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1.
Appl Environ Microbiol ; 89(4): e0203522, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-36920215

RESUMO

Despite a reduction of Salmonella contamination on final poultry products, the level of human salmonellosis cases attributed to poultry has remained unchanged over the last few years. There needs to be improved effort to target serovars which may survive antimicrobial interventions and cause illness, as well as to focus on lessening the amount of contamination entering the processing plant. Advances in molecular enumeration approaches allow for the rapid detection and quantification of Salmonella in pre- and postharvest samples, which can be combined with deep serotyping to properly assess the risk affiliated with a poultry flock. In this study, we collected a total of 160 boot sock samples from 20 broiler farms across four different integrators with different antibiotic management programs. Overall, Salmonella was found in 85% (68/80) of the houses, with each farm having at least one Salmonella-positive house. The average Salmonella quantity across all four complexes was 3.6 log10 CFU/sample. Eleven different serovars were identified through deep serotyping, including all three key performance indicators (KPIs; serovars Enteritidis, Infantis, and Typhimurium) defined by the U.S. Department of Agriculture-Food Safety and Inspection Service (USDA-FSIS). There were eight multidrug resistant isolates identified in this study, and seven which were serovar Infantis. We generated risk scores for each flock based on the presence or absence of KPIs, the relative abundance of each serovar as calculated with CRISPR-SeroSeq (serotyping by sequencing the clustered regularly interspaced palindromic repeats), and the quantity of Salmonella organisms detected. The work presented here provides a framework to develop directed processing approaches and highlights the limitations of conventional Salmonella sampling and culturing methods. IMPORTANCE Nearly one in five foodborne Salmonella illnesses are derived from chicken, making it the largest single food category to cause salmonellosis and indicating a need for effective pathogen mitigation. Although industry has successfully reduced Salmonella incidence in poultry products, there has not been a concurrent reduction in human salmonellosis linked to chicken consumption. New efforts are focused on improved control at preharvest, which requires improved Salmonella surveillance. Here, we present a high-resolution surveillance approach that combines quantity and identity of Salmonella in broiler flocks prior to processing which will further support improved Salmonella controls in poultry. We developed a framework for this approach, indicating that it is possible and important to harness deep serotyping and molecular enumeration to inform on-farm management practices and to minimize risk of cross-contamination between flocks at processing. Additionally, this framework could be adapted to Salmonella surveillance in other food animal production systems.


Assuntos
Intoxicação Alimentar por Salmonella , Salmonelose Animal , Infecções por Salmonella , Animais , Humanos , Sorotipagem/métodos , Galinhas , Salmonella , Intoxicação Alimentar por Salmonella/epidemiologia , Aves Domésticas , Salmonelose Animal/prevenção & controle , Salmonelose Animal/epidemiologia
2.
Cochrane Database Syst Rev ; 7: CD012711, 2019 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-31334846

RESUMO

BACKGROUND: Women with inflammatory bowel disease (IBD) may require surgery, which may result in higher risk of infertility. Restorative proctocolectomy with ileal anal pouch anastomosis (IPAA) may increase infertility, but the degree to which IPAA affects infertility remains unclear, and the impact of other surgical interventions on infertility is unknown. OBJECTIVES: Primary objective• To determine the effects of surgical interventions for IBD on female infertility.Secondary objectives• To evaluate the impact of surgical interventions on the need for assisted reproductive technology (ART), time to pregnancy, miscarriage, stillbirth, prematurity, mode of delivery (spontaneous vaginal, instrumental vaginal, or Caesarean section), infant requirement for resuscitation and neonatal intensive care, low and very low birth weight, small for gestational age, antenatal and postpartum hemorrhage, retained placenta, postpartum depression, gestational diabetes, and gestational hypertension/preeclampsia. SEARCH METHODS: We searched MEDLINE, Embase, CENTRAL, and the Cochrane IBD Group Specialized Register from inception to September 27, 2018, to identify relevant studies. We also searched references of relevant articles, conference abstracts, grey literature, and trials registers. SELECTION CRITERIA: We included observational studies that compared women of reproductive age (≥ 12 years of age) who underwent surgery to women with IBD who had a different type of surgery or no surgery (i.e. treated medically). We also included studies comparing women before and after surgery. Any type of IBD-related surgery was permitted. Infertility was defined as an inability to become pregnant following 12 months of unprotected intercourse. Infertility at 6, 18, and 24 months was included as a secondary outcome. We excluded studies that included women without IBD and those comparing women with IBD to women without IBD.. DATA COLLECTION AND ANALYSIS: Two review authors independently screened studies and extracted data. We used the Newcastle-Ottawa Scale to assess bias and GRADE to assess the overall certainty of evidence. We calculated the pooled risk ratio (RR) and 95% confidence interval (CI) using random-effects models. When individual studies reported odds ratios (ORs) and did not provide raw numbers, we pooled ORs instead. MAIN RESULTS: We identified 16 observational studies for inclusion. Ten studies were included in meta-analyses, of which nine compared women with and without a previous IBD-related surgery and the other compared women with open and laparoscopic IPAA. Of the ten studies included in meta-analyses, four evaluated infertility, one evaluated ART, and seven reported on pregnancy-related outcomes. Seven studies in which women were compared before and after colectomy and/or IPAA were summarized qualitatively, of which five included a comparison of infertility, three included the use of ART, and three included other pregnancy-related outcomes. One study included a comparison of women with and without IPAA, as well as before and after IPAA, and was therefore included in both the meta-analysis and the qualitative summary. All studies were at high risk of bias for at least two domains.We are very uncertain of the effect of IBD surgery on infertility at 12 months (RR 5.45, 95% CI 0.41 to 72.57; 114 participants; 2 studies) and at 24 months (RR 3.59, 95% CI 1.32 to 9.73; 190 participants; 1 study). Infertility was lower in women who received laparoscopic surgery compared to open restorative proctocolectomy at 12 months (RR 0.70, 95% CI 0.38 to 1.27; 37 participants; 1 study).We are very uncertain of the effect of IBD surgery on pregnancy-related outcomes, including miscarriage (OR 2.03, 95% CI 1.14 to 3.60; 776 pregnancies; 5 studies), use of ART (RR 25.09, 95% CI 1.56 to 403.76; 106 participants; 1 study), delivery via Caesarean section (RR 2.23, 95% CI 1.00 to 4.95; 20 pregnancies; 1 study), stillbirth (RR 1.96, 95% CI 0.42 to 9.18; 246 pregnancies; 3 studies), preterm birth (RR 1.91, 95% CI 0.67 to 5.48; 194 pregnancies; 3 studies), low birth weight (RR 0.61, 95% CI 0.08 to 4.83), and small for gestational age (RR 2.54, 95% CI 0.80 to 8.01; 65 pregnancies; 1 study).Studies comparing infertility before and after IBD-related surgery reported numerically higher rates of infertility at six months (before: 1/5, 20.0%; after: 9/15, 60.0%; 1 study), at 12 months (before: 68/327, 20.8%; after: 239/377, 63.4%; 5 studies), and at 24 months (before: 14/89, 15.7%; after: 115/164, 70.1%; 2 studies); use of ART (before: 5.3% to 42.2%; after: 30.3% to 34.3%; proportions varied across studies due to differences in which women were identified as at risk of using ART); and delivery via Caesarean section (before: 8/73, 11.0%; after: 36/75, 48.0%; 2 studies). In addition, women had a longer time to conception after surgery (two to five months; 2 studies) than before surgery (5 to 16 months; 2 studies). The proportions of women experiencing miscarriage (before: 19/123, 15.4%; after: 21/134, 15.7%; 3 studies) and stillbirth (before: 2/38, 5.3%; after: 3/80: 3.8%; 2 studies) were similar before and after surgery. Fewer women experienced gestational diabetes after surgery (before: 3/37, 8.1%; after: 0/37; 1 study), and the risk of preeclampsia was similar before and after surgery (before: 2/37, 5.4%; after: 0/37; 1 study). We are very uncertain of the effects of IBD-related surgery on these outcomes due to poor quality evidence, including confounding bias due to increased age of women after surgery.We rated evidence for all outcomes and comparisons as very low quality due to the observational nature of the data, inclusion of small studies with imprecise estimates, and high risk of bias among included studies. AUTHORS' CONCLUSIONS: The effect of surgical therapy for IBD on female infertility is uncertain. It is also uncertain if there are any differences in infertility among those undergoing open versus laparoscopic procedures. Previous surgery was associated with higher risk of miscarriage, use of ART, Caesarean section delivery, and giving birth to a low birth weight infant, but was not associated with risk of stillbirth, preterm delivery, or delivery of a small for gestational age infant. These findings are based on very low-quality evidence. As a result, definitive conclusions cannot be made, and future well-designed studies are needed to fully understand the impact of surgery on infertility and pregnancy outcomes.


Assuntos
Infertilidade Feminina/etiologia , Doenças Inflamatórias Intestinais/cirurgia , Taxa de Gravidez , Proctocolectomia Restauradora , Bolsas Cólicas/efeitos adversos , Feminino , Humanos , Infertilidade Feminina/epidemiologia , Complicações Pós-Operatórias/epidemiologia , Gravidez , Resultado da Gravidez , Proctocolectomia Restauradora/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Técnicas de Reprodução Assistida
3.
Pharm Dev Technol ; 23(9): 882-889, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28524719

RESUMO

Phosphine-borane complexes are recently developed redox-active drugs that are neuroprotective in models of optic nerve injury and radioprotective in endothelial cells. However, a single dose of these compounds is short-lived, necessitating the development of sustained-release formulations of these novel molecules. We screened a library of biodegradable co- and non-block polyester polymer systems for release of incorporated phosphine-borane complexes to evaluate them as drug delivery systems for use in chronic disease. Bis(3-propionic acid methyl ester)phenylphosphine borane complex (PB1) was combined with biodegradable polymers based on poly(D,L-lactide) (PDLLA), poly(L-lactide) (PLLA), poly(caprolactone) (PCL), poly(lactide-co-glycide) (PLGA), or poly(dioxanone-co-caprolactone) (PDOCL) to make polymer microdiscs, and release over time quantified. Of 22 polymer-PB1 formulations tested, 17 formed rigid polymers. Rates of release differed significantly based on the chemical structure of the polymer. PB1 released from PLGA microdiscs released most slowly, with the most linear release in polymers of 60:40 LA:GA, acid endcap, Mn 15 000-25 000 and 75:25 LA:GA, acid endcap, Mn 45 000-55 000. Biodegradable polymer systems can, therefore, be used to produce sustained-release formulations for redox-active phosphine-borane complexes, with PLGA-based systems most suitable for very slow release. The sustained release could enable translation to a clinical neuroprotective strategy for chronic diseases such as glaucoma.


Assuntos
Boranos/farmacocinética , Portadores de Fármacos/farmacocinética , Liberação Controlada de Fármacos , Fármacos Neuroprotetores/farmacocinética , Fosfinas/farmacocinética , Poliésteres/farmacocinética , Boranos/química , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Portadores de Fármacos/química , Fármacos Neuroprotetores/química , Fosfinas/química , Poliésteres/química
4.
Exp Eye Res ; 157: 34-37, 2017 04.
Artigo em Inglês | MEDLINE | ID: mdl-27955999

RESUMO

Within the field of glaucoma research, neuroprotection is defined as slowing the functional loss in glaucoma by a mechanism independent of lowering of intraocular pressure. There is currently a great potential for research surrounding neuroprotection as it relates to glaucoma. Anatomical targets for neuroprotection should focus on upstream rather than downstream factors, and could include any part of the retinal ganglion cell, the glia, especially astrocytes or Muller cells, and vasculature. The great number of anatomical targets is exceeded only by the number of possible biochemical pathways and potential treatments. Successful treatment may be accomplished through the targeting of one or even a combination of multiple pathways. Once a treatment is shown effective in vitro, it should be evaluated in vivo with carefully chosen animal models and studied in sufficient numbers to detect statistically and clinically significant effects. Such a drug should have few systemic side effects and its delivery should be optimized so as to encourage compliance. There are still a multitude of possible screens available to test the efficacy of a neuroprotective drug and a single gold standard is ideal for the accurate assessment and comparison of new drugs. Future studies in neuroprotection should investigate the genetic component of the disease, novel pharmaceutical agents for new or known pathways, modulations of scleral biomechanics, and relation to research of other complex disorders of the central nervous system.


Assuntos
Astrócitos/fisiologia , Glaucoma/tratamento farmacológico , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Doenças do Nervo Óptico/tratamento farmacológico , Células Ganglionares da Retina/efeitos dos fármacos , Pesquisa Translacional Biomédica , Animais , Axônios/fisiologia , Humanos , Células Ganglionares da Retina/fisiologia
5.
Thromb Res ; 218: 72-82, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36027629

RESUMO

Therapeutic anticoagulation remains a fundamental backbone in the treatment and prevention of venous thromboembolism. However, while modern therapies are increasingly safe, anticoagulation is not without risks, particularly in those at high risk for or with recent bleeding. When weighing concurrent risks and benefits in each challenging clinical scenario, an individualized assessment of the risk and acuity of bleeding should be balanced by the indication for anticoagulation. Addressing modifiable risk factors and routine re-evaluation of any changes in this balance is critical. This review outlines available data and current guidelines for the management of anticoagulation in high-risk populations, including those with thrombocytopenia, elderly and high-fall risk, inherited bleeding disorders, and in acute coronary syndrome. We also examine management after clinically significant bleeding episodes, including intracranial hemorrhage, gastrointestinal bleeding, hemoptysis, retroperitoneal bleeding, hematuria, and abnormal uterine bleeding. The aim is to provide a comprehensive review of available literature to guide clinicians in providing optimal, safe, and individualized care for patients in these challenging scenarios.


Assuntos
Trombocitopenia , Tromboembolia Venosa , Idoso , Anticoagulantes/uso terapêutico , Coagulação Sanguínea , Hemorragia/induzido quimicamente , Hemorragia/complicações , Hemorragia/prevenção & controle , Humanos , Trombocitopenia/induzido quimicamente , Tromboembolia Venosa/etiologia
6.
J Can Assoc Gastroenterol ; 4(3): 115-124, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-34056529

RESUMO

BACKGROUND AND AIMS: Surgical treatment of inflammatory bowel disease (IBD) may impair female fertility. We conducted a systematic review to determine the risk of infertility and pregnancy outcomes in women with IBD who underwent surgery. METHODS: We identified studies evaluating the impact of IBD surgery on infertility and pregnancy outcomes. Risk ratios (RR) and 95% confidence intervals (CIs) were pooled when data were presented using contingency tables. Odds ratios (OR) were pooled when raw numbers were not provided. GRADE was used to evaluate the certainty of evidence. RESULTS: Sixteen observational studies were included, comparing women with and without surgery, open and laparoscopic surgery and before and after surgery. All studies were of low quality. The effect of surgery on infertility at 12 months (RR 5.45, 95% CI 0.41 to 72.57) was uncertain. Similarly, the fertility effects of laparoscopic versus open surgery method were unclear (RR 0.70, 95% CI 0.38 to 1.27). The impact of IBD surgery on pregnancy outcomes should be interpreted with caution. Surgery was associated with miscarriage (OR 2.03, 95% CI 1.14 to 3.60), use of assisted reproductive technologies (RR 25.09, 95% CI 1.56 to 403.76) and caesarean section (RR 2.23, 95% CI 1.00 to 4.95), but not with stillbirth (RR 1.96, 95% CI 0.42 to 9.18), preterm birth (RR 1.91, 95% CI 0.67 to 5.48), low birth weight (RR 0.61, 95% CI 0.08 to 4.83) or small for gestational age (RR 2.54, 95% CI 0.80 to 8.01). CONCLUSION: The effect of surgical therapy for IBD on rates of female infertility and pregnancy-related outcomes was uncertain due to poor quality of existing literature.

7.
Can J Public Health ; 111(4): 515-522, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32285346

RESUMO

OBJECTIVES: To examine the four possible combinations of adherence to physical activity and screen time recommendations in adolescents and how the combinations relate to overweight and obesity. METHODS: A total of 9913 students in grades 7-12 were included in the present cross-sectional analyses. Moderate-to-vigorous physical activity (MVPA), screen time, and body mass index were self-reported. Multivariate logistic regression analysis was used to test the associations between combinations of MVPA (≥ 60 min/day [active] or < 60 min/day [inactive]) and screen time (≤ 2 h/day [not sedentary] or > 2 h/day [sedentary]) recommendations with overweight/obesity. RESULTS: We found that 53.1% of students in Ontario were considered "inactive+sedentary", 23.7% were considered "inactive+not sedentary", 12.1% were considered "active+sedentary", and 11.1% were considered "active+not sedentary". Some characteristics of "active+not sedentary" students (optimal category) included younger age, male gender, white ethnicity, higher socio-economic status, optimal sleep duration, and lower prevalence of cannabis use. After adjusting for relevant covariates, the "inactive+sedentary" group was more likely to report overweight/obesity than the "active+not sedentary" group (odds ratio [OR] = 1.71, 95% confidence interval [CI] = 1.26-2.32). The "inactive+not sedentary" group was also more likely to report overweight/obesity (OR = 1.54, 95% CI 1.20-1.97) while the "active+sedentary" group was not significantly associated with overweight/obesity (OR = 1.27, 95% CI 0.88-1.83). CONCLUSION: Children meeting both the physical activity and screen time recommendations are less likely to be classified as overweight/obese compared with any other combination. Future efforts are needed to target both MVPA and sedentary behaviour to address public health concerns such as excess weight.


Assuntos
Exercício Físico , Fidelidade a Diretrizes , Obesidade Infantil , Tempo de Tela , Adolescente , Estudos Transversais , Feminino , Fidelidade a Diretrizes/estatística & dados numéricos , Humanos , Masculino , Obesidade Infantil/epidemiologia
8.
Neurochem Int ; 99: 24-32, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27264910

RESUMO

Phosphine-borane complexes are novel cell-permeable drugs that protect neurons from axonal injury in vitro and in vivo. These drugs activate the extracellular signal-regulated kinases 1/2 (ERK1/2) cell survival pathway and are therefore neuroprotective, but do not scavenge superoxide. In order to understand the interaction between superoxide signaling of neuronal death and the action of phosphine-borane complexes, their biochemical activity in cell-free and in vitro assays was studied by electron paramagnetic resonance (EPR) spectrometry and using an intracellular dithiol reporter that becomes fluorescent when its disulfide bond is cleaved. These studies demonstrated that bis(3-propionic acid methyl ester) phenylphosphine-borane complex (PB1) and (3-propionic acid methyl ester) diphenylphosphine-borane complex (PB2) are potent intracellular disulfide reducing agents which are cell permeable. EPR and pharmacological studies demonstrated reducing activity but not scavenging of superoxide. Given that phosphine-borane complexes reduce cell injury from mitochondrial superoxide generation but do not scavenge superoxide, this implies a mechanism where an intracellular superoxide burst induces downstream formation of protein disulfides. The redox-dependent cleavage of the disulfides is therefore a novel mechanism of neuroprotection.


Assuntos
Boranos/metabolismo , Líquido Intracelular/metabolismo , Neuroproteção/fisiologia , Fosfinas/metabolismo , Animais , Boranos/química , Linhagem Celular , Dissulfetos/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Líquido Intracelular/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/fisiologia , Oxirredução , Fosfinas/química , Ratos , Suínos
9.
PLoS One ; 11(3): e0150416, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26958849

RESUMO

IMPORTANCE: RSV is a common illness among young children that causes significant morbidity and health care costs. OBJECTIVE: Routinely collected health administrative data can be used to track disease incidence, explore risk factors and conduct health services research. Due to potential for misclassification bias, the accuracy of data-elements should be validated prior to use. The objectives of this study were to validate an algorithm to accurately identify pediatric cases of hospitalized respiratory syncytial virus (RSV) from within Ontario's health administrative data, estimate annual incidence of hospitalization due to RSV and report the prevalence of major risk factors within hospitalized patients. STUDY DESIGN AND SETTING: A retrospective chart review was performed to establish a reference-standard cohort of children from the Ottawa region admitted to the Children's Hospital of Eastern Ontario (CHEO) for RSV-related disease in 2010 and 2011. Chart review data was linked to Ontario's administrative data and used to evaluate the diagnostic accuracy of algorithms of RSV-related ICD-10 codes within provincial hospitalization and emergency department databases. Age- and sex-standardized incidence was calculated over time, with trends in incidence assessed using Poisson regression. RESULTS: From a total of 1411 admissions, chart review identified 327 children hospitalized for laboratory confirmed RSV-related disease. Following linkage to administrative data and restriction to first admissions, there were 289 RSV patients in the reference-standard cohort. The best algorithm, based on hospitalization data, resulted in sensitivity 97.9% (95%CI: 95.5-99.2%), specificity 99.6% (95%CI: 98.2-99.8%), PPV 96.9% (95%CI: 94.2-98.6%), NPV 99.4% (95%CI: 99.4-99.9%). Incidence of hospitalized RSV in Ontario from 2005-2012 was 10.2 per 1000 children under 1 year and 4.8 per 1000 children aged 1 to 3 years. During the surveillance period, there was no identifiable increasing or decreasing linear trend in the incidence of hospitalized RSV, hospital length of stay and PICU admission rates. Among the Ontario RSV cohort, 16.3% had one or more major risk factors, with a decreasing trend observed over time. CONCLUSION: Children hospitalized for RSV-related disease can be accurately identified within population-based health administrative data. RSV is a major public health concern and incidence has not changed over time, suggesting a lack of progress in prevention.


Assuntos
Hospitalização/estatística & dados numéricos , Infecções por Vírus Respiratório Sincicial/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Incidência , Masculino , Ontário/epidemiologia , Estudos Retrospectivos
10.
PLoS One ; 10(12): e0145270, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26684837

RESUMO

PURPOSE: RGC-5 cells undergo differentiation into a neuronal phenotype with low concentrations of staurosporine. Although the RGC-5 cell line was initially thought to be of retinal ganglion cell origin, recent evidence suggests that the RGC-5 line could have been the result of contamination with 661W mouse cone photoreceptor cells. This raised the possibility that a cone photoreceptor cell line could be multipotent and could be differentiated to a neuronal phenotype. METHODS: 661W and RGC-5 cells, non-neuronal retinal astrocytes, retinal endothelial cells, retinal pericytes, M21 melanoma cells, K562 chronic myelogenous leukemia cells, and Daudi Burkitt lymphoma cells, were differentiated with staurosporine. The resulting morphology was quantitated using NeuronJ with respect to neurite counts and topology. RESULTS: Treatment with staurosporine induced similar-appearing morphological differentiation in both 661W and RGC-5 cells. The following measures were not significantly different between 661W and RGC-5 cells: number of neurites per cell, total neurite field length, number of neurite branch points, and cell viability. Neuronal-like differentiation was not observed in the other cell lines tested. CONCLUSIONS: 661W and RGC-5 cells have virtually identical and distinctive morphology when differentiated with low concentrations of staurosporine. This result demonstrates that a retinal neuronal precursor cell with cone photoreceptor lineage can be differentiated to express a neuronal morphology.


Assuntos
Diferenciação Celular/efeitos dos fármacos , Células Ganglionares da Retina/fisiologia , Animais , Linhagem Celular , Forma Celular/efeitos dos fármacos , Camundongos , Neuritos/efeitos dos fármacos , Neuritos/ultraestrutura , Ratos , Células Ganglionares da Retina/efeitos dos fármacos , Células Ganglionares da Retina/ultraestrutura , Estaurosporina/farmacologia
11.
Redox Biol ; 6: 73-79, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26188467

RESUMO

Exposure to radiation can damage endothelial cells in the irradiated area via the production of reactive oxygen species. We synthesized phosphine-borane complexes that reduce disulfide bonds and had previously been shown to interfere with redox-mediated signaling of cell death. We hypothesized that this class of drugs could interfere with the downstream effects of oxidative stress after irradiation and rescue endothelial cells from radiation damage. Cultured bovine aortic endothelial cells were plated for clonogenic assay prior to exposure to varying doses of irradiation from a (137)Cs irradiator and treated with various concentrations of bis(3-propionic acid methyl ester)phenylphosphine borane complex (PB1) at different time points. The clone-forming ability of the irradiated cells was assessed seven days after irradiation. We compared the radioprotective effects of PB1 with the aminothiol radioprotectant WR1065 and known superoxide scavengers. PB1 significantly protected bovine aortic endothelial cells from radiation damage, particularly when treated both before and after radiation. The radioprotection with 1 µM PB1 corresponded to a dose-reduction factor of 1.24. Radioprotection by PB1 was comparable to the aminothiol WR1065, but was significantly less toxic and required much lower concentrations of drug (1 µM vs. 4 mM, respectively). Superoxide scavengers were not radioprotective in this paradigm, indicating the mechanisms for both loss of clonogenicity and PB1 radioprotection are independent of superoxide signaling. These data demonstrate that PB1 is an effective redox-active radioprotectant for endothelial cells in vitro, and is radioprotective at a concentration approximately 4 orders of magnitude lower than the aminothiol WR1065 with less toxicity.


Assuntos
Boranos/farmacologia , Células Endoteliais/efeitos dos fármacos , Raios gama/efeitos adversos , Fosfinas/farmacologia , Protetores contra Radiação/farmacologia , Superóxidos/antagonistas & inibidores , Animais , Aorta/citologia , Aorta/efeitos dos fármacos , Aorta/metabolismo , Aorta/efeitos da radiação , Bovinos , Células Cultivadas , Células Clonais , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Células Endoteliais/efeitos da radiação , Humanos , Mercaptoetilaminas/farmacologia , Metaloporfirinas/farmacologia , Oxirredução , Polietilenoglicóis/farmacologia , Transdução de Sinais , Superóxido Dismutase/farmacologia , Superóxidos/metabolismo
12.
Invest Ophthalmol Vis Sci ; 53(7): 3990-8, 2012 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-22599583

RESUMO

PURPOSE: Light-induced oxidative stress is an important risk factor for age-related macular degeneration, but the downstream mediators of photoreceptor and retinal pigment epithelium cell death after photic injury are unknown. Given our previous identification of sulfhydryl/disulfide redox status as a factor in photoreceptor survival, we hypothesized that formation of one or more disulfide-linked homo- or hetero-dimeric proteins might signal photoreceptor death after light-induced injury. METHODS: Two-dimensional (non-reducing/reducing) gel electrophoresis of Wistar rat retinal homogenates after 10 hours of 10,000 lux (4200°K) light in vivo, followed by mass spectrometry identification of differentially oxidized proteins. RESULTS: The redox proteomic screen identified homodimers of visual arrestin (Arr1; S antigen) after toxic levels of light injury. Immunoblot analysis revealed a light duration-dependent formation of Arr1 homodimers, as well as other Arr1 oligomers. Immunoprecipitation studies revealed that the dimerization of Arr1 due to photic injury was distinct from association with its physiological binding partners, rhodopsin and enolase1. Systemic delivery of tris(2-carboxyethyl)phosphine, a specific disulfide reductant, both decreased Arr1 dimer formation and protected photoreceptors from light-induced degeneration in vivo. CONCLUSIONS: These findings suggest a novel arrestin-associated pathway by which oxidative stress could result in cell death, and identify disulfide-dependent dimerization as a potential therapeutic target in retinal degeneration.


Assuntos
Arrestina/metabolismo , Arrestinas/metabolismo , Dimerização , Traumatismos do Nervo Óptico/complicações , Células Fotorreceptoras/patologia , Proteômica/métodos , Degeneração Retiniana/metabolismo , Animais , Eletroforese em Gel Bidimensional , Immunoblotting , Imunoprecipitação , Luz/efeitos adversos , Masculino , Espectrometria de Massas , Traumatismos do Nervo Óptico/metabolismo , Traumatismos do Nervo Óptico/patologia , Oxirredução , Estresse Oxidativo , Células Fotorreceptoras/metabolismo , Lesões Experimentais por Radiação/complicações , Lesões Experimentais por Radiação/metabolismo , Lesões Experimentais por Radiação/patologia , Ratos , Ratos Wistar , Degeneração Retiniana/etiologia , Degeneração Retiniana/patologia , beta-Arrestina 1 , beta-Arrestinas
13.
J Int Soc Sports Nutr ; 7: 31, 2010 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-20932294

RESUMO

BACKGROUND: To determine the effects of supplemental fish oil (FO) on resting metabolic rate (RMR), body composition, and cortisol production in healthy adults. METHODS: A total of 44 men and women (34 ± 13y, mean+SD) participated in the study. All testing was performed first thing in the morning following an overnight fast. Baseline measurements of RMR were measured using indirect calorimetry using a facemask, and body composition was measured using air displacement plethysmography. Saliva was collected via passive drool and analyzed for cortisol concentration using ELISA. Following baseline testing, subjects were randomly assigned in a double blind manner to one of two groups: 4 g/d of Safflower Oil (SO); or 4 g/d of FO supplying 1,600 mg/d eicosapentaenoic acid (EPA) and 800 mg/d docosahexaenoic acid (DHA). All tests were repeated following 6 wk of treatment. Pre to post differences were analyzed using a treatment X time repeated measures ANOVA, and correlations were analyzed using Pearson's r. RESULTS: Compared to the SO group, there was a significant increase in fat free mass following treatment with FO (FO = +0.5 ± 0.5 kg, SO = -0.1 ± 1.2 kg, p = 0.03), a significant reduction in fat mass (FO = -0.5 ± 1.3 kg, SO = +0.2 ± 1.2 kg, p = 0.04), and a tendency for a decrease in body fat percentage (FO = -0.4 ± 1.3% body fat, SO = +0. 3 ± 1.5% body fat, p = 0.08). No significant differences were observed for body mass (FO = 0.0 ± 0.9 kg, SO = +0.2 ± 0.8 kg), RMR (FO = +17 ± 260 kcal, SO = -62 ± 184 kcal) or respiratory exchange ratio (FO = -0.02 ± 0.09, SO = +0.02 ± 0.05). There was a tendency for salivary cortisol to decrease in the FO group (FO = -0.064 ± 0.142 µg/dL, SO = +0.016 ± 0.272 µg/dL, p = 0.11). There was a significant correlation in the FO group between change in cortisol and change in fat free mass (r = -0.504, p = 0.02) and fat mass (r = 0.661, p = 0.001). CONCLUSION: 6 wk of supplementation with FO significantly increased lean mass and decreased fat mass. These changes were significantly correlated with a reduction in salivary cortisol following FO treatment.

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