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1.
Mol Cancer Ther ; 22(11): 1270-1279, 2023 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37550087

RESUMO

The NCI-60 human tumor cell line panel has proved to be a useful tool for the global cancer research community in the search for novel chemotherapeutics. The publicly available cell line characterization and compound screening data from the NCI-60 assay have significantly contributed to the understanding of cellular mechanisms targeted by new oncology agents. Signature sensitivity/resistance patterns generated for a given chemotherapeutic agent against the NCI-60 panel have long served as fingerprint presentations that encompass target information and the mechanism of action associated with the tested agent. We report the establishment of a new public NCI-60 resource based on the cell line screening of a large and growing set of 175 FDA-approved oncology drugs (AOD) plus >825 clinical and investigational oncology agents (IOA), representing a diverse set (>250) of therapeutic targets and mechanisms. This data resource is available to the public (https://ioa.cancer.gov) and includes the raw data from the screening of the IOA and AOD collection along with an extensive set of visualization and analysis tools to allow for comparative study of individual test compounds and multiple compound sets.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Linhagem Celular Tumoral , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico
2.
Sensors (Basel) ; 22(23)2022 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-36501963

RESUMO

Composite polymers have become widely used in industries such as the aerospace, automobile, and civil construction industries. Continuous monitoring is essential to optimize the composite components' performance and durability. This paper describes the concept of a distributed fiber optic smart textile (DFOST) embedded into a composite panel that can be implemented during the fabrication process of bridges, planes, or vehicles without damaging the integrity of the composite. The smart textile used an embroidery method to create DFOST for easy installation between composite laminates. It also allows different layout patterns to provide two- or three-dimensional measurements. The DFOST system can then measure strain, temperature, and displacement changes, providing critical information for structural assessment. The DFOST was interrogated by using an optical frequency domain reflectometry (OFDR). It could measure strain variation during the dynamic and static test with a spatial resolution of 2 mm and a minimum strain resolution of 10 µÏµ. This paper focuses on the study of strain measurement.

4.
ACS Cent Sci ; 8(8): 1145-1158, 2022 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-36032774

RESUMO

Genomic studies and experiments with permeability-deficient strains have revealed a variety of biological targets that can be engaged to kill Gram-negative bacteria. However, the formidable outer membrane and promiscuous efflux pumps of these pathogens prevent many candidate antibiotics from reaching these targets. One such promising target is the enzyme FabI, which catalyzes the rate-determining step in bacterial fatty acid biosynthesis. Notably, FabI inhibitors have advanced to clinical trials for Staphylococcus aureus infections but not for infections caused by Gram-negative bacteria. Here, we synthesize a suite of FabI inhibitors whose structures fit permeation rules for Gram-negative bacteria and leverage activity against a challenging panel of Gram-negative clinical isolates as a filter for advancement. The compound to emerge, called fabimycin, has impressive activity against >200 clinical isolates of Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii, and does not kill commensal bacteria. X-ray structures of fabimycin in complex with FabI provide molecular insights into the inhibition. Fabimycin demonstrates activity in multiple mouse models of infection caused by Gram-negative bacteria, including a challenging urinary tract infection model. Fabimycin has translational promise, and its discovery provides additional evidence that antibiotics can be systematically modified to accumulate in Gram-negative bacteria and kill these problematic pathogens.

5.
Antiviral Res ; 187: 105018, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33476709

RESUMO

MBX-2168 has a mechanism of action similar to that of acyclovir (ACV) and ganciclovir (GCV), but two unique steps differentiate this drug from ACV/GCV. First, MBX-2168 is, at least partially, phosphorylated by the endogenous cellular kinase TAOK3 to a monophosphate. The second involves the removal of a moiety at the 6-position of MBX-2168-MP by adenosine deaminase like protein-1 (ADAL-1). It has been previously demonstrated that co-incubation with pentostatin (dCF), an ADAL-1 inhibitor, antagonizes the anti-viral activity of MBX-2168. We therefore hypothesize that inhibiting ADAL-1 results in a reduction of active compound produced in virus-infected cells. To test this, we examined the effect dCF has on the conversion of MBX-2168 to a triphosphate in HSV-1 and HCMV-infected cells. Our results demonstrate incubation of MBX-2168 alone or with dCF in HCMV-infected cells resulted in 53.1 ± 0.7 and 39.4 ± 1.5 pmol triphosphate/106 cells at 120 h, respectively. Incubation of MBX-2168 alone or with dCF in Vero cells resulted in 12.8 ± 0.1 and 6.7 ± 0.7 pmol triphosphate/106 cells at 24 h, respectively. HSV-1-infected Vero cells demonstrated no statistical difference in triphosphate accumulation at 24 h (13.1 ± 0.3 pmol triphosphate/106 cells). As expected, incubation with dCF resulted in the accumulation of MBX-2168-MP in both HFF (9.8 ± 0.9 pmol MBX-2168-MP/106 cells at 120 h) and Vero cells (4.7 ± 0.3 pmol MBX-2168-MP/106 cells at 24 h) while no detectable levels of monophosphate were observed in cultures not incubated with dCF. We conclude that dCF antagonizes the anti-viral effect of MBX-2168 by inhibiting the production of triphosphate, the active compound.


Assuntos
Antivirais/antagonistas & inibidores , Antivirais/farmacologia , Ciclopropanos/antagonistas & inibidores , Citomegalovirus/efeitos dos fármacos , Guanina/análogos & derivados , Herpesvirus Humano 1/efeitos dos fármacos , Pentostatina/farmacologia , Polifosfatos/metabolismo , Aciclovir/farmacologia , Animais , Linhagem Celular , Chlorocebus aethiops , Ciclopropanos/farmacologia , Infecções por Citomegalovirus/tratamento farmacológico , Infecções por Citomegalovirus/virologia , Fibroblastos/virologia , Prepúcio do Pênis/citologia , Ganciclovir/farmacologia , Guanina/antagonistas & inibidores , Guanina/farmacologia , Herpes Simples/tratamento farmacológico , Herpes Simples/virologia , Interações entre Hospedeiro e Microrganismos , Humanos , Mutação com Perda de Função , Masculino , Fosforilação , Células Vero , Replicação Viral/efeitos dos fármacos
6.
J Bacteriol ; 202(18)2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32601072

RESUMO

The Pseudomonas aeruginosa type III secretion system (T3SS) needle comprised of multiple PscF subunits is essential for the translocation of effector toxins into human cells, facilitating the establishment and dissemination of infection. Mutations in the pscF gene provide resistance to the phenoxyacetamide (PhA) series of T3SS inhibitory chemical probes. To better understand PscF functions and interactions with PhA, alleles of pscF with 71 single mutations altering 49 of the 85 residues of the encoded protein were evaluated for their effects on T3SS phenotypes. Of these, 37% eliminated and 63% maintained secretion, with representatives of both evenly distributed across the entire protein. Mutations in 14 codons conferred a degree of PhA resistance without eliminating secretion, and all but one were in the alpha-helical C-terminal 25% of PscF. PhA-resistant mutants exhibited no cross-resistance to two T3SS inhibitors with different chemical scaffolds. Two mutations caused constitutive T3SS secretion. The pscF allele at its native locus, whether wild type (WT), constitutive, or PhA resistant, was dominant over other pscF alleles expressed from nonnative loci and promoters, but mixed phenotypes were observed in chromosomal ΔpscF strains with both WT and mutant alleles at nonnative loci. Some PhA-resistant mutants exhibited reduced translocation efficiency that was improved in a PhA dose-dependent manner, suggesting that PhA can bind to those resistant needles. In summary, these results are consistent with a direct interaction between PhA inhibitors and the T3SS needle, suggest a mechanism of blocking conformational changes, and demonstrate that PscF affects T3SS regulation, as well as carrying out secretion and translocation.IMPORTANCEP. aeruginosa effector toxin translocation into host innate immune cells is critical for the establishment and dissemination of P. aeruginosa infections. The medical need for new anti-P. aeruginosa agents is evident by the fact that P. aeruginosa ventilator-associated pneumonia is associated with a high mortality rate (40 to 69%) and recurs in >30% of patients, even with standard-of-care antibiotic therapy. The results described here confirm roles for the PscF needle in T3SS secretion and translocation and suggest that it affects regulation, possibly by interaction with T3SS regulatory proteins. The results also support a model of direct interaction of the needle with PhA and suggest that, with further development, members of the PhA series may prove useful as drugs for P. aeruginosa infection.


Assuntos
Proteínas de Bactérias/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Pseudomonas aeruginosa/efeitos dos fármacos , Sistemas de Secreção Tipo III/antagonistas & inibidores , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Resistência Microbiana a Medicamentos/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Mutação , Fenoxiacetatos/farmacologia , Pseudomonas aeruginosa/genética , Relação Estrutura-Atividade
7.
Antiviral Res ; 175: 104713, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31968222

RESUMO

The third generation of methylenecyclopropane nucleoside analogs (MCPNAs) elicit an anti-viral effect against all three sub-classes of herpes viruses without inducing cytotoxicity in vitro. It has been previously established that the mechanism of action of MCPNAs is similar to that of ganciclovir (GCV) or acyclovir (ACV). However, the activation of MBX-2168, a third generation MCPNA, involves additional and unique enzymatic steps and this process has not been examined in virus-infected cells. To that end, herpes virus-infected cells were incubated with MBX-2168, synguanol, GCV, or ACV. Incubation of HCMV-infected cells with five times the EC50 of MBX-2168 (4.0 µM), synguanol (10.5 µM), or GCV (25 µM) resulted in a time-dependent increase in triphosphate accumulation reaching a maximum of 48.1 ± 5.5, 45.5 ± 2.5, and 42.6 ± 3.7 pmol/106 cells at 120 h, respectively. Additionally, half-lives of these compounds were similar in HCMV-infected cells (GCV-TP = 25.5 ± 2.7 h; MBX-2168-TP/synguanol-TP = 23.0 ± 1.4 h). HSV-1-infected cells incubated with five times the EC50 of MBX-2168 (33.5 µM) or ACV (5.0 µM) demonstrated a time-dependent increase in triphosphate levels reaching a maximum of 12.3 ± 1.5 and 11.6 ± 0.7 pmol/106 cells at 24 h, respectively. ACV-TP and MBX-2168-TP also had similar half-lives under these conditions (27.3 ± 4.8 h and 22.2 ± 2.2 h, respectively). We therefore conclude that although MBX-2168 does not follow the classical route of nucleoside analog activation, the metabolic profile of MBX-2168 is similar to other nucleoside analogs such as GCV and ACV that do.


Assuntos
Antivirais/metabolismo , Ciclopropanos/metabolismo , Guanina/análogos & derivados , Herpesvirus Humano 1/efeitos dos fármacos , Polifosfatos/análise , Aciclovir/farmacologia , Animais , Chlorocebus aethiops , Citomegalovirus/efeitos dos fármacos , Citomegalovirus/fisiologia , Fibroblastos/virologia , Ganciclovir/farmacologia , Guanina/biossíntese , Guanina/metabolismo , Meia-Vida , Herpesvirus Humano 1/fisiologia , Humanos , Cinética , Masculino , Nucleosídeos/biossíntese , Nucleosídeos/metabolismo , Polifosfatos/metabolismo , Células Vero
8.
Nephrol Dial Transplant ; 35(8): 1361-1369, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31377810

RESUMO

BACKGROUND: This study examined the impact of recurrent episodes of acute kidney injury (AKI) on patient outcomes. METHODS: The Welsh National electronic AKI reporting system was used to identify all cases of AKI in patients ≥18 years of age between April 2015 and September 2018. Patients were grouped according to the number of AKI episodes they experienced with each patient's first episode described as their index episode. We compared the demography and patient outcomes of those patients with a single AKI episode with those patients with multiple AKI episodes. Analysis included 153 776 AKI episodes in 111 528 patients. RESULTS: Of those who experienced AKI and survived their index episode, 29.3% experienced a second episode, 9.9% a third episode and 4.0% experienced fourth or more episodes. Thirty-day mortality for those patients with multiple episodes of AKI was significantly higher than for those patients with a single episode (31.3% versus 24.9%, P < 0.001). Following a single episode, recovery to baseline renal function at 30 days was achieved in 83.6% of patients and was significantly higher than for patients who had repeated episodes (77.8%, P < 0.001). For surviving patients, non-recovery of renal function following any AKI episode was significantly associated with a higher probability of a further AKI episode (33.4% versus 41.0%, P < 0.001). Furthermore, with each episode of AKI the likelihood of a subsequent episode also increased (31.0% versus 43.2% versus 51.2% versus 51.7% following a first, second, third and fourth episode, P < 0.001 for all comparisons). CONCLUSIONS: The results of this study provide an important contribution to the debate regarding the need for risk stratification for recurrent AKI. The data suggest that such a tool would be useful given the poor patient and renal outcomes associated with recurrent AKI episodes as highlighted by this study.


Assuntos
Injúria Renal Aguda/epidemiologia , Rim/fisiopatologia , Índice de Gravidade de Doença , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/patologia , Idoso , Estudos de Coortes , Feminino , Humanos , Incidência , Masculino , Recidiva , Fatores de Risco , Reino Unido/epidemiologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-31332074

RESUMO

To determine the mechanism of action of third-generation methylenecyclopropane nucleoside analogs (MCPNAs), DNA sequencing of herpes simplex virus 1 (HSV-1) isolates resistant to third-generation MCPNAs resulted in the discovery of G841S and N815S mutations in HSV-1 UL30. Purified HSV-1 UL30 or human cytomegalovirus (HCMV) UL54 was then subjected to increasing concentrations of MBX-2168-triphosphate (TP), with results demonstrating a 50% inhibitory concentration (IC50) of ∼200 µM, indicating that MBX-2168-TP does not inhibit the viral DNA polymerase. Further metabolic studies showed the removal of a moiety on the guanine ring of MBX-2168. Therefore, we hypothesized that enzymatic removal of a moiety at the 6-position of the guanine ring of third-generation MCPNAs is an essential step in activation. To test this hypothesis, pentostatin (deoxycoformycin [dCF]), an adenosine deaminase-like protein 1 (ADAL-1) inhibitor, was coincubated with MBX-2168. The results showed that dCF antagonized the effect of MBX-2168, with a >40-fold increase in the 50% effective concentration (EC50) at 50 µM dCF (EC50 of 63.1 ± 8.7 µM), compared with MBX-2168 alone (EC50 of 0.2 ± 0.1 µM). Purified ADAL-1 demonstrated time-dependent removal of the moiety on the guanine ring of MBX-2168-monophosphate (MP), with a Km of 17.5 ± 2.4 µM and a Vmax of 0.12 ± 0.04 nmol min-1 Finally, synguanol-TP demonstrated concentration-dependent inhibition of HSV-1 UL30 and HCMV UL54, with IC50s of 0.33 ± 0.16 and 0.38 ± 0.11 µM, respectively. We conclude that ADAL-1 is the enzyme responsible for removing the moiety from the guanine ring of MBX-2168-MP prior to conversion to a TP, the active compound that inhibits the viral DNA polymerase.


Assuntos
Adenosina Desaminase/metabolismo , Ciclopropanos/química , Ciclopropanos/farmacologia , Nucleosídeos/análogos & derivados , Nucleosídeos/farmacologia , Adenosina Desaminase/genética , Animais , Chlorocebus aethiops , Cromatografia Líquida de Alta Pressão , Citomegalovirus/efeitos dos fármacos , Citomegalovirus/patogenicidade , DNA Viral/genética , Guanina/análogos & derivados , Guanina/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/patogenicidade , Humanos , Análise de Sequência de DNA/métodos , Células Vero , Proteínas Virais/genética , Proteínas Virais/metabolismo , Replicação Viral/genética , Replicação Viral/fisiologia
10.
Kidney Int Rep ; 4(6): 824-832, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31194105

RESUMO

INTRODUCTION: This study examined the relationship among age, measures of social deprivation, and incidence and outcome of acute kidney injury (AKI). METHODS: The Welsh National electronic AKI reporting system was used to identify all cases of AKI in patients 18 years or older between March 2015 and January 2017. Socioeconomic classification of patients was derived from the Welsh Index of Multiple Deprivation (WIMD). Patients were grouped according to their WIMD score, and Multivariate Cox proportional hazard modeling was used to adjust the data for age. The ranked data were categorized into percentiles and correlated with incidence, and measures of AKI severity and outcome. RESULTS: Analysis included 57,654 patients. For the whole cohort, the highest 90-day survival was associated with the most socially deprived cohorts. There was a significant negative relationship between age-adjusted incidence of AKI and the WIMD score. In patients 60 years or older, there was an inverse correlation between WIMD score and survival that was not evident in those younger than 60. AKI severity at presentation was worse in patients from areas of social deprivation. Social deprivation was associated with a significantly higher proportion of preexisting chronic kidney disease (CKD) in patients with AKI older than 60, but not in those younger than 60. CONCLUSION: Overall mortality following AKI was higher in least-deprived areas, reflecting an older patient cohort. In contrast, social deprivation was associated with higher age-adjusted AKI incidence and age-adjusted mortality following AKI. The excess mortality observed in more deprived areas was associated with more severe AKI and a higher proportion of preexisting CKD.

11.
J Crit Care ; 44: 185-190, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29145061

RESUMO

BACKGROUND: Electronic AKI alerts highlight changes in serum creatinine compared to the patient's own baseline. Our aim was to identify all AKI alerts and describe the relationship between electronic AKI alerts and outcome for AKI treated in the Intensive Care Unit (ICU) in a national multicentre cohort. METHODS: A prospective cohort study was undertaken between November 2013 and April 2016, collecting data on electronic AKI alerts issued. RESULTS: 10% of 47,090 incident AKI alerts were associated with ICU admission. 90-day mortality was 38.2%. Within the ICU cohort 48.8% alerted in ICU. 51.2% were transferred to ICU within 7days of the alert, of which 37.8% alerted in a hospital setting (HA-AKI) and 62.2% in a community setting (CA-AKI). Mortality was higher in patients transferred to ICU following the alert compared to those who had an incident alert on the ICU (p<0.001), and was higher in HA-AKI (45.3%) compared to CA-AKI (39.5%) (35.0%, p=0.01). In the surviving patients, the proportion of patient recovering renal function following, was significantly higher in HA-AKI alerting (84.2%, p=0.004) and CA-AKI alerting patients (87.6%, p<0.001) compared to patients alerting on the ICU (78.3%). CONCLUSION: The study provides a nationwide characterisation of AKI in ICU highlighting the high incidence and its impact on patient outcome. The data also suggests that within the cohort of AKI patients treated in the ICU there are significant differences in the presentation and outcome between those patients that require transfer to the ICU after AKI is identified and those who develop AKI following ICU admission. Moreover, the study demonstrates that using AKI e-alerts provides a centralised resource which does not rely on clinical diagnosis of AKI or coding, resulting in a robust data set which can be used to define the incidence and outcome of AKI in the ICU setting.


Assuntos
Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Creatinina/sangue , Cuidados Críticos/métodos , Diagnóstico por Computador , Unidades de Terapia Intensiva/estatística & dados numéricos , Monitorização Fisiológica/métodos , Injúria Renal Aguda/mortalidade , Adulto , Idoso , Feminino , Mortalidade Hospitalar , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , País de Gales/epidemiologia
12.
Kidney Int Rep ; 2(3): 342-349, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-29142963

RESUMO

INTRODUCTION: Automated acute kidney injury (AKI) electronic alerts are based on comparing creatinine with historic results. METHODS: We report the significance of AKI defined by 3 "rules" differing in the time period from which the baseline creatinine is obtained, and AKI with creatinine within the normal range. RESULTS: A total of 47,090 incident episodes of AKI occurred between November 2013 and April 2016. Rule 1 (>26 µmol/l increase in creatinine within 48 hours) accounted for 9.6%. Rule 2 (≥50% increase in creatinine within previous 7 days) and rule 3 (≥50% creatinine increase from the median value of results within the last 8-365 days) accounted for 27.3% and 63.1%, respectively. Hospital-acquired AKI was predominantly identified by rules 1 and 2 (71.7%), and community-acquired AKI (86.3%) by rule 3. Stages 2 and 3 were detected by rules 2 and 3. Ninety-day mortality was higher in AKI rule 2 (32.4%) than rule 1 (28.3%, P < 0.001) and rule 3 (26.6%, P < 0.001). Nonrecovery of renal function (90 days) was lower for rule 1 (7.9%) than rule 2 (22.4%, P < 0.001) and rule 3 (16.5%, P < 0.001). We found that 19.2% of AKI occurred with creatinine values within normal range, in which mortality was lower than that in AKI detected by a creatinine value outside the reference range (22.6% vs. 29.6%, P < 0.001). DISCUSSION: Rule 1 could only be invoked for stage 1 alerts and was associated with acute on chronic kidney disease acquired in hospital. Rule 2 was also associated with hospital-acquired AKI and had the highest mortality and nonrecovery. Rule 3 was the commonest cause of an alert and was associated with community-acquired AKI.

13.
Int J Clin Pract ; 71(9)2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28869717

RESUMO

OBJECTIVES: To identify any seasonal variation in the occurrence of, and outcome following Acute Kidney Injury. METHODS: The study utilised the biochemistry based AKI electronic (e)-alert system established across the Welsh National Health Service to collect data on all AKI episodes to identify changes in incidence and outcome over one calendar year (1st October 2015 and the 30th September 2016). RESULTS: There were total of 48 457 incident AKI alerts. The highest proportion of AKI episodes was seen in the quarter of January to March (26.2%), and the lowest in the quarter of October to December (23.3%, P < .001). The same trend was seen for both community-acquired and hospital-acquired AKI sub-sets. Overall 90 day mortality for all AKI was 27.3%. In contrast with the seasonal trend in AKI occurrence, 90 day mortality after the incident AKI alert was significantly higher in the quarters of January to March and October to December compared with the quarters of April to June and July to September (P < .001) consistent with excess winter mortality reported for likely underlying diseases which precipitate AKI. CONCLUSIONS: In summary we report for the first time in a large national cohort, a seasonal variation in the incidence and outcomes of AKI. The results demonstrate distinct trends in the incidence and outcome of AKI.


Assuntos
Injúria Renal Aguda/epidemiologia , Estações do Ano , Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/etiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fatores de Risco , País de Gales/epidemiologia , Adulto Jovem
14.
Artigo em Inglês | MEDLINE | ID: mdl-28807906

RESUMO

Pseudomonas aeruginosa is a leading cause of intra-abdominal infections, wound infections, and community-acquired folliculitis, each of which may involve macro- or microabscess formation. The rising incidence of multidrug resistance among P. aeruginosa isolates has increased both the economic burden and the morbidity and mortality associated with P. aeruginosa disease and necessitates a search for novel therapeutics. Previous work from our group detailed novel phenoxyacetamide inhibitors that block type III secretion and injection into host cells in vitro In this study, we used a mouse model of P. aeruginosa abscess formation to test the in vivo efficacy of these compounds against the P. aeruginosa type III secretion system (T3SS). Bacteria used the T3SS to intoxicate infiltrating neutrophils to establish abscesses. Despite this antagonism, sufficient numbers of functioning neutrophils remained for proper containment of the abscesses, as neutrophil depletion resulted in an increased abscess size, the formation of dermonecrotic lesions on the skin, and the dissemination of P. aeruginosa to internal organs. Consistent with the specificity of the T3SS-neutrophil interaction, P. aeruginosa bacteria lacking a functional T3SS were fully capable of causing abscesses in a neutropenic host. Phenoxyacetamide inhibitors attenuated abscess formation and aided in the immune clearance of the bacteria. Finally, a P. aeruginosa strain resistant to the phenoxyacetamide compound was fully capable of causing abscess formation even in the presence of the T3SS inhibitors. Together, our results further define the role of type III secretion in murine abscess formation and demonstrate the in vivo efficacy of phenoxyacetamide inhibitors in P. aeruginosa infection.


Assuntos
Abscesso/microbiologia , Antibacterianos/farmacologia , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Abscesso/tratamento farmacológico , Abscesso/patologia , Animais , Antibacterianos/química , Modelos Animais de Doenças , Interações Hospedeiro-Patógeno , Camundongos Endogâmicos C57BL , Neutropenia/microbiologia , Neutrófilos/patologia , Fenoxiacetatos/química , Infecções por Pseudomonas/complicações , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/patogenicidade , Sistemas de Secreção Tipo III , Fatores de Virulência/metabolismo
15.
Front Hum Neurosci ; 11: 186, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28484380

RESUMO

Malfunctioning sensory systems can severely impact quality of life and repair is not always possible. One solution, called sensory substitution, is to use another sensory system to bring lost information to the brain. This approach often involves the use of bioengineered devices that electrically stimulate somatosensory fibers. Interestingly, the tongue is an ideal location for electrotactile stimulation due to its dense innervation, moisture, and protected environment. Success with transmitting visual and vestibular information through the tongue indicates promise for future applications. However, sensitivity and discrimination ability varies between individuals and across the tongue surface complicating efforts to produce reliable and consistent sensations. The goals of the present study were to investigate these differences more precisely to better understand the mechanosensory innervation of the tongue so that future electrotactile devices can be designed more effectively. Specifically, we tested whether stimulation of certain regions of the tongue consistently result in better perception, whether the spacing of stimulating electrodes affects perceived intensity, and whether the orientation of electrodes affects perceived intensity and discrimination. To test these hypotheses, we built a custom tongue stimulation device, recruited 25 participants, and collected perceived intensity and discrimination data. We then subjected the data to thorough statistical analyses. Consistent with previous studies, we found that stimulation of the anterior medial tongue region was perceived as more intense than stimulation of lateral and posterior regions. This region also had the best discrimination ability for electrodes. Dividing the stimulated tongue area into 16 distinct regions allowed us to compare perception ability between anterior and posterior regions, medial and lateral regions, and the left and right sides of the tongue. Stimulation of the most anterior and medial tongue resulted in the highest perceived intensity and the best discrimination ability. Most individuals were able to perceive and discriminate electrotactile stimulation better on one side of the tongue, and orientation of stimulating electrodes affected perception. In conclusion, the present studies reveal new information about the somatosensory innervation of the tongue and will assist the design of future electrotactile tongue stimulation devices that will help provide sensory information to people with damaged sensory systems.

16.
Kidney Int ; 92(2): 432-439, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28483379

RESUMO

A prospective national cohort study was undertaken to collect data on all cases of pediatric (under 18 yrs of age) acute kidney injury (AKI) identified by a biochemistry-based electronic alert using the Welsh National electronic AKI reporting system. Herein we describe the utility and limitation of using this modification of the KDIGO creatinine-based system data set to characterize pediatric AKI. Of 1,343 incident episodes over a 30-month period, 34.5% occurred in neonates of which 83.8% were AKI stage 1. Neonatal 30-day mortality was 4.1%, with 73.3% of this being accounted for by patients treated in an Intensive Care Unit. In the non-neonatal group, 76.1% were AKI stage 1. Hospital-acquired AKI accounted for 40.1% of episodes while community-acquired AKI represented 29.4% of cases within which 33.9% were admitted to hospital and 30.5% of cases were unclassified. Non-neonatal 30-day mortality was 1.2%, with half of this accounted for by patients treated in the Intensive Care Unit. Nonrecovery of renal function at 30 days occurred in 28% and was significantly higher in patients not admitted to hospital (45% vs. 20%). The reported incidence of AKI in children was far greater than previously reported in studies reliant on clinical identification of adult AKI or hospital coding data. Mortality was highest in neonates and driven by those in the Intensive Care Unit. Nonrecovery of renal function and persistent renal impairment was more common in non-neonates and was especially high in patients with community-acquired AKI who were not hospitalized.


Assuntos
Injúria Renal Aguda/diagnóstico , Creatinina/sangue , Valores Críticos Laboratoriais , Injúria Renal Aguda/sangue , Injúria Renal Aguda/mortalidade , Adolescente , Biomarcadores/sangue , Criança , Pré-Escolar , Registros Eletrônicos de Saúde , Feminino , Humanos , Incidência , Lactente , Recém-Nascido , Masculino , Pediatria/normas , Estudos Prospectivos , País de Gales/epidemiologia
17.
Rev Sci Instrum ; 88(1): 013507, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28147644

RESUMO

A means is presented to determine the Hall current density distribution in a closed drift thruster by remotely measuring the magnetic field and solving the inverse problem for the current density. The magnetic field was measured by employing an array of eight tunneling magnetoresistive (TMR) sensors capable of milligauss sensitivity when placed in a high background field. The array was positioned just outside the thruster channel on a 1.5 kW Hall thruster equipped with a center-mounted hollow cathode. In the sensor array location, the static magnetic field is approximately 30 G, which is within the linear operating range of the TMR sensors. Furthermore, the induced field at this distance is approximately tens of milligauss, which is within the sensitivity range of the TMR sensors. Because of the nature of the inverse problem, the induced-field measurements do not provide the Hall current density by a simple inversion; however, a Tikhonov regularization of the induced field does provide the current density distributions. These distributions are shown as a function of time in contour plots. The measured ratios between the average Hall current and the average discharge current ranged from 6.1 to 7.3 over a range of operating conditions from 1.3 kW to 2.2 kW. The temporal inverse solution at 1.5 kW exhibited a breathing mode frequency of 24 kHz, which was in agreement with temporal measurements of the discharge current.

18.
Clin J Am Soc Nephrol ; 11(12): 2123-2131, 2016 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-27793961

RESUMO

BACKGROUND AND OBJECTIVES: Our aim was to use a national electronic AKI alert to define the incidence and outcome of all episodes of community- and hospital-acquired adult AKI. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: A prospective national cohort study was undertaken in a population of 3.06 million. Data were collected between March of 2015 and August of 2015. All patients with adult (≥18 years of age) AKI were identified to define the incidence and outcome of all episodes of community- and hospital-acquired AKI in adults. Mortality and renal outcomes were assessed at 90 days. RESULTS: There was a total of 31,601 alerts representing 17,689 incident episodes, giving an incidence of AKI of 577 per 100,000 population. Community-acquired AKI accounted for 49.3% of all incident episodes, and 42% occurred in the context of preexisting CKD (Chronic Kidney Disease Epidemiology Collaboration eGFR); 90-day mortality rate was 25.6%, and 23.7% of episodes progressed to a higher AKI stage than the stage associated with the alert. AKI electronic alert stage and peak AKI stage were associated with mortality, and mortality was significantly higher for hospital-acquired AKI compared with alerts generated in a community setting. Among patients who survived to 90 days after the AKI electronic alert, those who were not hospitalized had a lower rate of renal recovery and a greater likelihood of developing an eGFR<60 ml/min per 1.73 m2 for the first time, which may be indicative of development of de novo CKD. CONCLUSIONS: The reported incidence of AKI is far greater than the previously reported incidence in studies reliant on clinical identification of adult AKI or hospital coding data. Although an electronic alert system is Information Technology driven and therefore, lacks intelligence and clinical context, these data can be used to identify deficiencies in care, guide the development of appropriate intervention strategies, and provide a baseline against which the effectiveness of these interventions may be measured.


Assuntos
Injúria Renal Aguda/diagnóstico , Injúria Renal Aguda/epidemiologia , Diagnóstico por Computador , Insuficiência Renal Crônica/fisiopatologia , Injúria Renal Aguda/mortalidade , Injúria Renal Aguda/fisiopatologia , Idoso , Idoso de 80 Anos ou mais , Sistemas Computacionais , Diagnóstico Precoce , Feminino , Taxa de Filtração Glomerular , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Índice de Gravidade de Doença , País de Gales/epidemiologia
19.
J Virol ; 90(23): 10715-10727, 2016 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-27654292

RESUMO

Cytomegalovirus (CMV) is a ubiquitous human pathogen that increases the morbidity and mortality of immunocompromised individuals. The current FDA-approved treatments for CMV infection are intended to be virus specific, yet they have significant adverse side effects, including nephrotoxicity and hematological toxicity. Thus, there is a medical need for safer and more effective CMV therapeutics. Using a high-content screen, we identified the cardiac glycoside convallatoxin as an effective compound that inhibits CMV infection. Using a panel of cardiac glycoside variants, we assessed the structural elements critical for anti-CMV activity by both experimental and in silico methods. Analysis of the antiviral effects, toxicities, and pharmacodynamics of different variants of cardiac glycosides identified the mechanism of inhibition as reduction of methionine import, leading to decreased immediate-early gene translation without significant toxicity. Also, convallatoxin was found to dramatically reduce the proliferation of clinical CMV strains, implying that its mechanism of action is an effective strategy to block CMV dissemination. Our study has uncovered the mechanism and structural elements of convallatoxin, which are important for effectively inhibiting CMV infection by targeting the expression of immediate-early genes. IMPORTANCE: Cytomegalovirus is a highly prevalent virus capable of causing severe disease in certain populations. The current FDA-approved therapeutics all target the same stage of the viral life cycle and induce toxicity and viral resistance. We identified convallatoxin, a novel cell-targeting antiviral that inhibits CMV infection by decreasing the synthesis of viral proteins. At doses low enough for cells to tolerate, convallatoxin was able to inhibit primary isolates of CMV, including those resistant to the anti-CMV drug ganciclovir. In addition to identifying convallatoxin as a novel antiviral, limiting mRNA translation has a dramatic impact on CMV infection and proliferation.


Assuntos
Antivirais/farmacologia , Infecções por Citomegalovirus/prevenção & controle , Citomegalovirus/efeitos dos fármacos , Metionina/metabolismo , Estrofantinas/farmacologia , Antivirais/química , Transporte Biológico Ativo/efeitos dos fármacos , Glicosídeos Cardíacos/química , Glicosídeos Cardíacos/farmacologia , Linhagem Celular , Citomegalovirus/genética , Citomegalovirus/fisiologia , Infecções por Citomegalovirus/metabolismo , Infecções por Citomegalovirus/virologia , Genes Precoces/efeitos dos fármacos , Genes Virais/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Viral/genética , RNA Viral/metabolismo , Estrofantinas/química , Relação Estrutura-Atividade , Replicação Viral/efeitos dos fármacos
20.
Antimicrob Agents Chemother ; 60(12): 7067-7076, 2016 12.
Artigo em Inglês | MEDLINE | ID: mdl-27620482

RESUMO

We previously reported the synthesis and biological activity of a series of cationic bis-indoles with potent, broad-spectrum antibacterial properties. Here, we describe mechanism of action studies to test the hypothesis that these compounds bind to DNA and that this target plays an important role in their antibacterial outcome. The results reported here indicate that the bis-indoles bind selectively to DNA at A/T-rich sites, which is correlated with the inhibition of DNA and RNA synthesis in representative Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) organisms. Further, exposure of E. coli and S. aureus to representative bis-indoles resulted in induction of the DNA damage-inducible SOS response. In addition, the bis-indoles were found to be potent inhibitors of cell wall biosynthesis; however, they do not induce the cell wall stress stimulon in S. aureus, suggesting that this pathway is inhibited by an indirect mechanism. In light of these findings, the most likely basis for the observed activities of these compounds is their ability to bind to the minor groove of DNA, resulting in the inhibition of DNA and RNA synthesis and other secondary effects.


Assuntos
Antibacterianos/farmacologia , DNA/metabolismo , Indóis/farmacologia , Antibacterianos/química , Antibacterianos/metabolismo , Escherichia coli/efeitos dos fármacos , Células HeLa/efeitos dos fármacos , Humanos , Imidazóis/química , Imidazóis/metabolismo , Imidazóis/farmacologia , Indóis/química , Indóis/metabolismo , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência , Terapia de Alvo Molecular , Resposta SOS em Genética/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos
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