Validation of an Ultrasound Protocol to Measure Intervertebral Axial Twist during Functional Twisting Movements in Isolated Functional Spinal Units

Publication date: Available online 11 December 2018

Source: Ultrasound in Medicine & Biology

Author(s): Colin D. McKinnon, Jack P. Callaghan

Abstract

Ultrasound has potential for use in evaluation of bone and joint movement during axial twist of the lumbar spine both in vivo and in vitro. Such segmental rotations could then be measured under controlled external thoracic axial twist conditions and in response to mechanical loading. The purpose of this study was to measure vertebral segmental rotations in a porcine model of the human lumbar spine using an ultrasound imaging protocol and to validate use of this imaging technique with an optical motion capture system. In part 1, ultrasound transducer angle was confirmed to have no effect on sonogram point digitization. In part 2, 12 porcine functional spinal units were fixed to a mechanical testing system, and compression (15% of compressive tolerance), flexion–extension and axial twist (0°, 2°, 4° or 6°) were applied. Axial twist motion was tracked using an optical motion capture system and posterior surface ultrasound. Correlation between the two measurement systems was >0.903, and absolute system error was 0.01° across all flexion–extension postures. These findings indicate that ultrasound can be used to track axial twist motion in an in vitro spine motion segment and has the potential for use in vivo to evaluate absolute intervertebral axial twist motion.

from Imaging via a.sfakia on Inoreader https://ift.tt/2rEUpnf

Does MR enterography offer added value after a recent CT in the evaluation of abdominal pain in Crohn's disease patients?

Publication date: Available online 10 December 2018

Source: Clinical Imaging

Author(s): Michael Spektor, Mahan Mahtur, Guido Santacana, Daniella Asch, Steffen Huber, Lawrence Staib, Gary Israel

Abstract

Purpose

To determine if there is added value in performing MR enterography shortly after a contrast-enhanced CT of the abdomen and pelvis in patients with Crohn's disease presenting with acute abdominal pain.

Materials and methods

A total of 45 consecutive patients who underwent MRE examination <7 days after a CT met our strict inclusion criteria. Independent and blinded review of both MRE and CT exams was performed by two abdominal radiologists.

Results

There were no significant differences in detection of various findings associated with Crohn's disease between modalities. These findings included abscess, fistula, bowel wall thickening, free fluid, stricture, and bowel obstruction. There was moderate interobserver agreement with CT (Kappa: 0.52, 95% CI: [0.4–0.6]) and fair with MRE (Kappa: 0.36, 95% CI:[0.3 = 0.5]).

Conclusion

The routine use of MRE after a diagnostic CT should be avoided, as it provides no additional valuable information, at the expense of extra patient risks, discomfort, and higher health care costs.

from Imaging via a.sfakia on Inoreader https://ift.tt/2PxyMyo

Computed tomography imaging characteristics of primary atrial intimal sarcoma

Publication date: Available online 10 December 2018

Source: Clinical Imaging

Author(s): Mitchell Edquist, Christopher Lui, German Kilimnik, Hillel Karp

Abstract

We present a 36-year-old man who presented to our emergency department with acute onset shortness of breath and syncope. He was found to have a large left atrial mass on initial computed tomography (CT) which was confirmed by echocardiography. Tumor biopsy and attempted excision were performed, showing a primary cardiac spindle cell sarcoma that was unable to be resected, to which the patient eventually succumbed to. Spindle cell sarcomas of the heart are very rare primary cardiac tumors, with a variable, non-specific presentation. The most effective treatment is surgical resection, with chemotherapy and radiotherapy showing some benefit. Despite these treatments, the prognosis is poor. Given the uncommon nature of this tumor, the objective of this report is to demonstrate the clinical presentation and CT imaging characteristics of a case of primary cardiac spindle cell sarcoma, to raise awareness of this entity, and to increase the index of suspicion as a potential differential diagnosis to cardiac tumors seen on imaging.

from Imaging via a.sfakia on Inoreader https://ift.tt/2zS00Lg

Siglec-8 in eosinophilic disorders: receptor expression and targeting using chimeric antibodies

Publication date: Available online 10 December 2018

Source: Journal of Allergy and Clinical Immunology

Author(s): Fanny Legrand, Yun Cao, Joshua Wechsler, Xiang Zhu, Nives Zimmermann, Shakuntala Rampertaap, Joseph Monsale, Kimberly Romito, Bradford A. Youngblood, Emily C. Brock, Michelle Makiya, Nenad Tomasevic, Christopher Bebbington, Irina Maric, Dean D. Metcalfe, Bruce S. Bochner, Amy D. Klion

Abstract

Background

Sialic acid–binding immunoglobulin-like lectin (Siglec)-8 is selectively expressed on eosinophils, mast cells and basophils, and, when engaged on eosinophils, can cause cell death.

Objective

To characterize surface and soluble Siglec-8 levels in normal (ND) and eosinophilic (EO) subjects and assess the efficacy of anti-Siglec-8 antibodies in inducing eosinophil cell death in vitro.

Methods

Eosinophil expression of Siglec-8 was assessed using flow cytometry and quantitative PCR. Serum soluble Siglec-8 levels were measured by ELISA. Induction of eosinophil death by IgG4 (c2E2 IgG4) and afucosylated IgG1 (c2E2 IgG1) anti-Siglec-8 antibodies was evaluated in vitro by flow cytometry and in vivo in humanized mice.

Results

Siglec-8 was consistently expressed on eosinophils from ND and EO and did not correlate with absolute eosinophil count (AEC) or disease activity. Soluble Siglec-8 levels were measurable in serum from most donors, unrelated to AEC or Siglec-8 surface expression. c2E2 IgG1 and c2E2 IgG4 were equally effective at inducing cell death (Annexin-V positivity) of purified eosinophils from ND and EO after overnight IL-5 priming. In contrast, killing of purified eosinophils without IL-5 was only seen in EO subjects, and NK-mediated eosinophil killing was seen only with c2E2 IgG1. Finally, treatment of humanized mice with anti-Siglec antibody led to robust depletion of IL-5-induced eosinophilia in vivo.

Conclusions

Siglec-8 is highly expressed on blood eosinophils from EO and ND and represents a potential therapeutic target for eosinophilic disorders. Enhanced killing of eosinophils in the presence of IL-5 may lead to increased efficacy in patients with IL-5-driven eosinophilia.

Graphical abstract

from Allergy and Immunology via a.sfakia on Inoreader https://ift.tt/2QmtMSF

Integrating the PILP-mineralization process into a restorative dental treatment

Publication date: Available online 10 December 2018

Source: Dental Materials

Author(s): Margot Bacino, Vishavjeet Girn, Hamid Nurrohman, Kuniko Saeki, Sally J Marshall, Laurie Gower, Ella Saeed, Ray Stewart, Thuan Le, Grayson W Marshall, Stefan Habelitz

Abstract

The addition of charged polymers, like poly-aspartic acid (pAsp), to mineralizing solutions allows for transport of calcium and phosphate ions into the lumen of collagen fibrils and subsequent crystallization of oriented apatite crystals by the so-called Polymer-Induced Liquid Precursor (PILP) mineralization process, leading to the functional recovery of artificial dentin lesions by intrafibrillar mineralization of collagen.

Objective

To evaluate the feasibility of applying the PILP method as part of a restorative treatment and test for effectiveness to functionally remineralize artificial lesions in dentin.

Materials and Methods

Two methods of providing pAsp to standardized artificial lesions during a restorative procedure were applied: (A) pAsp was mixed into commercial RMGI (resin modified glass ionomer) cement formulations and (B) pAsp was added at high concentration (25 mg/ml) in solution to rehydrate lesions before restoring with a RMGI cement. All specimens were immersed in simulated body fluid for two weeks to allow for remineralization and then analyzed for dehydration shrinkage, integrity of cement-dentin interface, degree of mineralization, and changes in the nanomechanical profile (E-modulus) across the lesion.

Results

After the remineralization treatment, lesion shrinkage was significantly reduced for all treatment groups compared to demineralized samples. Pores developed in RMGI when pAsp was added. A thin layer at the dentin-cement interface, rich in polymer formed possibly from a reaction between pAsp and the RMGI. When analyzed by SEM under vacuum, most lesions delaminated from the cement interface. EDS-analysis showed some but not full recovery of calcium and phosphorous levels for treatment groups that involved pAsp. Nanoindentations placed across the interface indicated improvement for RMGI containing 40% pAsp, and were significantly elevated when lesions were rehydrated with pAsp before being restored with RMGI. In particular the most demineralized outer zone recovered substantially in the elastic modulus, suggesting that functional remineralization has been initiated by pAsp delivery upon rehydration of air-dried demineralized dentin. In contrast, the effectiveness of the RMGI on functional remineralization of dentin was minimal when pAsp was absent.

Significance

Incorporation of pAsp into restorative treatments using RMGIs promises to be a feasible way to induce the PILP-mineralization process in a clinical setting and to repair the structure and properties of dentin damaged by the caries process.

from OroFacial via a.sfakia on Inoreader https://ift.tt/2QI94Mx

Biomimetic regulation of dentine remineralization by amino acid in vitro

Publication date: Available online 10 December 2018

Source: Dental Materials

Author(s): Yuanmei Zhang, Zhejun Wang, Tao Jiang, Yining Wang

Abstract

Objective

The aim of this study was to evaluate the effect of conditioning solutions containing DL-aspartic amino (Asp) on dentine remineralization induced by bioactive glass 45S5 (BAG) in a simulated oral environment.

Methods

Sixty dentine discs from human third molars were used. Dentine specimens were treated with ethylene diamine tetraacetic acid (EDTA) to create a partially demineralization model and randomly divided to 4 groups: Artificial saliva (AS) group, Asp group (pretreated with Asp and remineralized with distilled water), BAG group (pretreated with distilled water and remineralized by BAG), Asp-BAG group (pretreated with Asp and remineralized by BAG).

Each samples were measured at various time points, and at the end of the experiment, 6% citric acid challenge were taken. The remineralization characteristics were analyzed by using the spectroscopic data from attenuated total reflectance spectroscopy (ATR-IR) and Raman spectroscopy. The micro-morphology and structure were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Dentine permeability was measured before and after each treatment to evaluate the resistance of remineralized layer to acid and simulated oral environment.

Results

Both BAG and Asp-BAG groups significantly reduced dentine permeability and formed enamel-like apatite layers on dentine surface. For the mineralization of BAG, Asp showed inhibition effect. The 7-day mineral matrix area ratio in BAG group (12.54 ± 2.29) was lower than the value in the Asp-BAG group (17.77 ± 2.27) (p < 0.05) and the Raman intensity (RI%) in Asp-BAG Group (1.49 ± 0.26) was also significantly higher than that of BAG group (1.34 ± 0.14) (p < 0.05). According to permeability test, the apatite layer in BAG group and Asp-BAG group effectively occluded the dentinal tubules (p < 0.05) and had certain acidic resistance (p > 0.05). Furthermore, adsorbed acidic amino acid on hydroxyapatite (HAP) altered the crystal to increase into a larger size in diameter during crystal growth.

Significance

The study demonstrated that a superior remineralization efficacy of BAG with Asp pretreatment on dentine.

from OroFacial via a.sfakia on Inoreader https://ift.tt/2SHj5XI

Performance of Diffusion Kurtosis Imaging Versus Diffusion Tensor Imaging in Discriminating Between Benign Tissue, Low and High Gleason Grade Prostate Cancer

Publication date: Available online 11 December 2018

Source: Academic Radiology

Author(s): Maria Giovanna Di Trani, Marco Nezzo, Alessandra S. Caporale, Riccardo De Feo, Roberto Miano, Alessandro Mauriello, Pierluigi Bove, Guglielmo Manenti, Silvia Capuani

Rationale and Objectives

To investigate the performance of diffusion kurtosis imaging (DKI) and diffusion tensor imaging (DTI) in discriminating benign tissue, low- and high-grade prostate adenocarcinoma (PCa).

Materials and Methods

Forty-eight patients with biopsy-proven PCa of different Gleason grade (GG), who provided written informed consent, were enrolled. All subjects underwent 3T DWI examinations by using b values 0, 500, 1000, 1500, 2000, and 2500 s/mm² and six gradient directions. Mean diffusivity, fractional anisotropy (FA), apparent kurtosis (K), apparent kurtosis-derived diffusivity (D), and proxy fractional kurtosis anisotropy (KFA) maps were obtained. Regions of interest were selected in PCa, in the contralateral benign zone, and in the peritumoral area. Histogram analysis was performed by measuring mean, 10th, 25th, and 90th (p90) percentile of the whole-lesion volume. Kruskal–Wallis test with Bonferroni correction was used to assess significant differences between different regions of interest. The correlation between diffusion metrics and GG and between DKI and DTI parameters was evaluated with Pearson's test. ROC curve analysis was carried out to analyze the ability of histogram variables to differentiate low- and high-GG PCa.

Results

All metrics significantly discriminated PCa from benign and from peritumoral tissue (except for K, KFA_p90, and FA). K_p90 showed the highest correlation with GG and the best diagnostic ability (area under the curve = 0.84) in discriminating low- from high-risk PCa.

Conclusion

Compared to DTI, DKI provides complementary and additional information about prostate cancer tissue, resulting more sensitive to PCa-derived modifications and more accurate in discriminating low- and high-risk PCa.

from Imaging via a.sfakia on Inoreader https://ift.tt/2SHuyGG