospectively reviewed, and data such as complications was obtained and compared between the two groups.RESULTS: A total complication rate of 4.5% ( n = 22) without any major complications (Cardiovascular and Interventional Radiological Society of Europe-grade (CIRSE) 5-6). Furthermore, a non-significant difference of 1.3% of the 1-h group and 3.4% in the 4-h group experiencing complications was found ( p = .18). A total biopsy-accuracy of 84% was observed. CONCLUSION: This study shows that renal mass biopsy is safe with no major complications. This suggests that an outpatient approach with 1-h-observation time can be safely implemented for renal mass biopsy.</p
MR arthrography of the shoulder; correlation with arthroscopy
Background: Shoulder dislocation is a common injury, particularly in the younger population. Common long-term sequelae include pain, recurrence, and shoulder arthritis. Immediate and correct diagnosis following shoulder dislocation is key to achieving optimum outcomes. Although magnetic resonance arthrography (MRA) is frequently used for diagnosing shoulder instabilities, arthroscopy is still considered the gold standard. Purpose: This study aims to compare the diagnostic value of arthroscopy and MRA of the shoulder joint. Materials and methods: This retrospective study estimates the sensitivity and specificity of MRA of the shoulder. Data from patients who had undergone shoulder MRA and subsequent arthroscopy during a 5-year period were retrospectively collected. Sensitivity and specificity were calculated using the arthroscopic findings as the gold standard. Moreover, diagnostic accuracy was estimated using McNemar's test. Results: In total, 205 cases were included from which 372 pathological findings were uncovered during the arthroscopic procedures as opposed to 360 findings diagnosed from the MRA images. The glenoid labral tear was the most common finding reported by MRA and arthroscopy. For the detection of glenoid labral tears on MRA, the sensitivity was 0.955 but with eight missed lesions; the specificity was 0.679. Capsular tears, rotator cuff tears, and cartilage lesions proved the most difficult to correctly diagnose using MRA with sensitivities of 0.2, 0.346, and 0.366, respectively. Conclusions: With a sensitivity of 95 MRA is a valuable diagnostic tool for assessing shoulder instabilities, particularly when diagnosing labral lesions, including bony and soft-tissue Bankart lesions. Sensitivities and specificities for other glenohumeral lesions are less convincing, however
Rtp1p Is a Karyopherin-Like Protein Required for RNA Polymerase II Biogenesis
The assembly and nuclear transport of RNA polymerase II (RNA pol II) are processes that require the participation of many auxiliary factors. In a yeast genetic screen, we identified a previously uncharacterized gene, YMR185w (renamed RTP1), which encodes a protein required for the nuclear import of RNA pol II. Using protein affinity purification coupled to mass spectrometry, we identified interactions between Rtp1p and members of the R2TP complex. Rtp1p also interacts, to a different extent, with several RNA pol II subunits. The pattern of interactions is compatible with a role for Rtp1p as an assembly factor that participates in the formation of the Rpb2/Rpb3 subassembly complex and its binding to the Rpb1p-containing subcomplex. Besides, Rtp1p has a molecular architecture characteristic of karyopherins, composed of HEAT repeats, and is able to interact with phenylalanine-glycine-containing nucleoporins. Our results define Rtp1p as a new component of the RNA pol II biogenesis machinery that plays roles in subunit assembly and likely in transport through the nuclear pore complex
Observer agreement of volar tilt of the wrist is influenced by forearm rotation
BACKGROUND: Dorsal/volar tilt is an important radiographic measurement commonly included in the treatment decision of distal radius fractures (DRFs). However, studies have shown that forearm positioning relative to rotation (i.e., supination and pronation) can affect the measured tilt value but with substantial interobserver variance.PURPOSE: To examine whether interobserver agreement on radiographic tilt measurement is influenced by forearm rotation.MATERIAL AND METHODS: We radiographed 21 cadaveric forearms at 5° rotational intervals between 15° supination and 15° pronation on lateral radiographs. A radiologist and a hand surgeon measured tilt in a blinded and randomized fashion. Bland-Altman analyses with bias and limits of agreement (LoA) were used to estimate interobserver agreement for forearms in all degrees of rotation, non-rotated forearms, supinated forearms, and pronated forearms.RESULTS: Interobserver agreement varied with forearm rotation. Bias (95% confidence interval [CI]; LoA) was -1.54° (95% CI: -2.53, -0.55; LoA: -13.46, 10.38) when measuring tilt on radiographs with all degrees of forearm rotation, and -1.48° (95% CI: -4.13, 1.17; LoA: -12.88, 9.92) when measuring tilt on true lateral 0° radiographs. When measuring on supinated and pronated radiographs, bias was -0.03° (95% CI: -1.35, 1.29; LoA: -8.34, 8.28) and -3.23° (95% CI: -5.41, -1.06; LoA: -16.90, 10.44), respectively.CONCLUSION: Interobserver agreement on tilt was similar when comparing measurements made on true lateral radiographs to those made on the group with all degrees of forearm rotation. However, interobserver agreement improved with supination and worsened with pronation.</p
Venous hemodynamics in neurological disorders: an analytical review with hydrodynamic analysis.
Venous abnormalities contribute to the pathophysiology of several neurological conditions. This paper reviews the literature regarding venous abnormalities in multiple sclerosis (MS), leukoaraiosis, and normal-pressure hydrocephalus (NPH). The review is supplemented with hydrodynamic analysis to assess the effects on cerebrospinal fluid (CSF) dynamics and cerebral blood flow (CBF) of venous hypertension in general, and chronic cerebrospinal venous insufficiency (CCSVI) in particular.CCSVI-like venous anomalies seem unlikely to account for reduced CBF in patients with MS, thus other mechanisms must be at work, which increase the hydraulic resistance of the cerebral vascular bed in MS. Similarly, hydrodynamic changes appear to be responsible for reduced CBF in leukoaraiosis. The hydrodynamic properties of the periventricular veins make these vessels particularly vulnerable to ischemia and plaque formation.Venous hypertension in the dural sinuses can alter intracranial compliance. Consequently, venous hypertension may change the CSF dynamics, affecting the intracranial windkessel mechanism. MS and NPH appear to share some similar characteristics, with both conditions exhibiting increased CSF pulsatility in the aqueduct of Sylvius.CCSVI appears to be a real phenomenon associated with MS, which causes venous hypertension in the dural sinuses. However, the role of CCSVI in the pathophysiology of MS remains unclear
Intelligent optical methods in image analysis for human detection
This thesis introduces the concept of a person recognition system for use on an integrated autonomous surveillance camera. Developed to enable generic surveillance tasks without the need for complex setup procedures nor operator assistance, this is achieved through the novel use of a simple dynamic noise reduction and object detection algorithm requiring no previous knowledge of the installation environment and without any need to train the system to its installation. The combination of this initial processing stage with a novel hybrid neural network structure composed of a SOM mapper and an MLP classifier using a combination of common and individual input data lines has enabled the development of a reliable detection process, capable of dealing with both noisy environments and partial occlusion of valid targets. With a final correct classification rate of 94% on a single image analysis, this provides a huge step forwards as compared to the reported 97% failure rate of standard camera surveillance systems.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
Isolation of Two Strong Poly (U) Binding Proteins from Moderate Halophile Halomonas eurihalina and Their Identification as Cold Shock Proteins
Cold shock proteins (Csp) are known to be expressed in response to sudden decrease in temperature. They are thought to be involved in a number of cellular processes viz., RNA chaperone activity, translation, transcription, nucleoid condensation. During our studies on ribosomal protein S1 in moderate halophile Halomonas eurihalina, we observed the presence of two strong poly (U) binding proteins in abundance in cell extracts from cells grown under normal growth conditions. The proteins can be isolated in a single step using Poly (U) cellulose chromatography. The proteins were identified as major cold shock proteins belonging to Csp A family by MALDI-TOF and bioinformatic analysis. Csp 12 kDa was found in both exponential and stationary phases whereas Csp 8 kDa is found only in exponential phase
Accuracy of radiographic measurements of fracture-induced deformity in the distal radius
BACKGROUND: Management of the distal radius fracture (DRF) is to some extent based on radiographic characterization of fracture displacement. It remains unclear, however, if the measurements used to quantify displacement are accurate.PURPOSE: To quantify accuracy of two radiographic measurements: dorsal/volar tilt and fracture compression, measured indirectly as ulnar variance (UV), using radiostereometric analyses (RSA) as reference standard.MATERIAL AND METHODS: Twenty-one fresh frozen non-fractured human cadaveric forearms (right = 11, left = 10) were thawed and eligible for inclusion. The forearms were mounted on a custom made platform that allowed for controlled forearm rotation, and they underwent two rounds of imaging (both rounds consisted of RSA and radiographs). In round one, the non-fractured forearms were radiographed. In round two, artificial DRF´s with compression and dorsal angulation were created and imaging procedures repeated. Change in tilt and UV between the non-fractured and later fractured forearms was defined as fracture-induced deformity. Deformity was measured radiographically and additionally calculated using RSA. Bland Altman analyses were used to estimate agreement between radiographically measured, and RSA calculated, fracture-induced deformity.RESULTS: Our results indicated that radiographs underestimate the amount of fracture-induced deformity. Mean measured differences (bias) in dorsal tilt deformity between radiographs and RSA were -2.5° for both observers. The corresponding values for UV were -1.4 mm and -1.5 mm.CONCLUSION: Quantifying fracture-induced deformity on radiographs underestimated the actual deformity when compared to RSA calculated deformity. These findings suggest that clinicians, at least in part, base fracture management and potentially corrective surgery on inaccurate measurements.</p
The effect of forearm rotation on radiographic measurements of the wrist:an experimental study using radiostereometric analyses on cadavers
BACKGROUND: Although dorsal/palmar tilt, radial inclination (RI), and ulnar variance (UV) are measurements commonly performed in wrist radiographs, the impact of forearm rotation on those measurements during the radiographic procedure is uncertain. Our aim was to determine the impact of supination and pronation on the reliability of measurements of tilt, RI, and UV.METHODS: Tantalum markers were inserted into the distal radius of 21 unfractured cadaver forearms. The forearms were radiographed in different degrees of supination and pronation. The exact degree of rotation was calculated with radiostereometric analyses. Tilt, RI, and UV were measured by two independent readers in a random and anonymised fashion. Association between forearm rotation and radiographic measurements was examined using linear regression.RESULTS: Forearm rotation significantly impacted the radiographically measured tilt. One degree of supination and pronation respectively increased and decreased palmar tilt with 0.68° and 0.44°, observers 1 and 2, respectively. As opposed to observer 1, observer 2 found that RI was significantly impacted by rotation with a slope of 0.08. Ulnar variance was not significantly impacted by rotation with linear regression slopes of 0.01° (95% confidence interval [CI] - 0.02-0.05, p = 0.490) and 0.02° (95% CI - 0.02-0.07; p = 0.288), observer 1 and observer 2, respectively.CONCLUSION: In unfractured forearms, the radiographically measured tilt was significantly affected by rotation. Palmar tilt increased with supination and decreased with pronation. Rotation significantly affected radial inclination, although of a magnitude that is probably not clinically relevant. No significant impact on UV was found.</p
Bacillus subtilis RarA Acts as a Positive RecA Accessory Protein
Ubiquitous RarA AAA+ ATPases play crucial roles in the cellular response to blocked replication forks in pro- and eukaryotes. Here, we provide evidence that RarA regulates the activity of the central player in homologous recombination (HR), RecA, in response to DNA damage. During unperturbed growth, absence of RarA reduced the viability of recA, recO and recF15 cells, and during repair of H2O2- or MMS-induced DNA damage, rarA was epistatic to recA, recO and recF. Conversely, the inactivation of rarA partially suppressed the HR defect of mutants lacking end-resection (addAB, recJ, recQ, recS) or branch migration (ruvAB, recG, radA) activity. RarA contributes to RecA thread formation, that are thought to be the active forms of RecA during homology search. The absence of RarA reduced RecA accumulation, and the formation of visible RecA threads in vivo upon DNA damage. When rarA was combined with mutations in genuine RecA accessory genes, RecA accumulation was further reduced in rarA recU and rarA recX double mutant cells, and was blocked in rarA recF15 cells. These results suggest that RarA contributes to the assembly of RecA nucleoprotein filaments onto single-stranded DNA (ssDNA), in concert with RecF, and possibly antagonizes RecA filament disassembly by RecX or RecU.Peer reviewe
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