AN INTRODUCTION TO HEAVY METAL POLLUTION AND DIFFERENT TECHNOLOGIES AVAILABLE FOR REMEDIATION

This paper revises the fundamental facts about potentially toxic elements belonging to the group of heavy metals. The study highlights the ongoing soil pollution status affected by these non-biodegradable elements, the basic characteristics of these metals that make them toxic, their mode of accumulation in different trophic levels, their toxic effect on human beings and the probable remediation technologies being used to remediate soils contaminated with heavy metal when the pollution problem has evolved. The technologies focused on solidification, soil washing, soil flushing, electro-kinetic remediation and phytoremediation are presented. The choice of the technology to be used for remediation depends on the condition of the soil and the extent of contamination. Conventional electro-kinetics is the most effective and rapid technology, but on the scale of ecosystem restoration, phytoremediation is an eco-friendly, green and cost-effective solution

Mitochondrial Cytopathies of the Renal System

Mitochondria are major intracellular organelles with a variety of critical roles like adenosine triphosphate production, metabolic modulation, generation of reactive oxygen species, maintenance of intracellular calcium homeostasis, and the regulation of apoptosis. Mitochondria often undergo transformation in both physiological and pathological conditions. New concepts point that mitochondrial shape and structure are intimately linked with their function in the kidneys and diseases related to mitochondrial dysfunction have been identified. Diseases associated with mitochondrial dysfunction are termed as “mitochondrial cytopathies”. Evidence support that there is a role of mitochondrial dysfunction in the pathogenesis of two common pathways of end-stage kidney disease, namely, chronic kidney disease (CKD) and acute kidney injury (AKI). Mitochondrial cytopathies in kidneys mainly manifest as focal segmental glomerular sclerosis, tubular defects, and as cystic kidney diseases. The defects implicated are mutations in mtDNA and nDNA. The proximal tubular cells are relatively vulnerable to oxidative stress and are therefore apt to suffer from respiratory chain defects and manifest as either loss of electrolyte or low-molecular-weight proteins. Patients with mitochondrial tubulopathy are usually accompanied by myoclonic epilepsy and ragged red muscle fibers (MERRF), and Pearson’s, Kearns-Sayre, and Leigh syndromes. The majority of genetic mutations detected in these diseases are fragment deletions of mtDNA. Studies have shown significantly increased ROS production, upregulation of COX I and IV expressions, and inactivation of complex IV in peripheral blood mononuclear cells of patients with stage IV–V CKD, thereby demonstrating the close association between mitochondrial dysfunction and progression to CKD. Furthermore, the mechanisms that translate cellular cues and demands into mitochondrial remodeling and cellular damage, including the role of microRNAs and lncRNAs, are examined with the final goal of identifying mitochondrial targets to improve treatment of patients with chronic kidney diseases

The black rim susceptibility sign in the MRI evaluation of intracranial colloid cysts

Background and Purpose Colloid cysts are relatively rare intracranial lesions located in the rostral aspect of third ventricle. They may produce acute hydrocephalus, brain herniation, and death. On conventional MRI, the appearance of a colloid cyst varies depending on its composition. Small isointense cysts can be missed. The purpose of this study is to introduce a new sign, "black rim susceptibility" sign for the accurate diagnosis of colloid cyst on susceptibility weighted imaging (SWI). Methods A retrospective case-control study consisted of 100 MRI brain scans (19 cases and 81 controls) performed from January 2012 to September 2018. Two fellowship trained neuroradiologists individually interpreted SWI sequences for the presence of the "black rim susceptibility" sign (thin rim of dark signal along the periphery of a rounded, hyperintense focus). Results The sample was 43% male and 57% female, with an average age of 51.8 +/- 17.7. Out of 19 cases, 9 had undergone surgery in which pathology had confirmed colloid cyst. Sensitivity, specificity, and accuracy for reader 1 was 94.8%, 98.8%, and 98% and for reader 2 was 89.5%, 100%, and 98%, respectively. Positive predictive value and negative predictive value for reader 1 was 94.7% and 98.8% and for reader 2 was 100% and 97.6%, respectively. Interrater correlation between the two readers was calculated with kappa of 0.93. Conclusion The black rim susceptibility appearance of colloid cyst on SWI is a novel description and an effective sign that can be used by radiologists for accurate diagnosis

Pharyngeal Emergencies

Pharyngeal emergencies, which can be subdivided into traumatic versus nontraumatic, are a common cause of Emergency Department visits. Patients often present to Emergency Department with a wide variety of pharyngeal symptoms, for which computed tomography imaging has become the first line imaging modality. Familiarity with these conditions enables a radiologist to make a prompt diagnosis, assess the extent of disease, and evaluate for potential complications. In this chapter, we present a brief overview of nontraumatic pharyngeal emergencies based on anatomic subdivisions (nasopharynx, oropharynx, and hypopharynx), discuss their etiologies, clinical presentations, computed tomography imaging findings, and management options. We will also discuss differential diagnoses based on imaging findings

Epithelioid sarcoma presenting as radial mononeuropathy: anatomical, magnetic resonance neurography and diffusion tensor imaging appearances

The authors report an unusual case of radial mononeuropathy caused by epithelioid sarcoma and describe the anatomical 3-Tesla MR neurography and the functional diffusion tensor imaging findings of the case, which were subsequently confirmed on surgical excision and histopathology

Imaging the Postoperative Spine

Imaging assessment of the postoperative spine is complex and depends on many factors. Postoperative imaging studies evaluate the position of implants, adequacy of decompression, fusion status, and potential complications. This article provides a review of various imaging techniques, with their advantages and disadvantages, for the evaluation of the postoperative spine. It also gives an overview of normal and abnormal postoperative appearances of the spine as seen via various modalities, with an emphasis on postoperative complications

2D versus 3D fluoroscopy-based navigation in posterior pelvic fixation: review of the literature on current technology

Purpose Percutaneous sacroiliac (SI) fixation of unstable posterior pelvic ring injuries is a widely accepted procedure. The complex sacral anatomy with narrow osseous corridors for SI screw placement makes this procedure technically challenging. Techniques are constantly evolving as a result of better understanding of the posterior pelvic anatomy. Recently developed tools include fluoroscopy-based computer-assisted navigation, which can be two-dimensional (2D) or three-dimensional (3D). Our goal is to determine the relevant technical considerations and clinical outcomes associated with these modalities by reviewing the published research. We hypothesize that 3D fluoroscopy-based navigation is safer and superior to its 2D predecessor with respect to lower radiation dose and more accurate SI screw placement. Methods We searched four medical databases to identify English-language studies of 2D and 3D fluoroscopy-based navigation from January 1990 through August 2015. We included articles reporting imaging techniques and outcomes of closed posterior pelvic ring fixation with percutaneous SI screw fixation. Injuries included in the study were sacral fractures (52 patients), sacroiliac fractures (88 patients), lateral compression fractures (20 patients), and anteroposterior compression type pelvic fractures (8 patients). We excluded articles on open reduction of posterior pelvic ring injuries and solely anatomic studies. We then reviewed these studies for technical considerations and outcomes associated with these technologies. Results Six studies were included in our analysis. Results of these studies indicate that 3D fluoroscopy-based navigation is associated with a lower radiation dose and lower rate of screw malpositioning compared with 2D fluoroscopy-based systems. Conclusions It may be advantageous to combine modern imaging modalities such as 3D fluoroscopy with computer-assisted navigation for percutaneous screw fixation in the posterior pelvis

Coexistence of central nucleus, cores, and rods: Diagnostic relevance

Background: Congenital myopathies (CMs) though considered distinct disorders, simultaneous occurrence of central nucleus, nemaline rods, and cores in the same biopsy are scarcely reported. Objective: A retrospective reassessment of cases diagnosed as CMs to look for multiple pathologies missed, if any, during the initial diagnosis. Materials and Methods: Enzyme histochemical, and immunohistochemical-stained slides from 125 cases diagnosed as congenital myopathy were reassessed. Results: The study revealed 15 cases (12%) of congenital myopathy with more than one morphological feature. Central nucleus with cores (n = 11), central nucleus, nemaline rods and cores (n = 3), and nemaline rods with cores (n = 1). 4/11 cases were diagnosed as centronuclear myopathy (CNM) in the first instance; in addition, cores were revealed on reassessment. Discussion: The prevalence of CMs of all neuromuscular disorders is approximately 6 in 100,000 live births, with regional variations. Three main defined CMs include centro nuclear myopathy (CNM), nemaline rod myopathy (NRM), and central core disease (CCD). However, they are more diverse with overlapping clinical and histopathological features, thus broadening the spectra within each category of congenital myopathy. Conclusion: Identification of cases with overlap of pathological features has diagnostic relevance

Cartilage magnetic resonance imaging techniques at 3 T: current status and future directions

Magnetic resonance imaging (MRI) remains the imaging modality of choice for morphological and compositional evaluation of the articular cartilage. Accurate detection and characterization of cartilage lesions are necessary to guide the medical and surgical therapy and are also critical for longitudinal studies of the cartilage. Recent work using 3.0-T MRI systems shows promise in improving detection and characterization of the cartilage lesions, particularly with increasing use of high-resolution and high-contrast 3-dimensional sequences, which allow detailed morphological assessment of cartilage in arbitrary imaging planes. In addition, implementation of biochemical sequences in clinically feasible scan times has a potential in the early detection of cartilage lesions before they become morphologically apparent. This article discusses relative advantages and disadvantages of various commonly used as well as experimental MRI techniques to directly assess the morphology and indirectly evaluate the biochemical composition of the articular cartilage