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1.
Small ; : e2404729, 2024 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-39113671

RESUMO

Development of high-performance, low-cost catalysts for electrochemical water splitting is key to sustainable hydrogen production. Herein, ultrafast synthesis of carbon-supported ruthenium-copper (RuCu/C) nanocomposites is reported by magnetic induction heating, where the rapid Joule's heating of RuCl3 and CuCl2 at 200 A for 10 s produces Ru-Cl residues-decorated Ru nanocrystals dispersed on a CuClx scaffold, featuring effective Ru to Cu charge transfer. Among the series, the RuCu/C-3 sample exhibits the best activity in 1 m KOH toward both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with an overpotential of only -23 and +270 mV to reach 10 mA cm-2, respectively. When RuCu/C-3 is used as bifunctional catalysts for electrochemical water splitting, a low cell voltage of 1.53 V is needed to produce 10 mA cm-2, markedly better than that with a mixture of commercial Pt/C+RuO2 (1.59 V). In situ X-ray absorption spectroscopy measurements show that the bifunctional activity is due to reduction of the Ru-Cl residues at low electrode potentials that enriches metallic Ru and oxidation at high electrode potentials that facilitates the formation of amorphous RuOx. These findings highlight the unique potential of MIH in the ultrafast synthesis of high-performance catalysts for electrochemical water splitting.

2.
Ophthalmic Plast Reconstr Surg ; 39(5): e145-e148, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37010054

RESUMO

Congenital orbital fibrosis (COF) is a rare disorder characterized by an infiltrating orbital mass with secondary involvement of the extraocular muscles that may present with extraocular muscle dysfunction, and globe and eyelid abnormalities in infancy. This condition is thought to be a nonprogressive process and literature on longitudinal assessment of COF is limited. The authors describe a case of COF which was followed for 15 years. The patient had stable symptoms of ocular dysmotility and ptosis but was noted to have spontaneous regression of the orbital mass on serial MRI.


Assuntos
Blefaroptose , Doenças Palpebrais , Doenças Orbitárias , Neoplasias Orbitárias , Humanos , Neoplasias Orbitárias/patologia , Músculos Oculomotores/patologia , Doenças Palpebrais/diagnóstico , Blefaroptose/diagnóstico , Blefaroptose/etiologia , Blefaroptose/patologia , Doenças Orbitárias/patologia , Fibrose
3.
Neuropediatrics ; 53(5): 344-350, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35453165

RESUMO

Botulinum toxin type A (BoNT-A) has shown to be a safe and effective treatment for children with chronic migraines. Our study was to assess the efficacy of the Onabotulinum toxin type A at different intervals after initiation of therapy. We conducted a retrospective and prospective analysis of 34 patients at a children's hospital where children received four rounds of the BoNT-A therapy for the treatment of chronic migraine. Among the 34 patients, 25 patients (age range: 13-21 years), who responded to the BoNT-A therapy, were included in the analysis. Patients received standard 31 injection, 155 unit's protocol. Patients were assessed every 3 months after their initial injection. Reasons for discontinuation of therapy were analyzed. After the first two BoNT-A sessions, significant improvement was observed with a decrease in headache frequency and intensity (p < 0.001). There was further reduction in headache frequency and intensity with the fourth round of BoNT-A therapy, with comparative analysis between the second and fourth round showing a p-value of <0.001. In terms of reduction of emergency room visits and hospitalization, a significant improvement was seen after the third round of BoNT-A therapy (p < 0.01). A significant decrease in the number of abortive and preventive medications was seen after the second round of BoNT-A therapy (p < 0.001). The efficacy of BoNT-A treatment in decreasing headache frequency, intensity, and the number of abortive and preventive medications can be assessed effectively after two treatment sessions. This trend continued to be observed with additional third and fourth sessions.


Assuntos
Toxinas Botulínicas Tipo A , Transtornos de Enxaqueca , Fármacos Neuromusculares , Adolescente , Adulto , Toxinas Botulínicas Tipo A/uso terapêutico , Criança , Cefaleia , Humanos , Transtornos de Enxaqueca/tratamento farmacológico , Transtornos de Enxaqueca/prevenção & controle , Fármacos Neuromusculares/uso terapêutico , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
4.
Graefes Arch Clin Exp Ophthalmol ; 260(5): 1475-1489, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-34783892

RESUMO

PURPOSE: To develop methods to assess the effects of epiretinal membranes (ERM) and macular holes (MH) coexisting with glaucoma on pre-operative retinal structure and function and evaluate post-operative outcomes. METHODS: Seven eyes of 7 patients with glaucoma, 6 with ERMs and 1 with MH, were enrolled; 4 underwent vitrectomy for ERM and one for MH. Visual fields (VFs) and optical coherence tomography (OCT) scans were obtained pre- and post-operatively. The 10-2VF deviation map was overlayed on ganglion cell and inner plexiform layer (GCL + IPL) and retinal nerve fiber layer (RNFL) deviation maps derived from OCT macula and disc cube scans. Optic nerve circle scans were obtained to assess RNFL thickness, and OCT b-scans associated with VF defects were compared pre- and post-operatively. RESULTS: Examination of pre-operative VFs and OCT scans showed the importance of determining the extent to which glaucomatous damage contributed to VF loss; verifying automated segmentation of the GCL + IPL and RNFL; and assessing foveal anatomy. Evaluation of post-operative structure-function outcomes required correction of magnification changes in OCT scans and repeated follow-up visits to clarify the origin of VF changes. CONCLUSIONS: Pre-operative comparisons of VFs and OCT scans may be beneficial in guiding surgical planning, and evaluating outcomes, in eyes with glaucoma undergoing macular surgery.


Assuntos
Glaucoma , Fibras Nervosas , Glaucoma/complicações , Glaucoma/diagnóstico , Glaucoma/cirurgia , Humanos , Pressão Intraocular , Células Ganglionares da Retina , Tomografia de Coerência Óptica/métodos , Campos Visuais
5.
PLoS Med ; 18(7): e1003717, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34260579

RESUMO

BACKGROUND: Public-private mix (PPM) programs on tuberculosis (TB) have a critical role in engaging and integrating the private sector into the national TB control efforts in order to meet the End TB Strategy targets. South Korea's PPM program can provide important insights on the long-term impact and policy gaps in the development and expansion of PPM as a nationwide program. METHODS AND FINDINGS: Healthcare is privatized in South Korea, and a majority (80.3% in 2009) of TB patients sought care in the private sector. Since 2009, South Korea has rapidly expanded its PPM program coverage under the National Health Insurance (NHI) scheme as a formal national program with dedicated PPM nurses managing TB patients in both the private and public sectors. Using the difference in differences (DID) analytic framework, we compared relative changes in TB treatment outcomes-treatment success (TS) and loss to follow-up (LTFU)-in the private and public sector between the 2009 and 2014 TB patient cohorts. Propensity score matching (PSM) using the kernel method was done to adjust for imbalances in the covariates between the 2 population cohorts. The 2009 cohort included 6,195 (63.0% male, 37.0% female; mean age: 42.1) and 27,396 (56.1% male, 43.9% female; mean age: 45.7) TB patients in the public and private sectors, respectively. The 2014 cohort included 2,803 (63.2% male, 36.8% female; mean age: 50.1) and 29,988 (56.5% male, 43.5% female; mean age: 54.7) patients. In both the private and public sectors, the proportion of patients with transfer history decreased (public: 23.8% to 21.7% and private: 20.8% to 17.6%), and bacteriological confirmed disease increased (public: 48.9% to 62.3% and private: 48.8% to 58.1%) in 2014 compared to 2009. After expanding nationwide PPM, absolute TS rates improved by 9.10% (87.5% to 93.4%) and by 13.6% (from 70.3% to 83.9%) in the public and private sectors. Relative to the public, the private saw 4.1% (95% confidence interval [CI] 2.9% to 5.3%, p-value < 0.001) and -8.7% (95% CI -9.7% to -7.7%, p-value <0.001) higher rates of improvement in TS and reduction in LTFU. Treatment outcomes did not improve in patients who experienced at least 1 transfer during their TB treatment. Study limitations include non-longitudinal nature of our original dataset, inability to assess the regional disparities, and verify PPM program's impact on TB mortality. CONCLUSIONS: We found that the nationwide scale-up of the PPM program was associated with improvements in TB treatment outcomes in the private sector in South Korea. Centralized financial governance and regulatory mechanisms were integral in facilitating the integration of highly diverse South Korean private sector into the national TB control program and scaling up of the PPM intervention nationwide. However, TB care gaps continued to exist for patients who transferred at least once during their treatment. These programmatic gaps may be improved through reducing administrative hurdles and making programmatic amendments that can help facilitate management TB patients between institutions and healthcare sectors, as well as across administrative regions.


Assuntos
Programas Nacionais de Saúde , Setor Privado , Setor Público , Tuberculose/terapia , Conjuntos de Dados como Assunto , Erradicação de Doenças , Feminino , Programas Governamentais , Política de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , República da Coreia , Resultado do Tratamento , Tuberculose/prevenção & controle
6.
BMC Infect Dis ; 21(1): 1206, 2021 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-34861855

RESUMO

BACKGROUND: Approximately one-fourth of the global population is latently infected with Mycobacterium tuberculosis. An understanding of the burden of latent tuberculosis infection (LTBI) among immigrants compared with the general Korean population should be the first step in identifying priority groups for LTBI diagnosis and treatment. The study aimed to compute the age-standardized LTBI prevalence and predictors among immigrants with LTBI in South Korea. METHODS: In 2018, the Korea Disease Control and Prevention Agency implemented a pilot LTBI screening project for immigrants using a chest radiography and the QuantiFERON Gold In-Tube assay. A standardized prevalence ratio (SPR) was computed to compare the LTBI burden in immigrants and the general Korean population. RESULTS: During the duration of the project, a total of 8108 immigrants (5134 males and 2974 females) underwent LTBI screening. The SPR of 1.547 (95% confidence interval [CI] 1.468-1.629) in males and 1.261 (95% CI 1.177-1.349) in females were both higher than the Korean reference population. Furthermore, among the immigrants, those aged < 40 years and Korean diaspora visa holders had a higher SPR. CONCLUSION: This study found a higher LTBI prevalence among immigrant population in South Korea compared to that in the general Korean population, and the SPR was higher among those aged < 40 years and the Korean diaspora. The findings can be used as baseline evidence for including immigrants in South Korea in the at-risk group with a priority need for LTBI screening and treatment.


Assuntos
Emigrantes e Imigrantes , Tuberculose Latente , Estudos Transversais , Feminino , Humanos , Tuberculose Latente/diagnóstico , Tuberculose Latente/epidemiologia , Masculino , Prevalência , República da Coreia/epidemiologia , Estudos Retrospectivos , Teste Tuberculínico
7.
Technol Soc ; 64: 101467, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33324025

RESUMO

Accessibility of public health websites allows important information to reach as many audiences as possible. This is vital during a public health crisis such as the current COVID-19 pandemic. This paper reviews public health information portals provided by the Australian Capital Territory local government against the Web Content Accessibility Guidelines.

8.
J Card Fail ; 26(4): 300-307, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31672621

RESUMO

BACKGROUND: Left ventricular assist device (LVAD) therapy has revolutionized the treatment options for patients with advanced heart failure. Patient selection is essential for obtaining successful results. However, few data exist concerning the outcomes of patients evaluated for LVAD therapy but subsequently rejected or deferred. METHODS AND RESULTS: This is a retrospective review of all patients referred for LVAD therapy at our institution between January 2009 and December 2016. Baseline demographics and Interagency Registry for Mechanically Assisted Circulatory Support profiles were collected, and reasons for rejection or deferral for LVAD placement were investigated. A total of 669 patients were referred for LVAD therapy, and 228 patients (34%) were turned down. The yearly acceptance rate ranged between 57% and 75%. The average age of the turned-down cohort was 60.8 ± 12.5 years; 83% were men. Reasons for rejection included: patient being too sick (34%); psychosocial concerns (25%); patient declined (16%); decision was deferred for medical optimization (15%); or patient being too well (10%). The percentage of patients who were rejected due to psychosocial concerns has increased over time (P = 0.02), whereas the rate of deferral for medical optimization has remained stable (P = 0.10). One-year survival after initial LVAD consultation was 42% in those who were too sick, 64% in those with psychosocial concerns, 68% in patients who declined, 86% in those deferred for medical optimization; and 100% in those too well (P < 0.01). CONCLUSIONS: One-year survival is reduced among patients who were initially turned down for LVAD therapy, except for those in whom this decision was deferred for medical optimization or because the patient was too well. Psychosocial concerns have become a significant barrier to LVAD therapy.


Assuntos
Insuficiência Cardíaca , Coração Auxiliar , Idoso , Insuficiência Cardíaca/diagnóstico , Insuficiência Cardíaca/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Encaminhamento e Consulta , Estudos Retrospectivos , Resultado do Tratamento
9.
Cardiology ; 145(3): 161-167, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32007988

RESUMO

OBJECTIVE: Mitral regurgitation (MR) induced by systolic anterior motion in patients with hypertrophic cardiomyopathy (HCM) can frequently be abolished with a proficient septal myectomy (SM) without the need for mitral-valve replacement (MVR). ACC guidelines stress the importance of volume in improving outcomes after SM, but there is a lack of data measuring the impact of volume on the need for MVR during SM. This study was designed to assess the impact of institutional volume on MVR rates using national outcomes data. METHODS: The Nationwide Inpatient Sample was queried from 1998 to 2011 and a total of 6,207 patients had a diagnosis of HCM and a procedure code for SM. Outcomes were compared between patients who underwent SM (group I) and SM and MVR (group II). Furthermore, patients were stratified into 3 groups based on the number of SMs at the performing institution: low experience (1-24 cumulative SMs), medium experience (25-49 SMs), and high experience (>50 SMs). These patients underwent multivariable analysis to determine the impact of institutional volume on MVR rate. RESULTS: The total MVR rate was 26%. Perioperative outcomes were worse, i.e., there were higher rates of mortality, kidney injury, and urinary complications, in group II than in group I. Only 37.6% of patients were operated on at institutions meeting the guideline criteria of >50 cumulative SMs. When compared to patients in the high-experience group, patients in the low- (OR 2.7, 95% CI 2.3-3.2, p < 0.05) and medium-experience (OR 3.0, 95% CI 2.5-3.6, p < 0.05) groups were more likely to undergo MVR. CONCLUSION: Compared to reports from SM reference centers, national data suggest that MVR rates are quite high at SM. Patients undergoing SM at centers that do not meet the guideline standard have >2.5× the odds of undergoing MVR compared to those operated on at guideline-endorsed centers.


Assuntos
Cardiomiopatia Hipertrófica/cirurgia , Septos Cardíacos/cirurgia , Insuficiência da Valva Mitral/cirurgia , Valva Mitral/cirurgia , Adulto , Idoso , Bases de Dados como Assunto , Feminino , Implante de Prótese de Valva Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Estados Unidos
10.
Nature ; 510(7506): 503-6, 2014 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-24965651

RESUMO

The emergence and spread of carbapenem-resistant Gram-negative pathogens is a global public health problem. The acquisition of metallo-ß-lactamases (MBLs) such as NDM-1 is a principle contributor to the emergence of carbapenem-resistant Gram-negative pathogens that threatens the use of penicillin, cephalosporin and carbapenem antibiotics to treat infections. To date, a clinical inhibitor of MBLs that could reverse resistance and re-sensitize resistant Gram-negative pathogens to carbapenems has not been found. Here we have identified a fungal natural product, aspergillomarasmine A (AMA), that is a rapid and potent inhibitor of the NDM-1 enzyme and another clinically relevant MBL, VIM-2. AMA also fully restored the activity of meropenem against Enterobacteriaceae, Acinetobacter spp. and Pseudomonas spp. possessing either VIM or NDM-type alleles. In mice infected with NDM-1-expressing Klebsiella pneumoniae, AMA efficiently restored meropenem activity, demonstrating that a combination of AMA and a carbapenem antibiotic has therapeutic potential to address the clinical challenge of MBL-positive carbapenem-resistant Gram-negative pathogens.


Assuntos
Ácido Aspártico/análogos & derivados , Carbapenêmicos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Tienamicinas/farmacologia , Resistência beta-Lactâmica/efeitos dos fármacos , Inibidores de beta-Lactamases , Animais , Antibacterianos/farmacologia , Ácido Aspártico/isolamento & purificação , Ácido Aspártico/farmacologia , Aspergillus/química , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Sinergismo Farmacológico , Feminino , Bactérias Gram-Negativas/enzimologia , Bactérias Gram-Negativas/genética , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/enzimologia , Klebsiella pneumoniae/genética , Meropeném , Camundongos , beta-Lactamases/genética , beta-Lactamases/metabolismo
11.
PLoS Pathog ; 11(2): e1004648, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25643352

RESUMO

Chemokines have been shown to be effective bactericidal molecules against a variety of bacteria and fungi in vitro. These direct antimicrobial effects are independent of their chemotactic activities involving immunological receptors. However, the direct biological role that these proteins may play in host defense, particularly against intestinal pathogens, is poorly understood. Here, we show that CXCL9, an ELR- chemokine, exhibits direct antimicrobial activity against Citrobacter rodentium, an attaching/effacing pathogen that infects the gut mucosa. Inhibition of this antimicrobial activity in vivo using anti-CXCL9 antibodies increases host susceptibility to C. rodentium infection with pronounced bacterial penetration into crypts, increased bacterial load, and worsened tissue pathology. Using Rag1(-/-) mice and CXCR3(-/-) mice, we demonstrate that the role for CXCL9 in protecting the gut mucosa is independent of an adaptive response or its immunological receptor, CXCR3. Finally, we provide evidence that phagocytes function in tandem with NK cells for robust CXCL9 responses to C. rodentium. These findings identify a novel role for the immune cell-derived CXCL9 chemokine in directing a protective antimicrobial response in the intestinal mucosa.


Assuntos
Quimiocina CXCL9/imunologia , Infecções por Enterobacteriaceae/imunologia , Mucosa Intestinal/imunologia , Transdução de Sinais/imunologia , Animais , Quimiocinas/imunologia , Citrobacter rodentium/imunologia , Ensaio de Imunoadsorção Enzimática , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout
12.
Mol Microbiol ; 95(4): 678-91, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25442048

RESUMO

The two-component regulatory system SsrA-SsrB in Salmonella enterica controls expression of a virulence gene program required for intracellular survival in host cells. SsrA signaling is induced within the acidic host vacuole in which the bacteria reside; however, the mechanism by which SsrA senses this intracellular environment is unknown. Here, we show that the periplasmic sensor domain of SsrA is enriched in histidine residues that increase SsrA signaling below external pH of 6. While no single histidine accounted for the full acid-responsiveness of SsrA, we localized the acid-responsiveness principally to five histidines in the C-terminal end of the periplasmic sensor domain, with input from additional histidines in the N-terminal end of the senor. A sensor mutant lacking critical pH-responsive histidines was defective for acid-promoted activity, yet retained basal activity similar to wild type at neutral pH, indicating that the role of these histidines is to enhance signaling in response to acidification. In support of this, a pH-blind mutant was insensitive to the vacuole acidification blocking activity of bafilomycin, and was attenuated for competitive fitness during infection of mice. Our data demonstrate that SsrA contains a histidine-rich periplasmic sensor that enhances signaling in response to the innate host defense of vacuolar acidification.


Assuntos
Regulação Bacteriana da Expressão Gênica , Histidina/metabolismo , Proteínas Quinases/química , Proteínas Quinases/metabolismo , Salmonella typhimurium/metabolismo , Animais , Proteínas de Bactérias/metabolismo , Inibidores Enzimáticos/farmacologia , Aptidão Genética , Concentração de Íons de Hidrogênio , Macrolídeos/farmacologia , Macrófagos/microbiologia , Camundongos , Camundongos Endogâmicos C57BL , Mutagênese , Periplasma , Estrutura Terciária de Proteína , Salmonelose Animal/microbiologia , Salmonella typhimurium/enzimologia , Salmonella typhimurium/patogenicidade , Transdução de Sinais , Vacúolos/metabolismo , Virulência
13.
PLoS Pathog ; 10(5): e1004132, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24830429

RESUMO

Mycobacterium tuberculosis (Mtb) employs multiple strategies to evade host immune responses and persist within macrophages. We have previously shown that the cell envelope-associated Mtb serine hydrolase, Hip1, prevents robust macrophage activation and dampens host pro-inflammatory responses, allowing Mtb to delay immune detection and accelerate disease progression. We now provide key mechanistic insights into the molecular and biochemical basis of Hip1 function. We establish that Hip1 is a serine protease with activity against protein and peptide substrates. Further, we show that the Mtb GroEL2 protein is a direct substrate of Hip1 protease activity. Cleavage of GroEL2 is specifically inhibited by serine protease inhibitors. We mapped the cleavage site within the N-terminus of GroEL2 and confirmed that this site is required for proteolysis of GroEL2 during Mtb growth. Interestingly, we discovered that Hip1-mediated cleavage of GroEL2 converts the protein from a multimeric to a monomeric form. Moreover, ectopic expression of cleaved GroEL2 monomers into the hip1 mutant complemented the hyperinflammatory phenotype of the hip1 mutant and restored wild type levels of cytokine responses in infected macrophages. Our studies point to Hip1-dependent proteolysis as a novel regulatory mechanism that helps Mtb respond rapidly to changing host immune environments during infection. These findings position Hip1 as an attractive target for inhibition for developing immunomodulatory therapeutics against Mtb.


Assuntos
Proteínas de Bactérias/fisiologia , Chaperonina 60/metabolismo , Macrófagos/imunologia , Macrófagos/metabolismo , Mycobacterium tuberculosis/enzimologia , Serina Endopeptidases/fisiologia , Serina Proteases/fisiologia , Animais , Proteínas de Bactérias/metabolismo , Células Cultivadas , Interações Hospedeiro-Patógeno/genética , Interações Hospedeiro-Patógeno/imunologia , Ativação de Macrófagos , Camundongos , Camundongos Endogâmicos C57BL , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/imunologia , Ligação Proteica , Multimerização Proteica , Proteólise , Serina Endopeptidases/metabolismo , Serina Proteases/metabolismo
15.
AJR Am J Roentgenol ; 205(5): 1061-7, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26496554

RESUMO

OBJECTIVE: The calcaneus is the primary weight bearing bone in the heel, and its many surface contours render it a relatively difficult bone to visualize in its entirety. The stabilizing ligaments that hold the calcaneus in place occupy very specific locations, and the Achilles tendon enthesis is in a relatively constant location; therefore, avulsion fractures occur in reproducible locations. CONCLUSION: The mechanisms of injuries include overuse and neuropathic conditions, although most cases are related to trauma.


Assuntos
Calcâneo/lesões , Diagnóstico por Imagem , Fraturas Ósseas/diagnóstico , Tendão do Calcâneo/lesões , Diagnóstico Diferencial , Humanos , Ligamentos/lesões , Traumatismos dos Tendões/diagnóstico
16.
Proc Natl Acad Sci U S A ; 109(43): E2939-48, 2012 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-23019585

RESUMO

Chemoresistance to platinum therapy is a major obstacle that needs to be overcome in the treatment of ovarian cancer patients. The high rates and patterns of therapeutic failure seen in patients are consistent with a steady accumulation of drug-resistant cancer stem cells (CSCs). This study demonstrates that the Notch signaling pathway and Notch3 in particular are critical for the regulation of CSCs and tumor resistance to platinum. We show that Notch3 overexpression in tumor cells results in expansion of CSCs and increased platinum chemoresistance. In contrast, γ-secretase inhibitor (GSI), a Notch pathway inhibitor, depletes CSCs and increases tumor sensitivity to platinum. Similarly, a Notch3 siRNA knockdown increases the response to platinum therapy, further demonstrating that modulation of tumor chemosensitivity by GSI is Notch specific. Most importantly, the cisplatin/GSI combination is the only treatment that effectively eliminates both CSCs and the bulk of tumor cells, indicating that a dual combination targeting both populations is needed for tumor eradication. In addition, we found that the cisplatin/GSI combination therapy has a synergistic cytotoxic effect in Notch-dependent tumor cells by enhancing the DNA-damage response, G(2)/M cell-cycle arrest, and apoptosis. Based on these results, we conclude that targeting the Notch pathway could significantly increase tumor sensitivity to platinum therapy. Our study suggests important clinical applications for targeting Notch as part of novel treatment strategies upon diagnosis of ovarian cancer and at recurrence. Both platinum-resistant and platinum-sensitive relapses may benefit from such an approach as clinical data suggest that all relapses after platinum therapy are increasingly platinum resistant.


Assuntos
Antineoplásicos/uso terapêutico , Cisplatino/uso terapêutico , Células-Tronco Neoplásicas/patologia , Neoplasias Ovarianas/patologia , Receptores Notch/metabolismo , Animais , Ciclo Celular , Morte Celular , Dano ao DNA , Resistencia a Medicamentos Antineoplásicos , Feminino , Humanos , Camundongos , Neoplasias Ovarianas/tratamento farmacológico , Receptor Notch3 , Ensaios Antitumorais Modelo de Xenoenxerto
17.
Emerg Radiol ; 22(5): 595-600, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25917635

RESUMO

Radiographs often depict unusually appearing variations in the skeleton that have the appearance of holes, clefts, and prominent notches. Although certain variants are recognizable, others may not be as familiar. Knowledge of characteristic locations of nutrient foramina is also important. The aim of this pictorial essay are to review the anatomic variants in the trunk of the skeleton that manifest as holes, cleft, or notches in the bone and to specify the differentiating features of these variants from those that constitute true pathologic conditions.


Assuntos
Osso e Ossos/anatomia & histologia , Osso e Ossos/diagnóstico por imagem , Diagnóstico Diferencial , Humanos , Radiografia
18.
Infect Immun ; 82(8): 3383-93, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24866805

RESUMO

Host defense peptides secreted by colonocytes and Paneth cells play a key role in innate host defenses in the gut. In Crohn's disease, the burden of tissue-associated Escherichia coli commonly increases at epithelial surfaces where host defense peptides concentrate, suggesting that this bacterial population might actively resist this mechanism of bacterial killing. Adherent-invasive E. coli (AIEC) is associated with Crohn's disease; however, the colonization determinants of AIEC in the inflamed gut are undefined. Here, we establish that host defense peptide resistance contributes to host colonization by Crohn's-associated AIEC. We identified a plasmid-encoded genomic island (called PI-6) in AIEC strain NRG857c that confers high-level resistance to α-helical cationic peptides and α- and ß-defensins. Deletion of PI-6 sensitized strain NRG857c to these host defense molecules, reduced its competitive fitness in a mouse model of infection, and attenuated its ability to induce cecal pathology. This phenotype is due to two genes in PI-6, arlA, which encodes a Mig-14 family protein implicated in defensin resistance, and arlC, an OmpT family outer membrane protease. Implicit in these findings are new bacterial targets whose inhibition might limit AIEC burden and disease in the gut.


Assuntos
Peptídeos Catiônicos Antimicrobianos/imunologia , Doença de Crohn/microbiologia , Farmacorresistência Bacteriana , Proteínas de Escherichia coli/metabolismo , Escherichia coli/imunologia , Peptídeo Hidrolases/metabolismo , Fatores de Virulência/metabolismo , Animais , Modelos Animais de Doenças , Proteínas de Escherichia coli/genética , Feminino , Deleção de Genes , Ilhas Genômicas , Humanos , Camundongos , Peptídeo Hidrolases/genética , Plasmídeos , Fatores de Virulência/genética
19.
Eur J Immunol ; 43(10): 2638-49, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23775576

RESUMO

Extracellular attaching and effacing (A/E) pathogens including pathogenic Escherichia coli colonize the host gut causing diarrhea and inflammation. Although much is known regarding the pathogenesis of A/E bacteria, there remains an incomplete understanding of host immune responses to these microbes. NK cells are an important source of IFN-γ and are essential for early innate responses to viral pathogens; however, their role during extracellular bacterial infections is still largely unexplored. We studied the host response to the murine A/E pathogen Citrobacter rodentium to investigate NK-cell function during infection. NK1.1⁺ cell depletions and analysis of colonic intestinal inflammation following Citrobacter infection demonstrated that CD3⁻NK1.1⁺ cells play an important role in the initial clearance of C. rodentium, as evidenced by higher bacterial load, intestinal pathology, and crypt hyperplasia at the peak of inflammation in depleted mice. Loss of CD3⁻NK1.1⁺ cells resulted in lower colonic IFN-γ, TNF-α, and IL-12, and a delay in homing of IFN-γ⁺CD4⁺ T cells to the gut. Loss of this response resulted in lower anti-C. rodentium IgG in NK1.1-depleted mice. These data establish that CD3⁻NK1.1⁺ cells are critical for inducing an early Th1 response involved in clearance of a pathogen that is restricted to the gastrointestinal tract.


Assuntos
Citrobacter rodentium/imunologia , Colo/imunologia , Infecções por Enterobacteriaceae/imunologia , Escherichia coli/imunologia , Hiperplasia/imunologia , Células Matadoras Naturais/imunologia , Células Th1/imunologia , Animais , Anticorpos Antibacterianos/sangue , Antígenos Ly/metabolismo , Carga Bacteriana/imunologia , Complexo CD3/metabolismo , Movimento Celular/imunologia , Colo/microbiologia , Colo/patologia , Feminino , Hiperplasia/microbiologia , Interferon gama/genética , Interferon gama/metabolismo , Ativação Linfocitária , Depleção Linfocítica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Subfamília B de Receptores Semelhantes a Lectina de Células NK/metabolismo
20.
PLoS Pathog ; 8(6): e1002773, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22761574

RESUMO

Bacterial pathogens often manipulate host immune pathways to establish acute and chronic infection. Many Gram-negative bacteria do this by secreting effector proteins through a type III secretion system that alter the host response to the pathogen. In this study, we determined that the phage-encoded GogB effector protein in Salmonella targets the host SCF E3 type ubiquitin ligase through an interaction with Skp1 and the human F-box only 22 (FBXO22) protein. Domain mapping and functional knockdown studies indicated that GogB-containing bacteria inhibited IκB degradation and NFκB activation in macrophages, which required Skp1 and a eukaryotic-like F-box motif in the C-terminal domain of GogB. GogB-deficient Salmonella were unable to limit NFκB activation, which lead to increased proinflammatory responses in infected mice accompanied by extensive tissue damage and enhanced colonization in the gut during long-term chronic infections. We conclude that GogB is an anti-inflammatory effector that helps regulate inflammation-enhanced colonization by limiting tissue damage during infection.


Assuntos
Proteínas de Bactérias/metabolismo , Proteínas F-Box/metabolismo , Interações Hospedeiro-Parasita/imunologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Proteínas Quinases Associadas a Fase S/metabolismo , Infecções por Salmonella/metabolismo , Animais , Proteínas de Bactérias/imunologia , Western Blotting , Proteínas F-Box/imunologia , Feminino , Técnicas de Silenciamento de Genes , Transferência Genética Horizontal , Humanos , Imunoprecipitação , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/imunologia , NF-kappa B/metabolismo , Reação em Cadeia da Polimerase em Tempo Real , Receptores Citoplasmáticos e Nucleares/imunologia , Proteínas Quinases Associadas a Fase S/imunologia , Infecções por Salmonella/imunologia
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