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1.
Cell ; 183(5): 1383-1401.e19, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33159858

RESUMO

Ebola virus (EBOV) causes epidemics with high mortality yet remains understudied due to the challenge of experimentation in high-containment and outbreak settings. Here, we used single-cell transcriptomics and CyTOF-based single-cell protein quantification to characterize peripheral immune cells during EBOV infection in rhesus monkeys. We obtained 100,000 transcriptomes and 15,000,000 protein profiles, finding that immature, proliferative monocyte-lineage cells with reduced antigen-presentation capacity replace conventional monocyte subsets, while lymphocytes upregulate apoptosis genes and decline in abundance. By quantifying intracellular viral RNA, we identify molecular determinants of tropism among circulating immune cells and examine temporal dynamics in viral and host gene expression. Within infected cells, EBOV downregulates STAT1 mRNA and interferon signaling, and it upregulates putative pro-viral genes (e.g., DYNLL1 and HSPA5), nominating pathways the virus manipulates for its replication. This study sheds light on EBOV tropism, replication dynamics, and elicited immune response and provides a framework for characterizing host-virus interactions under maximum containment.


Assuntos
Ebolavirus/fisiologia , Doença pelo Vírus Ebola/genética , Doença pelo Vírus Ebola/virologia , Interações Hospedeiro-Patógeno/genética , Análise de Célula Única , Animais , Antígenos CD/metabolismo , Biomarcadores/metabolismo , Efeito Espectador , Diferenciação Celular , Proliferação de Células , Citocinas/metabolismo , Ebolavirus/genética , Chaperona BiP do Retículo Endoplasmático , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Regulação Viral da Expressão Gênica , Doença pelo Vírus Ebola/imunologia , Doença pelo Vírus Ebola/patologia , Antígenos de Histocompatibilidade Classe II/metabolismo , Interferons/genética , Interferons/metabolismo , Macaca mulatta , Macrófagos/metabolismo , Monócitos/metabolismo , Mielopoese , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fatores de Tempo , Transcriptoma/genética
2.
Cell ; 181(5): 1016-1035.e19, 2020 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-32413319

RESUMO

There is pressing urgency to understand the pathogenesis of the severe acute respiratory syndrome coronavirus clade 2 (SARS-CoV-2), which causes the disease COVID-19. SARS-CoV-2 spike (S) protein binds angiotensin-converting enzyme 2 (ACE2), and in concert with host proteases, principally transmembrane serine protease 2 (TMPRSS2), promotes cellular entry. The cell subsets targeted by SARS-CoV-2 in host tissues and the factors that regulate ACE2 expression remain unknown. Here, we leverage human, non-human primate, and mouse single-cell RNA-sequencing (scRNA-seq) datasets across health and disease to uncover putative targets of SARS-CoV-2 among tissue-resident cell subsets. We identify ACE2 and TMPRSS2 co-expressing cells within lung type II pneumocytes, ileal absorptive enterocytes, and nasal goblet secretory cells. Strikingly, we discovered that ACE2 is a human interferon-stimulated gene (ISG) in vitro using airway epithelial cells and extend our findings to in vivo viral infections. Our data suggest that SARS-CoV-2 could exploit species-specific interferon-driven upregulation of ACE2, a tissue-protective mediator during lung injury, to enhance infection.


Assuntos
Células Epiteliais Alveolares/metabolismo , Enterócitos/metabolismo , Células Caliciformes/metabolismo , Interferon Tipo I/metabolismo , Mucosa Nasal/citologia , Peptidil Dipeptidase A/genética , Adolescente , Células Epiteliais Alveolares/imunologia , Enzima de Conversão de Angiotensina 2 , Animais , Betacoronavirus/fisiologia , COVID-19 , Linhagem Celular , Células Cultivadas , Criança , Infecções por Coronavirus/virologia , Enterócitos/imunologia , Células Caliciformes/imunologia , Infecções por HIV/imunologia , Humanos , Influenza Humana/imunologia , Interferon Tipo I/imunologia , Pulmão/citologia , Pulmão/patologia , Macaca mulatta , Camundongos , Mycobacterium tuberculosis , Mucosa Nasal/imunologia , Pandemias , Peptidil Dipeptidase A/metabolismo , Pneumonia Viral/virologia , Receptores Virais/genética , SARS-CoV-2 , Serina Endopeptidases/metabolismo , Análise de Célula Única , Tuberculose/imunologia , Regulação para Cima
3.
Cell ; 176(6): 1265-1281.e24, 2019 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-30827681

RESUMO

Acute myeloid leukemia (AML) is a heterogeneous disease that resides within a complex microenvironment, complicating efforts to understand how different cell types contribute to disease progression. We combined single-cell RNA sequencing and genotyping to profile 38,410 cells from 40 bone marrow aspirates, including 16 AML patients and five healthy donors. We then applied a machine learning classifier to distinguish a spectrum of malignant cell types whose abundances varied between patients and between subclones in the same tumor. Cell type compositions correlated with prototypic genetic lesions, including an association of FLT3-ITD with abundant progenitor-like cells. Primitive AML cells exhibited dysregulated transcriptional programs with co-expression of stemness and myeloid priming genes and had prognostic significance. Differentiated monocyte-like AML cells expressed diverse immunomodulatory genes and suppressed T cell activity in vitro. In conclusion, we provide single-cell technologies and an atlas of AML cell states, regulators, and markers with implications for precision medicine and immune therapies. VIDEO ABSTRACT.


Assuntos
Leucemia Mieloide Aguda/genética , Transcriptoma/genética , Adulto , Sequência de Bases/genética , Medula Óssea , Células da Medula Óssea/citologia , Linhagem Celular Tumoral , Progressão da Doença , Feminino , Genótipo , Humanos , Leucemia Mieloide Aguda/imunologia , Leucemia Mieloide Aguda/fisiopatologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Mutação , Prognóstico , RNA , Transdução de Sinais , Análise de Célula Única/métodos , Microambiente Tumoral , Sequenciamento do Exoma/métodos
4.
Nat Immunol ; 22(7): 839-850, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34168371

RESUMO

Granulomas are complex cellular structures composed predominantly of macrophages and lymphocytes that function to contain and kill invading pathogens. Here, we investigated the single-cell phenotypes associated with antimicrobial responses in human leprosy granulomas by applying single-cell and spatial sequencing to leprosy biopsy specimens. We focused on reversal reactions (RRs), a dynamic process whereby some patients with disseminated lepromatous leprosy (L-lep) transition toward self-limiting tuberculoid leprosy (T-lep), mounting effective antimicrobial responses. We identified a set of genes encoding proteins involved in antimicrobial responses that are differentially expressed in RR versus L-lep lesions and regulated by interferon-γ and interleukin-1ß. By integrating the spatial coordinates of the key cell types and antimicrobial gene expression in RR and T-lep lesions, we constructed a map revealing the organized architecture of granulomas depicting compositional and functional layers by which macrophages, T cells, keratinocytes and fibroblasts can each contribute to the antimicrobial response.


Assuntos
Hanseníase Virchowiana/imunologia , Hanseníase Tuberculoide/imunologia , Mycobacterium leprae/imunologia , Pele/imunologia , Adolescente , Adulto , Idoso , Feminino , Fibroblastos/imunologia , Fibroblastos/microbiologia , Fibroblastos/patologia , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Queratinócitos/imunologia , Queratinócitos/microbiologia , Queratinócitos/patologia , Hanseníase Virchowiana/genética , Hanseníase Virchowiana/microbiologia , Hanseníase Virchowiana/patologia , Hanseníase Tuberculoide/genética , Hanseníase Tuberculoide/microbiologia , Hanseníase Tuberculoide/patologia , Macrófagos/imunologia , Macrófagos/microbiologia , Macrófagos/patologia , Masculino , Pessoa de Meia-Idade , Mycobacterium leprae/patogenicidade , RNA-Seq , Análise de Célula Única , Pele/microbiologia , Pele/patologia , Linfócitos T/imunologia , Linfócitos T/microbiologia , Linfócitos T/patologia , Transcriptoma
5.
Immunity ; 55(5): 827-846.e10, 2022 05 10.
Artigo em Inglês | MEDLINE | ID: mdl-35483355

RESUMO

Mycobacterium tuberculosis lung infection results in a complex multicellular structure: the granuloma. In some granulomas, immune activity promotes bacterial clearance, but in others, bacteria persist and grow. We identified correlates of bacterial control in cynomolgus macaque lung granulomas by co-registering longitudinal positron emission tomography and computed tomography imaging, single-cell RNA sequencing, and measures of bacterial clearance. Bacterial persistence occurred in granulomas enriched for mast, endothelial, fibroblast, and plasma cells, signaling amongst themselves via type 2 immunity and wound-healing pathways. Granulomas that drove bacterial control were characterized by cellular ecosystems enriched for type 1-type 17, stem-like, and cytotoxic T cells engaged in pro-inflammatory signaling networks involving diverse cell populations. Granulomas that arose later in infection displayed functional characteristics of restrictive granulomas and were more capable of killing Mtb. Our results define the complex multicellular ecosystems underlying (lack of) granuloma resolution and highlight host immune targets that can be leveraged to develop new vaccine and therapeutic strategies for TB.


Assuntos
Mycobacterium tuberculosis , Fibrose Pulmonar , Tuberculose , Animais , Ecossistema , Granuloma , Pulmão , Macaca fascicularis , Fibrose Pulmonar/patologia
6.
Immunity ; 53(4): 878-894.e7, 2020 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-33053333

RESUMO

High-throughput single-cell RNA-sequencing (scRNA-seq) methodologies enable characterization of complex biological samples by increasing the number of cells that can be profiled contemporaneously. Nevertheless, these approaches recover less information per cell than low-throughput strategies. To accurately report the expression of key phenotypic features of cells, scRNA-seq platforms are needed that are both high fidelity and high throughput. To address this need, we created Seq-Well S3 ("Second-Strand Synthesis"), a massively parallel scRNA-seq protocol that uses a randomly primed second-strand synthesis to recover complementary DNA (cDNA) molecules that were successfully reverse transcribed but to which a second oligonucleotide handle, necessary for subsequent whole transcriptome amplification, was not appended due to inefficient template switching. Seq-Well S3 increased the efficiency of transcript capture and gene detection compared with that of previous iterations by up to 10- and 5-fold, respectively. We used Seq-Well S3 to chart the transcriptional landscape of five human inflammatory skin diseases, thus providing a resource for the further study of human skin inflammation.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala/métodos , Inflamação/genética , RNA Citoplasmático Pequeno/genética , Pele/patologia , Animais , Linhagem Celular , DNA Complementar/genética , Células HEK293 , Humanos , Camundongos , Células NIH 3T3 , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Transcrição Gênica/genética , Transcriptoma/genética
7.
Development ; 150(6)2023 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-36971361

RESUMO

The development and function of male gametes is dependent on a dynamic microtubule network, yet how this is regulated remains poorly understood. We have recently shown that microtubule severing, via the action of the meiotic AAA ATPase protein clade, plays a crucial role in this process. Here, we sought to elucidate the roles of spastin, an as-yet-unexplored member of this clade in spermatogenesis. Using a SpastKO/KO mouse model, we reveal that spastin loss resulted in a complete loss of functional germ cells. Spastin plays a crucial role in the assembly and function of the male meiotic spindle. Consistent with meiotic failure, round spermatid nuclei were enlarged, indicating aneuploidy, but were still able to enter spermiogenesis. During spermiogenesis, we observed extreme abnormalities in manchette structure, acrosome biogenesis and, commonly, a catastrophic loss of nuclear integrity. This work defines an essential role for spastin in regulating microtubule dynamics during spermatogenesis, and is of potential relevance to individuals carrying spastin variants and to the medically assisted reproductive technology industry.


Assuntos
Acrossomo , Microtúbulos , Animais , Camundongos , Masculino , Espastina/genética , Acrossomo/metabolismo , Microtúbulos/metabolismo , Espermatogênese/genética , Meiose/genética
8.
Nature ; 577(7788): 95-102, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31894150

RESUMO

Mycobacterium tuberculosis (Mtb) is the leading cause of death from infection worldwide1. The only available vaccine, BCG (Bacillus Calmette-Guérin), is given intradermally and has variable efficacy against pulmonary tuberculosis, the major cause of mortality and disease transmission1,2. Here we show that intravenous administration of BCG profoundly alters the protective outcome of Mtb challenge in non-human primates (Macaca mulatta). Compared with intradermal or aerosol delivery, intravenous immunization induced substantially more antigen-responsive CD4 and CD8 T cell responses in blood, spleen, bronchoalveolar lavage and lung lymph nodes. Moreover, intravenous immunization induced a high frequency of antigen-responsive T cells across all lung parenchymal tissues. Six months after BCG vaccination, macaques were challenged with virulent Mtb. Notably, nine out of ten macaques that received intravenous BCG vaccination were highly protected, with six macaques showing no detectable levels of infection, as determined by positron emission tomography-computed tomography imaging, mycobacterial growth, pathology and granuloma formation. The finding that intravenous BCG prevents or substantially limits Mtb infection in highly susceptible rhesus macaques has important implications for vaccine delivery and clinical development, and provides a model for defining immune correlates and mechanisms of vaccine-elicited protection against tuberculosis.


Assuntos
Administração Intravenosa , Vacina BCG/administração & dosagem , Vacina BCG/imunologia , Tuberculose/prevenção & controle , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Modelos Animais de Doenças , Macaca mulatta , Tuberculose/imunologia , Vacinação/normas
9.
J Pharmacol Exp Ther ; 388(3): 774-787, 2024 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-38135509

RESUMO

This study provides a unique translational research opportunity to help both humans and dogs diagnosed with diseases that carry dismal prognoses in both species: histiocytic sarcoma (HS), hemangiosarcoma (HSA), and disseminated mastocytosis/mast cell tumor (MCT). Although exceedingly rare in humans, these so called "orphan diseases" are relatively more common in dogs. For these and other more commonplace cancers like lymphoma (Lym), dogs are an excellent translational model for human disease due to remarkably similar disease biology. In this study, assays were performed to assess the therapeutic potential of parthenolide (PTL), a known canonical nuclear factor kappa B (NF-κB) signaling inhibitor with additional mechanisms of antineoplastic activity, including alteration of cellular reduction-oxidation balance. Canine cell lines and primary cells are sensitive to PTL and undergo dose-dependent apoptosis after exposure to drug. PTL exposure also leads to glutathione depletion, reactive oxygen species generation, and NF-κB inhibition in canine cells. Standard-of-care therapeutics broadly synergize with PTL. In two canine HS cell lines, expression of NF-κB pathway signaling partners is downregulated with PTL therapy. Preliminary data suggest that PTL inhibits NF-κB activity of cells and extends survival time in a mouse model of disseminated canine HS. These data support further investigation of compounds that can antagonize canonical NF-κB pathway signaling in these cancers and pave the way for clinical trials of PTL in affected dogs. As dogs are an excellent natural disease model for these cancers, these data will ultimately improve our understanding of their human disease counterparts and hopefully improve care for both species. SIGNIFICANCE STATEMENT: Disseminated neoplasms in human and canine cancers are challenging to treat, and novel therapeutic approaches are needed to improve outcomes. Parthenolide is a promising treatment for histiocytic sarcoma, hemangiosarcoma, and mast cell neoplasia.


Assuntos
Hemangiossarcoma , Sarcoma Histiocítico , Sesquiterpenos , Camundongos , Humanos , Animais , Cães , NF-kappa B/metabolismo , Linhagem Celular Tumoral , Sarcoma Histiocítico/tratamento farmacológico , Hemangiossarcoma/tratamento farmacológico , Sesquiterpenos/farmacologia , Sesquiterpenos/uso terapêutico , Apoptose
10.
Arterioscler Thromb Vasc Biol ; 43(12): 2265-2281, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37732484

RESUMO

BACKGROUND: Endothelial cells (ECs) are capable of quickly responding in a coordinated manner to a wide array of stresses to maintain vascular homeostasis. Loss of EC cellular adaptation may be a potential marker for cardiovascular disease and a predictor of poor response to endovascular pharmacological interventions such as drug-eluting stents. Here, we report single-cell transcriptional profiling of ECs exposed to multiple stimulus classes to evaluate EC adaptation. METHODS: Human aortic ECs were costimulated with both pathophysiological flows mimicking shear stress levels found in the human aorta (laminar and turbulent, ranging from 2.5 to 30 dynes/cm2) and clinically relevant antiproliferative drugs, namely paclitaxel and rapamycin. EC state in response to these stimuli was defined using single-cell RNA sequencing. RESULTS: We identified differentially expressed genes and inferred the TF (transcription factor) landscape modulated by flow shear stress using single-cell RNA sequencing. These flow-sensitive markers differentiated previously identified spatially distinct subpopulations of ECs in the murine aorta. Moreover, distinct transcriptional modules defined flow- and drug-responsive EC adaptation singly and in combination. Flow shear stress was the dominant driver of EC state, altering their response to pharmacological therapies. CONCLUSIONS: We showed that flow shear stress modulates the cellular capacity of ECs to respond to paclitaxel and rapamycin administration, suggesting that while responding to different flow patterns, ECs experience an impairment in their transcriptional adaptation to other stimuli.


Assuntos
Aorta , Células Endoteliais , Humanos , Camundongos , Animais , Sirolimo/farmacologia , Paclitaxel/farmacologia , Análise de Sequência de RNA , Estresse Mecânico , Células Cultivadas
11.
Nature ; 560(7720): 649-654, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30135581

RESUMO

Barrier tissue dysfunction is a fundamental feature of chronic human inflammatory diseases1. Specialized subsets of epithelial cells-including secretory and ciliated cells-differentiate from basal stem cells to collectively protect the upper airway2-4. Allergic inflammation can develop from persistent activation5 of type 2 immunity6 in the upper airway, resulting in chronic rhinosinusitis, which ranges in severity from rhinitis to severe nasal polyps7. Basal cell hyperplasia is a hallmark of severe disease7-9, but it is not known how these progenitor cells2,10,11 contribute to clinical presentation and barrier tissue dysfunction in humans. Here we profile primary human surgical chronic rhinosinusitis samples (18,036 cells, n = 12) that span the disease spectrum using Seq-Well for massively parallel single-cell RNA sequencing12, report transcriptomes for human respiratory epithelial, immune and stromal cell types and subsets from a type 2 inflammatory disease, and map key mediators. By comparison with nasal scrapings (18,704 cells, n = 9), we define signatures of core, healthy, inflamed and polyp secretory cells. We reveal marked differences between the epithelial compartments of the non-polyp and polyp cellular ecosystems, identifying and validating a global reduction in cellular diversity of polyps characterized by basal cell hyperplasia, concomitant decreases in glandular cells, and phenotypic shifts in secretory cell antimicrobial expression. We detect an aberrant basal progenitor differentiation trajectory in polyps, and propose cell-intrinsic13, epigenetic14,15 and extrinsic factors11,16,17 that lock polyp basal cells into this uncommitted state. Finally, we functionally demonstrate that ex vivo cultured basal cells retain intrinsic memory of IL-4/IL-13 exposure, and test the potential for clinical blockade of the IL-4 receptor α-subunit to modify basal and secretory cell states in vivo. Overall, we find that reduced epithelial diversity stemming from functional shifts in basal cells is a key characteristic of type 2 immune-mediated barrier tissue dysfunction. Our results demonstrate that epithelial stem cells may contribute to the persistence of human disease by serving as repositories for allergic memories.


Assuntos
Hipersensibilidade/imunologia , Hipersensibilidade/patologia , Mucosa Respiratória/imunologia , Mucosa Respiratória/patologia , Células-Tronco/imunologia , Células-Tronco/patologia , Adolescente , Adulto , Idoso , Estudos de Casos e Controles , Células Cultivadas , Epigênese Genética , Células Epiteliais/imunologia , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Humanos , Hiperplasia/metabolismo , Hiperplasia/patologia , Interleucina-13/imunologia , Interleucina-4/imunologia , Subunidade alfa de Receptor de Interleucina-4/antagonistas & inibidores , Subunidade alfa de Receptor de Interleucina-4/imunologia , Pessoa de Meia-Idade , Pólipos Nasais/imunologia , Pólipos Nasais/patologia , Rinite/imunologia , Rinite/patologia , Análise de Sequência de RNA , Análise de Célula Única , Sinusite/imunologia , Sinusite/patologia , Transcrição Gênica , Transcriptoma , Adulto Jovem
12.
J Bacteriol ; 205(6): e0012623, 2023 06 27.
Artigo em Inglês | MEDLINE | ID: mdl-37249472

RESUMO

DNA interstrand cross-links, such as those formed by psoralen-UVA irradiation, are highly toxic lesions in both humans and bacteria, with a single lesion being lethal in Escherichia coli. Despite the lack of effective repair, human cancers and bacteria can develop resistance to cross-linking treatments, although the mechanisms of resistance remain poorly defined. Here, we subjected E. coli to repeated psoralen-UVA exposure to isolate three independently derived strains that were >10,000-fold more resistant to this treatment than the parental strain. Analysis of these strains identified gain-of-function mutations in the transcriptional regulator AcrR and the alpha subunit of RNA polymerase that together could account for the resistance of these strains. Resistance conferred by the AcrR mutation is mediated at least in part through the regulation of the AcrAB-TolC efflux pump. Resistance via mutations in the alpha subunit of RNA polymerase occurs through a still-uncharacterized mechanism that has an additive effect with mutations in AcrR. Both acrR and rpoA mutations reduced cross-link formation in vivo. We discuss potential mechanisms in relation to the ability to repair and survive interstrand DNA cross-links. IMPORTANCE Psoralen DNA interstrand cross-links are highly toxic lesions with antimicrobial and anticancer properties. Despite the lack of effective mechanisms for repair, cells can become resistant to cross-linking agents through mechanisms that remain poorly defined. We derived resistant mutants and identified that two gain-of-function mutations in AcrR and the alpha subunit of RNA polymerase confer high levels of resistance to E. coli treated with psoralen-UVA. Resistance conferred by AcrR mutations occurs through regulation of the AcrAB-TolC efflux pump, has an additive effect with RNA polymerase mutations, acts by reducing the formation of cross-links in vivo, and reveals a novel mechanism by which these environmentally and clinically important agents are processed by the cell.


Assuntos
Proteínas de Escherichia coli , Escherichia coli , Humanos , Antibacterianos/efeitos da radiação , DNA , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Ficusina/farmacologia , Mutação
13.
J Am Chem Soc ; 145(1): 465-475, 2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36534937

RESUMO

A series of quaternary Np(IV) fluorides was synthesized using a mild hydrothermal synthesis approach. The compositions are all of the type NaxMNp6F30, where M = Ti(III), V(III), Cr(III), Mn(II), Fe(III), Co(II), Ni(II), Al(III), and Ga(III) and x = 4 for divalent metals, x = 3 for trivalent metals. The compounds all crystallize in the P-3c1 space group and are isotypic with actinide analogues NaxMAn6F30 (An = Ce, U, Th, Pu). Structure data from the neptunium crystals were combined with data from the other actinide analogues to establish the tetravalent, nine-coordinated ionic radii of neptunium (1.030(2) Å), plutonium (1.014(1) Å), and cerium (1.012(2) Å). Radiation damage studies were also carried out on a surrogate material, the cerium analogue Na3AlCe6F30, which indicates that the structure type has low resistance to amorphization. Density functional theory calculations were carried out to compute the band gaps and enthalpies of formation variations among the isotypic cerium and actinide structures to compare the stability of the structures.

14.
J Am Chem Soc ; 145(18): 10007-10014, 2023 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-37097728

RESUMO

As part of our exploration of plutonium-containing materials as potential nuclear waste forms, we report the first extended structure Pu(V) material and the first Pu(V) borate. Crystals of Na2(PuO2)(BO3) were grown out of mixed hydroxide/boric acid flux and found to crystallize in the orthorhombic space group Cmcm with lattice parameters of a = 9.9067(4) Å, b = 6.5909(2) Å, and c = 6.9724(2) Å. Na2(PuO2)(BO3) adopts a layered structure in which layers of PuO2(BO3)2- are separated by sodium cations. Plutonium is found in a pentagonal bipyramidal coordination environment, with axial Pu(V)-O plutonyl bond lengths of 1.876(3) Å and equatorial Pu-O bond lengths ranging from 2.325(5) to 2.467(3) Å. We find that the Pu(V)-O plutonyl bond lengths are approximately 0.1 Å longer than the reported Pu(VI)-O plutonyl bond lengths and shorter by approximately 0.033 Å than the corresponding U(V) uranyl bond lengths. Raman spectroscopy on single crystals was used to determine the PuO2+ plutonyl stretching and the equatorial breathing mode frequencies of the pentagonal bipyramidal coordination environment around plutonium. Density functional theory calculations were used to calculate the Raman spectrum to help identify the Raman bands at 690 and 630 cm-1 as corresponding to the plutonyl(V) ν1 stretch and the equatorial PuO5 breathing mode, respectively. UV-vis measurements on single crystals indicate semiconducting behavior with a band gap of ∼2.60 eV.

15.
Curr Opin Ophthalmol ; 34(3): 261-266, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36728651

RESUMO

PURPOSE OF REVIEW: Assistive (nonautonomous) artificial intelligence (AI) models designed to support (rather than function independently of) clinicians have received increasing attention in medicine. This review aims to highlight several recent developments in these models over the past year and their ophthalmic implications. RECENT FINDINGS: Artificial intelligence models with a diverse range of applications in ophthalmology have been reported in the literature over the past year. Many of these systems have reported high performance in detection, classification, prognostication, and/or monitoring of retinal, glaucomatous, anterior segment, and other ocular pathologies. SUMMARY: Over the past year, developments in AI have been made that have implications affecting ophthalmic surgical training and refractive outcomes after cataract surgery, therapeutic monitoring of disease, disease classification, and prognostication. Many of these recently developed models have obtained encouraging results and have the potential to serve as powerful clinical decision-making tools pending further external validation and evaluation of their generalizability.


Assuntos
Glaucoma , Oftalmologia , Procedimentos Cirúrgicos Refrativos , Humanos , Inteligência Artificial , Oftalmologia/métodos
16.
Vet Pathol ; : 3009858231207021, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37905509

RESUMO

Tumors in dogs and humans share many similar molecular and genetic features, incentivizing a better understanding of canine neoplasms not only for the purpose of treating companion animals, but also to facilitate research of spontaneously developing tumors with similar biologic behavior and treatment approaches in an immunologically competent animal model. Multiple tumor types of both species have similar dysregulation of signal transduction through phosphatidylinositol 3-kinase (PI3K), protein kinase B (PKB; AKT), and mechanistic target of rapamycin (mTOR), collectively known as the PI3K-AKT-mTOR pathway. This review aims to delineate the pertinent aspects of the PI3K-AKT-mTOR signaling pathway in health and in tumor development. It will then present a synopsis of current understanding of PI3K-AKT-mTOR signaling in important canine cancers and advancements in targeted inhibitors of this pathway.

17.
Transpl Infect Dis ; 24(3): e13822, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35253965

RESUMO

BACKGROUND: Mycoplasma hominis can cause significant infections after solid organ transplantation (SOT). Treatment should be guided by susceptibility testing, but conventional lab methods are laborious with prolonged turnaround time (TAT). This case series compares the phenotypic and genotypic susceptibility profiles of M. hominis isolates identified from SOT patients. METHODS: This is a single-center retrospective study evaluating SOT recipients with confirmed M. hominis infections. Patients' demographic, clinical, microbiological, and radiographic data were collected. Culture of M. hominis isolates was performed according to current Clinical and Laboratory Standards Institute guidelines. Phenotypic susceptibility testing was performed by University of Alabama Diagnostic Mycoplasma Laboratory. Whole genome sequencing (WGS) was performed followed by bioinformatic analysis of known genetic determinants of resistance. RESULTS: Seven SOT recipients with M. hominis infections were identified. Two out of seven (28.5%) patients had resistance detected by phenotypic susceptibility testing (Case 5 to levofloxacin and Case 7 to tetracycline). Genomic analyses confirmed the presence of mutations in the parC and parE topoisomerase genes at positions conferring to fluoroquinolone resistance in the isolate from Case 5, while the tetracycline-resistant isolate from Case 7 harbored the tetM gene. The median TAT from the date of specimen collection was 24 days for phenotypic susceptibility testing and 14 days for genotypic susceptibility testing. All seven patients received antimicrobials directed toward M. hominis and recovered with complete resolution of infection. CONCLUSIONS: WGS may offer a novel and more rapid methodology for M. hominis susceptibility testing to help optimize antimicrobial usage, but more data are needed.


Assuntos
Anti-Infecciosos , Infecções por Mycoplasma , Transplante de Órgãos , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Anti-Infecciosos/uso terapêutico , Humanos , Testes de Sensibilidade Microbiana , Infecções por Mycoplasma/diagnóstico , Infecções por Mycoplasma/tratamento farmacológico , Infecções por Mycoplasma/microbiologia , Mycoplasma hominis/genética , Transplante de Órgãos/efeitos adversos , Estudos Retrospectivos , Tetraciclina/uso terapêutico , Resultado do Tratamento
18.
Nature ; 531(7594): 381-5, 2016 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-26934220

RESUMO

The most recent Ebola virus outbreak in West Africa, which was unprecedented in the number of cases and fatalities, geographic distribution, and number of nations affected, highlights the need for safe, effective, and readily available antiviral agents for treatment and prevention of acute Ebola virus (EBOV) disease (EVD) or sequelae. No antiviral therapeutics have yet received regulatory approval or demonstrated clinical efficacy. Here we report the discovery of a novel small molecule GS-5734, a monophosphoramidate prodrug of an adenosine analogue, with antiviral activity against EBOV. GS-5734 exhibits antiviral activity against multiple variants of EBOV and other filoviruses in cell-based assays. The pharmacologically active nucleoside triphosphate (NTP) is efficiently formed in multiple human cell types incubated with GS-5734 in vitro, and the NTP acts as an alternative substrate and RNA-chain terminator in primer-extension assays using a surrogate respiratory syncytial virus RNA polymerase. Intravenous administration of GS-5734 to nonhuman primates resulted in persistent NTP levels in peripheral blood mononuclear cells (half-life, 14 h) and distribution to sanctuary sites for viral replication including testes, eyes, and brain. In a rhesus monkey model of EVD, once-daily intravenous administration of 10 mg kg(-1) GS-5734 for 12 days resulted in profound suppression of EBOV replication and protected 100% of EBOV-infected animals against lethal disease, ameliorating clinical disease signs and pathophysiological markers, even when treatments were initiated three days after virus exposure when systemic viral RNA was detected in two out of six treated animals. These results show the first substantive post-exposure protection by a small-molecule antiviral compound against EBOV in nonhuman primates. The broad-spectrum antiviral activity of GS-5734 in vitro against other pathogenic RNA viruses, including filoviruses, arenaviruses, and coronaviruses, suggests the potential for wider medical use. GS-5734 is amenable to large-scale manufacturing, and clinical studies investigating the drug safety and pharmacokinetics are ongoing.


Assuntos
Alanina/análogos & derivados , Antivirais/uso terapêutico , Doença pelo Vírus Ebola/tratamento farmacológico , Macaca mulatta/virologia , Ribonucleotídeos/uso terapêutico , Monofosfato de Adenosina/análogos & derivados , Alanina/farmacocinética , Alanina/farmacologia , Alanina/uso terapêutico , Sequência de Aminoácidos , Animais , Antivirais/farmacocinética , Antivirais/farmacologia , Linhagem Celular Tumoral , Ebolavirus/efeitos dos fármacos , Feminino , Células HeLa , Doença pelo Vírus Ebola/prevenção & controle , Humanos , Masculino , Dados de Sequência Molecular , Especificidade de Órgãos , Pró-Fármacos/farmacocinética , Pró-Fármacos/farmacologia , Pró-Fármacos/uso terapêutico , Ribonucleotídeos/farmacocinética , Ribonucleotídeos/farmacologia
19.
Cereb Cortex ; 31(2): 1211-1226, 2021 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-33095854

RESUMO

Brain development and aging are complex processes that unfold in multiple brain regions simultaneously. Recently, models of brain age prediction have aroused great interest, as these models can potentially help to understand neurological diseases and elucidate basic neurobiological mechanisms. We test whether quantitative magnetic resonance imaging can contribute to such age prediction models. Using R1, the longitudinal rate of relaxation, we explore lifespan dynamics in cortical gray matter. We compare R1 with cortical thickness, a well-established biomarker of brain development and aging. Using 160 healthy individuals (6-81 years old), we found that R1 and cortical thickness predicted age similarly, but the regions contributing to the prediction differed. Next, we characterized R1 development and aging dynamics. Compared with anterior regions, in posterior regions we found an earlier R1 peak but a steeper postpeak decline. We replicate these findings: firstly, we tested a subset (N = 10) of the original dataset for whom we had additional scans at a lower resolution; and second, we verified the results on an independent dataset (N = 34). Finally, we compared the age prediction models on a subset of 10 patients with multiple sclerosis. The patients are predicted older than their chronological age using R1 but not with cortical thickness.


Assuntos
Envelhecimento/fisiologia , Espessura Cortical do Cérebro , Córtex Cerebral/diagnóstico por imagem , Córtex Cerebral/fisiologia , Longevidade/fisiologia , Imageamento por Ressonância Magnética/métodos , Esclerose Múltipla/diagnóstico por imagem , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Envelhecimento/patologia , Córtex Cerebral/patologia , Criança , Feminino , Substância Cinzenta/diagnóstico por imagem , Substância Cinzenta/patologia , Substância Cinzenta/fisiologia , Humanos , Imageamento por Ressonância Magnética/tendências , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/patologia , Adulto Jovem
20.
Int Urogynecol J ; 33(3): 563-570, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33852041

RESUMO

INTRODUCTION AND HYPOTHESIS: Many clinicians utilize standard culture of voided urine to guide treatment for women with recurrent urinary tract infections (RUTI). However, despite antibiotic treatment, symptoms may persist and events frequently recur. The cyclic nature and ineffective treatment of RUTI suggest that underlying uropathogens pass undetected because of the preferential growth of Escherichia coli. Expanded quantitative urine culture (EQUC) detects more clinically relevant microbes. The objective of this study was to assess how urine collection and culture methods influence microbial detection in RUTI patients. METHODS: This cross-sectional study enrolled symptomatic adult women with an established RUTI diagnosis. Participants contributed both midstream voided and catheterized urine specimens for culture via both standard urine culture (SUC) and EQUC. Presence and abundance of microbiota were compared between culture and collection methods. RESULTS: Forty-three symptomatic women participants (mean age 67 years) contributed specimens. Compared to SUC, EQUC detected more unique bacterial species and consistently detected more uropathogens from catheterized and voided urine specimens. For both collection methods, the most commonly detected uropathogens by EQUC were E. coli (catheterized: n = 8, voided: n = 12) and E. faecalis (catheterized: n = 7, voided: n = 17). Compared to catheterized urine samples assessed by EQUC, SUC often missed uropathogens, and culture of voided urines by either method yielded high false-positive rates. CONCLUSIONS: In women with symptomatic RUTI, SUC and assessment of voided urines have clinically relevant limitations in uropathogen detection. These results suggest that, in this population, catheterized specimens analyzed via EQUC provide clinically relevant information for appropriate diagnosis.


Assuntos
Microbiota , Infecções Urinárias , Adulto , Idoso , Estudos Transversais , Escherichia coli , Feminino , Humanos , Urinálise , Infecções Urinárias/diagnóstico , Infecções Urinárias/microbiologia
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