Monoclonal Antibodies against the Drosophila Nervous System

A panel of 148 monoclonal antibodies directed against Drosophila neural antigens has been prepared by using mice immunized with homogenates of Drosophila tissue. Antibodies were screened immunohistochemically on cryostat sections of fly heads. A large diversity of staining patterns was observed. Some antigens were broadly distributed among tissues; others were highly specific to nerve fibers, neuropil, muscle, the tracheal system, cell nuclei, photoreceptors, or other structures. The antigens for many of the antibodies have been identified on immunoblots. Monoclonal antibodies that identify specific molecules within the nervous system should prove useful in the study of the molecular genetics of neural development

A Biochemical and Genetic Analysis of the Cyclic AMP Phosphodiesterase Defect in dunce, a Memory Mutant of Drosophila

Drosophila can learn in several associative conditioning paradigms. Flies carrying the mutation dunce were selected for their poor performance in one such task, a negative reinforcement olfactory conditioning paradigm (Dudai et al., 1976). dunce flies express two other mutant phenotypes, female sterility, and reduced activity for one of the two cyclic AMP phosphodiesterases present in normal flies, PDE II (Byers et al., 1981) . . The experiments described below indicate that the normal dunce gene (dunce+) probably codes for PDE II itself, rather than for a regulator that affects PDE II and possibly other activities. A micro-assay technique is described that allows the separate measurement of PDE I and PDE II when both are present in mixture. PDE II is shown to occur at high specific activity in the nervous system, which is consistent with a role for this enzyme in neuronal function. The phenotype of female sterility associated with dunce mutants can be suppressed by any of three suppressor mutations. These do not suppress the other two phenotypes of reduced PDE II activity and poor learning, indicating that these phenotypes are closer to the primary defect associated with dunce mutants. Reduced PDE II activity correlates with poor learning in dunce flies in all three developmental stages that were tested (first and third instar larvae, and adults), as well as in response to genetic modifications of dunce gene activity. The results of several biochemical and genetic experiments fail to reveal any abnormal regulation of PDE II activity in dunce flies. In Drosophila, as a rule, the activity level of an enzyme correlates linearly with the activity of the enzyme's structural gene. The specific activity of PDE II is shown to correlate in a one to one fashion with the level of normal dunce gene activity at five different doses of dunce+. Taken as a whole, these experiments provide strong support for the hypothesis that PDE II represents the primary product of the dunce gene, indicating a role for this enzyme in the learning of Drosophila.</p

Synthesis and Characterization of ortho-Phenyleneethynylenes and Diphenylamine Polymers

In the first part of this thesis, the synthesis, characterization and investigation of ortho-phenyleneethynylenes containing heterocycles, are presented. These compounds display changes in absorption and emission spectra varying with their functionalization and size. These compounds also have the ability to coordinate with metals. The synthesis of coordination compounds and their crystallographic data are reported. The synthesis and characterization of tetraethynyl thiophene compounds containing pyridines are also presented. These compounds exhibit differences in absorption and emission spectra upon exposure to various metal salts. The final topic to be discussed is the synthesis and characterization of diphenyl amine polymers. These polymers could in principle be used in NLO applications or light emitting devices.Ph.D.Committee Chair: Dr. Uwe Bunz; Committee Member: Dr. Anselm Griffin; Committee Member: Dr. David Collard; Committee Member: Dr. Joseph Perry; Committee Member: Dr. Laren Tolber

Three unique coordination geometries involving 1,2-dimethoxy-4,5-bis(2-pyridylethynyl)benzene

Reaction of the new ligand 1,2-dimethoxy-4,5-bis(2-pyridylethynyl) benzene with different metal centers under similar reaction conditions led to three distinct structure formation processes: molecular ring closure, dimerization, and polymer formation

Channel-Containing Structures Generated from Linear Coordination Polymer Chains Containing -Bidentate Ligands and Cu–Cu Dimetal Units

Four new one-dimensional coordination polymers containing the dimetal cluster Cu2(OAc)4 have been synthesized by reacting Cu(OAc)2 ⋅ H2O with two different -bidentate ligands. Reaction of the flexible ligand, 1,2-bis(4-pyridyl)ethane (L1), with the copper starting material produced two, co-crystallizing coordination polymers: catena-Poly[Cu2(OAc)4(L1)] ⋅ 2H2O (1) and catena-Poly[Cu2(OAc)4(L1)]. In the solid state, 1 (monoclinic, C2/c ) features linear chains which are organized into layers. These layers stack along the crystallographic c-axis forming small hexagonal channels occupied by the solvent of crystallization. Compound 2 (triclinic, P-1) also features linear chains of the coordination polymer, but differs from 1 in that the chains are packed so as to leave no significant channels. Reaction of the rigid ligand, 1,4-bis(4-pyridyl)buta-1,3-diyne (L2), with the copper starting material also afforded two co-crystallizing coordination polymers: catena-Poly[Cu2(OAc)4(L2)] (3) and catena-Poly[Cu2(OAc)4(L2)] ⋅ solvents (4). 3 (monoclinic, P21/m, ), like 2, features linear chains and contains no significant solvent accessible void space. 4 (monoclinic, C2/c, ) also consists of linear chains of the coordination polymer. However, the overall topology of 4 is identical to that of 1, with the generated hexagonal channels containing crystallographically unidentifiable solvents of crystallization. Compounds 1 and 2 and compounds 3 and 4 are pairs of polymorphic coordination polymers neglecting the solvents of crystallization in 1 and 4. The compounds, which represent four new examples of coordination polymers containing dimetal units, have been characterized by IR, elemental analysis, and thermogravimetric analysis in addition to X-ray crystallography

Adverse Reactions in a Phase 1 Trial of the Anti-Malarial DM1157: An Example of Pharmacokinetic Modeling and Simulation Guiding Clinical Trial Decisions

Introduction: There is an urgent need to develop new drugs to treat malaria due to increasing resistance to first-line therapeutics targeting the causative organism, Plasmodium falciparum (P. falciparum). One drug candidate is DM1157, a small molecule that inhibits the formation of hemozoin, which protects P. falciparum from heme toxicity. We describe a first-in-human, phase 1 trial of DM1157 in healthy adult volunteers that was halted early because of significant toxicity. Methods: Adverse events were summarized using descriptive statistics. We used pharmacokinetic modeling to quantitatively assess whether the DM1157 exposure needed for P. falciparum inhibition was achievable at safe doses. Results: We found that there was no dose where both the safety and efficacy target were simultaneously achieved; conversely, the model predicted that 27 mg was the highest dosage at which patients would consistently maintain safe exposure with multiple dosing. By pre-defining dose escalation stopping rules and conducting an interim pharmacokinetic/pharmacodynamic analysis, we determined that the study would be unable to safely achieve a dosage needed to observe an anti-malarial effect, thereby providing strong rationale to halt the study. Conclusion: This study provides an important example of the risks and challenges of conducting early phase research as well as the role of modeling and simulation to optimize participant safety (ClinicalTrials.gov, NCT03490162)

A patient-centered deprescribing intervention for hospitalized older patients with polypharmacy: rationale and design of the Shed-MEDS randomized controlled trial

Abstract Background Polypharmacy is prevalent among hospitalized older adults, particularly those being discharged to a post-care care facility (PAC). The aim of this randomized controlled trial is to determine if a patient-centered deprescribing intervention initiated in the hospital and continued in the PAC setting reduces the total number of medications among older patients. Methods The Shed-MEDS study is a 5-year, randomized controlled clinical intervention trial comparing a patient-centered describing intervention with usual care among older (≥50 years) hospitalized patients discharged to PAC, either a skilled nursing facility (SNF) or an inpatient rehabilitation facility (IPR). Patient measurements occur at hospital enrollment, hospital discharge, within 7 days of PAC discharge, and at 60 and 90 days following PAC discharge. Patients are randomized in a permuted block fashion, with block sizes of two to four. The overall effectiveness of the intervention will be evaluated using total medication count as the primary outcome measure. We estimate that 576 patients will enroll in the study. Following attrition due to death or loss to follow-up, 420 patients will contribute measurements at 90 days, which provides 90% power to detect a 30% versus 25% reduction in total medications with an alpha error of 0.05. Secondary outcomes include the number of medications associated with geriatric syndromes, drug burden index, medication adherence, the prevalence and severity of geriatric syndromes and functional health status. Discussion The Shed-MEDS trial aims to test the hypothesis that a patient-centered deprescribing intervention initiated in the hospital and continuing through the PAC stay will reduce the total number of medications 90 days following PAC discharge and result in improvements in geriatric syndromes and functional health status. The results of this trial will quantify the health outcomes associated with reducing medications for hospitalized older adults with polypharmacy who are discharged to post-acute care facilities. Trial registration This trial was prospectively registered at clinicaltrials.gov (NCT02979353). The trial was first registered on 12/1/2016, with an update on 09/28/17 and 10/12/2018