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1.
Cell ; 146(1): 80-91, 2011 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-21729781

RESUMEN

Proper eukaryotic DNA replication requires temporal separation of helicase loading from helicase activation and replisome assembly. Using an in vitro assay for eukaryotic origin-dependent replication initiation, we investigated the control of these events. After helicase loading, we found that the Dbf4-dependent Cdc7 kinase (DDK) but not S phase cyclin-dependent kinase (S-CDK) is required for the initial origin recruitment of Sld3 and the Cdc45 helicase-activating protein. Likewise, in vivo, DDK drives early-firing-origin recruitment of Cdc45 before activation of S-CDK. After S-CDK activation, a second helicase-activating protein (GINS) and the remainder of the replisome are recruited to the origin. Finally, recruitment of lagging but not leading strand DNA polymerases depends on Mcm10 and DNA unwinding. Our studies identify distinct roles for DDK and S-CDK during helicase activation and support a model in which the leading strand DNA polymerase is recruited prior to origin DNA unwinding and RNA primer synthesis.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Quinasas Ciclina-Dependientes/metabolismo , Replicación del ADN , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , ADN Polimerasa I/metabolismo , Proteínas de Unión al ADN/metabolismo , Fase G1 , Proteínas Nucleares/metabolismo , Origen de Réplica , Fase S , Saccharomyces cerevisiae/citología
2.
Ophthalmology ; 131(5): 595-610, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38007198

RESUMEN

TOPIC: Review of the efficacy and safety of standard versus soft topical steroid application after cataract surgery. CLINICAL RELEVANCE: The control of postoperative inflammation is the mainstay of treatment after cataract surgery. However, no consensus exists regarding the postoperative steroid of choice. Basing the choice of topical postoperative steroidal treatment on high-quality data regarding both risks and benefits of various drugs would be advantageous for both patients and clinicians. METHODS: A systematic search of the PubMed, Scopus, and Embase electronic databases for all peer-reviewed published randomized control trials that included clinical outcomes of topical steroidal treatment after uneventful cataract surgery was performed. Individual study data were extracted and evaluated in a weighted pooled analysis including grading of total anterior chamber (AC) inflammation, AC cells, AC flare, postoperative visual acuity (VA), intraocular pressure (IOP), and rate of adverse events (AEs). RESULTS: Overall, 508 studies were found, of which 7 were eligible for the systematic review and ultimately were included for analysis, reporting on 593 patients from 5 countries. Age of included patients, when available, ranged between 3.7 and 73.4 years. Follow-up data were available for analysis at 1, 7, and 28 days after surgery. Except for a significantly lower grade of AC flare in the standard steroid group at day 7 (standardized mean difference, 0.26; 95% confidence interval, 0.05-0.47; I2 = 0%), inflammatory activity measurements displayed insignificant differences at every other follow-up (days 1 and 28 after surgery). Pooled analysis of IOP at each follow-up demonstrated a higher IOP at the 7-day visit in the standard steroid group, whereas IOP at other time points was comparable among the groups. Qualitative analysis of ocular AEs showed similarities among the groups. DISCUSSION: The findings of this study suggest that for the average patient, both groups produce a comparable effect on both AC inflammation and postoperative IOP and VA. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

3.
Cardiovasc Diabetol ; 23(1): 70, 2024 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-38360721

RESUMEN

BACKGROUND: Angiogenin, an enzyme belonging to the ribonucleases A superfamily, plays an important role in vascular biology. Here, we sought to study the association of plasma angiogenin and major adverse cardiovascular events (MACEs) in patients with type 2 diabetes (T2D). METHODS: This prospective study included 1083 T2D individuals recruited from a secondary hospital and a primary care facility. The primary outcome was a composite of four-point MACE (nonfatal myocardial infarction, stroke, unstable angina pectoris leading to hospitalization and cardiovascular death). Circulating angiogenin was measured by a proximity extension assay. Cox regression models were used to evaluate the association of baseline plasma angiogenin with the risk of MACE. RESULTS: During a median follow-up of 9.3 years, 109 (10%) MACE were identified. Plasma angiogenin was significantly higher in participants with MACE than in those without MACE (P < 0.001). Doubling of plasma angiogenin concentration was associated with a 3.10-fold (95% CI 1.84-5.22) increased risk for MACE. The association was only moderately attenuated after adjustment for demographic and cardiometabolic risk factors (adjusted HR 2.38, 95% CI 1.34-4.23) and remained statistically significant after additional adjustment for estimated glomerular filtration rate (eGFR) and urinary albumin to creatinine ratio (uACR) (adjusted HR 1.90, 95% CI 1.02-3.53). A consistent outcome was obtained when plasma angiogenin was analysed as a categorical variable in tertiles. CONCLUSIONS: Plasma angiogenin was associated with the risk of future cardiovascular events in patients with T2D and may be a promising novel biomarker for identifying high-risk T2D patients for early management.


Asunto(s)
Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Humanos , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/complicaciones , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/diagnóstico , Infarto del Miocardio/complicaciones , Estudios Prospectivos , Ribonucleasa Pancreática , Factores de Riesgo
4.
Cardiovasc Diabetol ; 23(1): 204, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38879473

RESUMEN

BACKGROUND: Diabetic kidney disease is an established risk factor for heart failure. However, the impact of incident heart failure on the subsequent risk of renal failure has not been systematically assessed in diabetic population. We sought to study the risk of progression to end stage kidney disease (ESKD) after incident heart failure in Asian patients with type 2 diabetes. METHODS: In this prospective cohort study, 1985 outpatients with type 2 diabetes from a regional hospital and a primary care facility in Singapore were followed for a median of 8.6 (interquartile range 6.2-9.6) years. ESKD was defined as a composite of progression to sustained eGFR below 15 ml/min/1.73m2, maintenance dialysis or renal death, whichever occurred first. RESULTS: 180 incident heart failure events and 181 incident ESKD events were identified during follow-up. Of 181 ESKD events, 38 (21%) occurred after incident heart failure. Compared to those did not progress to ESKD after incident heart failure (n = 142), participants who progressed to ESKD after heart failure occurrence were younger, had higher HbA1c and higher urine albumin-to-creatinine ratio at baseline. The excess risk of ESKD manifested immediately after heart failure occurrence, persisted for two years and was moderated thereafter. Cox regression suggested that, compared to counterparts with no heart failure event, participants with heart failure occurrence had 9.6 (95% CI 5.0- 18.3) fold increased risk for incident ESKD after adjustment for baseline cardio-renal risk factors including eGFR and albuminuria. It appeared that heart failure with preserved ejection fraction had a higher risk for ESKD as compared to those with reduced ejection fraction (adjusted HR 13.7 [6.3-29.5] versus 6.5 [2.3-18.6]). CONCLUSION: Incident heart failure impinges a high risk for progression to ESKD in individuals with type 2 diabetes. Our data highlight the need for intensive surveillance of kidney function after incident heart failure, especially within the first two years after heart failure diagnosis.


Asunto(s)
Diabetes Mellitus Tipo 2 , Nefropatías Diabéticas , Progresión de la Enfermedad , Tasa de Filtración Glomerular , Insuficiencia Cardíaca , Fallo Renal Crónico , Riñón , Humanos , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/fisiopatología , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiología , Masculino , Femenino , Persona de Mediana Edad , Factores de Riesgo , Anciano , Estudios Prospectivos , Incidencia , Factores de Tiempo , Nefropatías Diabéticas/epidemiología , Nefropatías Diabéticas/diagnóstico , Nefropatías Diabéticas/fisiopatología , Fallo Renal Crónico/epidemiología , Fallo Renal Crónico/diagnóstico , Fallo Renal Crónico/fisiopatología , Medición de Riesgo , Singapur/epidemiología , Riñón/fisiopatología , Pronóstico , Biomarcadores/sangre
5.
Retina ; 44(6): 950-953, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38215455

RESUMEN

INTRODUCTION: To determine whether the two popular artificial intelligence chatbots, ChatGPT and Bard, can provide high-quality information concerning procedure description, risks, benefits, and alternatives of various ophthalmic surgeries. METHODS: ChatGPT and Bard were prompted with questions pertaining to the description, potential risks, benefits, alternatives, and implications of not proceeding with various surgeries in different subspecialties of ophthalmology. Six common ophthalmic procedures were included in the authors' analysis. Two comprehensive ophthalmologists and one subspecialist graded each response independently using a 5-point Likert scale. RESULTS: Likert grading for accuracy was significantly higher for ChatGPT in comparison with Bard (4.5 ± 0.6 vs. 3.8 ± 0.8, P < 0.0001). Generally, ChatGPT performed better than Bard even when questions were stratified by the type of ophthalmic surgery. There was no significant difference between ChatGPT and Bard for response length (2,104.7 ± 271.4 characters vs. 2,441.0 ± 633.9 characters, P = 0.12). ChatGPT responded significantly slower than Bard (46.0 ± 3.0 vs. 6.6 ± 1.2 seconds, P < 0.0001). CONCLUSION: Both ChatGPT and Bard may offer accessible and high-quality information relevant to the informed consent process for various ophthalmic procedures. Nonetheless, both artificial intelligence chatbots overlooked the probability of adverse events, hence limiting their potential and introducing patients to information that may be difficult to interpret.


Asunto(s)
Inteligencia Artificial , Procedimientos Quirúrgicos Oftalmológicos , Humanos , Educación del Paciente como Asunto/métodos , Internet
6.
Appl Environ Microbiol ; 89(12): e0057023, 2023 12 21.
Artículo en Inglés | MEDLINE | ID: mdl-38009924

RESUMEN

IMPORTANCE: In waterlogged soils, iron plaque forms a reactive barrier between the root and soil, collecting phosphate and metals such as arsenic and cadmium. It is well established that iron-reducing bacteria solubilize iron, releasing these associated elements. In contrast, microbial roles in plaque formation have not been clear. Here, we show that there is a substantial population of iron oxidizers in plaque, and furthermore, that these organisms (Sideroxydans and Gallionella) are distinguished by genes for plant colonization and nutrient fixation. Our results suggest that iron-oxidizing and iron-reducing bacteria form and remodel iron plaque, making it a dynamic system that represents both a temporary sink for elements (P, As, Cd, C, etc.) as well as a source. In contrast to abiotic iron oxidation, microbial iron oxidation results in coupled Fe-C-N cycling, as well as microbe-microbe and microbe-plant ecological interactions that need to be considered in soil biogeochemistry, ecosystem dynamics, and crop management.


Asunto(s)
Gallionellaceae , Oryza , Contaminantes del Suelo , Hierro/metabolismo , Gallionellaceae/metabolismo , Oryza/microbiología , Ecosistema , Oxidación-Reducción , Bacterias/genética , Bacterias/metabolismo , Suelo/química , Contaminantes del Suelo/metabolismo , Raíces de Plantas/microbiología , Cadmio/metabolismo
7.
Appl Environ Microbiol ; 88(2): e0159521, 2022 01 25.
Artículo en Inglés | MEDLINE | ID: mdl-34788064

RESUMEN

Sideroxydans lithotrophicus ES-1 grows autotrophically either by Fe(II) oxidation or by thiosulfate oxidation, in contrast to most other isolates of neutrophilic Fe(II)-oxidizing bacteria (FeOB). This provides a unique opportunity to explore the physiology of a facultative FeOB and constrain the genes specific to Fe(II) oxidation. We compared the growth of S. lithotrophicus ES-1 on Fe(II), thiosulfate, and both substrates together. While initial growth rates were similar, thiosulfate-grown cultures had higher yield with or without Fe(II) present, which may give ES-1 an advantage over obligate FeOB. To investigate the Fe(II) and S oxidation pathways, we conducted transcriptomics experiments, validated with reverse transcription-quantitative PCR (RT-qPCR). We explored the long-term gene expression response at different growth phases (over days to a week) and expression changes during a short-term switch from thiosulfate to Fe(II) (90 min). The dsr and sox sulfur oxidation genes were upregulated in thiosulfate cultures. The Fe(II) oxidase gene cyc2 was among the top expressed genes during both Fe(II) and thiosulfate oxidation, and addition of Fe(II) to thiosulfate-grown cells caused an increase in cyc2 expression. These results support the role of Cyc2 as the Fe(II) oxidase and suggest that ES-1 maintains readiness to oxidize Fe(II), even in the absence of Fe(II). We used gene expression profiles to further constrain the ES-1 Fe(II) oxidation pathway. Notably, among the most highly upregulated genes during Fe(II) oxidation were genes for alternative complex III, reverse electron transport, and carbon fixation. This implies a direct connection between Fe(II) oxidation and carbon fixation, suggesting that CO2 is an important electron sink for Fe(II) oxidation. IMPORTANCE Neutrophilic FeOB are increasingly observed in various environments, but knowledge of their ecophysiology and Fe(II) oxidation mechanisms is still relatively limited. Sideroxydans isolates are widely observed in aquifers, wetlands, and sediments, and genome analysis suggests metabolic flexibility contributes to their success. The type strain ES-1 is unusual among neutrophilic FeOB isolates, as it can grow on either Fe(II) or a non-Fe(II) substrate, thiosulfate. Almost all our knowledge of neutrophilic Fe(II) oxidation pathways comes from genome analyses, with some work on metatranscriptomes. This study used culture-based experiments to test the genes specific to Fe(II) oxidation in a facultative FeOB and refine our model of the Fe(II) oxidation pathway. We gained insight into how facultative FeOB like ES-1 connect Fe, S, and C biogeochemical cycling in the environment and suggest a multigene indicator would improve understanding of Fe(II) oxidation activity in environments with facultative FeOB.


Asunto(s)
Transcripción Reversa , Transcriptoma , Compuestos Ferrosos/metabolismo , Gallionellaceae , Oxidación-Reducción , Reacción en Cadena de la Polimerasa
8.
Med Mycol ; 60(7)2022 Jul 08.
Artículo en Inglés | MEDLINE | ID: mdl-35749577

RESUMEN

Fungal keratitis is a devastating and difficult-to-treat ocular infection with high morbidity. Understanding geographic microbiological and clinical trends helps to guide rapid and effective treatment. We therefore report the characteristics and outcomes of fungal keratitis in Toronto,ON Canada, over a 20-year period. An electronic search of microbiology records at University Health Network, Toronto, ON, Canada identified all patients with positive corneal fungal culture over a 20-year period seen at our tertiary referral cornea practice. Review of corresponding patient charts identified demographic and microbiological details, clinical course, treatment regimen, and final outcomes associated with each episode of culture-positive fungal keratitis. A total of 46 patients with 51 discrete fungal keratitis episodes were included. Five patients experienced recurrent fungal keratitis. Candida species accounted for 60.8% of positive fungal cultures, followed by Filamentous species at 35.3%. Preferred initial anti-fungal treatment was topical amphotericin at 36.7% followed by topical voriconazole at 32.6%. Surgical intervention was required in 48.9% with therapeutic penetrating keratoplasty being the most common procedure (22.4%). Final visual acuity (VA) of <20/200 was attributed to 58% of patients in this study. Risk factors for poor outcomes included poor VA, topical steroid use at presentation, Candida involvement, history of ocular surface disease, organic ocular trauma, or prior corneal transplantation. Candida is the most frequent keratomycotic pathogen in Toronto. Risk factors for poor visual outcome include prior corneal transplantation, ocular surface disease/trauma, or pre-existing topical steroid use. Early suspicion, diagnosis and treatment are paramount for best clinical outcomes. LAY SUMMARY: Fungal keratitis can cause severe vision loss without effective treatment. In Toronto, Candida had been the most common species over a 20-year period. Poor clinical outcome was associated with low presenting visual acuity, previous corneal transplant, topical steroid use, trauma, and Candida involvement.


Asunto(s)
Úlcera de la Córnea , Infecciones Fúngicas del Ojo , Animales , Antifúngicos/uso terapéutico , Candida , Córnea/microbiología , Úlcera de la Córnea/microbiología , Úlcera de la Córnea/veterinaria , Infecciones Fúngicas del Ojo/diagnóstico , Infecciones Fúngicas del Ojo/tratamiento farmacológico , Infecciones Fúngicas del Ojo/epidemiología , Infecciones Fúngicas del Ojo/veterinaria , Humanos , Estudios Retrospectivos , Voriconazol/uso terapéutico
9.
Environ Sci Technol ; 56(23): 17443-17453, 2022 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-36417801

RESUMEN

Fe(II) clays are common across many environments, making them a potentially significant microbial substrate, yet clays are not well established as an electron donor. Therefore, we explored whether Fe(II)-smectite supports the growth of Sideroxydans lithotrophicus ES-1, a microaerophilic Fe(II)-oxidizing bacterium (FeOB), using synthesized trioctahedral Fe(II)-smectite and 2% oxygen. S. lithotrophicus grew substantially and can oxidize Fe(II)-smectite to a higher extent than abiotic oxidation, based on X-ray near-edge spectroscopy (XANES). Sequential extraction showed that edge-Fe(II) is oxidized before interior-Fe(II) in both biotic and abiotic experiments. The resulting Fe(III) remains in smectite, as secondary minerals were not detected in biotic and abiotic oxidation products by XANES and Mössbauer spectroscopy. To determine the genes involved, we compared S. lithotrophicus grown on smectite versus Fe(II)-citrate using reverse-transcription quantitative PCR and found that cyc2 genes were highly expressed on both substrates, while mtoA was upregulated on smectite. Proteomics confirmed that Mto proteins were only expressed on smectite, indicating that ES-1 uses the Mto pathway to access solid Fe(II). We integrate our results into a biochemical and mineralogical model of microbial smectite oxidation. This work increases the known substrates for FeOB growth and expands the mechanisms of Fe(II)-smectite alteration in the environment.


Asunto(s)
Compuestos Ferrosos , Hierro , Hierro/química , Arcilla , Oxidación-Reducción , Compuestos Ferrosos/metabolismo
10.
Eye Contact Lens ; 48(12): 493-496, 2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-35984104

RESUMEN

OBJECTIVES: To assess outcomes of limbal stem cell deficiency (LSCD) in patients treated with Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE). METHODS: Retrospective case series. Patients with LSCD who received PROSE treatment were included. Data including best-corrected visual acuity (BCVA) and LSCD staging before and after PROSE dispensing were collected to characterize each case. RESULTS: Five eyes of four patients were included. All patients were female, with an age range of 21 to 80 years. Each patient received a PROSE device with diameters ranging from 16 to 18.5 mm. Follow-up ranged from 11 to 29 months. Tolerated wear times ranged from 3.5 to 10 hr daily. Four eyes showed improved BCVA and unchanged LSCD staging as per the global consensus after PROSE treatment. Three of these eyes had stage 3 and one had stage 1C LSCD at diagnosis. The fifth eye had worse BCVA and recurrence of stage 3 LSCD post-living-related conjunctival limbal allograft transplant despite PROSE treatment. CONCLUSIONS: Prosthetic Replacement of the Ocular Surface Ecosystem may be a viable treatment for LSCD, including severe cases, because it can provide symptom relief and improve vision. Its customizability, as demonstrated in this study, is beneficial for troubleshooting issues with fitting. Future studies are needed to further assess PROSE as treatment for LSCD.


Asunto(s)
Enfermedades de la Córnea , Limbo de la Córnea , Humanos , Femenino , Adulto Joven , Adulto , Persona de Mediana Edad , Anciano , Anciano de 80 o más Años , Masculino , Estudios Retrospectivos , Ecosistema , Agudeza Visual , Estudios de Seguimiento , Enfermedades de la Córnea/cirugía , Enfermedades de la Córnea/diagnóstico , Células Madre
11.
Eye Contact Lens ; 48(11): 471-478, 2022 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-35973371

RESUMEN

OBJECTIVES: To assess outcomes of the Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) treatment in patients with advanced Terrien marginal degeneration (TMD). METHODS: This is a retrospective case series of patients with advanced TMD who were assessed and fit with customized PROSE lenses. Data were collected on PROSE fitting details including visual acuity (VA) before and after PROSE, slit-lamp findings, and corneal tomography scans. RESULTS: Six eyes in four patients were included. All patients attempted at least one other contact lens (CL) modality before PROSE. Some patients had corneal comorbidities such as pseudopterygium and pseudobleb that contributed to intolerance to previous lenses and warranted extra considerations in the fitting process. With PROSE, VA improved in all six eyes. Patients with structural corneal comorbidities achieved improved vision, comfort, and lens tolerance with PROSE. Two eyes had noncorneal ocular comorbidities that limited PROSE efficacy. Another eye discontinued PROSE wear because of limbal stem-cell disease progression necessitating a limbal stem-cell transplant. CONCLUSIONS: PROSE treatment can be an effective option to improve vision and comfort for patients with advanced TMD who are intolerant to first-line therapeutic CL modalities, even in the presence of other corneal comorbidities.


Asunto(s)
Enfermedades de la Córnea , Distrofias Hereditarias de la Córnea , Humanos , Esclerótica , Estudios Retrospectivos , Ecosistema , Ajuste de Prótesis/efectos adversos , Enfermedades de la Córnea/cirugía , Enfermedades de la Córnea/etiología
12.
Cell Tissue Bank ; 23(4): 685-693, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34773206

RESUMEN

To gather information from stakeholders involved in corneal donation and transplantation to inform discussion at the "National Consensus Forum on Improving Cornea Donation and Transplantation Access in Canada" held in February 2020, survey questions were posed to eye banks, transplanting ophthalmologists and organ donation organizations across Canada to learn more about demand, wait times, and access to tissue for transplant. The survey response rate was one hundred percent (100%) for eye banks and organ donation organizations while 64 percent (64%) of transplant ophthalmologists provided feedback. A number of opportunities for improvement were identified including: demand forecasting; infrastructure and strategies to align supply with demand; data collection and benchmarking of wait times for assessment and transplant to support consistency, equitability and transparency in access; and national collaboration in the development of a data strategy to accurately measure demand and access to cornea transplants in a consistent manner across all provinces to facilitate equity in access nationally.


Asunto(s)
Trasplante de Córnea , Obtención de Tejidos y Órganos , Humanos , Donantes de Tejidos , Canadá , Bancos de Ojos
13.
Environ Sci Technol ; 55(13): 9362-9371, 2021 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-34110796

RESUMEN

Organic ligands are widely distributed and can affect microbially driven Fe biogeochemical cycles, but effects on microbial iron oxidation have not been well quantified. Our work used a model microaerophilic Fe(II)-oxidizing bacterium Sideroxydans lithotrophicus ES-1 to quantify biotic Fe(II) oxidation rates in the presence of organic ligands at 0.02 atm O2 and pH 6.0. We used two common Fe chelators with different binding strengths: citrate (log KFe(II)-citrate = 3.20) and nitrilotriacetic acid (NTA) (log KFe(II)-NTA = 8.09) and two standard humic substances, Pahokee peat humic acid (PPHA) and Suwannee River fulvic acid (SRFA). Our results provide rate constants for biotic and abiotic Fe(II) oxidation over different ligand concentrations and furthermore demonstrate that various models and natural iron-binding ligands each have distinct effects on abiotic versus biotic Fe(II) oxidation rates. We show that NTA accelerates abiotic oxidation and citrate has negligible effects, making it a better laboratory chelator. The humic substances only affect biotic Fe(II) oxidation, via a combination of chelation and electron transfer. PPHA accelerates biotic Fe(II) oxidation, while SRFA decelerates or accelerates the rate depending on concentration. The specific nature of organic-Fe microbe interactions may play key roles in environmental Fe(II) oxidation, which have cascading influences on cycling of nutrients and contaminants that associate with Fe oxide minerals.


Asunto(s)
Compuestos Férricos , Compuestos Ferrosos , Gallionellaceae , Ligandos , Oxidación-Reducción
14.
Eye Contact Lens ; 47(3): 149-153, 2021 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-33196502

RESUMEN

PURPOSE: To review the surgical modalities available to treat Mackie stage 2 and stage 3 neurotrophic keratopathy. METHODS: Literature review and technique descriptions. RESULTS: The following procedures are described in detail with accompanying videos: temporary, permanent, and botox-assisted tarsorrhaphy; amniotic membrane transplant; keratoplasty with amniotic membrane and tarsorrhaphy augmentation; Gunderson and conjunctival pedicle flaps; buccal graft transplantation; and neurotization. CONCLUSION: A variety of surgical options exist to manage neurotrophic keratopathy when medical treatments alone fail to resolve epitheliopathy. Ongoing protection and optimization of the ocular surface health remains crucial to prevent recurrent epithelial breakdown.


Asunto(s)
Distrofias Hereditarias de la Córnea , Trasplante de Córnea , Queratitis , Transferencia de Nervios , Amnios/trasplante , Humanos
15.
Eye Contact Lens ; 47(7): 394-400, 2021 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-33769992

RESUMEN

OBJECTIVES: To investigate underlying diagnoses and outcomes of patients undergoing Prosthetic Replacement of the Ocular Surface Ecosystem (PROSE) treatment at the first Canadian PROSE center. METHODS: A retrospective chart review was conducted on patients referred for PROSE treatment and fitted with PROSE devices from 2018 to 2020. Data were collected on diagnoses, presenting symptoms, previous lens modalities attempted, best-corrected visual acuities (BCVAs) pre-PROSE and post-PROSE, daily wear time, and failure rates. Best-corrected visual acuities pre-PROSE and post-PROSE were compared to evaluate visual improvement. RESULTS: In total, 78 patients (126 eyes) were analyzed. The most common diagnoses were keratoconus (n=39 eyes) and postcorneal graft (n=15) in the distorted cornea group, and limbal stem cell deficiency (n=17) and graft versus host disease (n=15) in the ocular surface disease (OSD) group. Most frequent symptoms included blur, photophobia, and pain. Most common lens modalities attempted pre-PROSE were conventional scleral lenses and glasses. The overall mean BCVA improvement was 0.40 logarithm of the minimal angle of resolution (logMAR) (4-lines Snellen) (P<0.0001). Best-corrected visual acuities improvement in the distorted cornea group (0.52 logMAR, 5-lines) was significantly greater than in the OSD group (0.29 logMAR, 3-lines) (P=0.004). CONCLUSIONS: Prosthetic replacement of the ocular surface ecosystem treatment can provide significant visual improvement for patients with distorted corneal surfaces and OSDs who failed other lens modalities.


Asunto(s)
Lentes de Contacto , Enfermedades de la Córnea , Queratocono , Canadá , Enfermedades de la Córnea/cirugía , Ecosistema , Humanos , Estudios Retrospectivos , Esclerótica
16.
Appl Environ Microbiol ; 86(24)2020 11 24.
Artículo en Inglés | MEDLINE | ID: mdl-33008825

RESUMEN

Natural attenuation of heavy metals occurs via coupled microbial iron cycling and metal precipitation in creeks impacted by acid mine drainage (AMD). Here, we describe the isolation, characterization, and genomic sequencing of two iron-oxidizing bacteria (FeOB) species: Thiomonas ferrovorans FB-6 and Thiomonas metallidurans FB-Cd, isolated from slightly acidic (pH 6.3), Fe-rich, AMD-impacted creek sediments. These strains precipitated amorphous iron oxides, lepidocrocite, goethite, and magnetite or maghemite and grew at a pH optimum of 5.5. While Thiomonas spp. are known as mixotrophic sulfur oxidizers and As oxidizers, the FB strains oxidized Fe, which suggests they can efficiently remove Fe and other metals via coprecipitation. Previous evidence for Thiomonas sp. Fe oxidation is largely ambiguous, possibly because of difficulty demonstrating Fe oxidation in heterotrophic/mixotrophic organisms. Therefore, we also conducted a genomic analysis to identify genetic mechanisms of Fe oxidation, other metal transformations, and additional adaptations, comparing the two FB strain genomes with 12 other Thiomonas genomes. The FB strains fall within a relatively novel group of Thiomonas strains that includes another strain (b6) with solid evidence of Fe oxidation. Most Thiomonas isolates, including the FB strains, have the putative iron oxidation gene cyc2, but only the two FB strains possess the putative Fe oxidase genes mtoAB The two FB strain genomes contain the highest numbers of strain-specific gene clusters, greatly increasing the known Thiomonas genetic potential. Our results revealed that the FB strains are two distinct novel species of Thiomonas with the genetic potential for bioremediation of AMD via iron oxidation.IMPORTANCE As AMD moves through the environment, it impacts aquatic ecosystems, but at the same time, these ecosystems can naturally attenuate contaminated waters via acid neutralization and catalyzing metal precipitation. This is the case in the former Ronneburg uranium-mining district, where AMD impacts creek sediments. We isolated and characterized two iron-oxidizing Thiomonas species that are mildly acidophilic to neutrophilic and that have two genetic pathways for iron oxidation. These Thiomonas species are well positioned to naturally attenuate AMD as it discharges across the landscape.


Asunto(s)
Burkholderiales/metabolismo , Hierro/metabolismo , Ríos/microbiología , Aguas Residuales/microbiología , Alemania , Minería , Oxidación-Reducción
17.
Cancer ; 125(14): 2409-2422, 2019 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-31012964

RESUMEN

BACKGROUND: Over 96% of high-grade ovarian carcinomas and 50% of all cancers are characterized by alterations in the p53 gene. Therapeutic strategies to restore and/or reactivate the p53 pathway have been challenging. By contrast, p63, which shares many of the downstream targets and functions of p53, is rarely mutated in cancer. METHODS: A novel strategy is presented for circumventing alterations in p53 by inducing the tumor-suppressor isoform TAp63 (transactivation domain of tumor protein p63) through its direct downstream target, microRNA-130b (miR-130b), which is epigenetically silenced and/or downregulated in chemoresistant ovarian cancer. RESULTS: Treatment with miR-130b resulted in: 1) decreased migration/invasion in HEYA8 cells (p53 wild-type) and disruption of multicellular spheroids in OVCAR8 cells (p53-mutant) in vitro, 2) sensitization of HEYA8 and OVCAR8 cells to cisplatin (CDDP) in vitro and in vivo, and 3) transcriptional activation of TAp63 and the B-cell lymphoma (Bcl)-inhibitor B-cell lymphoma 2-like protein 11 (BIM). Overexpression of TAp63 was sufficient to decrease cell viability, suggesting that it is a critical downstream effector of miR-130b. In vivo, combined miR-130b plus CDDP exhibited greater therapeutic efficacy than miR-130b or CDDP alone. Mice that carried OVCAR8 xenograft tumors and were injected with miR-130b in 1,2-dioleoyl-sn-glycero-3-phosphatidylcholine (DOPC) liposomes had a significant decrease in tumor burden at rates similar to those observed in CDDP-treated mice, and 20% of DOPC-miR-130b plus CDDP-treated mice were living tumor free. Systemic injections of scL-miR-130b plus CDDP in a clinically tested, tumor-targeted nanocomplex (scL) improved survival in 60% and complete remissions in 40% of mice that carried HEYA8 xenografts. CONCLUSIONS: The miR-130b/TAp63 axis is proposed as a new druggable pathway that has the potential to uncover broad-spectrum therapeutic options for the majority of p53-altered cancers.


Asunto(s)
MicroARNs/uso terapéutico , Mutación Missense , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/genética , Factores de Transcripción/genética , Activación Transcripcional/genética , Proteína p53 Supresora de Tumor/genética , Proteínas Supresoras de Tumor/genética , Animales , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Sitios de Unión , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Cisplatino/farmacología , Cisplatino/uso terapéutico , Resistencia a Antineoplásicos/efectos de los fármacos , Femenino , Humanos , Liposomas , Ratones , Ratones Desnudos , MicroARNs/administración & dosificación , MicroARNs/genética , MicroARNs/metabolismo , Invasividad Neoplásica/prevención & control , Isoformas de Proteínas/genética , Transducción de Señal/efectos de los fármacos , Factores de Transcripción/metabolismo , Transfección , Proteína p53 Supresora de Tumor/metabolismo , Proteínas Supresoras de Tumor/metabolismo , Ensayos Antitumor por Modelo de Xenoinjerto
18.
Cardiovasc Diabetol ; 18(1): 65, 2019 05 30.
Artículo en Inglés | MEDLINE | ID: mdl-31146758

RESUMEN

BACKGROUND: Haptoglobin (Hp) is an abundant plasma protein with anti-oxidant properties. Hp polymorphism is associated with cardio-metabolic dysfunction but the allele conferring risk of developing acute myocardial infarction (AMI) in type 2 diabetes (T2D) patients is unclear. This study aimed to investigate the association of Hp phenotype (Hp 1-1, 2-1 and 2-2) with incident AMI in Chinese T2D patients. METHODS: This prospective study included Chinese T2D participants from the Singapore Study of Macro-angiopathy and Micro-vascular Reactivity in Type 2 Diabetes (SMART2D) and Diabetic Nephropathy (DN) cohorts. Information on incidence of non-fatal AMI was collected by data linkage with the Singapore Myocardial Infarction Registry. Hp phenotype was determined using enzyme-linked immunosorbent assay. Cox proportional hazards regression models were used to evaluate the association of Hp phenotype with incident AMI, adjusted for traditional risk factors separately in two cohorts, then meta-analysed. RESULTS: In total, 2324 Chinese participants (SMART2D; N = 1034, mean age [SD] of 59 [11]) and (DN: N = 1290, mean age [SD] of 58 [12]) were included in this study. There were total of 30 (56 events per 10,000 patient-years) and 99 (128 events per 10,000 patient-years) AMI events in SMART2D and DN cohorts respectively. In meta-analysis, presence of Hp 1 allele conferred 43% (hazard ratio [HR] = 1.43 [95% CI 1.10-1.87], P = 0.008, Phet = 0.413) increased risk of incident AMI, independent of age, sex, smoking, body mass index, HbA1c, diabetes duration, lipids, hypertension, renal function and usage of insulin and RAS antagonist. In adjusted model, compared to Hp 2-2 groups, individuals with Hp 1-1 (HR = 2.18 [95% CI 1.19-3.76], P = 0.010, Phet = 0.193) and Hp 2-1 (HR = 1.45 [95% CI 0.98-2.14], P = 0.065, Phet = 0.576) were at a higher risk of incident AMI. Moreover, compared to Hp 2-2 groups, non-Hp 2-2 groups (Hp 1-1 and Hp 2-1) were at 55% increased risk of incident AMI (HR = 1.55 [95% CI 1.07-2.24], P = 0.021, Phet = 0.940). CONCLUSIONS: Hp 1-1 phenotype was associated with increased risk of incident AMI, independent of traditional risk factors, in Chinese patients with T2D. Hp phenotyping may allow for identification of T2D individuals at higher risk for onset of AMI. However, further studies are needed to understand the underlying mechanism between Hp alleles and risk for AMI.


Asunto(s)
Pueblo Asiatico , Diabetes Mellitus Tipo 2/etnología , Haptoglobinas/metabolismo , Infarto del Miocardio/etnología , Anciano , China/etnología , Diabetes Mellitus Tipo 2/sangre , Diabetes Mellitus Tipo 2/diagnóstico , Femenino , Haptoglobinas/genética , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Infarto del Miocardio/sangre , Infarto del Miocardio/diagnóstico , Infarto del Miocardio/genética , Polimorfismo Genético , Pronóstico , Estudios Prospectivos , Medición de Riesgo , Factores de Riesgo , Singapur/epidemiología , Factores de Tiempo
19.
J Pharm Pharm Sci ; 22(1): 49-56, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30636670

RESUMEN

Dry eye disease (DED) is a common inflammatory disorder of the ocular surface. Millions of people are affected by DED worldwide. Lifitegrast is a novel drug designed to inhibit DED-associated ocular inflammation. Four clinical trials have shown that lifitegrast is well tolerated and effective in improving symptoms and signs of DED over 12 weeks. A fifth trial showed long-term safety over 1 year. Lifitegrast has been in clinical use for more than one year in the United States and was recently approved in Canada (in December 2017). In this review, we discuss lifitegrast's novel mechanism of action and provide an overview of its clinical trial program.


Asunto(s)
Síndromes de Ojo Seco/tratamiento farmacológico , Soluciones Oftálmicas/uso terapéutico , Fenilalanina/análogos & derivados , Sulfonas/uso terapéutico , Animales , Ensayos Clínicos como Asunto , Humanos , Fenilalanina/uso terapéutico , Resultado del Tratamiento
20.
Mol Cell ; 40(3): 353-63, 2010 Nov 12.
Artículo en Inglés | MEDLINE | ID: mdl-21070963

RESUMEN

Activation of the eukaryotic replicative DNA helicase, the Mcm2-7 complex, requires phosphorylation by Cdc7/Dbf4 (Dbf4-dependent kinase or DDK), which, in turn, depends on prior phosphorylation of Mcm2-7 by an unknown kinase (or kinases). We identified DDK phosphorylation sites on Mcm4 and Mcm6 and found that phosphorylation of either subunit suffices for cell proliferation. Importantly, prior phosphorylation of either S/T-P or S/T-Q motifs on these subunits is required for DDK phosphorylation of Mcm2-7 and for normal S phase passage. Phosphomimetic mutations of DDK target sites bypass both DDK function and mutation of the priming phosphorylation sites. Mrc1 facilitates Mec1 phosphorylation of the S/T-Q motifs of chromatin-bound Mcm2-7 during S phase to activate replication. Genetic interactions between priming site mutations and MRC1 or TOF1 deletion support a role for these modifications in replication fork stability. These findings identify regulatory mechanisms that modulate origin firing and replication fork assembly during cell cycle progression.


Asunto(s)
Proteínas de Ciclo Celular/metabolismo , Proteínas Cromosómicas no Histona/metabolismo , Proteínas de Unión al ADN/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/enzimología , Secuencia de Aminoácidos , Aminoácidos , Ciclo Celular , Cromatina/metabolismo , Componente 7 del Complejo de Mantenimiento de Minicromosoma , Modelos Biológicos , Datos de Secuencia Molecular , Mutación/genética , Fenotipo , Fosforilación , Saccharomyces cerevisiae/citología , Proteínas de Saccharomyces cerevisiae/química
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