Publications by authors named "Amy Gryshuk"

To assemble and characterize an electronic health record (EHR) dataset for a large cohort of US military Veterans diagnosed with ALS (Amyotrophic Lateral Sclerosis). An EHR dataset for 19,662 Veterans diagnosed with ALS between January 1, 2000 to December 31, 2020 was compiled from the Veterans Health Administration (VHA) EHR database by a query for ICD9 diagnosis (335.20) or ICD10 diagnosis (G12.

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Background: The interaction between cancer diagnoses and COVID-19 infection and outcomes is unclear. We leveraged a state-wide, multi-institutional database to assess cancer-related risk factors for poor COVID-19 outcomes.

Methods: We conducted a retrospective cohort study using the University of California Health COVID Research Dataset, which includes electronic health data of patients tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at 17 California medical centers.

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The application of data science in cancer research has been boosted by major advances in three primary areas: (1) Data: diversity, amount, and availability of biomedical data; (2) Advances in Artificial Intelligence (AI) and Machine Learning (ML) algorithms that enable learning from complex, large-scale data; and (3) Advances in computer architectures allowing unprecedented acceleration of simulation and machine learning algorithms. These advances help build ML models that can provide transformative insights from data including: molecular dynamics simulations, next-generation sequencing, omics, imaging, and unstructured clinical text documents. Unique challenges persist, however, in building ML models related to cancer, including: (1) access, sharing, labeling, and integration of multimodal and multi-institutional data across different cancer types; (2) developing AI models for cancer research capable of scaling on next generation high performance computers; and (3) assessing robustness and reliability in the AI models.

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Raman spectroscopy is a powerful tool for label-free, single cell characterization. In many reported studies, a Raman spectrum is acquired from a fraction of the cell volume and used as a representative signature of the whole cell to identify and discriminate between cell populations. It has remained an open question whether this is the most suitable approach since the spectra may not truly represent the cell as a whole and critical biochemical information could therefore be lost.

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The 2012 International Breath Analysis meeting was held in Sonoma, CA (USA) from 28 October-01 November 2012. The focus of the meeting covered several important topics within the research area, including both engineering and the biomedical sciences. As human breath analysis further develops as a multi-disciplinary field, it is clear that sensor development, instrumentation systems and algorithms play critical roles.

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In this paper we report the development of two attachments to a commercial cell phone that transform the phone's integrated lens and image sensor into a 350x microscope and visible-light spectrometer. The microscope is capable of transmission and polarized microscopy modes and is shown to have 1.5 micron resolution and a usable field-of-view of 150 x 50 with no image processing, and approximately 350 x 350 when post-processing is applied.

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At similar lipophilicity, compared to the nonfluorinated purpurinimide 11, the corresponding fluorinated analog 8 with a trifluoromethyl substituent at the lower half (position-132) of the molecule showed enhanced photosensitizing efficacy. The structural parameters established in purpurinimides (lambdamax: 700 nm) were successfully translated to the bacteriopurpurin imide system 19 (lambdamax: 792 nm) and within both series, a monotonic relationship between the lipophilicity and the in vivo PDT activity was observed. For preparing water-soluble compounds, the photosensitizers 8 and 19 were converted into the corresponding aminobenzyl-diethylenetriamine pentaacetate conjugates 23 and 26.

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The purpose of this review is to call attention in the use of chlorophyll-a and bacteriochlorophyll-a to develop more than 600 photosensitizers (lambda (max) 660 nm-800 nm) during the last 15 years (1990-2005) at the Photodynamic Therapy Center, Roswell Park Cancer Institute, Buffalo. This article mainly includes the chemistry, preclinical results, and brief clinical data of some of the most effective photosensitizers. The utility of the tumor-avid photosensitizers in developing multimodality agents (imaging and therapy) is also presented.

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The stable bacteriopurpurinimide (788 nm, epsilon: 38,600 in CH2Cl2), obtained by reducing the corresponding unstable Schiff base (803 nm, epsilon: 50,900 in CH2Cl2) that was isolated by reacting bacteriopurpurin methyl ester with 3,5-bis-(trifluoromethyl)benzylamine, produced promising photosensitizing efficacy. 1H NMR, mass spectrometry, and HPLC analyses confirmed the structures of new bacteriopurpurinimides and the metabolic product. The preliminary in vivo photosensitizing efficacy of this stable bacteriopurpurinimide was determined in C3H mice bearing radiation induced fibrosarcoma tumors as a function of variable drug doses.

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Methyl 3-(1'-m-iodobenzyloxyethyl)-3-devinylpyropheophorbide-a (2), obtained in a sequence of reactions from pyropheophorbide-a (a chlorophyll-a derivative), was found to be a promising imaging agent and a photosensitizer for photodynamic therapy (PDT). The electrophilic aromatic iodination of the corresponding trimethylstannyl intermediate with Na124I in the presence of an Iodogen bead afforded 124I-labeled photosensitizer 4 with >95% radioactive specificity. In addition to drug-uptake, the light fluence and fluence rate that were used for the light treatment had a significant impact in long-term tumor cure.

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Optical imaging has attracted a great attention for studying molecular recognitions because minute fluorescent tracers can be detected in homogeneous and heterogeneous media with existing laboratory instruments. In our preliminary study, a clinically relevant photosensitizer (HPPH, a chlorophyll-a analog) was linked with a cyanine dye (with required photophysical characteristics but limited tumor selectivity), and the resulting conjugate was found to be an efficient tumor imaging (fluorescence imaging) and photosensitizing agent. Compared to HPPH, the presence of the cyanine dye moiety in the conjugate produced a significantly higher uptake in tumor than skin.

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Pyropheophorbides and their metal complexes were synthesized to investigate their applications as nonradioactive peripheral benzodiazepine receptor (PBR) binding probes and photosensitizers for use in photodynamic therapy. They were found to be localized in mitochondria and showed significant binding to PBR. In some cases, the PBR binding values were similar to that for 17 (PK11195, 1-(2-chlorophenyl)-N-methyl-N-(1-methylpropyl)isoquinoline-3-carboxamide).

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The isomerically pure 3-deacetyl-3-(1-heptyloxy)ethylbacteriopurpurin-N-hexylimides exhibiting long-wavelength absorption near 800 nm were obtained from 3-acetylbacteriopurpurin-N-hexylimide in high stereospecificity by following Corey's synthetic approach. Both heptyl ether derivatives (R- and S-isomers) showed similar in vitro photosensitizing efficacy and limited skin phototoxicity and were found to localize in mitochondria. However, in preliminary in vivo screening, compared to the S-isomer, the corresponding R-isomer produced enhanced in vivo photodynamic therapy efficacy.

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Plumieride was isolated as one of the major components from the biologically active methanolic extract of the bark of Plumeria bicolor (family Apocynaceae). For investigating the effect of substituents on cytotoxic activity it was modified into a series of compounds. Replacing the methyl ester functionality of plumieride with alkyl amides of variable carbon units improved the cytotoxic activity, and a correlation between overall lipophilicity and cytotoxic activity was observed.

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meso-(2-Formylvinyl)octaethylporphyrin on reaction with cyanotrimethylsilane in the presence of various catalysts [copper triflate [Cu(OTf)(2)], indium triflate [In(OTf)(3)], or magnesium bromide diethyl etherate (MgBr(2).Et(2)O)] produced a mixture of the intermediate 3-hydroxy-3-cyanopropenoporphyrin, the corresponding trimethylsilyl ether derivative, and the unexpected propenochlorins. The yields of the reaction products were found to depend on the reaction conditions and the catalysts used.

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A first report on the synthesis and comparative in vitro-in vivo photosensitizing efficacy of various fluorinated and the corresponding nonfluorinated, purpurinimide-based photosensitizers is discussed. In preliminary in vivo screening, compared with the nonfluorinated analogs, purpurinimides bearing trifluoromethyl substituents showed enhanced photosensitizing efficacy. Among compounds (isomers) with similar lipophilicity, the position of the substituents was found to play a decisive role in biological efficacy.

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