Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 31
Filter
1.
J Intensive Care Med ; : 8850666241253537, 2024 May 09.
Article in English | MEDLINE | ID: mdl-38725286

ABSTRACT

Objectives:The aim of the study was to examine the incidence, baseline characteristics, and outcomes of Chimeric Antigen Receptor T-cell (CAR-T) therapy admissions in individuals who developed acute respiratory failure (ARF). The study utilized the National Inpatient Sample (NIS) database for the years 2017 to 2020. Methods: The study identified CAR-T cell therapy hospitalizations through the International Classification of Diseases, Tenth Revision, Procedure Coding System (ICD-10-PCS) codes. Patients with acute respiratory failure (ARF) were further classified using specific International Classification of Disease, Tenth Revision, Clinical Modification (ICD-10-CM) codes. Descriptive statistics were performed to analyze baseline characteristics, comorbidities, complications, and outcomes. Results: Analysis of the NIS Database identified 5545 CAR-T therapy admissions between 2017 and 2020, revealing a rising trend over time. In our study, we found that hypertension (39%), dyslipidemia (21.7%), and venous thromboembolism (13%) were the most frequently observed comorbidities in CAR-T cell therapy admissions. Acute respiratory failure (ARF) was reported in 7.1% of admissions, and they had higher all-cause in-hospital mortality than CAR-T cell therapy admissions without ARF (32.9% vs 1.3%, P < 0.001). ARF admissions that required invasive mechanical ventilation (IMV) also had higher all-cause in-hospital mortality compared to admissions not requiring IMV (48.9% vs 11.8%, P = 0.001). There was no difference in the mortality rate among admissions with non-Hodgkin's Lymphoma, Multiple Myeloma, and Leukemia that utilized CAR-T therapy. Conclusions: In this largest study to date, we illuminate the incidence and outcomes of CAR-T cell therapy admissions with ARF. Higher mortality rates were observed in CAR-T cell therapy admissions with ARF. The study emphasizes the crucial role of interdisciplinary collaboration in CAR-T patient management and calls for additional research to clarify ARF's etiology and inform effective management strategies.

2.
Chem Soc Rev ; 52(20): 7137-7169, 2023 Oct 16.
Article in English | MEDLINE | ID: mdl-37750006

ABSTRACT

Proton transfer reactions involving transition metal hydride complexes are prevalent in a number of catalytic fuel-forming reactions, where the proton transfer kinetics to or from the metal center can have significant impacts on the efficiency, selectivity, and stability associated with the catalytic cycle. This review correlates the often slow proton transfer rate constants of transition metal hydride complexes to their electronic and structural descriptors and provides perspective on how to exploit these parameters to control proton transfer kinetics to and from the metal center. A toolbox of techniques for experimental determination of proton transfer rate constants is discussed, and case studies where proton transfer rate constant determination informs fuel-forming reactions are highlighted. Opportunities for extending proton transfer kinetic measurements to additional systems are presented, and the importance of synergizing the thermodynamics and kinetics of proton transfer involving transition metal hydride complexes is emphasized.

3.
Inorg Chem ; 61(32): 12625-12634, 2022 Aug 15.
Article in English | MEDLINE | ID: mdl-35920800

ABSTRACT

We report the isolation and characterization of a series of three cobalt(II) bis(phosphine) complexes with varying numbers of coordinated solvent ligands in the axial position. X-ray quality crystals of [Co(dppv)2][BF4]2 (1), [Co(dppv)2(NCCH3)][BPh4]2 (2), and [Co(dppv)2(NCCH3)2][BF4]2 (3) (dppv = cis-1,2-bis(diphenylphosphino)ethylene) were grown under slightly different conditions, and their structures were compared. This analysis revealed multiple crystallization motifs for divalent cobalt(II) complexes with the same set of phosphine ligands. Notably, the 4-coordinate complex 1 is a rare example of a square-planar cobalt(II) complex, the first crystallographically characterized square-planar Co(II) complex containing only neutral, bidentate ligands. Characterization of the different axial geometries via EPR and UV-visible spectroscopies showed that there is a very shallow energy landscape for axial ligation. Ligand field angular overlap model calculations support this conclusion, and we provide a strategy for tuning other ligands to be axially labile on a phosphine scaffold. This methodology is proposed to be used for designing cobalt phosphine catalysts for a variety of oxidation and reduction reactions.


Subject(s)
Cobalt , Cobalt/chemistry , Crystallography, X-Ray , Ligands , Oxidation-Reduction , Phosphines
4.
J Am Chem Soc ; 143(50): 21388-21401, 2021 12 22.
Article in English | MEDLINE | ID: mdl-34878278

ABSTRACT

Molecules capable of both harvesting light and forming new chemical bonds hold promise for applications in the generation of solar fuels, but such first-row transition metal photoelectrocatalysts are lacking. Here we report nickel photoelectrocatalysts for H2 evolution, leveraging visible-light-driven photochemical H2 evolution from bis(diphosphine)nickel hydride complexes. A suite of experimental and theoretical analyses, including time-resolved spectroscopy and continuous irradiation quantum yield measurements, led to a proposed mechanism of H2 evolution involving a short-lived singlet excited state that undergoes homolysis of the Ni-H bond. Thermodynamic analyses provide a basis for understanding and predicting the observed photoelectrocatalytic H2 evolution by a 3d transition metal based catalyst. Of particular note is the dramatic change in the electrochemical overpotential: in the dark, the nickel complexes require strong acids and therefore high overpotentials for electrocatalysis; but under illumination, the use of weaker acids at the same applied potential results in a more than 500 mV improvement in electrochemical overpotential. New insight into first-row transition metal hydride photochemistry thus enables photoelectrocatalytic H2 evolution without electrochemical overpotential (at the thermodynamic potential or 0 mV overpotential). This catalyst system does not require sacrificial chemical reductants or light-harvesting semiconductor materials and produces H2 at rates similar to molecular catalysts attached to silicon.

5.
J Am Chem Soc ; 143(9): 3393-3406, 2021 03 10.
Article in English | MEDLINE | ID: mdl-33621088

ABSTRACT

Two-electron, one-proton reactions of a family of [CoCp(dxpe)(NCCH3)]2+ complexes (Cp = cyclopentadienyl, dxpe = 1,2-bis(di(aryl/alkyl)phosphino)ethane) form the corresponding hydride species [HCoCp(dxpe)]+ (dxpe = dppe (1,2-bis(diphenylphosphino)ethane), depe (1,2-bis(diethylphosphino)ethane), and dcpe (1,2-bis(dicyclohexylphosphino)ethane)) through a stepwise proton-coupled electron transfer process. For three [CoCp(dxpe)(NCCH3)]2+ complexes, peak shift analysis was employed to quantify apparent proton transfer rate constants from cyclic voltammograms recorded with acids ranging 22 pKa units. The apparent proton transfer rate constants correlate with the strength of the proton source for weak acids, but these apparent proton transfer rate constants curiously plateau (kpl) as the reaction becomes increasingly exergonic. The absolute apparent proton transfer rate constants across both these regions correlate with the steric bulk of the chelating diphosphine ligand, with bulkier ligands leading to slower kinetics (kplateau,depe = 3.5 × 107 M-1 s-1, kplateau,dppe = 1.7 × 107 M-1 s-1, kplateau,dcpe = 7.1 × 104 M-1 s-1). Mechanistic studies were conducted to identify the cause of the aberrant kPTapp-ΔpKa trends. When deuterated acids are employed, deuterium incorporation in the Cp ring is observed, indicating protonation of the CoCp(dxpe) species to form the corresponding hydride proceeds via initial ligand protonation. Digital simulations of cyclic voltammograms show ligand loss accompanying initial reduction gates subsequent PCET activity at higher driving forces. Together, these experiments reveal the details of the reaction mechanism: reduction of the Co(III) species is followed by dissociation of the bound acetonitrile ligand, subsequent reduction of the unligated Co(II) species to form a Co(I) species is followed by protonation, which occurs at the Cp ring, followed by tautomerization to generate the stable Co(III)-hydride product [HCoCp(dxpe)]+. Analysis as a function of chelating disphosphine ligand, solvent, and acid strength reveals that the ligand dissociation equilibrium is directly influenced by the steric bulk of the phosphine ligands and gates protonation, giving rise to the plateau of the apparent proton transfer rate constant with strong acids. The complexity of the reaction mechanism underpinning hydride formation, encompassing dynamic behavior of the entire ligand set, highlights the critical need to understand elementary reaction steps in proton-coupled electron transfer reactions.


Subject(s)
Cobalt/chemistry , Coordination Complexes/chemical synthesis , Electrons , Hydrogen/chemistry , Protons , Electrochemical Techniques , Kinetics , Ligands , Oxidation-Reduction , Phosphines/chemistry
6.
Inorg Chem ; 60(23): 17445-17449, 2021 Dec 06.
Article in English | MEDLINE | ID: mdl-34813328

ABSTRACT

Here we report electrochemical, spectroscopic, and crystallographic characterization of a redox series of cobalt complexes in five sequential oxidation states. A simple bidentate phosphine ligand, cis-1,2-bis(diphenylphosphino)ethylene (dppv), allows for isolation of the 3+, 2+, 1+, 0, and 1- oxidation states of cobalt─the only known example of transition-metal complexes with redox-innocent ligands in five oxidation states. Electrochemistry of [Co(dppv)2]2+ reveals three reversible reductions and one reversible oxidation. Complexes in each oxidation state are characterized using single-crystal X-ray diffraction. The coordination number and geometry of the complex changes as a function of the oxidation state: including acetonitrile ligands, the Co3+ complex is pseudo-octahedral, the Co2+ complex is square-pyramidal, the Co+ complex is pseudo-square-planar, and the Co0 and Co- complexes approach pseudo-tetrahedral, illustrating structures predicted by crystal-field theory of inorganic transition-metal complexes.

7.
Inorg Chem ; 59(14): 9618-9626, 2020 Jul 20.
Article in English | MEDLINE | ID: mdl-32501711

ABSTRACT

The characteristic red color of many natural tourmalines is due to the presence of Mn(III) cations substituting for aluminum and lithium. These sites originate as Mn(II) and are oxidized by natural γ-irradiation over geologic time as they sit in the Earth's crust. Presented here is a thorough analysis of the spin-allowed and spin-forbidden transitions which give rise to the color of these gemstones. Ligand field analysis, supplemented by time-dependent density functional theory, was used to correct the historical assignments of the symmetry-allowed transitions in the polarized UV-visible absorption spectrum. Heat-induced reduction of the oxidized manganese sites provided a probe of the relationship between the spin-allowed and spin-forbidden bands. Notably, the intensity of the spin-forbidden transition was highly dependent on the neighboring ions in the Y-site. Simulations and modeling showed that increased intensity was observed only when two Mn(III) ions occupied adjacent substitutions in the Y-site via a proposed exchange-coupling mechanism.

8.
Genome Res ; 26(12): 1627-1638, 2016 12.
Article in English | MEDLINE | ID: mdl-27934696

ABSTRACT

Gene-by-environment (GxE) interactions determine common disease risk factors and biomedically relevant complex traits. However, quantifying how the environment modulates genetic effects on human quantitative phenotypes presents unique challenges. Environmental covariates are complex and difficult to measure and control at the organismal level, as found in GWAS and epidemiological studies. An alternative approach focuses on the cellular environment using in vitro treatments as a proxy for the organismal environment. These cellular environments simplify the organism-level environmental exposures to provide a tractable influence on subcellular phenotypes, such as gene expression. Expression quantitative trait loci (eQTL) mapping studies identified GxE interactions in response to drug treatment and pathogen exposure. However, eQTL mapping approaches are infeasible for large-scale analysis of multiple cellular environments. Recently, allele-specific expression (ASE) analysis emerged as a powerful tool to identify GxE interactions in gene expression patterns by exploiting naturally occurring environmental exposures. Here we characterized genetic effects on the transcriptional response to 50 treatments in five cell types. We discovered 1455 genes with ASE (FDR < 10%) and 215 genes with GxE interactions. We demonstrated a major role for GxE interactions in complex traits. Genes with a transcriptional response to environmental perturbations showed sevenfold higher odds of being found in GWAS. Additionally, 105 genes that indicated GxE interactions (49%) were identified by GWAS as associated with complex traits. Examples include GIPR-caffeine interaction and obesity and include LAMP3-selenium interaction and Parkinson disease. Our results demonstrate that comprehensive catalogs of GxE interactions are indispensable to thoroughly annotate genes and bridge epidemiological and genome-wide association studies.


Subject(s)
Gene Expression Profiling/methods , Genome-Wide Association Study/methods , Quantitative Trait Loci/drug effects , Alleles , Caffeine/pharmacology , Cell Line , Gene Expression Regulation/drug effects , Gene-Environment Interaction , Human Umbilical Vein Endothelial Cells , Humans , Melanocytes/cytology , Melanocytes/drug effects , Selenium/pharmacology , Tunicamycin/pharmacology
9.
Inorg Chem ; 58(24): 16510-16517, 2019 Dec 16.
Article in English | MEDLINE | ID: mdl-31755267

ABSTRACT

Studying the formation of transition metal hydride complexes via proton-coupled electron transfer is important for developing next-generation molecular catalysts for hydrogen evolution. We report herein the study of stepwise photoinduced reduction and protonation of [CoIICp(dppe)]+ (Cp = cyclopentadienyl, dppe = 1,2-bis(diphenylphosphino)ethane) to form the corresponding hydride complex [HCoIIICp(dppe)]+. Reaction intermediates were optically tracked using transient absorption spectroscopy, and a combination of experimental fitting and kinetic simulations was used to determine apparent rate constants for electron transfer and proton transfer with a range of acid sources. A linear free energy relationship is observed between measured apparent proton transfer rate constants and acid strength, but marked differences from previously electrochemically determined protonation rate constants are found. These deviations, which stem from ground-state reactivity present in photochemical experiments, highlight the challenges in comparing mechanistic studies using different techniques.

10.
Inorg Chem ; 57(9): 5389-5399, 2018 May 07.
Article in English | MEDLINE | ID: mdl-29648794

ABSTRACT

A series of rhenium diimine carbonyl complexes was prepared and characterized in order to examine the influence of axial ligands on electronic structure. Systematic substitution of the axial carbonyl and acetonitrile ligands of [Re(deeb)(CO)3(NCCH3)]+ (deeb = 4,4'-diethylester-2,2'-bipyridine) with trimethylphosphine and chloride, respectively, gives rise to red-shifted absorbance features. These bathochromic shifts result from destabilization of the occupied d-orbitals involved in metal-to-ligand charge-transfer transitions. Time-Dependent Density Functional Theory identified the orbitals involved in each transition and provided support for the changes in orbital energies induced by ligand substitution.

11.
J Am Chem Soc ; 139(1): 239-244, 2017 01 11.
Article in English | MEDLINE | ID: mdl-27997157

ABSTRACT

The need for benchmarking hydrogen evolution catalysts has increasingly been recognized. The influence of acid choice on activity is often reduced to the overpotential for catalysis. Through the study of a stable cobalt hydride complex, we demonstrate the influence of acid choice, beyond pKa, on the kinetics of hydride formation. A linear free energy relationship between acid pKa and second-order rate constants is observed for weaker acids. For stronger acids, however, further increases in pKa do not correlate to increases in rate constants. Further, steric bulk around the acidic proton is shown to influence rate constants dramatically. Together, these observations reveal the complex factors dictating catalyst performance.

13.
J Am Chem Soc ; 138(41): 13509-13512, 2016 10 19.
Article in English | MEDLINE | ID: mdl-27673375

ABSTRACT

Artificial photosynthesis relies on coupling light absorption with chemical fuel generation. A mechanistic study of visible light-driven H2 production from [Cp*Ir(bpy)H]+ (1) has revealed a new, highly efficient pathway for integrating light absorption with bond formation. The net reaction of 1 with a proton source produces H2, but the rate of excited state quenching is surprisingly acid-independent and displays no observable deuterium kinetic isotopic effect. Time-resolved photoluminescence and labeling studies are consistent with diffusion-limited bimetallic self-quenching by electron transfer. Accordingly, the quantum yield of H2 release nearly reaches unity as the concentration of 1 increases. This unique pathway for photochemical H2 generation provides insight into transformations catalyzed by 1.

14.
BMC Biol ; 13: 92, 2015 Nov 05.
Article in English | MEDLINE | ID: mdl-26541816

ABSTRACT

BACKGROUND: Metagenomes provide access to the taxonomic composition and functional capabilities of microbial communities. Although metagenomic analysis methods exist for estimating overall community composition or metabolic potential, identifying specific taxa that encode specific functions or pathways of interest can be more challenging. Here we present MetAnnotate, which addresses the common question: "which organisms perform my function of interest within my metagenome(s) of interest?" MetAnnotate uses profile hidden Markov models to analyze shotgun metagenomes for genes and pathways of interest, classifies retrieved sequences either through a phylogenetic placement or best hit approach, and enables comparison of these profiles between metagenomes. RESULTS: Based on a simulated metagenome dataset, the tool achieves high taxonomic classification accuracy for a broad range of genes, including both markers of community abundance and specific biological pathways. Lastly, we demonstrate MetAnnotate by analyzing for cobalamin (vitamin B12) synthesis genes across hundreds of aquatic metagenomes in a fraction of the time required by the commonly used Basic Local Alignment Search Tool top hit approach. CONCLUSIONS: MetAnnotate is multi-threaded and installable as a local web application or command-line tool on Linux systems. Metannotate is a useful framework for general and/or function-specific taxonomic profiling and comparison of metagenomes.


Subject(s)
Archaea/genetics , Bacteria/genetics , Metagenome , Molecular Sequence Annotation/methods , Vitamin B 12/genetics , Archaea/metabolism , Bacteria/metabolism , Classification , Software , Vitamin B 12/metabolism
15.
Article in English | MEDLINE | ID: mdl-36703567

ABSTRACT

Therapeutic release from hydrogels is traditionally controlled by encapsulation within nanoparticles; however, this strategy is limited for the release of proteins due to poor efficiency and denaturation. To overcome this problem, we designed an encapsulation-free release platform where negatively charged proteins are adsorbed to the exterior of transiently cationic nanoparticles, thus allowing the nanoparticles to be formulated separately from the proteins. Release is then governed by the change in nanoparticle surface charge from positive to neutral. To achieve this, we synthesized eight zwitterionic poly(lactide-block-carboxybetaine) copolymer derivatives and formulated them into nanoparticles with differing surface chemistry. The nanoparticles were colloidally stable and lost positive charge at rates dependent on the hydrolytic stability of their surface ester groups. The nanoparticles (NPs) were dispersed in a physically cross-linked hyaluronan-based hydrogel with one of three negatively charged proteins (transferrin, panitumumab, or granulocyte-macrophage colony-stimulating factor) to assess their ability to control release. For all three proteins, dispersing NPs within the gels resulted in significant attenuation of release, with the extent modulated by the hydrolytic stability of the surface groups. Release was rapid from fast-hydrolyzing ester groups, reduced with slow-hydrolyzing bulky ester groups, and very slow with nonhydrolyzing amide groups. When positively charged lysozyme was loaded into the nanocomposite gel, there was no significant attenuation of release compared to gel alone. These data demonstrate that electrostatic interactions between the protein and NP are the primary driver of protein release from the hydrogel. All released proteins retained bioactivity as determined with in vitro cell assays. This release strategy shows tremendous versatility and provides a promising new platform for controlled release of anionic protein therapeutics.

16.
Endocrinology ; 164(6)2023 04 17.
Article in English | MEDLINE | ID: mdl-37042477

ABSTRACT

Lymphangioleiomyomatosis (LAM) is a rare cystic lung disease caused by smooth muscle cell-like tumors containing tuberous sclerosis (TSC) gene mutations and found almost exclusively in females. Patient studies suggest LAM progression is estrogen dependent, an observation supported by in vivo mouse models. However, in vitro data using TSC-null cell lines demonstrate modest estradiol (E2) responses, suggesting E2 effects in vivo may involve pathways independent of direct tumor stimulation. We previously reported tumor-dependent neutrophil expansion and promotion of TSC2-null tumor growth in an E2-sensitive LAM mouse model. We therefore hypothesized that E2 stimulates tumor growth in part by promoting neutrophil production. Here we report that E2-enhanced lung colonization of TSC2-null cells is indeed dependent on neutrophils. We demonstrate that E2 induces granulopoiesis via estrogen receptor α in male and female bone marrow cultures. With our novel TSC2-null mouse myometrial cell line, we show that factors released from these cells drive E2-sensitive neutrophil production. Last, we analyzed single-cell RNA sequencing data from LAM patients and demonstrate the presence of tumor-activated neutrophils. Our data suggest a powerful positive feedback loop whereby E2 and tumor factors induce neutrophil expansion, which in turn intensifies tumor growth and production of neutrophil-stimulating factors, resulting in continued TSC2-null tumor growth.


Subject(s)
Lymphangioleiomyomatosis , Mice , Male , Female , Animals , Lymphangioleiomyomatosis/genetics , Lymphangioleiomyomatosis/metabolism , Lymphangioleiomyomatosis/pathology , Tumor Suppressor Proteins/genetics , Estradiol/pharmacology , Neutrophils , Tuberous Sclerosis Complex 2 Protein/genetics
17.
ACS Energy Lett ; 7(1): 358-365, 2022 Jan 14.
Article in English | MEDLINE | ID: mdl-35059502

ABSTRACT

Halide mixing is one of the most powerful techniques to tune the optical bandgap of metal-halide perovskites. However, halide mixing has commonly been observed to result in phase segregation, which reduces excited-state transport and limits device performance. While the current emphasis lies on the development of strategies to prevent phase segregation, it remains unclear how halide mixing may affect excited-state transport even if phase purity is maintained. Here, we study exciton transport in phase pure mixed-halide 2D perovskites of (PEA)2Pb(I1-x Br x )4. Using transient photoluminescence microscopy, we show that, despite phase purity, halide mixing inhibits exciton transport. We find a significant reduction even for relatively low alloying concentrations. By performing Brownian dynamics simulations, we are able to reproduce our experimental results and attribute the decrease in diffusivity to the energetically disordered potential landscape that arises due to the intrinsic random distribution of alloying sites.

18.
J Community Hosp Intern Med Perspect ; 11(2): 253-255, 2021 Mar 23.
Article in English | MEDLINE | ID: mdl-33889331

ABSTRACT

Bile cast nephropathy (BCN) is a rare form of acute kidney injury (AKI) that occurs in the setting of hyperbilirubinemia. We present the case of a 67 year-old male with severe kidney injury who was found to have obstructive cholestasis. By way of this report, we aim to expand upon the existing literature and showcase the importance of timely endoscopic retrograde cholangio-pancreatography (ERCP) in this setting, in order to prevent irreversible kidney damage.

19.
Clin Case Rep ; 8(12): 3547-3548, 2020 Dec.
Article in English | MEDLINE | ID: mdl-33363971

ABSTRACT

Xylophagia is a form of pica where patients have the unusual craving for ingestion of paper. After treating the underlying cause of pica, in this case treating iron deficiency anemia with iron replacement therapy, these unusual cravings resolve.

20.
Chem Sci ; 11(25): 6442-6449, 2020 Mar 06.
Article in English | MEDLINE | ID: mdl-34094109

ABSTRACT

The photochemistry of metal hydride complexes is dominated by H2 evolution, limiting access to reductive transformations based on photochemical hydride transfer. In this article, the innate H2 evolution photochemistry of the iridium hydride complexes [Cp*Ir(bpy-OMe)H]+ (1, bpy-OMe = 4,4'-dimethoxy-2,2'-bipyridine) and [Cp*Ir(bpy)H]+ (2, bpy = 2,2'-bipyridine) is diverted towards photochemical hydrodechlorination. Net hydride transfer from 1 and 2 to dichloromethane produces chloromethane with high selectivity and exceptional photochemical quantum yield (Φ ≤ 1.3). Thermodynamic and kinetic mechanistic studies are consistent with a non-radical-chain reaction sequence initiated by "self-quenching" electron transfer between excited state and ground state hydride complexes, followed by proton-coupled electron transfer (PCET) hydrodechlorination that outcompetes H-H coupling. This unique photochemical mechanism provides a new hope for the development of light-driven hydride transfer reactions.

SELECTION OF CITATIONS
SEARCH DETAIL