Τρίτη, 17 Απριλίου 2018

‘Omic’ technologies as a helpful tool in radioecological research

Publication date: September 2018
Source:Journal of Environmental Radioactivity, Volume 189
Author(s): Polina Yu. Volkova, Stanislav A. Geras'kin
This article presents a brief review of the modern 'omic' technologies, namely genomics, epigenomics, transcriptomics, proteomics, and metabolomics, as well as the examples of their possible use in radioecology. For each technology, a short description of advances, limitations, and instrumental applications is given. In addition, the review contains examples of successful use of 'omic' technologies in the assessment of biological effects of pollutants in the field conditions.



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Comparing panoramic radiographs and CBCT: impact on radiographic features and differential diagnoses

The aims of this study were to determine whether lesion features appear differently on panoramic radiographs (PAN) and cone beam computed tomography (CBCT), and whether using CBCT changes diagnostic accuracy and observers' confidence compared to PAN.

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Osteonecrosis of the jaw in patients treated by denosumab for malignant bone disease: descriptive study on 9 cases.

This study examines the epidemiological and clinical characteristics and therapeutic outcomes in patients with denosumab related-osteonecrosis of the jaw (DRONJ).Study design: The patients included are all being monitored by three oral and maxillofacial surgery departments for an osteonecrosis of the jaw (ONJ) linked to denosumab alone for the treatment of malignant bone disease between 2010 and 2016. Clinical and epidemiological data of these patients was indexed and characteristics of the DRONJ were analyzed.

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Letter to editor – oral surgery, oral medicine, oral pathology, oral radiology re: goldblatt li, adams wr, spolnik kj, deardorf ka, parks et. chronic fibrosing osteomyelitis of the jaws: an important cause of recalcitrant facial pain. A clinicopathologic study of 331 cases in 227 patients. oral surg oral med oral pathol oral radiol. 2017 oct;124(4):403-412.

The recent paper by Goldblatt et al. 1 attempts to resurrect an orofacial pain concept that has come and gone several times in the past 30-40 years. As they correctly point out in their first paragraph, this concept has had many different names in the past (ischemic osteonecrosis, bone marrow edema syndrome, neuralgia-inducing cavitational osteonecrosis (NICO), Ratner bone cavity, and alveolar cavitational osteopathosis). Now these authors have presented similar findings under the new name of chronic fibrosing osteomyelitis of the jaws (CFOJ), but clearly they are still invoking a familiar theory that they believe can explain certain cases of orofacial pain.

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Diagnostic performance of 18 F-FDG PET/CT and whole-body diffusion-weighted imaging with background body suppression (DWIBS) in detection of lymph node and bone metastases from pediatric neuroblastoma

Abstract

Objective

Recent many studies have shown that whole body "diffusion-weighted imaging with background body signal suppression" (DWIBS) seems a beneficial tool having higher tumor detection sensitivity without ionizing radiation exposure for pediatric tumors. In this study, we evaluated the diagnostic performance of whole body DWIBS and 18F-FDG PET/CT for detecting lymph node and bone metastases in pediatric patients with neuroblastoma.

Methods

Subjects in this retrospective study comprised 13 consecutive pediatric patients with neuroblastoma (7 males, 6 females; mean age, 2.9 ± 2.0 years old) who underwent both 18F-FDG PET/CT and whole-body DWIBS. All patients were diagnosed as neuroblastoma on the basis of pathological findings. Eight regions of lymph nodes and 17 segments of skeletons in all patients were evaluated. The images of 123I-MIBG scintigraphy/SPECT-CT, bone scintigraphy/SPECT, and CT were used to confirm the presence of lymph node and bone metastases. Two radiologists trained in nuclear medicine evaluated independently the uptake of lesions in 18F-FDG PET/CT and the signal-intensity of lesions in whole-body DWIBS visually. Interobserver difference was overcome through discussion to reach a consensus. The sensitivities, specificities, and overall accuracies of 18F-FDG PET/CT and whole-body DWIBS were compared using McNemer's test. Positive predictive values (PPVs) and negative predictive values (NPVs) of both modalities were compared using Fisher's exact test.

Results

The total numbers of lymph node regions and bone segments which were confirmed to have metastasis in the total 13 patients were 19 and 75, respectively. The sensitivity, specificity, overall accuracy, PPV, and NPV of 18F-FDG PET/CT for detecting lymph node metastasis from pediatric neuroblastoma were 100, 98.7, 98.9, 95.0, and 100%, respectively, and those for detecting bone metastasis were 90.7, 73.1, 80.3, 70.1, and 91.9%, respectively. In contrast, the sensitivity, specificity, overall accuracy, PPV, and NPV of whole-body DWIBS for detecting bone metastasis from pediatric neuroblastoma were 94.7, 24.0, 53.0, 46.4 and 86.7%, respectively, whereas those for detecting lymph node metastasis were 94.7, 85.3, 87.2, 62.1, and 98.5%, respectively. The low specificity, overall accuracy, and PPV of whole-body DWIBS for detecting bone metastasis were due to a high incidence of false-positive findings (82/108, 75.9%). The specificity, overall accuracy, and PPV of whole-body DWIBS for detecting lymph node metastasis were also significantly lower than those of 18F-FDG PET/CT for detecting lymph node metastasis, although the difference between these 2 modalities was less than that for detecting bone metastasis.

Conclusion

The specificity, overall accuracy, and PPV of whole-body DWIBS are significantly lower than those of 18F-FDG PET/CT because of a high incidence of false-positive findings particularly for detecting bone metastasis, whereas whole-body DWIBS shows a similar level of sensitivities for detecting lymph node and bone metastases to those of 18F-FDG PET/CT. DWIBS should be carefully used for cancer staging in children because of its high incidence of false-positive findings in skeletons.



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Pathological factors contributing to crossed cerebellar diaschisis in cerebral gliomas: a study combining perfusion, diffusion, and structural MR imaging

Abstract

Purpose

To investigate imaging features of crossed cerebellar diaschisis (CCD) in cerebral gliomas, and its underlying pathophysiological mechanisms.

Methods

Thirty-three pre-surgical patients with cerebral gliomas and 33 healthy controls underwent arterial spin-labeling, diffusion tensor imaging, and high-resolution T1-weighted imaging using MRI, in order to estimate cerebral blood flow (CBF), white matter integrity, and lesion volume, respectively. Asymmetry indices of CBF in the cerebellum were used for evaluating the level of CCD in the patients. These indices were correlated with clinical variables (lesion size and position, tumor histological grade, and CBF asymmetry) and diffusion tensor imaging parameters (fractional anisotropy and number of fibers in the cortico-ponto-cerebellar pathway and across the cerebral hemispheres), respectively.

Results

The patients showed decreased CBF in the cerebellar hemisphere contralateral to the supratentorial tumor, and increased CBF asymmetry in the cerebellum (both P < 0.05). CCD levels in high-grade gliomas were higher than those of low-grade gliomas (P < 0.05). CCD levels were negatively correlated with the size of the supratentorial lesions, and positively correlated with FA asymmetry in the cerebral fibers (both P < 0.05).

Conclusions

CCD in cerebral gliomas was specifically associated with tumor histological grade, lesion size, and white matter impairments in the hemisphere ipsilateral to the tumor. The findings implicated that observing CCD might have potential for assisting grading diagnosis of cerebral gliomas.



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Management update of potentially premalignant oral epithelial lesions.

Related Articles

Management update of potentially premalignant oral epithelial lesions.

Oral Surg Oral Med Oral Pathol Oral Radiol. 2018 Mar 23;:

Authors: Awadallah M, Idle M, Patel K, Kademani D

Abstract
The term oral potentially malignant disorders, proposed at the World Health Organization workshop in 2005, has now been renamed potentially premalignant oral epithelial lesions (PPOELs). It is important to differentiate among PPOELs, which is a broad term to define a wide variety of clinical lesions, and oral epithelial dysplasia, which should be reserved specifically for lesions with biopsy-proven foci of dysplasia. PPOELs encompass lesions that include leukoplakia, erythroplakia, erythroleukoplakia, lichen planus, and oral submucous fibrosis. The primary goal of management of dysplasia includes prevention, early detection, and treatment before malignant transformation. The aim of this article is to inform the clinician about management of PPOELs.

PMID: 29656948 [PubMed - as supplied by publisher]



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FEM-based elasticity reconstruction using ultrasound for imaging tissue ablation

Abstract

Purpose

Success of ablation treatment depends on the accurate placement of the target ablation focus and the complete destruction of the pathological tissue. Thus, monitoring the formation, location, and size of the ablated lesion is essential. As ablated tissue gets stiffer, an option for ablation monitoring is ultrasound elastography, for imaging the tissue mechanical properties. Reconstruction of elasticity distribution can be achieved by solving an inverse problem from observed displacements, based on a deformable tissue model, commonly discretized by the finite element method (FEM). However, available reconstruction techniques are prone to noise and may achieve suboptimal accuracy.

Methods

We propose a novel inverse problem formulation and elasticity reconstruction method, in which both the elasticity parameters and the model displacements are estimated as independent parameters of an unconstrained optimization problem. Total variation regularization of spatial elasticity distribution is introduced in this formulation, providing robustness to noise.

Results

Our approach was compared to state of the art direct and iterative harmonic elastography techniques. We employed numerical simulation studies using various noise and inclusion contrasts, given multiple excitation frequencies. Compared to alternatives, our method leads to a decrease in RMSE of up to 50% and an increase in CNR of up to 11 dB in numerical simulations. The methods were also compared on an ex vivo bovine liver sample that was locally subjected to ablation, for which improved lesion delineation was obtained with our proposed method. Our method takes \(\sim 4\,\hbox {s}\) for \(20\times 20\) reconstruction grid.

Conclusions

We present a novel FEM problem formulation that improves reconstruction accuracy and inclusion delineation compared to currently available techniques.



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Pathological factors contributing to crossed cerebellar diaschisis in cerebral gliomas: a study combining perfusion, diffusion, and structural MR imaging

Abstract

Purpose

To investigate imaging features of crossed cerebellar diaschisis (CCD) in cerebral gliomas, and its underlying pathophysiological mechanisms.

Methods

Thirty-three pre-surgical patients with cerebral gliomas and 33 healthy controls underwent arterial spin-labeling, diffusion tensor imaging, and high-resolution T1-weighted imaging using MRI, in order to estimate cerebral blood flow (CBF), white matter integrity, and lesion volume, respectively. Asymmetry indices of CBF in the cerebellum were used for evaluating the level of CCD in the patients. These indices were correlated with clinical variables (lesion size and position, tumor histological grade, and CBF asymmetry) and diffusion tensor imaging parameters (fractional anisotropy and number of fibers in the cortico-ponto-cerebellar pathway and across the cerebral hemispheres), respectively.

Results

The patients showed decreased CBF in the cerebellar hemisphere contralateral to the supratentorial tumor, and increased CBF asymmetry in the cerebellum (both P < 0.05). CCD levels in high-grade gliomas were higher than those of low-grade gliomas (P < 0.05). CCD levels were negatively correlated with the size of the supratentorial lesions, and positively correlated with FA asymmetry in the cerebral fibers (both P < 0.05).

Conclusions

CCD in cerebral gliomas was specifically associated with tumor histological grade, lesion size, and white matter impairments in the hemisphere ipsilateral to the tumor. The findings implicated that observing CCD might have potential for assisting grading diagnosis of cerebral gliomas.



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