Homiletics: Outlines on the Nassau Pericopes

Outlines on the Nassau Pericope

Malarial parasite pathogenesis and drug targets

This report highlights recent insights into malarial parasite pathogenesis that are relevant for new antimalarial drug discovery

A Bayesian Approach to Investigating Age-at-Death of Subadults in a Forensic Context

Estimating age at death is among the first steps in the identification of an unknown individual. For subadults, dental formation stage remains the most accurate aging indicator due to minimal environmental impact. Even the most accurate method, however, is affected by "mimicry bias," where the age profile of the target population "mimics" the age profile of the reference population used to develop the age estimation method. Bayesian statistics and transition analysis can control for this bias in archaeological and forensic samples through calculating the average age of transition from one development phase to another, followed by estimating the probability that someone of a certain age has a given phase of development based on a sample of individuals of known age. Here, Bayesian-derived age ranges related to the dental formation phases of Moorrees et al. (1963) were generated using a sample of 201 children of known age (Orthodontics Case File System, Maxwell Museum of Anthropology). In this study, I present age ranges at an exact 50% probability for each tooth at various stages of development. These ranges can be used in forensic cases wishing to control for "mimicry bias" in assessments that rely on sage estimation via dental formation.  M.A

The Hidden Language of Emotion: Cognitive Romanticism in Wordsworth and Shelley

A question central to mind studies that literature provides insight into has been (and perhaps always will be) whether the complexities of human emotion can be captured and conveyed to other people – and, if they can, how to achieve this through language. We typically do not consider background textual elements like pronouns or prepositions as carriers of emotion, but close readings of poetics informed by the conclusions from recent brain imaging studies suggest that not all emotional labor in a text is explicit. The orientating work that deixis does can subtly guide readers’ evaluative judgments in a given context, with the ultimate effect of immersing that reader in the text itself. On the other hand, metaphor relies on shared judgment of subjects and objects in the external world between speaker and reader to communicate value. Though they function differently in the English language, these two parts of speech each rely on a reader’s perception of emotional content in a poetic text and therefore affect how they might interact with the poet’s intended message. This dissertation argues that without investing a reader in a poem’s prescribed value system, there is no true understanding of poetic content. In other words: emotion truly is at the heart of comprehension. To test this theory, I read closely the work of two British Romantic poets, a group whose poetics shifted from previous literary movements to champion emotion as the primary arbiter of experience. The first poet, William Wordsworth, composed for his collection Lyrical Ballads (1798) in response to the social mobilization he witnessed in revolutionary France, contrasted against a more capitalist and individualistic English monarchy. In these poems, deixis – perhaps unintentionally – functions to quite literally point to the perceived boundaries of English community, indicating who we do and do not consider as part of our cultural circle. Though initially inspired by Wordsworth’s earlier and more radical work, Percy Bysshe Shelley would grow to resent his aging conservativism. 20 years later, Shelley would collect nine poems to be featured in his 1820 collection of Prometheus Unbound, with Other Poems, responding to the mounting Spanish revolution. In Shelley’s poems, metaphor serves to broaden our ideas of what is possible in the universe. However, Shelley sabotages his goals in expanding the English mind by failing to consider how metaphor is actually processed, and what kinds of minds might be excluded from these culturally-dependent “in-jokes.” A neurodiverse perspective will help us to critically examine the unconscious assumptions that underlie social communication, especially when it comes to emotion. With revisions to the concept of emotion itself, this thesis thus brings together three distinct fields of inquiry – literary criticism, cognitive poetics, and neuroscience – to make larger claims about where meaning comes from in a text and how we might conceptualize the process of reading from multiple mental perspectives. All three fields serve to support, inform, and clarify one another to advance a theory of reading that relies foremost on judgment, value, and feeling.

Tyrosine protonation changes in bacteriorhodopsin: a Fourier transform infrared study of BR548 and its primary photoproduct

Bio-organic Synthesi

A Process Similar to Autophagy is Associated with Cytocidal Chloroquine Resistance in Plasmodium Falciparum

Resistance to the cytostatic activity of the antimalarial drug chloroquine (CQ) is becoming well understood, however, resistance to cytocidal effects of CQ is largely unexplored. We find that PfCRT mutations that almost fully recapitulate P. falciparum cytostatic CQ resistance (CQR(CS)) as quantified by CQ IC50 shift, account for only 10-20% of cytocidal CQR (CQR(CC)) as quantified by CQ LD50 shift. Quantitative trait loci (QTL) analysis of the progeny of a chloroquine sensitive (CQS; strain HB3)×chloroquine resistant (CQR; strain Dd2) genetic cross identifies distinct genetic architectures for CQR(CS) vs CQR(CC) phenotypes, including identification of novel interacting chromosomal loci that influence CQ LD50. Candidate genes in these loci are consistent with a role for autophagy in CQR(CC), leading us to directly examine the autophagy pathway in intraerythrocytic CQR parasites. Indirect immunofluorescence of RBC infected with synchronized CQS vs CQR trophozoite stage parasites reveals differences in the distribution of the autophagy marker protein PfATG8 coinciding with CQR(CC). Taken together, the data show that an unusual autophagy-like process is either activated or inhibited for intraerythrocytic trophozoite parasites at LD50 doses (but not IC50 doses) of CQ, that the pathway is altered in CQR P. falciparum, and that it may contribute along with mutations in PfCRT to confer the CQR(CC) phenotype

A Process Similar to Autophagy is Associated with Cytocidal Chloroquine Resistance in Plasmodium Falciparum

Resistance to the cytostatic activity of the antimalarial drug chloroquine (CQ) is becoming well understood, however, resistance to cytocidal effects of CQ is largely unexplored. We find that PfCRT mutations that almost fully recapitulate P. falciparum cytostatic CQ resistance (CQR(CS)) as quantified by CQ IC50 shift, account for only 10-20% of cytocidal CQR (CQR(CC)) as quantified by CQ LD50 shift. Quantitative trait loci (QTL) analysis of the progeny of a chloroquine sensitive (CQS; strain HB3)×chloroquine resistant (CQR; strain Dd2) genetic cross identifies distinct genetic architectures for CQR(CS) vs CQR(CC) phenotypes, including identification of novel interacting chromosomal loci that influence CQ LD50. Candidate genes in these loci are consistent with a role for autophagy in CQR(CC), leading us to directly examine the autophagy pathway in intraerythrocytic CQR parasites. Indirect immunofluorescence of RBC infected with synchronized CQS vs CQR trophozoite stage parasites reveals differences in the distribution of the autophagy marker protein PfATG8 coinciding with CQR(CC). Taken together, the data show that an unusual autophagy-like process is either activated or inhibited for intraerythrocytic trophozoite parasites at LD50 doses (but not IC50 doses) of CQ, that the pathway is altered in CQR P. falciparum, and that it may contribute along with mutations in PfCRT to confer the CQR(CC) phenotype

Evolution of Fitness Cost-Neutral Mutant PfCRT Conferring P. falciparum 4-Aminoquinoline Drug Resistance Is Accompanied by Altered Parasite Metabolism and Digestive Vacuole Physiology

Southeast Asia is an epicenter of multidrug-resistant Plasmodium falciparum strains. Selective pressures on the subcontinent have recurrently produced several allelic variants of parasite drug resistance genes, including the P. falciparum chloroquine resistance transporter (pfcrt). Despite significant reductions in the deployment of the 4-aminoquinoline drug chloroquine (CQ), which selected for the mutant pfcrt alleles that halted CQ efficacy decades ago, the parasite pfcrt locus is continuously evolving. This is highlighted by the presence of a highly mutated allele, Cam734 pfcrt, which has acquired the singular ability to confer parasite CQ resistance without an associated fitness cost. Here, we used pfcrt-specific zinc-finger nucleases to genetically dissect this allele in the pathogenic setting of asexual blood-stage infection. Comparative analysis of drug resistance and growth profiles of recombinant parasites that express Cam734 or variants thereof, Dd2 (the most common Southeast Asian variant), or wild-type pfcrt, revealed previously unknown roles for PfCRT mutations in modulating parasite susceptibility to multiple antimalarial agents. These results were generated in the GC03 strain, used in multiple earlier pfcrt studies, and might differ in natural isolates harboring this allele. Results presented herein show that Cam734-mediated CQ resistance is dependent on the rare A144F mutation that has not been observed beyond Southeast Asia, and reveal distinct impacts of this and other Cam734-specific mutations on CQ resistance and parasite growth rates. Biochemical assays revealed a broad impact of mutant PfCRT isoforms on parasite metabolism, including nucleoside triphosphate levels, hemoglobin catabolism and disposition of heme, as well as digestive vacuole volume and pH. Results from our study provide new insights into the complex molecular basis and physiological impact of PfCRT-mediated antimalarial drug resistance, and inform ongoing efforts to characterize novel pfcrt alleles that can undermine the efficacy of first-line antimalarial drug regimens

The hydroxyl functionality and a rigid proximal N are required for forming a novel non-covalent quinine-heme complex

Quinoline antimalarial drugs bind both monomeric and dimeric forms of free heme, with distinct preferences depending on the chemical environment. Under biological conditions, chloroquine (CQ) appears to prefer to bind to μ-oxo dimeric heme, while quinine (QN) preferentially binds monomer. To further explore this important distinction, we study three newly synthesized and several commercially available QN analogues lacking various functional groups. We find that removal of the QN hydroxyl lowers heme affinity, hemozoin (Hz) inhibition efficiency, and antiplasmodial activity. Elimination of the rigid quinuclidyl ring has similar effects, but elimination of either the vinyl or methoxy group does not. Replacing the quinuclidyl N with a less rigid tertiary aliphatic N only partially restores activity. To further study these trends, we probe drug-heme interactions via NMR studies with both Fe and Zn protoporphyrin IX (FPIX, ZnPIX) for QN, dehydroxyQN (DHQN), dequinuclidylQN (DQQN), and deamino-dequinuclidylQN (DADQQN). Magnetic susceptibility measurements in the presence of FPIX demonstrate that these compounds differentially perturb FPIX monomer-dimer equilibrium. We also isolate the QN-FPIX complex formed under mild aqueous conditions and analyze it by mass spectrometry, as well as fluorescence, vibrational, and solid state NMR spectroscopies. The data elucidate key features of QN pharmacology and allow us to propose a refined model for the preferred binding of QN to monomeric FPIX under biologically relevant conditions. With this model in hand, we also propose how QN, CQ, and amodiaquine (AQ) differ in their ability to inhibit Hz formation

Importance of the difference in surface pressures of the cell membrane in doxorubicin resistant cells that do not express Pgp and ABCG2

P-glycoprotein (Pgp) represents the archetypal mechanism of drug resistance. But Pgp alone cannot expel drugs. A small but growing body of works has demonstrated that the membrane biophysical properties are central to Pgp-mediated drug resistance. For example, a change in the membrane surface pressure is expected to support drug–Pgp interaction. An interesting aspect from these models is that under specific conditions, the membrane is predicted to take over Pgp concerning the mechanism of drug resistance especially when the surface pressure is high enough, at which point drugs remain physically blocked at the membrane level. However it remains to be determined experimentally whether the membrane itself could, on its own, affect drug entry into cells that have been selected by a low concentration of drug and that do not express transporters. We demonstrate here that in the case of the drug doxorubicin, alteration of the surface pressure of membrane leaflets drive drug resistance