45 research outputs found
Ionizing Radiation in Glioblastoma Initiating Cells
Glioblastoma (GBM) is the most common primary malignant brain tumor in adults with a median survival of 12–15 months with treatment consisting of surgical resection followed by ionizing radiation (IR) and chemotherapy. Even aggressive treatment is often palliative due to near universal recurrence. Therapeutic resistance has been linked to a subpopulation of GBM cells with stem cell-like properties termed GBM initiating cells (GICs). Recent efforts have focused on elucidating resistance mechanisms activated in GICs in response to IR. Among these, GICs preferentially activate the DNA damage response (DDR) to result in a faster rate of double-strand break (DSB) repair induced by IR as compared to the bulk tumor cells. IR also activates NOTCH and the hepatic growth factor (HGF) receptor, c-MET, signaling cascades that play critical roles in promoting proliferation, invasion, and resistance to apoptosis. These pathways are preferentially activated in GICs and represent targets for pharmacologic intervention. While IR provides the benefit of improved survival, it paradoxically promotes selection of more malignant cellular phenotypes of GBM. As reviewed here, finding effective combinations of radiation and molecular inhibitors to target GICs and non-GICs is essential for the development of more effective therapies
Study of tractive efficiency as an effect of ballast and tire inflation pressure in sandy loam soil
The experiments were conducted in sandy loam soil in stubble field.  Tillage operations were performed using   55 hp tractor with two bottom mouldboard plough and disc plough for four combinations of rear and front ballast (i.e. no ballast, 90 daN front, 90 daN front and 200 daN rear, 200 daN rear) and four combinations of inflation pressure in front and rear tires (i.e. 90 kPa rear and 140 kPa front, 90 kPa rear and 200 kPa front, 130 kPa rear and 140 kPa front and 130 kPa rear and 200 kPa front tire) to study their effects on tractive efficiency of tractor for primary tillage operations.  The test was conducted at recommended speed of operation 2.7 - 4 km h-1. It was found from the results that combination of 200 daN rear ballast and inflation pressure of 130 kPa at rear, 200 kPa at front was found suitable for improving the performance of agricultural tractor with maximum tractive efficiency of 72.43% and 71.27% for mouldboard plough and disc plough respectively.  Keywords: tractor, ballast, inflation pressure, plough, tractive efficiency, sandy loam, primary tillag
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The Differentiation and Stress Response Factor XBP-1 Drives Multiple Myeloma Pathogenesis
Multiple myeloma (MM) evolves from a highly prevalent premalignant condition termed MGUS. The factors underlying the malignant transformation of MGUS are unknown. We report a MGUS/MM phenotype in transgenic mice with EÎĽ-directed expression of the XBP-1 spliced isoform (XBP-1s), a factor governing unfolded protein/ER stress response and plasma-cell development. EÎĽ-XBP-1s elicited elevated serum Ig and skin alterations. With age, EÎĽ-xbp-1s transgenics develop features diagnostic of human MM, including bone lytic lesions and subendothelial Ig deposition. Furthermore, transcriptional profiles of EÎĽ-xbp-1s lymphoid and MM cells show aberrant expression of known human MM dysregulated genes. The similarities of this model with the human disease, coupled with documented frequent XBP-1s overexpression in human MM, serve to implicate XBP-1s dysregulation in MM pathogenesis
High expression of endoplasmic reticulum chaperone grp94 is a novel molecular hallmark of malignant plasma cells in multiple myeloma
The PTEN and INK4A/ARF tumor suppressors maintain myelolymphoid homeostasis and cooperate to constrain histiocytic sarcoma development in humans.
Histiocytic sarcoma (HS) is a rare malignant proliferation of histiocytes of uncertain molecular pathogenesis. Here, genetic analysis of coincident loss of Pten and Ink4a/Arf tumor suppressors in the mouse revealed a neoplastic phenotype dominated by a premalignant expansion of biphenotypic myelolymphoid cells followed by the development of HS. Pten protein loss occurred only in the histiocytic portion of tumors, suggesting a stepwise genetic inactivation in the generation of HS. Similarly, human HS showed genetic or epigenetic inactivation of PTEN, p16(INK4A), and p14(ARF), supporting the relevance of this genetically engineered mouse model of HS. These genetic and translational observations establish a cooperative role of Pten and Ink4a/Arf in the development of HS and provide mechanistic insights into the pathogenesis of human HS
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Generalized hyperhidrosis secondary to presumed eccrine gland dysfunction with possible apocrine metaplasia.
We present a 57 year-old man presented with generalized hyperhidrosis and widespread, smooth, flesh colored papules on the torso and extremities.Histological examination from multiple biopsies demonstrated morphologic alteration of the eccrine glands with an apocrine phenotype, suggesting eitherapocrine metaplasia or the presence of “apoeccrine glands.” The morphologic similarities between eccrine, apocrine, and apoeccrine as they relate to ourpatient’s histologic findings are discussed. We consider secondary causes of generalized hyperhidrosis, which may also play a role in this patient’s presentation. Treatment and further workup are discussed, whilemanagement of this patient remains in progress
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Generalized hyperhidrosis secondary to presumed eccrine gland dysfunction with possible apocrine metaplasia.
We present a 57 year-old man presented with generalized hyperhidrosis and widespread, smooth, flesh colored papules on the torso and extremities.Histological examination from multiple biopsies demonstrated morphologic alteration of the eccrine glands with an apocrine phenotype, suggesting eitherapocrine metaplasia or the presence of “apoeccrine glands.” The morphologic similarities between eccrine, apocrine, and apoeccrine as they relate to ourpatient’s histologic findings are discussed. We consider secondary causes of generalized hyperhidrosis, which may also play a role in this patient’s presentation. Treatment and further workup are discussed, whilemanagement of this patient remains in progress
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Papular mucinosis, or localized lichen myxedematosis (LM) (discrete papular type)
Lichen myxedematosus is condition characterized by localized areas of dermal deposition of mucin, presenting with firm papules localized to few areas of the body. The condition needs to be excluded from scleromyxedema, which, in addition to the firm papular eruption, has areas of induration and is usually associated with a monoclonal gammopathyand systemic symptoms. We present a 62-year-old woman with a several-year history of asymptomatic, firm papules over the face and arms with no evidence of thyroid disease or a monoclonal gammopathy,which is consistent with a diagnosis of localized lichen myxedematosus, the discrete papular variant. The patient is being treated with a topical calcineurininhibitor