Interobserver agreement in fusion status assessment after instrumental desis of the lower lumbar spine using 64-slice multidetector computed tomography: impact of observer experience

Purpose

Persistent lower back pain after instrumental posterolateral desis may arise from incomplete fusion. We investigate the impact of experience on interobserver agreement in fusion estimation.

Methods

Four independent observers, two residents and two musculoskeletal radiologists, reviewed dedicated lumbar 64-MDCT scans and scored vertebral levels 1–5 after Glassman’s grades, 1: solid bilateral fusion, 2: solid unilateral fusion, 3: partial bilateral fusion, 4: partial unilateral fusion, 5: non-fusion. We investigated two simplifying dichotomizations, solid bilateral fusion (Glassman 1) versus all others and uni- or bilateral fusion (Glassman 1–2) versus partial or non-fusion.

Results

Thirty-six patients with 61 operated lumbar levels were included. Interobserver agreement rates for four observers using Glassman’s system were fair (kappa 0.32), either dichotomization showed moderate agreement (kappa 0.53 and 0.59). Observer pairs had comparable prevalence adjusted interobserver agreement rates (residents: PABAK 0.67 and 0.54; consultants: PABAK 0.57 and 0.71).

Conclusions

Difference in observer experience seems of minor impact.     

Clear cell papillary renal cell carcinoma: Incidence,morphological features,immunohistochemical profile,and biologic behavior: A single institution study

This study was undertaken to determine the incidence and the clinicopathologic characteristics of those tumors that qualify as clear cell papillary renal cell carcinoma (CCPRCC) by the current definitions. From January 1, 2003 to April 30, 2013, a total of twenty-eight CCPRCC were identified (28/648, 4.3%). CCPRCC showed variable architectural patterns including cystic, papillary, tubular, and acinar. Irrespective of the architecture, the tumors were composed of cuboidal or columnar cells with clear cytoplasm, small vesicular, round or oval nuclei, and inconspicuous nucleoli. Variably thick bundles of smooth muscle actin-positive soft tissue encircled the whole tumors, forming a continuous pseudocapsule. CCPRCC strongly expressed PAX8, CA-IX, CK7, cytokeratin 34betaE12, and vimentin, and were negative for RCC, P504s/AMACR, and TFE3. On ultrastructural examination, CCPRCC showed short microvilli, cytoplasmic interdigitations, nuclear pseudoinclusions, and stromal myofibroblasts. To the best of our knowledge, this is first comprehensive ultrastructural study of CCPRCC in the literature. The major differential diagnostic considerations are clear cell renal cell carcinoma, multilocular cystic renal cell carcinoma, papillary renal cell carcinoma with clear cell changes, and Xp11.2 translocation renal cell carcinoma. CCPRCC seems to have a favorable prognosis. In the current series, none of the patients had local recurrence or metastatic disease.     

Monolayer formed by l-Asp-based gemini surfactants self-assembled in 1D nanostructures

Herein, studies on the surface activities of newly synthesized l-Asp-based gemini surfactants, both nonionic and anionic, are presented. Conductometry, tensiometry, and the Langmuir–Blodgett (LB) film technique were applied for this purpose. π–A isotherms were obtained with a Langmuir trough and Wilhelmy balance. The structures of the monolayers assembled at the air/water interface and those deposited as LB films were studied via Brewster angle microscopy (BAM) and atomic force microscopy (AFM). The 2D films formed by the anion-active compounds show a well-known pattern of a monolayer film, whereas the nonionogenic amphiphiles have been found to be 1D structures with nano-widths and micro-lengths that align with each other during the process of compression; this is the first study where the organization of 1D fibrils in 2D films during compression is reported. The scanning electron microscopy (SEM) study reveals that 1D nanostructure formation is an intrinsic tendency of these molecules as not only nonionogenic surfactants, but also the anion active representatives have been constructed in the solid state by fibrillary structures.

l-Asp-based gemini surfactants form primary fibrils (1D structure) that interact with each other and arrange in a film (2D structure).     

The pathogenesis of bone metastasis in solid tumors: a review

Owing to its frequent occurrence and severe clinical picture, bone metastasis is an important problem in the clinical course of tumor diseases. Bone metastasis develops when the physiological remodeling process is disrupted by tumor cells via the same molecular mechanisms used by native bone cells. The process includes molecular crosstalk between osteocytes and osteoblasts and osteoclasts. Osteolytic bone metastasis, most often seen in breast cancer, is characterized by promoted differentiation and function of osteoclasts and reduced osteoblast function. Tumor cells take advantage of factors released by bone tissue resorption, thus establishing a vicious cycle that promotes the metastatic process. In osteoblastic metastasis, most often seen in prostate cancer, osteoblast function and differentiation are promoted, while osteoclast activity is reduced, resulting in net gain of bone tissue. Mechanisms involved in the early stages of bone metastasis and cancer cell dormancy have been understudied, and their exploration may pave the way for potential therapeutic strategies. Tumor affects the bone marrow microenvironment via exosomes, soluble factors, and membrane-bound ligands. In this way, an initial lesion is established, which after a variable duration of disseminated tumor cells dormancy progresses to an overt condition. The current review deals with basic mechanisms involved in bone metastasis formation and propagation. We illustrated a disparity between the diversity and number of factors included in the disease pathophysiology and the number of available and developing therapeutic options. We also examined new therapeutic strategies affecting molecular pathways.

The bone is the third most frequent metastasis site, behind the lungs and liver (1). Given common clinical manifestation and a high degree of related disability, bone metastases pose a serious problem in the clinical course of tumor diseases. Since bone metastases present frequently in tumor diseases, they have an important predictive role. Namely, the median survival from the diagnosis of bone metastases is 12-53 months for prostate cancer, 19-25 months for breast cancer, 48 months for thyroid cancer, 6-7 months for lung cancer, 6 months for melanoma, 6-9 months for bladder cancer, and 12 months for kidney cancer (2).All known mechanisms taking part in bone metastasis process are related to the disorders of physiological bone remodeling. Although the traditional division of bone metastases into osteolytic and osteoblastic is still widely accepted, these categories are increasingly viewed as only extremes of a continuum (3).     

Long-term efficacy of single procedure remote magnetic catheter navigation for ablation of ischemic ventricular tachycardia: a retrospective study

Long‐Term Efficacy of Single Procedure Remote Magnetic Catheter Navigation .
Background: Remote magnetic navigation (RMN) aims to reduce some inherent limitations of manual radiofrequency (RF) ablation. However, data comparing the effectiveness of both methods are scarce. This study evaluated the acute and long‐term success of RMN guided versus manual RF ablation in patients with ischemic sustained ventricular tachycardia (sVT). Methods: One hundred two consecutive patients (age 68 ± 10 years, LVEF 32 ± 12%, 88 men) with ischemic sVT were ablated with RMN (Stereotaxis; 49%) or manually (51%) using substrate and/or activation mapping (Carto) and open‐irrigated‐tip catheters. All received implantable defibrillators or loop recorders. Acute success was defined as noninducibility of any sVT at the end of the ablation procedure and long‐term success as freedom from VT upon follow‐up. Results: There was no difference in the baseline characteristics between the groups. Three patients died in hospital. Acute success rate was similar for RMN and manual ablation (82% vs 71%, P = 0.246). RMN was associated with significantly shorter fluoroscopy time (13 ± 12 minutes vs 32 ± 17 minutes, P = 0.0001) and RF time (2337.59 ± 1248.22 seconds vs 1589.95 ± 1047.42 seconds, P = 0.049), although total procedure time was similar (157 ± 40 minutes vs 148 ± 50 minutes, P = 0.42). There was a nonsignificant trend toward better long‐term success in RMN group: after a median of 13 (range 1–34) months, 63% in the RMN and 53% in the manual ablation group were free from VT recurrence (P = 0.206). Conclusion: RMN guided RF ablation of ischemic sustained VT is equally efficient compared with manual ablation in terms of acute and long‐term success rate. These results are achieved with a significantly reduced fluoroscopy time and shorter RF time. (J Cardiovasc Electrophysiol Vol. 23, pp. 499‐505, May 2012)     

Raman-shifted alexandrite laser for soft tissue ablation in the 6- to 7-µm wavelength range

Prior work with free-electron lasers (FELs) showed that wavelengths in the 6- to 7-μm range could ablate soft tissues efficiently with little collateral damage; however, FELs proved too costly and too complex for widespread surgical use. Several alternative 6- to 7-μm laser systems have demonstrated the ability to cut soft tissues cleanly, but at rates that were much too low for surgical applications. Here, we present initial results with a Raman-shifted, pulsed alexandrite laser that is tunable from 6 to 7 μm and cuts soft tissues cleanly-approximately 15 μm of thermal damage surrounding ablation craters in cornea-and does so with volumetric ablation rates of 2-5 × 10(-3) mm(3)/s. These rates are comparable to those attained in prior successful surgical trials using the FEL for optic nerve sheath fenestration.     

Extensive retraction artefact predicts biochemical recurrence-free survival in prostatic carcinoma

Tomas D, Spaji? B, Milo?evi? M, Demirovi? A, Maru?i? Z & Kru?lin B
(2011) Histopathology 58 , 447–454
Extensive retraction artefact predicts biochemical recurrence‐free survival in prostatic carcinoma Aims: To determine whether the presence and extent of peritumoral retraction artefact could be used to predict biochemical recurrence‐free survival in prostatic carcinoma. Methods and results: The study included 162 consecutive patients treated by radical retropubic prostatectomy and bilateral lymphadenectomy for clinically localized prostatic carcinoma. A variable degree of retraction artefact was present in all 162 analysed tumours. The extent of retraction artefact in prostatic carcinomas ranged from 5% to 55% with a median value of 15% (interquartile range 10–25%). We found no correlation between the extent of retraction artefact in the tumours and patient’s age (P = 0.608), preoperative (P = 0.362) and postoperative (P = 0.279) Gleason score or lymph node metastases (P = 0.084). In contrast, the extent of retraction artefact correlated with high preoperative prostate‐specific antigen (P < 0.001), short follow‐up time (P < 0.001), seminal vesicle invasion and/or extracapsular extension of the tumour (T3 stage tumours) (P < 0.001) and positive surgical margins (P < 0.001). Furthermore, extensive retraction artefact was associated with poor biochemical recurrence‐free survival in both univariate (P < 0.001) and multivariate analyses (P = 0.013). Conclusion: The presence of extensive retraction artefact in prostatic carcinoma correlates with tumour characteristics signifying aggressive behaviour and indicates poor biochemical recurrence‐free survival.