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1.
Development ; 151(12)2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38814743

RESUMO

Apical expansion of calvarial osteoblast progenitors from the cranial mesenchyme (CM) above the eye is integral to calvarial growth and enclosure of the brain. The cellular behaviors and signals underlying the morphogenetic process of calvarial expansion are unknown. Time-lapse light-sheet imaging of mouse embryos revealed calvarial progenitors intercalate in 3D in the CM above the eye, and exhibit protrusive and crawling activity more apically. CM cells express non-canonical Wnt/planar cell polarity (PCP) core components and calvarial osteoblasts are bidirectionally polarized. We found non-canonical ligand Wnt5a-/- mutants have less dynamic cell rearrangements and protrusive activity. Loss of CM-restricted Wntless (CM-Wls), a gene required for secretion of all Wnt ligands, led to diminished apical expansion of Osx+ calvarial osteoblasts in the frontal bone primordia in a non-cell autonomous manner without perturbing proliferation or survival. Calvarial osteoblast polarization, progressive cell elongation and enrichment for actin along the baso-apical axis were dependent on CM-Wnts. Thus, CM-Wnts regulate cellular behaviors during calvarial morphogenesis for efficient apical expansion of calvarial osteoblasts. These findings also offer potential insights into the etiologies of calvarial dysplasias.


Assuntos
Mesoderma , Morfogênese , Osteoblastos , Crânio , Proteínas Wnt , Animais , Osteoblastos/metabolismo , Osteoblastos/citologia , Crânio/embriologia , Camundongos , Mesoderma/citologia , Mesoderma/metabolismo , Proteínas Wnt/metabolismo , Proteínas Wnt/genética , Polaridade Celular , Proteína Wnt-5a/metabolismo , Proteína Wnt-5a/genética , Movimento Celular , Proliferação de Células
2.
Development ; 147(19)2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-32907847

RESUMO

Pattern formation is influenced by transcriptional regulation as well as by morphogenetic mechanisms that shape organ primordia, although factors that link these processes remain under-appreciated. Here we show that, apart from their established transcriptional roles in pattern formation, IRX3/5 help to shape the limb bud primordium by promoting the separation and intercalation of dividing mesodermal cells. Surprisingly, IRX3/5 are required for appropriate cell cycle progression and chromatid segregation during mitosis, possibly in a nontranscriptional manner. IRX3/5 associate with, promote the abundance of, and share overlapping functions with co-regulators of cell division such as the cohesin subunits SMC1, SMC3, NIPBL and CUX1. The findings imply that IRX3/5 coordinate early limb bud morphogenesis with skeletal pattern formation.


Assuntos
Cromátides/metabolismo , Proteínas de Homeodomínio/metabolismo , Botões de Extremidades/embriologia , Botões de Extremidades/metabolismo , Fatores de Transcrição/metabolismo , Animais , Western Blotting , Segregação de Cromossomos/genética , Segregação de Cromossomos/fisiologia , Feminino , Imunofluorescência , Células HEK293 , Proteínas de Homeodomínio/genética , Humanos , Imunoprecipitação , Espectrometria de Massas , Camundongos , Mitose/genética , Mitose/fisiologia , Gravidez , RNA-Seq , Reação em Cadeia da Polimerase em Tempo Real , Fatores de Transcrição/genética
3.
Br J Haematol ; 197(1): 63-70, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35174480

RESUMO

We investigated the incidence of invasive fungal infections (IFIs) and other infectious complications in patients receiving venetoclax and hypomethylating agent therapy for acute myeloid leukaemia (AML). This retrospective, multicentre cohort study included adult patients with AML who received at least one cycle of venetoclax and either azacitidine or decitabine between January 2016 and August 2020. The primary outcome was the incidence of probable or confirmed IFI. Secondary outcomes included antifungal prophylaxis prescribing patterns, incidence of bacterial infections, and incidence of neutropenic fever hospital admissions. Among 235 patients, the incidence of probable or confirmed IFI was 5.1%. IFI incidence did not differ significantly according to age, antifungal prophylaxis use, or disease status. In the subgroup of patients with probable or confirmed IFIs, six (50%) were receiving antifungal prophylaxis at the time of infection. The overall incidence of developing at least one bacterial infection was 33.6% and 127 (54%) patients had at least one hospital admission for febrile neutropenia. This study demonstrated an overall low risk of developing probable or confirmed IFI as well as a notable percentage of documented bacterial infections and hospital admissions due to neutropenic fever.


Assuntos
Infecções Fúngicas Invasivas , Leucemia Mieloide Aguda , Adulto , Antifúngicos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes , Estudos de Coortes , Humanos , Infecções Fúngicas Invasivas/epidemiologia , Leucemia Mieloide Aguda/complicações , Estudos Retrospectivos , Sulfonamidas
4.
J Oncol Pharm Pract ; 27(4): 821-826, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32605497

RESUMO

INTRODUCTION: Blinatumomab is a CD19/CD3 bispecific T-cell engager (BiTE) antibody that simultaneously binds CD19 on the surface of B-cells and CD3 on the surface of T-cells, resulting in tumor cell lysis. It is approved for the treatment of patients with relapsed/refractory B-cell acute lymphoblastic leukemia (B-ALL) and in patients with minimal residual disease after intensive induction chemotherapy. Relapse patterns after treatment with blinatumomab have not been well characterized. METHODS: We reviewed patients treated with blinatumomab with relapsed, refractory or minimal residual disease-positive B-ALL from 1 December 2014 to 31 December 2018 at a single academic medical center. Patient demographics, blast percentage prior to blinatumomab initiation, prior lines of therapy, blinatumomab treatment duration, sites of relapse, progression free survival, and overall survival were collected. RESULTS: A total of 20 patients were identified. Four (20%) patients developed extramedullary relapse following blinatumomab. The median time from treatment initiation to extramedullary relapse was 179 days (range 47-241). Sites of extramedullary relapse included the pancreas, adrenal gland, kidneys, liver, parotid gland, and brain. CONCLUSION: Extramedullary relapse occurs frequently following treatment of B-ALL with blinatumomab. Further studies aimed at preventing extramedullary relapse following blinatumomab treatment are warranted.


Assuntos
Anticorpos Biespecíficos/uso terapêutico , Antineoplásicos/uso terapêutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adulto , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Metástase Neoplásica , Estadiamento de Neoplasias , Leucemia-Linfoma Linfoblástico de Células Precursoras/patologia , Intervalo Livre de Progressão , Recidiva , Fatores Socioeconômicos , Análise de Sobrevida
5.
J Cell Sci ; 131(13)2018 07 04.
Artigo em Inglês | MEDLINE | ID: mdl-29777038

RESUMO

Extracellular forces transmitted through the cytoskeleton can deform the cell nucleus. Large nuclear deformations increase the risk of disrupting the integrity of the nuclear envelope and causing DNA damage. The mechanical stability of the nucleus defines its capability to maintain nuclear shape by minimizing nuclear deformation and allowing strain to be minimized when deformed. Understanding the deformation and recovery behavior of the nucleus requires characterization of nuclear viscoelastic properties. Here, we quantified the decoupled viscoelastic parameters of the cell membrane, cytoskeleton, and the nucleus. The results indicate that the cytoskeleton enhances nuclear mechanical stability by lowering the effective deformability of the nucleus while maintaining nuclear sensitivity to mechanical stimuli. Additionally, the cytoskeleton decreases the strain energy release rate of the nucleus and might thus prevent shape change-induced structural damage to chromatin.


Assuntos
Núcleo Celular/química , Linhagem Celular , Membrana Celular/química , Membrana Celular/genética , Membrana Celular/metabolismo , Núcleo Celular/genética , Núcleo Celular/metabolismo , Forma do Núcleo Celular , Citoesqueleto/química , Citoesqueleto/genética , Citoesqueleto/metabolismo , Humanos , Membrana Nuclear/química , Membrana Nuclear/genética , Membrana Nuclear/metabolismo , Estresse Mecânico
6.
J Pathol ; 247(1): 86-98, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30246301

RESUMO

Wilms tumour is a paediatric malignancy with features of halted kidney development. Here, we demonstrate that the Iroquois homeobox genes IRX3 and IRX5 are essential for mammalian nephrogenesis and govern the differentiation of Wilms tumour. Knock-out Irx3- /Irx5- mice showed a strongly reduced embryonic nephron formation. In human foetal kidney and Wilms tumour, IRX5 expression was already activated in early proliferative blastema, whereas IRX3 protein levels peaked at tubular differentiation. Accordingly, an orthotopic xenograft mouse model of Wilms tumour showed that IRX3-/- cells formed bulky renal tumours dominated by immature mesenchyme and active canonical WNT/ß-catenin-signalling. In contrast, IRX5-/- cells displayed activation of Hippo and non-canonical WNT-signalling and generated small tumours with abundant tubulogenesis. Our findings suggest that promotion of IRX3 signalling or inhibition of IRX5 signalling could be a route towards differentiation therapy for Wilms tumour, in which WNT5A is a candidate molecule for enforced tubular maturation. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Assuntos
Proteínas de Homeodomínio/metabolismo , Neoplasias Renais/metabolismo , Néfrons/metabolismo , Fatores de Transcrição/metabolismo , Tumor de Wilms/metabolismo , Animais , Carcinogênese , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Proteínas de Homeodomínio/genética , Humanos , Neoplasias Renais/genética , Neoplasias Renais/patologia , Camundongos Knockout , Morfogênese , Néfrons/crescimento & desenvolvimento , Fatores de Transcrição/deficiência , Fatores de Transcrição/genética , Tumor de Wilms/genética , Tumor de Wilms/patologia , Via de Sinalização Wnt , Proteína Wnt-5a/genética , Proteína Wnt-5a/metabolismo
7.
J Oncol Pharm Pract ; 26(1): 193-199, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30823860

RESUMO

Pegaspargase, a long acting formulation of L-asparaginase, is an asparagine specific enzyme that selectively kills leukemic cells by depleting plasma asparagine. Pegaspargase is FDA approved for the first-line treatment of adult acute lymphoblastic leukemia and is a critical component of numerous multi-chemotherapeutic regimens. Pegaspargase is associated with well-described toxicities including hypersensitivity reactions, hepatotoxicity, and thrombosis. However, hypertriglyceridemia is a much rarer complication of pegaspargase and has only been described in a limited number of reports. We present a case of severe hypertriglyceridemia after a single dose of pegaspargase. The patient was re-challenged with pegaspargase and again developed hypertriglyceridemia which was complicated by pancreatitis. Here, we summarize published reports and a literature review describing the incidence of pegaspargase-induced hypertriglyceridemia in common acute lymphoblastic leukemia protocols.


Assuntos
Antineoplásicos/efeitos adversos , Asparaginase/efeitos adversos , Hipertrigliceridemia/induzido quimicamente , Polietilenoglicóis/efeitos adversos , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Adulto , Feminino , Humanos
8.
J Oncol Pharm Pract ; 26(6): 1390-1396, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31937188

RESUMO

INTRODUCTION: Head and neck cancers (HNC) are a complex and heterogeneous group of cancers, often necessitating a multidisciplinary approach across the care continuum. Oncology pharmacists are uniquely qualified to play a vital role on a multidisciplinary team and provide specialized care to optimize medication therapy. METHODS: This was a retrospective chart review evaluating the role of a board-certified oncology pharmacist in the head and neck oncology clinic at an academic, comprehensive cancer center from April 2017 through March 2018. The primary objective of the study was to describe the types of interventions made by the oncology pharmacists. Secondary objectives included quantifying time spent on patient education and number of prescriptions sent to pharmacies. RESULTS: The pharmacist had 873 encounters with 151 patients, resulting in 2080 interventions. Approximately 57% of the interventions were performed in the clinic. Patient education (58%), facilitation of new prescriptions or refill requests (49.9%), and supportive care management (32.6%) were the most frequent interventions. The oncology pharmacist spent 154.1 h on patient education and sent 811 prescriptions to pharmacies, with 63.6% of prescriptions sent to the institution's cancer center pharmacy. CONCLUSION: The incorporation of an oncology pharmacist in the HNC team optimized patient care through comprehensive and timely interventions across the care continuum. Our study is the first to highlight the vital role oncology pharmacists have in improving the overall quality of care of HNC patients. Future directions include exploring the impact of oncology pharmacist interventions on select Quality Oncology Practice Initiative measures by the American Society of Clinical Oncology.


Assuntos
Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Assistência Farmacêutica/organização & administração , Farmacêuticos/organização & administração , Adulto , Idoso , Idoso de 80 Anos ou mais , Instituições de Assistência Ambulatorial/organização & administração , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Equipe de Assistência ao Paciente/organização & administração , Estudos Retrospectivos , Adulto Jovem
9.
J Org Chem ; 84(1): 239-256, 2019 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-30484650

RESUMO

Porpholactones are porphyrinoids in which one or more ß,ß'-bonds of the parent chromophore were replaced by lactone moieties. Accessible to varying degrees by direct and nonselective oxidations of porphyrins, the rational syntheses of all five dilactone isomers along stepwise, controlled, and high-yielding routes via porphyrin → tetrahydroxyisobacteriochlorin metal complexes → isobacteriochlorindilactone metal complexes or porphyrin → tetrahydroxybacteriochlorin → bacteriochlorindilactone (and related) pathways, respectively, are described. A major benefit of these complementary routes over established methods is the simplicity of the isolation of the dilactones because of the reduced number of side products formed. In an alternative approach we report the direct and selective conversion of free base meso-tetrakis(pentafluorophenyl)porphyrin to all isomers of free base isobacteriodilactones using the oxidant cetyltrimethylN+MnO4-. The solid-state structures of some of the isomers and their precursors are reported, providing data on the conformational modulation induced by the derivatizations. We also rationalize computationally their differing thermodynamic stability and electronic properties. In making new efficient routes toward these dilactone isomers available, we enable the further study of this diverse class of porphyrinoids.


Assuntos
Lactonas/química , Porfirinas/química , Hidroxilação , Modelos Moleculares , Conformação Molecular , Oxirredução
10.
Environ Sci Technol ; 53(7): 3399-3409, 2019 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-30807121

RESUMO

Uranium (U) groundwater contamination is a major concern at numerous former mining and milling sites across the Upper Colorado River Basin (UCRB), USA, where U(IV)-bearing solids have accumulated within naturally reduced zones (NRZs). Understanding the processes governing U reduction and oxidation within NRZs is critical for assessing the persistence of U in groundwater. To evaluate the redox cycling of uranium, we measured the U concentrations and isotopic compositions (δ238U) of sediments and pore waters from four study sites across the UCRB that span a gradient in sediment texture and composition. We observe that U accumulation occurs primarily within fine-grained (low-permeability) NRZs that show active redox variations. Low-permeability NRZs display high accumulation and low export of U, with internal redox cycling of U. In contrast, within high-permeability NRZs, U is remobilized under oxidative conditions, possibly without any fractionation, and transported outside the NRZs. The low δ238U of sediments outside of defined NRZs suggests that these reduced zones act as additional U sources. Collectively, our results indicate that fine-grained NRZs have a greater potential to retain uranium, whereas NRZs with higher permeability may constitute a more-persistent but dilute U source.


Assuntos
Água Subterrânea , Urânio , Poluentes Radioativos da Água , Colorado , Sedimentos Geológicos , Oxirredução , Rios
11.
Proc Natl Acad Sci U S A ; 113(9): 2360-5, 2016 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26884155

RESUMO

Delayed Earth system recovery following the end-Permian mass extinction is often attributed to severe ocean anoxia. However, the extent and duration of Early Triassic anoxia remains poorly constrained. Here we use paired records of uranium concentrations ([U]) and (238)U/(235)U isotopic compositions (δ(238)U) of Upper Permian-Upper Triassic marine limestones from China and Turkey to quantify variations in global seafloor redox conditions. We observe abrupt decreases in [U] and δ(238)U across the end-Permian extinction horizon, from ∼3 ppm and -0.15‰ to ∼0.3 ppm and -0.77‰, followed by a gradual return to preextinction values over the subsequent 5 million years. These trends imply a factor of 100 increase in the extent of seafloor anoxia and suggest the presence of a shallow oxygen minimum zone (OMZ) that inhibited the recovery of benthic animal diversity and marine ecosystem function. We hypothesize that in the Early Triassic oceans-characterized by prolonged shallow anoxia that may have impinged onto continental shelves-global biogeochemical cycles and marine ecosystem structure became more sensitive to variation in the position of the OMZ. Under this hypothesis, the Middle Triassic decline in bottom water anoxia, stabilization of biogeochemical cycles, and diversification of marine animals together reflect the development of a deeper and less extensive OMZ, which regulated Earth system recovery following the end-Permian catastrophe.


Assuntos
Planeta Terra , Extinção Biológica , Oxigênio/análise , Água do Mar , Ecossistema
12.
P T ; 44(8): 481-496, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31447536

RESUMO

BACKGROUND: Restricting oncology and hematology medications to outpatient infusion centers may be considered when infrequent administration is required, a low risk of serious adverse effects exists, or when prompt amelioration of a condition is not expected. At the University of California, San Diego (UCSD), we created a new formulary status for medications designated "formulary, outpatient-restricted use only." This designation could optimize payer reimbursement, as well as improve patient comfort, by negating the need for inpatient admission. When the inpatient administration of a restricted medication is requested at UCSD, there ensues a loosely defined review process involving an informal conversation between the requesting prescriber and the oncology pharmacy and therapeutics (P&T) chair. Patient outcomes associated with this formulary status and informal request process are limited. The purpose of this study is to describe the use of formulary, outpatient-restricted oncology and hematology medications in the inpatient setting at a single-center, academic, and comprehensive cancer center. METHODS: A retrospective chart review was conducted between January 1, 2015 and May 1, 2017. The primary outcome was to determine the percentage of formulary, outpatient-restricted oncology or hematology medications that were administered in the inpatient setting and continued to the outpatient setting. Secondary outcomes included overall survival, hospice enrollment, disease progression status, level of evidence supporting the medication usage, and cost. RESULTS: Twenty-three patients and 24 outpatient-restricted medications met the inclusion criteria. Thirteen (54%) medications were continued upon discharge and eight (33%) were not continued in the outpatient setting. Five of those eight medications were discontinued as a result of patient death. CONCLUSION: In this single-center study, approximately one-third of the outpatient-restricted medications were not continued upon discharge. The findings suggest that our informal approval process could result in the suboptimal use of formulary outpatient-restricted medications for oncology and hematology indications. A more formalized request process might lead to the more effective utilization of these medications.

13.
Biophys J ; 112(10): 2209-2218, 2017 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-28538157

RESUMO

What motivates animal cells to intercalate is a longstanding question that is fundamental to morphogenesis. A basic mode of cell rearrangement involves dynamic multicellular structures called tetrads and rosettes. The contribution of cell-intrinsic and tissue-scale forces to the formation and resolution of these structures remains unclear, especially in vertebrates. Here, we show that Fgfr2 regulates both the formation and resolution of tetrads and rosettes in the mouse embryo, possibly in part by spatially restricting atypical protein kinase C, a negative regulator of non-muscle myosin IIB. We employ micropipette aspiration to show that anisotropic tension is sufficient to rescue the resolution, but not the formation, of tetrads and rosettes in Fgfr2 mutant limb-bud ectoderm. The findings underscore the importance of cell contractility and tissue stress to multicellular vertex formation and resolution, respectively.


Assuntos
Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/química , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Animais , Ectoderma/embriologia , Ectoderma/metabolismo , Módulo de Elasticidade , Análise de Elementos Finitos , Imunofluorescência , Membro Anterior/embriologia , Membro Anterior/metabolismo , Camundongos Transgênicos , Microscopia de Força Atômica , Microscopia Confocal , Mutação , Miosina não Muscular Tipo IIB/metabolismo , Pressão , Proteína Quinase C/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/genética , Estresse Fisiológico , Tomografia Óptica
14.
J Hum Genet ; 61(5): 443-6, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26791356

RESUMO

Tibial hemimelia is a rare, debilitating and often sporadic congenital deficiency. In syndromic cases, mutations of a Sonic hedgehog (SHH) enhancer have been identified. Here we describe an ~5 kb deletion within the SHH repressor GLI3 in two patients with bilateral tibial hemimelia. This deletion results in a truncated GLI3 protein that lacks a DNA-binding domain and cannot repress hedgehog signaling. These findings strengthen the concept that tibial hemimelia arises because of failure to restrict SHH activity to the posterior aspect of the limb bud.


Assuntos
Ectromelia/diagnóstico , Ectromelia/genética , Fatores de Transcrição Kruppel-Like , Mutação , Proteínas do Tecido Nervoso , Fenótipo , Tíbia/anormalidades , Animais , Linhagem Celular , Biologia Computacional/métodos , Variações do Número de Cópias de DNA , Éxons , Estudos de Associação Genética , Humanos , Mutação INDEL , Camundongos , Polimorfismo de Nucleotídeo Único , Esqueleto/diagnóstico por imagem , Esqueleto/patologia , Proteína Gli3 com Dedos de Zinco
15.
J Card Surg ; 31(3): 132-8, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26756284

RESUMO

BACKGROUND: Complete heart block (CHB) is a common complication of cardiac surgery, which may resolve spontaneously. The optimal number of days to wait for resolution of CHB prior to proceeding with a permanent pacemaker (PPM) and the long-term utility of PPMs placed in this setting remain uncertain. METHODS AND RESULTS: This was a retrospective cohort study, which included members of Kaiser Permanente Northern California who had cardiac surgery, a PPM placed within 30 days after surgery, and one year of follow-up time. Chart review was performed to determine the frequency of ventricular pacing at each PPM interrogation visit up to one year after surgery. A PPM was categorized as underutilized at the time of an interrogation if none of the following were present: underlying rhythm <40 bpm, persistent CHB, or >1% ventricular pacing. The study included 247 patients with a mean time from cardiac surgery to PPM of 6.5 days. In 33 cases (13%), underutilized status was confirmed. The time from surgery to PPM implant was significantly higher in the underutilized group (8.1 ± 4.2 days vs. 6.2 ± 4.2 days, p = 0.003). CONCLUSIONS: The majority of PPMs placed early after cardiac surgery are not underutilized. In this retrospective, observational study, longer delay from surgery to PPM implantation was not associated with a greater likelihood that the PPM would be utilized long term. A prospective study is required to determine optimal timing of PPM implantation in this setting.


Assuntos
Bloqueio Cardíaco/terapia , Marca-Passo Artificial/estatística & dados numéricos , Complicações Pós-Operatórias/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Coortes , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Observacionais como Assunto , Estudos Retrospectivos , Fatores de Tempo , Adulto Jovem
16.
Nature ; 459(7250): 1141-5, 2009 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-19553998

RESUMO

The integrity of polarized epithelia is critical for development and human health. Many questions remain concerning the full complement and the function of the proteins that regulate cell polarity. Here we report that the Drosophila FERM proteins Yurt (Yrt) and Coracle (Cora) and the membrane proteins Neurexin IV (Nrx-IV) and Na(+),K(+)-ATPase are a new group of functionally cooperating epithelial polarity proteins. This 'Yrt/Cora group' promotes basolateral membrane stability and shows negative regulatory interactions with the apical determinant Crumbs (Crb). Genetic analyses indicate that Nrx-IV and Na(+),K(+)-ATPase act together with Cora in one pathway, whereas Yrt acts in a second redundant pathway. Moreover, we show that the Yrt/Cora group is essential for epithelial polarity during organogenesis but not when epithelial polarity is first established or during terminal differentiation. This property of Yrt/Cora group proteins explains the recovery of polarity in embryos lacking the function of the Lethal giant larvae (Lgl) group of basolateral polarity proteins. We also find that the mammalian Yrt orthologue EPB41L5 (also known as YMO1 and Limulus) is required for lateral membrane formation, indicating a conserved function of Yrt proteins in epithelial polarity.


Assuntos
Moléculas de Adesão Celular Neuronais/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/embriologia , Epitélio/fisiologia , Proteínas de Membrana/metabolismo , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Moléculas de Adesão Celular Neuronais/genética , Linhagem Celular , Polaridade Celular , Proteínas de Drosophila/genética , Drosophila melanogaster/enzimologia , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Epitélio/embriologia , Técnicas de Silenciamento de Genes , Proteínas de Membrana/genética , Mutação , Fenótipo , ATPase Trocadora de Sódio-Potássio/genética
17.
Mol Pharm ; 11(4): 1259-72, 2014 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-24588659

RESUMO

Oxidative damage to proteins is one of the most prominent chemical degradation pathways that are of concern for drug product development in the biotechnology industry. Especially susceptible to oxidation are the Met and Trp residues in proteins. While L-Met and L-Trp have been shown to act as antioxidants typically protecting proteins against Met and Trp oxidation, respectively, l-Trp has been shown to be particularly sensitive to light, thereby producing various reactive oxygen species (ROS), including H2O2. There is hence a need to identify nonphotosensitive molecules that can protect Trp oxidation in proteins so that they can be easily handled under drug product manufacturing conditions. A combination of screening methods, namely, cyclic voltammetry (CV) and hydrogen peroxide generation upon photoirradiation, was used to screen several molecules to identify compounds that can act as antioxidants. Specifically, indole and tryptophan with hydroxy groups on the six-membered aromatic ring were found to have lower oxidation potentials than the parent compounds and produced the least amount of H2O2 upon light exposure. These derivatives were also found to sufficiently protect tryptophan oxidation in mAb1 against a variety of reactive oxygen species such as alkyl peroxides, hydroxyl radicals, and singlet oxygen and may be useful as part of the formulation toolkit to protect against protein degradation via oxidation.


Assuntos
Antioxidantes/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Indóis/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Triptofano/metabolismo , Oxirredução , Relação Estrutura-Atividade
18.
Mol Pharm ; 10(1): 278-88, 2013 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-23136850

RESUMO

The reaction of singlet oxygen with water to form hydrogen peroxide was catalyzed by antibodies and has been termed as the antibody catalyzed water oxidation pathway (ACWOP) (Nieva and Wentworth, Trends Biochem. Sci. 2004, 29, 274-278; Nieva et al. Immunol. Lett. 2006, 103, 33-38). While conserved and buried tryptophans in the antibody are thought to play a major role in this pathway, our studies with a monoclonal antibody, mAb-1 and its mutant W53A, clearly demonstrate the role of surface-exposed tryptophans in production of hydrogen peroxide, via the photo-oxidation pathway. Reactive oxygen species (ROS) such as singlet oxygen and superoxide were detected and site-specific tryptophan (Trp53) oxidation was observed under these conditions using RP-HPLC and mass spectrometry. The single mutant of the surface exposed Trp53 to Ala53 (W53A) results in a 50% reduction in hydrogen peroxide generated under these conditions, indicating that surface exposed tryptophans are highly efficient in transferring light energy to oxygen and contribute significantly to ROS generation. ACWOP potentially leads to the chemical instability of mAb-1 via the generation of ROS and is important to consider during clinical and pharmaceutical development of mAbs.


Assuntos
Anticorpos Catalíticos/metabolismo , Anticorpos Monoclonais/metabolismo , Triptofano/metabolismo , Água/metabolismo , Animais , Células CHO , Cricetinae , Peróxido de Hidrogênio/metabolismo , Luz , Modelos Moleculares , Oxirredução , Espécies Reativas de Oxigênio/metabolismo , Oxigênio Singlete/metabolismo , Superóxidos/metabolismo
19.
Cureus ; 15(9): e45866, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37885521

RESUMO

In this case report, a patient with neuroretinitis from a Bartonella henselae infection is described, and insights into methods to distinguish this type of case from more common etiologies of optic nerve edema are presented. A 21-year-old female with a history of right monocular vision loss due to amblyopia presented to the emergency department (ED) with occipital headache, fever, dizziness, nasal congestion, and painless blurry vision in the left eye for one day. A lumbar puncture found a slightly high opening pressure but no evidence of meningitis. The patient was diagnosed with a viral illness and discharged with outpatient follow-up. The patient, however, had persistent central vision loss and recurring headaches and returned to the ED. Subsequent ultrasound of the patient's optic nerve revealed significant optic nerve swelling. A new working diagnosis of idiopathic intracranial hypertension was made, and the patient was started on oral acetazolamide. On the next day, she was seen by ophthalmology, and recent scratches from her cat were noted on her arm. She tested positive for B. henselae and was started on doxycycline and rifampin. Nearly two weeks after the initial presentation, a macular star pattern, indicative of neuroretinitis, was noted on the fundoscopic exam. The patient had recovered her vision by three months later. In ED cases with unilateral vision loss, early use of point-of-care ultrasound and infection with B. henselae should always be considered. Early serology testing may be warranted to allow for earlier treatment since classic signs of neuroretinitis may not be apparent at the onset.

20.
Geobiology ; 21(2): 175-192, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36329603

RESUMO

The end-Triassic biodiversity crisis was one of the most severe mass extinctions in the history of animal life. However, the extent to which the loss of taxonomic diversity was coupled with a reduction in organismal abundance remains to be quantified. Further, the temporal relationship between organismal abundance and local marine redox conditions is lacking in carbonate sections. To address these questions, we measured skeletal grain abundance in shallow-marine limestones by point counting 293 thin sections from four stratigraphic sections across the Triassic/Jurassic boundary in the Lombardy Basin and Apennine Platform of western Tethys. Skeletal abundance decreased abruptly across the Triassic/Jurassic boundary in all stratigraphic sections. The abundance of skeletal organisms remained low throughout the lower-middle Hettangian strata and began to rebound during the late Hettangian and early Sinemurian. A two-way ANOVA indicates that sample age (p < .01, η2  = 0.30) explains more of the variation in skeletal abundance than the depositional environment or paleobathymetry (p < .01, η2  = 0.15). Measured I/Ca ratios, a proxy for local shallow-marine redox conditions, show this same pattern with the lowest I/Ca ratios occurring in the early Hettangian. The close correspondence between oceanic water column oxygen levels and skeletal abundance indicates a connection between redox conditions and benthic organismal abundance across the Triassic/Jurassic boundary. These findings indicate that the end-Triassic mass extinction reduced not only the biodiversity but also the carrying capacity for skeletal organisms in early Hettangian ecosystems, adding to evidence that mass extinction of species generally leads to mass rarity among survivors.


Assuntos
Ecossistema , Extinção Biológica , Animais , Fósseis , Oxigênio , Biodiversidade , Evolução Biológica
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