Nanotechnology for colorectal cancer detection and treatment

Colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of cancer-related mortality in the United States. Across the globe, people in the age group older than 50 are at a higher risk of CRC. Genetic and environmental risk factors play a significant role in the development of CRC. If detected early, CRC is preventable and treatable. Currently, available screening methods and therapies for CRC treatment reduce the incidence rate among the population, but the micrometastasis of cancer may lead to recurrence. Therefore, the challenge is to develop an alternative therapy to overcome this complication. Nanotechnology plays a vital role in cancer treatment and offers targeted chemotherapies directly and selectively to cancer cells, with enhanced therapeutic efficacy. Additionally, nanotechnology elevates the chances of patient survival in comparison to traditional chemotherapies. The potential of nanoparticles includes that they may be used simultaneously for diagnosis and treatment. These exciting properties of nanoparticles have enticed researchers worldwide to unveil their use in early CRC detection and as effective treatment. This review discusses contemporary methods of CRC screening and therapies for CRC treatment, while the primary focus is on the theranostic approach of nanotechnology in CRC treatment and its prospects. In addition, this review aims to provide knowledge on the advancement of nanotechnology in CRC and as a starting point for researchers to think about new therapeutic approaches using nanotechnology.     

Clinico-Radio-Histopathological Correlation by C-Arm Image-Guided Biopsy in Spinal Tuberculosis

Background/Purpose of the StudyC-arm-guided biopsy is a safe and effective technique for evaluating TB spine and is useful in planning therapy. The purpose of this study was to find a correlation between clinically and radiologically suspected TB spine and C-arm image-guided biopsy-proven cases and to study the complications encountered.MethodsAfter evaluating the clinical, laboratory, X-ray and MRI findings, 92 patients with provisionally diagnosed tubercular spine were subjected to C-arm image-guided biopsy.ResultsAmong our 92 cases, histopathology was positive in 55 cases (59.78%). Out of these 55 histologically positive cases, CBNAAT was positive in 42 cases and negative in the rest 13 cases. Overall, among the 92 cases, CBNAAT was positive in 51(55.43%) of cases, and out of these, histopathology turned out to be positive in 42 of cases. Out of 41 cases with negative CBNAAT, histopathology was suggestive of tuberculosis in 13. The strength of agreement between CBNAAT and histopathology was statistically significant (p < 0.0001; kappa = 0.511). No complication such as bleeding, nerve/cord injury, infection, injury to aorta or pneumothorax was encountered during and after the C-arm biopsy in any case.ConclusionC-arm image-guided biopsy is reasonably accurate and should be used as a tool for diagnosis of TB spine. We recommend histopathological examination as a key component for the diagnosis of TB spine, as it is precise and consumes relatively shorter time. CBNAAT is more rapid but is not a substitute for histopathology for spine TB diagnosis.     

Extracardiac applications of MR blood pool contrast agent in children

Magnetic resonance (MR) angiography has significantly reduced the need for diagnostic conventional angiography and is preferred over CT angiography in children because of its lack of ionizing radiation. The availability of gadofosveset trisodium (the only clinically approved blood pool MR contrast agent) has led to an increase in applications of MR for vascular imaging and an improvement in diagnostic quality of MR angiography. Gadofosveset is a gadolinium-based contrast agent that binds reversibly to albumin, resulting in increased paramagnetic effect and longer intravascular residence. This allows for high-resolution arterial and venous MR angiography, assessment of flow characteristics of vascular malformations, dynamic vascular imaging, and multi-station imaging with a single low-dose gadolinium contrast injection. The purpose of this pictorial essay is to facilitate understanding of the kinetics and safety profile of gadofosveset trisodium, discuss technical aspects of imaging, and illustrate advantages and extracardiac applications in pediatric body imaging.     

Oncogenic KIT-containing exosomes increase gastrointestinal stromal tumor cell invasion

During tumor development, constant interplay occurs between tumor cells and surrounding stromal cells. We report evidence that gastrointestinal stromal tumor (GIST) cells invade the interstitial stroma through the release of the oncogenic protein tyrosine kinase (KIT)-containing exosomes, which triggers the phenotypic conversion of progenitor smooth muscle cells to tumor-promoting cells. These recipient cells display morphologic changes and acquire tumor-associated phenotypes, including enhanced adhesion to extracellular matrix proteins, activation of intracellular pathways downstream of KIT, expression of Interstitial Cell of Cajal–like markers, and release of various matrix metalloproteinases (MMPs), particularly MMP1. This report shows stimulation of MMP1 production by stromal cells via uptake of tumor-derived exosomes, which leads to tumor cell invasion. Exosomes derived from GIST patients but not healthy donors show enhanced MMP1 secretion by smooth muscle cells and tumor cell invasion, whereas selective blocking of exosome-mediated MMP1 secretion decreases tumor invasiveness. Our study indicates that exosome release and subsequent MMP1 induction creates a positive feedback mechanism established between tumor and stromal cells that drives GIST development and offers unique insights for potential therapeutic strategies to block GIST progression and metastatic spread.With the ultimate goal of fulfilling their needs for exogenous supply of growth factors, chemokines, cytokines, and matrix-degrading enzymes, tumor cells communicate with their surrounding stroma using several intercellular communication mechanisms (1, 2). In the last decade, various tumors have been shown to rely on the release of bioactive membrane vesicles known as exosomes (3). Tumor cells of various origins constitutively release these vesicles, which are believed to be important in the processes of malignant transformation and tumor progression. Exosomes share certain common characteristics, including their shape, size, density, and general protein composition (3). Their effects are mediated via transfer of cargo that comprises an array of proteins (4), RNA (5), and mitochondrial DNA (6). Accordingly, their role as mediators in tumor progression has been the focus of several recent studies (7, 8). However, the majority of these studies focused on human malignancies of epithelial origin (i.e., carcinomas), whereas little attention has been given to the tumor microenvironment associated with malignancies of mesenchymal origin (i.e., sarcomas).Sarcomas represent an interesting and unique tumor type in which cancer cells of mesenchymal origin are surrounded by stromal cells of the same origin. The focus of this study is on the most common mesenchymal tumor of the digestive tract, gastrointestinal stromal tumor (GIST) (9). Approximately 75% of GISTs contain oncogenic mutations in the receptor tyrosine kinase c-KIT [normal cellular homolog of the viral oncoprotein v-Kit (v-Kit, Hardy Zuckerman 4 feline sarcoma viral oncogene homolog)] (10, 11), which plays a central role in the pathogenesis of this disease (10, 12). GISTs are believed to arise from the Interstitial Cells of Cajal (ICCs) (13), the pacemaker cells of the gastrointestinal tract, or interstitial mesenchymal precursor stem cells (14). This similarity between GISTs and ICCs is further borne out by the expression of the KIT protein (also called CD117) in nonneoplastic ICC and most GISTs (11). The identification of a fundamental hallmark of the biology of GISTs (i.e., gain-of-function KIT mutations) resulted in the rapid transformation of the treatment paradigm for this tumor type (15, 16). Small molecule tyrosine kinase inhibitors, most notably imatinib mesylate (also known as Gleevec), have been developed and were found to be effective in the treatment of GISTs (16–18). However, the median time to recurrence for patients with metastatic GIST receiving imatinib is only 2 y. Although much is known about the molecular genetic features of GIST, the importance of their interactions with the stromal microenvironment during metastasis has received little attention. Therefore, we investigated the role of exosomes in mediating the complex interplay between tumor and stroma during progression. We report evidence that (i) GIST cells secrete a high number of oncogenic KIT-containing exosomes, (ii) stromal cell uptake of GIST-derived exosomes promotes the generation of ICC-like cells and induce tumor invasiveness, and (iii) circulating exosomes from GIST patients induce matrix metalloproteinase 1 (MMP1) secretion by host stromal cells.     

Thrombotic microangiopathy and acute kidney injury following vivax malaria

Background

Infection with Plasmodium vivax, a common human parasite, is occasionally recognized to cause severe organ dysfunction similar to P. falciparum infection. Acute kidney injury (AKI) in malaria is attributed to acute tubular necrosis; thrombotic microangiopathy is not described.

Methods

This observational study includes patients referred to a tertiary care center in North India during June to September 2011 with severe AKI, anemia, and thrombocytopenia following vivax malaria. Renal biopsies were processed by light, immunofluorescence, and electron microscopy.

Results

Nine patients (including 5 children) had persistent AKI with thrombocytopenia and variable anemia following the diagnosis of malaria. Based on peripheral smear, eight patients were diagnosed with vivax malaria and had received antimalarial therapy prior to referral; a laboratory diagnosis of P. vivax infection was made for one patient at this center. Renal histology in all cases showed features of thrombotic microangiopathy, including fibrin thrombi, subendothelial widening, and mesangiolysis, along with variable tubulointerstitial nephritis and acute tubular or cortical necrosis. Ultrastructural examination confirmed endothelial injury and subendothelial widening. All patients required hemodialysis, and six were dialysis dependent at four weeks. Delayed presentation to the hospital (P = 0.019), hemolysis on peripheral smear (P = 0.083), and prolonged oligoanuria (P = 0.036) were associated with dialysis dependence.

Conclusion

The association of anemia, thrombocytopenia, and renal histological evidence of thrombotic microangiopathy with vivax malaria is novel, and suggests the presence of severe endothelial injury. Further studies are necessary to confirm the association and examine the factors associated with its occurrence.     

Imaging of pediatric liver tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Primary hepatic malignancies are relatively rare in the pediatric population, accounting for approximately 1%–2% of all pediatric tumors. Hepatoblastoma and hepatocellular carcinoma are the most common primary liver malignancies in children under the age of 5 years and over the age of 10 years, respectively. This paper provides consensus-based imaging recommendations for evaluation of patients with primary hepatic malignancies at diagnosis and follow-up during and after therapy.     

Protective Effect of Gymnema sylvestre Ethanol Extract on High Fat Diet-induced Obese Diabetic Wistar Rats

Obesity is associated with numerous co-morbidities such as cardiovascular diseases, type 2 diabetes, hypertension and others. Therefore, the present study was planned to investigate the effect of water- soluble fraction of Gymnema sylvestre ethanol extract on biochemical and molecular alterations in obese diabetic rats. Diabetes was induced by single i.v. injection of streptozotocin (45 mg/kg) via tail vein. Obesity was induced by oral feeding of high fat diet for a period of 28 days in diabetic rats. Body weight gain, food intake, water intake, hemodynamic parameters (systolic, diastolic, mean arterial blood pressures and heart rate), serum biochemical parameters (leptin, insulin, lipid levels, apolipoprotein B and glucose), cardiomyocyte apoptosis (cardiac caspase-3, Na⁺/K⁺ ATPase activity and DNA fragmentation) organs and visceral fat pad weight and oxidative stress parameters were measured. Oral treatment with water soluble fraction of Gymnema sylvestre ethanol extracts (120 mg/kg/p.o.) for a period of 21 days, resulted in significant reduction in heart rate, mean arterial pressure, serum leptin, insulin, apolipoprotein B, lipids, glucose, cardiac caspase-3 levels, Na⁺/K⁺ ATPase activity and DNA laddering, visceral fat pad and organ''s weight and improved the antioxidant enzymes levels in the high fat diet induced obesity in diabetic rats. The results of present study reveal that water soluble fraction of Gymnema sylvestre ethanol extract could be useful intervention in the treatment of obesity and type-2 diabetes mellitus.