Investigation into the relevance of BCR-ABL for the survival of cancer stem cells in chronic myeloid leukaemia

Chronic myeloid leukaemia (CML) is a clonal myeloproliferative disorder of the haemopoietic stem cell, defined by the Philadelphia chromosome (Ph) - the outcome of a balanced, reciprocal translocation between the long arms of chromosomes 9 and 22. The novel fusion oncogene generated on chromosome 22 as a result of this translocation is called BCR-ABL. In the majority of patients, this oncogene transcribes a 210-kDa constitutively active protein tyrosine kinase, often referred to as p210BCR-ABL, which is necessary for the transformation of the disease. The introduction of the orally available, tyrosine kinase inhibitor (TKI) - imatinib mesylate (IM) - marked a major advance in CML treatment in terms of efficacy and tolerability and has now become the first line of therapy. IM acts by competing with ATP to block ABL-kinase activity, resulting in the selective apoptosis induction of BCR-ABL+ cells. However, despite the success of IM as standard therapy for CML, only a small proportion of patients obtain a complete molecular response, where they become negative for BCR-ABL transcripts by RTPCR. It is hypothesised that this minimal residual disease is the result of a primitive quiescent subpopulation of leukaemic cells, which may be the cause for relapse at a later date. Another major clinical concern is the observation of molecular resistance in IM-treated patients. Proposed mechanisms of resistance include BCR-ABL amplification, decreased intracellular IM concentrations caused by drug efflux proteins such as multi drug resistance-1 and the development of point mutations within the ABL-kinase domain. In an attempt to overcome IMresistance, a second generation of BCR-ABL inhibitors has been developed. Dasatinib (BMS-354825, Sprycel) is a TKI developed for the treatment of IM resistant or -intolerant patients with Ph+ leukaemias, which has a 325-fold greater potency than IM against cells expressing wild-type BCR-ABL, and is effective against all IM-resistant BCR-ABL mutants tested in vitro, except T315I. Previously, we showed that dasatinib induced durable inhibition of BCR-ABL and impressive clearance of Ph+ cells, however, the primitive quiescent cell population did not appear to undergo apoptosis even after several days TKI exposure. Therefore, it was still not clear whether early CML progenitor cells depend on BCR-ABL for their growth and survival. In this study we have attempted to determine whether CML stem cells are dependent on BCR-ABL TK activity for their survival and/or proliferation using dasatinib treatment and aimed to characterise the cells which survived drug exposure. We found that 10% of the CML cells were able to survive the dasatinib treatment. We also showed that maximal BCR-ABL TK inhibition was achieved in the surviving CML cells, both in the bulk population of cells and the more problematic primitive stem cell population. Those cells which survived the dasatinib treatment were found to be primitive, residing mainly in the undivided cell fraction and the very early cell divisions. Since these BCR-ABL TK-inhibited, resistant cells were also able to grow when re-cultured in cytokines and form longterm culture-initiating cell (LTC-IC) colonies; these data suggested that ~10% of primitive CD34+ CML cells are not addicted to BCR-ABL TK activity for their survival. This also suggested that these primitive, resistant CML cells appeared to survive and proliferate by BCR-ABL-independent mechanisms. Therefore, the next experiments were then designed to investigate the cellular process of autophagy as a potential means of primitive CML cell survival. Analysis of the properties of CD34+ CML cells which remained viable following dasatinib treatment, revealed the existence of cytoplasmic autophagic structures determined by electron microscopy and significantly increased autophagosome-asociated LC3-II, particularly in the cells cultured without growth factors (GF)s. This suggested that autophagy is induced following GF deprivation of CML cells and is significantly increased within these cells, upon BCR-ABL inhibition following dasatinib treatment. Furthermore, we also found that the inhibition of autophagy greatly potentiated the effect of TKI treatment on the reduction of primitive CML progenitor cells, in terms of the effective eradication of functionally defined colony forming cells and LTC-ICs. Overall, this thesis has shown for the first time that the most TKI-resistant primitive CML cells are likely to be independent of BCR-ABL TK activity for their proliferation and/or survival. Furthermore, we have shown that these resistant CML stem cells rely on the BCR-ABL independent autophagy process for survival in response to stressful conditions, such as, GF deprivation and TKI treatment

Cabelo Crespo: A Struggle for Inclusion in Brazilian Society

Present-day Brazilian society presents a disproportionate number of economic, social and political challenges for Black women. The phenomenon of this structural inequality has causes that are rooted deep in the history of Brazil, and is built upon the foundation lain by slavery, resulting in the economic prosperity of the elite that was built upon the foundation of the labor provided by people of color. The effects of colonization and the profitable slave trade that ensued continue to contribute still, to the plight of people of color in general, though the focus of this project will be on the effects these historic institutions continue to have on Black women in Salvador, Bahia, in specific. The context of the various struggles of these women is often characterized by the intersectionality of their varying oppressions, which are largely propagated through systems of structural and cultural violence. These different types of violence promote sentiments of inferiority among Black people; they strip an entire race of black people of pride in their culture, their identities and their physical aesthetics. By studying closely the stories and political struggles of three women in Salvador, Bahia, in addition to actively participating as a visiting member of Salvadorian society, I will analyze the ways in which hair helps to foster and promote a sense of pride in Black identity while combatting the rejection and oppression of Black people, aesthetic and culture in Brazilian society. The conclusion of my study shows, amongst my subjects, a strong and resilient connection between the choice to embrace, rather than to alter their “cabelo crespo” and their conscious battle against the multiple oppressions constructed within Brazilian society. I have learned that the process of identity construction is a complex ideal that cannot be limited, simply to natural hair, but in the same way, it must be noted that for some self-identified Black women, embracing their natural “cabelo crespo” was, indeed, a major part of that process of identity construction. In the study of these three, self-identified Black women, hair is a part of identity that is deeper than fashion, but rather, is worn as a banner of their negritude

Antigravity

This dissertation contains two parts: Part I, which discusses the elegy of possessive intent, a subgenre of the contemporary American elegy; and Part II, Antigravity, a collection of poems. English elegies have been closely rooted to a specific grief, making the poems closer to occasional poems. The poet—or at least the poet’s speaker—seeks some kind of public consolation for (often) a private loss. The Americanized form does stray from the traditional elegy yet retains some of its characteristics. Some American elegies memorialize failed romantic relationships rather than the dead. In their memorials, these speakers seek a completion for the lack the broken relationship has created in the speakers’ lives. What they can’t replace, they substitute with something personal. As the contemporary poem becomes further removed from tradition, it’s no surprise that the elegy has evolved as well. Discussions of elegies have never ventured into the type of elegy that concerns itself with the sort of unacknowledged loss found in some contemporary American poems of unrequited love. These poems all have speakers who willfully refuse to acknowledge the loss of their love-objects and strive to maintain control/ownership of their beloveds even in the face of rejection

Technique for improving the reception of scattering signal behind an obstacle

This thesis presents a solution to the problem of receiving a signal in the shadow and fringe areas. Theoretical and experimental investigation of the field behind an obstacle in a line of sight transmission path for UHF / microwave signals has resulted in a new approach to the analysis of electromagnetic fields in the shadow of an obstacle. Analysis using this approach showed the field to consist of varying amplitude and phase distribution. Additional analysis predicted an increase in received signal could be achieved if correlation between the field and antenna structure could be obtained. This was accomplished with a new antenna design. The thesis presents experimental and photographic evidence to support the theory. A novel technique involving the matching of the antenna structure to the field distribution, resulted in an increase of received signal in the diffracted field of up to 4 dB

Stress Hardiness and Lawyers

This article empirically analyzes original data to look at stress and stress hardiness in the legal profession A number of studies address stress in the legal profession and its impact on the mental health of lawyers Our study is the first to examine stress hardiness in the legal profession Drawing on quantitative data gathered from 20132016 in surveys of 530 law students and lawyers and qualitative data from 106 indepth interviews with lawyers and building on the work of research psychologists Salvatore Maddi and Suzanne Kobasa we look at whether some lawyers more stress hardy than others and if so what makes them stress hardy and whether their strategies teachable and learnable Our data show the following 1 some lawyers are more stress hardy than others 2 although no demographic factors correlate to stress hardiness three behaviors maintaining a sense of control a sense of purpose and cognitive flexibility show a significant correlation to stress hardiness 3these behaviors build on each other such that use of one strengthens the use of others 4 maintaining a sense of purpose a sense of control and cognitive flexibility are teachable and learnable 5 the type of stress lawyers experience varies by practice area 6 the level of stress experienced by law students and lawyers remains fairly constant throughout law school and law practice 7 law students and lawyers report using the following strategies to help manage stress exercise social connectedness and three habits of thought planning and organization perspective and gratitude 8 lawyers report less reliance on exercise and social connectedness as they age and greater reliance on substance use 9 reliance on drugs and alcohol to manage stress correlates to greater stres

Henderson News 3.2

In This Issue: Celebrating El Dia de los Muertos at Henderson Library Open Access Week International Journeys at the Library Instant Study Rooms

Treating infections caused by carbapenemase-producing Enterobacterales (CPE): a pragmatic approach to antimicrobial stewardship on behalf of the UKCPA Pharmacy Infection Network (PIN)

open access articleThe emergence of carbapenemase-producing Enterobacterales (CPE) as a major cause of invasive infection both within the UK and internationally poses a very real concern for all providers of healthcare. The burden of morbidity and mortality associated with CPE infections is well described. The need for early, targeted, effective and safe antimicrobial therapy remains key for the management of these infected patients yet reliable antimicrobial treatment options remain scarce. In the absence of a universal treatment for these CPE invasive infections, individual treatment options tailored to susceptibilities and severity of infection are required. This working group from within the UK Clinical Pharmacy Association (UKCPA) Pharmacy Infection Network has developed evidence-based treatment recommendations to support infection specialists in managing these complex infections. A systematic review of peer-reviewed research was performed and analysed. We report consensus recommendations for the management of CPE-associated infections. The national expert panel makes therapeutic recommendations regarding the pharmacokinetic and pharmacodynamic properties of the drugs and pharmacokinetic targets, dosing, dosage adjustment and monitoring of parameters for novel and established antimicrobial therapies with CPE activity. This manuscript provides the infection specialist with pragmatic and evidence-based options for the management of CPE infections

A Comparison of Molecular and Histopathological Changes in Mouse Intestinal Tissue Following Whole-Body Proton- or Gamma-Irradiation

There are many consequences following exposure to the space radiation environment which can adversely affect the health of a crew member. Acute radiation syndrome (ARS) involving nausea and vomiting, damage to radio-sensitive tissue such as the blood forming organs and gastrointestinal tract, and cancer are some of these negative effects. The space radiation environment is ample with protons and contains gamma rays as well. Little knowledge exists to this point, however, regarding the effects of protons on mammalian systems; conversely several studies have been performed observing the effects of gamma rays on different animal models. For the research presented here, we wish to compare our previous work looking at whole-body exposure to protons using a mouse model to our studies of mice experiencing whole-body exposure to gamma rays as part of the radio-adaptive response. Radio-adaptation is a well-documented phenomenon in which cells exposed to a priming low dose of radiation prior to a higher dose display a reduction in endpoints like chromosomal aberrations, cell death, micronucleus formation, and more when compared to their counterparts receiving high dose-irradiation only. Our group has recently completed a radio-adaptive experiment with C57BL/6 mice. For both this study and the preceding proton research, the gastrointestinal tract of each animal was dissected four hours post-irradiation and the isolated small intestinal tissue was fixed in formalin for histopathological examination or snap-frozen in liquid nitrogen for RNA isolation. Histopathologic observation of the tissue using standard H&E staining methods to screen for morphologic changes showed an increase in apoptotic lesions for even the lowest doses of 0.1 Gy of protons and 0.05 Gy of gamma rays, and the percentage of apoptotic cells increased with increasing dose. A smaller percentage of crypts showed 3 or more apoptotic lesions in animals that received 6 Gy of gamma-irradiation compared to mice receiving only 2 Gy of protons. Tissue of the gastrointestinal tract was also homogenized and RNA was isolated for cDNA synthesis and real-time PCR analysis. Inspecting apoptotic lesions of the duodenum of the small intestine as an endpoint of damage did not reveal a radio-adaptive response in C57BL/6 mice at the four hour time point. Results of gene expression changes showed consistent up or down regulation of a number of genes for all of the exposure doses that may play a role in proton-induced apoptosis. Preliminary results of gene expression alterations as a result of gamma-irradiation revealed a wealth of genes involved in oxidative stress and antioxidant defense processes being up- or down-regulated only at the highest exposure dose of 6 Gy and the combined dose of 5 cGy with 6 Gy. Those animals undergoing only 5 cGy of gamma-irradiation showed very little modification of gene expression. Taken together these results lead us to conclude that protons cause more severe morphologic damage to the duodenum of the small intestine at a dose of 2 Gy than a higher dose of 6 Gy of gamma rays to the same organ. Both protons and gamma rays lead to significant variation in gene expression at high doses in the small intestine and these changes may provide insight into the mechanism of injury seen in the gastrointestinal tract following radiation exposure. Astronauts experiencing prolonged exposure to protons in the low Earth orbit and in deep space, and experiencing acute exposure to protons from solar particle events, may face biological consequences that will impact a mission s success. We will continue this work by studying, quantifying, and comparing damage due to protons and gamma rays in the small intestine as well as other organs in a time-dependent manner