Search

Development of antimalarial compounds into clinical candidates remains costly and arduous without detailed knowledge of the target. As resistance increases and treatment options at various stages of disease are limited, it is critical to identify multistage drug targets that are readily interrogated in biochemical assays. Whole-genome sequencing of 18 parasite clones evolved using thienopyrimidine compounds with submicromolar, rapid-killing, pan–life cycle antiparasitic activity showed that all had acquired mutations in the P. falciparum cytoplasmic isoleucyl tRNA synthetase (cIRS). Engineering two of the mutations into drug-naïve parasites recapitulated the resistance phenotype, and parasites with conditional knockdowns of cIRS became hypersensitive to two thienopyrimidines. Purified recombinant P. vivax cIRS inhibition, cross-resistance, and biochemical assays indicated a noncompetitive, allosteric binding site that is distinct from that of known cIRS inhibitors mupirocin and reveromycin A. Our data show that Plasmodium cIRS is an important chemically and genetically validated target for next-generation medicines for malaria.

Most phenotypic screens aiming to discover new antimalarial chemotypes begin with low cost, high-throughput tests against the asexual blood stage (ABS) of the malaria parasite life cycle. Compounds active against the ABS are then sequentially tested in more difficult assays that predict whether a compound has other beneficial attributes. Although applying this strategy to new chemical libraries may yield new leads, repeated iterations may lead to diminishing returns and the rediscovery of chemotypes hitting well-known targets. Here, we adopted a different strategy to find starting points, testing ∼70,000 open source small molecules from the Global Health Chemical Diversity Library for activity against the liver stage, mature sexual stage, and asexual blood stage malaria parasites in parallel. In addition, instead of using an asexual assay that measures accumulated parasite DNA in the presence of compound (SYBR green), a real time luciferase-dependent parasite viability assay was used that distinguishes slow-acting (delayed death) from fast-acting compounds. Among 382 scaffolds with the activity confirmed by dose response (

Novel bis-1,2,4-triazine compounds with potent in vitro activity against Plasmodium falciparum parasites were recently identified. The bis-1,2,4-triazines represent a unique antimalarial pharmacophore and are proposed to act by a novel but as-yet-unknown mechanism of action. This study investigated the activity of the bis-1,2,4-triazine MIPS-0004373 across the mammalian life cycle stages of the parasite and profiled the kinetics of activity against blood and transmission stage parasites in vitro and in vivo. MIPS-0004373 demonstrated rapid and potent activity against P. falciparum, with excellent in vitro activity against all asexual blood stages. Prolonged in vitro drug exposure failed to generate stable resistance de novo, suggesting a low propensity for the emergence of resistance. Excellent activity was observed against sexually committed ring stage parasites, but activity against mature gametocytes was limited to inhibiting male gametogenesis. Assessment of liver stage activity demonstrated good activity in an in vitro P. berghei model but no activity against Plasmodium cynomolgi hypnozoites or liver schizonts. The bis-1,2,4-triazine MIPS-0004373 efficiently cleared an established P. berghei infection in vivo, with efficacy similar to that of artesunate and chloroquine and a recrudescence profile comparable to that of chloroquine. This study demonstrates the suitability of bis-1,2,4-triazines for further development toward a novel treatment for acute malaria.

This chapter focuses on Steven Salaita’s tweets from the summer of 2014 to illustrate how civility becomes deployed in a larger struggle to control scholars of color seeking to bring clarity to, and shed light on, the various material and intellectual complicities informing the US-Israel-Palestinian conflict. It also focuses on what happened to Salaita with the self-promoting exercises of Jason Hill, which represent a predictable but nonetheless harmful form of political and intellectual opportunism. Expressing anger at the killing and maiming of Palestinians in Gaza by Israeli munitions is, by definition, uncivilized – and for some – anti-Semitic because to recognize Palestinian pain and loss is to condemn Israel’s role in producing that pain and loss. To have given Salaita a place among the faculty at Illinois would be to grant the Palestinians, what the late Edward Said called, “the permission to narrate” – which supposedly represents an existential threat to Israel.

SummaryIn vitro evolution and whole genome analysis were used to comprehensively identify the genetic determinants of chemical resistance in the model microbe, Saccharomyces cerevisiae. Analysis of 355 curated, laboratory-evolved clones, resistant to 80 different compounds, demonstrates differences in the types of mutations that are identified in selected versus neutral evolution and reveals numerous new, compound-target interactions. Through enrichment analysis we further identify a set of 137 genes strongly associated with or conferring drug resistance as indicated by CRISPR-Cas9 engineering. The set of 25 most frequently mutated genes was enriched for transcription factors and for almost 25 percent of the compounds, resistance was mediated by one of 100 independently derived, gain-of-function, single nucleotide variants found in 170-amino-acid domains in two Zn2C6 transcription factors, YRR1 and YRM1 (p < 1x 10 −100). This remarkable enrichment for transcription factors as drug resistance genes may explain why it is challenging to develop effective antifungal killing agents and highlights their important role in evolution.

To discover leads for next-generation chemoprotective antimalarial drugs,we tested more than 500,000 compounds for their ability to inhibit liver-stage development of luciferase-expressing Plasmodium spp. parasites (681 compounds showed a half-maximal inhibitory concentration of less than 1micromolar).Cluster analysis identified potent and previously unreported scaffold families as well as other series previously associated with chemoprophylaxis. Further testing through multiple phenotypic assays that predict stage-specific and multispecies antimalarial activity distinguished compound classes that are likely to provide symptomatic relief by reducing asexual blood-stage parasitemia from those which are likely to only prevent malaria. Target identification by using functional assays, in vitro evolution, or metabolic profiling revealed 58 mitochondrial inhibitors but also many chemotypes possibly with previously unidentified mechanisms of action. INTRODUCTION Malaria remains a devastating disease, affecting 216 million people annually, with 445,000 deaths occurring primarily in children under 5 years old. Malaria treatment relies primarily on drugs that target the diseasecausing asexual blood stages (ABS) of Plasmodium parasites, the organisms responsible for human malaria. Whereas travelers may rely on shortterm daily chemoprotective drugs, those living in endemic regions require long-termmalaria protection such as insecticide-treated nets (ITNs) and vector control. However, ITNs do not fully shield individuals from malaria, may lose potency with time, and can be bulky and difficult to use. Another concern is that mosquitosmay become resistant to the active insecticides that are used in ITNs and vector control. RATIONALE As the possibility of malaria elimination becomesmore tangible, the ideal antimalarial medicine profile should include chemoprotection. Chemoprotectivemedicines typically work against the exoerythrocytic parasite forms that invade and develop in the liver and are responsible for the earliest asymptomatic stage of the infection. Such medicines could be formulated to provide long-acting prophylaxis, safeguarding individuals that are living near or traveling to areas that have been cleared of parasites. Long-acting chemoprotection in endemic regions could also greatly reduce circulating parasite numbersandpotentially replace a vaccine in an elimination campaign. Although millions of compounds have been screened for activity against parasiteABS, and some have been subsequently tested for potential prophylactic activity, large-scale searches that beginwith prophylactic activity have not been performed because of the complexity of the assay: This assay requires the production of infected laboratory-rearedmosquitoes and hand-dissection of the sporozoiteinfected salivary glands frommosquito thoraxes. A Plasmodium vivax liver-stage schizont on a lawn of hepatocytes. The parasite schizont has been stained with antibodies to parasite HSP70 (red) and UIS4 (yellow). Cell (parasite and hepatoma) nuclei are shown in blue. This study identifies compounds that can prevent the development of these liver-stage parasites and may function as chemoprotective drugs for malaria. RESULTS To discover leads for next-generation chemoprotective antimalarial drugs, we used luciferase-expressing Plasmodium spp. parasites, dissected from more than a million mosquitoes over a 2-year period, to test more than 500,000 compounds for their ability to inhibit liver-stage development of malaria (681 compounds showed a half-maximal inhibitory concentration of

Dissecting Plasmodium drug resistance Malaria is a deadly disease with no effective vaccine. Physicians thus depend on antimalarial drugs to save lives, but such compounds are often rendered ineffective when parasites evolve resistance. Cowell et al. systematically studied patterns of Plasmodium falciparum genome evolution by analyzing the sequences of clones that were resistant to diverse antimalarial compounds across the P. falciparum life cycle (see the Perspective by Carlton). The findings identify hitherto unrecognized drug targets and drug-resistance genes, as well as additional alleles in known drug-resistance genes. Science , this issue p. 191 ; see also p. 159

The quinolone decoquinate is coadministered with feed for treatment of parasites which cause coccidiosis in poultry. However, from a drug-development perspective, the biological activity is often not adequately exploited due to poor physicochemical properties. Here we convert decoquinate into N-alkyl quinolone amides that, in contrast to decoquinate, are active against the tuberculosis bacterium with MIC90 values ranging from 1.4 to 3.64 µM, and quinoline O-carbamates active against apicomplexan parasites that cause malaria, toxoplasmosis, and neosporosis with IC50 values of 0.32–1.5 nM for the best derivative. Uniquely for the TB-active amides, disruption of cell wall homoeostasis is identified as one target. With IC50 values against fetal lung fibroblast cells of 40 to >100 μM, the derivatives are selective for the pathogens. Structures of the most active derivatives are determined by NMR spectroscopy and X-ray crystallography. Analogues lacking the decyl side chain of decoquinate are inactive. Decoquinate is a drug used in veterinary practice, which displays antimalarial activity in vitro but has poor bioavailability. Here, the authors convert decoquinate into more soluble amide and carbamate derivatives and assess their efficacy against tuberculosis bacteria and apicomplexan parasites.

Understanding the mechanisms of drug resistance in Plasmodium vivax, the parasite that causes the most widespread form of human malaria, is complicated by the lack of a suitable long-term cell culture system for this parasite. In contrast to P. falciparum, which can be more readily manipulated in the laboratory, insights about parasite biology need to be inferred from human studies. Here we analyze the genomes of parasites within 10 human P. vivax infections from the Peruvian Amazon. Using next-generation sequencing we show that some P. vivax infections analyzed from the region are likely polyclonal. Despite their polyclonality we observe limited parasite genetic diversity by showing that three or fewer haplotypes comprise 94% of the examined genomes, suggesting the recent introduction of parasites into this geographic region. In contrast we find more than three haplotypes in putative drug-resistance genes, including the gene encoding dihydrofolate reductase-thymidylate synthase and the P. vivax multidrug resistance associated transporter, suggesting that resistance mutations have arisen independently. Additionally, several drug-resistance genes are located in genomic regions with evidence of increased copy number. Our data suggest that whole genome sequencing of malaria parasites from patients may provide more insight about the evolution of drug resistance than genetic linkage or association studies, especially in geographical regions with limited parasite genetic diversity.

What is the concept of academic freedom, what are the justifications for its existence, and to whom does it belong? These are important questions to ask in determining what, if any, special protect...

Chemogenetic characterization throughin vitroevolution combined with whole genome analysis is a powerful tool to discover novel antimalarial drug targets and identify drug resistance genes. Our comprehensive genome analysis of 262Plasmodium falciparumparasites treated with 37 diverse compounds reveals how the parasite evolves to evade the action of small molecule growth inhibitors. This detailed data set revealed 159 gene amplifications and 148 nonsynonymous changes in 83 genes which developed during resistance acquisition. Using a new algorithm, we show that gene amplifications contribute to 1/3 of drug resistance acquisition events. In addition to confirming known multidrug resistance mechanisms, we discovered novel multidrug resistance genes. Furthermore, we identified promising new drug target-inhibitor pairs to advance the malaria elimination campaign, including: thymidylate synthase and a benzoquinazolinone, farnesyltransferase and a pyrimidinedione, and a dipeptidylpeptidase and an arylurea. This deep exploration of theP. falciparumresistome and drug-able genome will guide future drug discovery and structural biology efforts, while also advancing our understanding of resistance mechanisms of the deadliest malaria parasite.One Sentence SummaryWhole genome sequencing reveals howPlasmodium falciparumevolves resistance to diverse compounds and identifies new antimalarial drug targets.

Drawing upon Fanon’s central insights in Wretched of the Earth, this essay seeks to explore how Palestinian suicide bombers in the context of the Israel-Palestine conflict enact a biopolitical strategy, as part of an anti-colonial politics of struggle, to resist Israeli colonization. This biopolitical strategy of resistance views the act of self-destruction as paradoxically enabling the continuation of communal life; the decision to terminate an individual life, then, represents an affirmation of Palestinian communal life as it resists defeat, despair, and humiliation.

This essay argues that the reception of Noam Chomsky's political scholarship by progressive academics demonstrates that the state of theory in the humanities has reached a point of crisis; that is, Chomsky's unpopularity in certain academic circles indicates that conceptions of intellectual labor have been radically reconfigured within the academy since the late 1970s and early 1980s. In the wake of much of his political writing about 9/11, an interesting phenomenon has emerged: Chomsky repels his onetime allies within progressive circles, while attracting more and more people among the general public to his point of view, providing an extremely interesting commentary on the state of intellectual labor in the academy. Chomsky's popular base seems to have expanded while his academic base has contracted. How can we account for these opposed tendencies? Is it that Chomsky has embarrassed “elite educated opinion” in a way that some can no longer tolerate? In “Crude Wars,” Timothy Brennan and Keya Ganguly write, “It has become fashionable for cultural critics to reject supposedly outmoded theories of political economy, to disdain the simple exposure of hidden agendas, to scoff at the likes of Noam Chomsky or Armand Mattelart on the grounds that their notions have been superseded by the ever-inventive strategies of the market.” To what within current conceptions of intellectual labor can we really attribute this tendency? It is this question to which my essay turns.

This essay uses Fouzi El-Asmar's To Be an Arab in Israel as a point of departure to examine the plight of Israel's Palestinian Arab citizens since 1948, while also exploring the inherent contradictions within the logic and political economy of Zionism that situate Palestinians as a persistent and disturbing reminder of Israel's settler colonial aspirations. By taking inventory of the various ontological crises attending what it means to be a Palestinian living in Israel, as well as the historical vectors informing Zionism's various attempts to prevent the development of Palestinian civil society, Abraham argues that there are clear analogues between Palestinian and Jewish suffering. After completing a theoretical survey of the arguments informing defenses of, and apologies for, Israel's occupation of the West Bank and destruction of Gaza, Abraham turns to the ways in which the Holocaust has been used to shore up connections between Zionist and Jewish history. Finally, the essay turns to recent intellectual and media controversies attending comparisons between Israeli and South African apartheid, focusing on the attacks on Jimmy Carter's Palestine: Peace Not Apartheid. In conclusion, Abraham argues that the Israel-Palestinian conflict cannot be solved until Israel's Palestinian Arab citizens are recognized as equals with their Jewish brethren.

In an interview in the summer of 2000 concerning the 1947–1948 Palestinian dispossession at the hands of the yet-to-be-formed Israeli Defense Forces in the form of the Haganah and the Irgun (IZL), Ha’aretz’s Ari Shavit and the famed cultural critic Edward Said reflected on the possibilities of an Israeli-Palestinian binational state, something Said had advocated for quite some time— long before the failure of the Oslo Accords and Camp David II. This interview took place just a few months before the outbreak of violence that began the Second Intifada in the occupied territories, a possible reaction to the failure of Camp David II talks where, brought together by then-president Bill Clinton, Ehud Barak had supposedly offered Arafat (in exchange for the Palestinian recognition of “Israel’s right to exist as a Jewish state”) nearly 80 percent of the West Bank for a viable Palestinian state, a deal of a lifetime. Many, however, considered the offer a call for Palestinian submission to a Bantustan arrangement reminiscent of the South African national territories.1 As he came to fully understand Said’s nuanced position, which clearly placed reconciliation between the Israelis and the Palestinians ahead of revenge or retribution for either group’s historical grievances and the identification of a mutual interest in peace and coexistence in a future binational state before the assignment of blame, Shavit proclaimed, “You sound very Jewish.”

In his critique of the first one thousand days of President Barak Obama’s presidency, and what he calls the “Obama Syndrome,” political commentator Tariq Ali notes, “From Palestine through Iraq to Iran, Obama has acted as just another steward of the American empire, pursuing the same aims as his predecessors, with the same means but with a more emollient rhetoric.”1 In an assessment of Obama’s June 2009 Cairo speech, and in seeming agreement with Ali’s characterization of Obama’s presidency, Deepa Kumar writes, “What Obama’s speech represents is a repackaging of U.S. imperial aims in liberal terms. It heralds a new rhetorical approach built on the ashes of the now widely discredited cowboy diplomacy of the Bush era.”2

The US invasion of Iraq in March 2003 and the disastrous results of the ensuing occupation placed American Jewry in a difficult and undeserving position. As the US occupation seemed to descend into increasingly more chaos, and as the original justifications for the war emerged as untenable, an unfortunate caricature emerged of American Jews’ political perspectives, which are presumably as diverse as those of any ethnoreligious group might be.1 Such caricaturing enabled reactionaries to resurrect, and to deploy with great effectiveness, the nasty “dual loyalty” charge against prominent American Jewish neoconservatives who served in the Bush administration, which unfairly suggested that— within the context of formulating Middle East policy as US officials— these figures will always place Israel’s interests ahead of those of the United States.2 While “Richard Perle,” “Paul Wolfowitz,” “Douglas Feith,” “Scooter Libby,” “Eliot Abrams,” “Dov Zakheim,” and “Eliot Cohen” are the names offered up as examples of high-standing American Jewish neo-conservatives in the Bush administration who were eager to see the United States invade Iraq, they very well may have believed that US and Israeli interests coincided with respect to toppling Iraq’s Saddam Hussein.

As mentioned in the previous chapter, Ari Shavit of Israel’s leading daily newspaper Ha’aretz spent three days in New York interviewing Edward W. Said in the summer of 2000. In this interview, which was— in Said’s words— “eminently fair” and accurately reproduced in print throughout Israel— he traced the events surrounding the 1947–1949 expulsions of nearly 800,000 Arab inhabitants in an area known simply as “Palestine,” culminating in the birth of Israel.1 He also stressed the necessity of acknowledging what so many are pained to admit: the existence of nearly three million people, currently living under military occupation, who share among themselves the “Palestinian” identity, an identity that— while continuously contested— represents a suffering and tragic dispossession that stands at the very heart of the present Middle East conflict.

Vena cava filters are now widely used as a safe and effective means of reducing the risk of pulmonary embolus in patients hospitalized with acute stroke or trauma. We report a case of traumatic disruption of a vena cava filter resulting from guidewire manipulation with migration of the main structure to the heart after successful initial placement of the filter.

The antitumor effect of intralesionally administered recombinant interleukin-2 was highly effective (90% complete response) in murine bladder cancer. We postulated that interleukin-2 may be integral to the Bacillus Calmette-Guerin-induced antitumor response in human bladder cancer. Flow cytometric evaluation of the tumor infiltrates was compared before and after intralesional treatment of an established, untreated murine bladder tumor model with recombinant interleukin-2, Bacillus Calmette-Guerin or saline. Large increases in the number of tumor infiltrating immune cells occurred between the day of randomization and the second day (one day after the first treatment) in all three groups. However, since tumor volume was reduced by treatment, the ratios of the immune cells to tumor volume was increased. The ratios of T(helper), T(cytotoxic)/suppressor cells, macrophages, and natural killer cells to tumor volume were 1.5 to 3.4 times higher in the interleukin-2 and Bacillus Calmette-Guerin groups in comparison to the saline group. The ratio of T(helper)/T(cytotoxic)/suppressor cells however, remained approximately the same despite treatment. Over the next 22 days all subpopulations of tumor infiltrating immune cells decreased in number and frequency to less than measurable levels. The similar modulation of infiltrating immune cell subpopulations by Bacillus Calmette-Guerin and interleukin-2 may indicate that the production of interleukin-2 is part of the tumor modulating mechanism of Bacillus Calmette-Guerin.