Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 1.178
Filtrar
1.
Arch. argent. pediatr ; 122(2): e202202948, abr. 2024. tab
Artigo em Inglês, Espanhol | LILACS, BINACIS | ID: biblio-1537622

RESUMO

Objetivo. Proporcionar un marco para profesionales de la salud que tratan a pacientes pediátricos bajo terapia con glucocorticoides (GC) y desarrollar recomendaciones para la prevención y el tratamiento de la osteoporosis inducida por GC en la población pediátrica. Métodos. Un panel de expertos en enfermedades óseas y pediátricas generó una serie de preguntas PICO que abordan aspectos relacionados con la prevención y el tratamiento de osteoporosis en pacientes bajo tratamiento con GC. Siguiendo la metodología GRADE, se realizó una revisión sistemática de la literatura, se resumieron las estimaciones del efecto y se calificó la calidad de la evidencia. Luego se procedió a la votación y a la formulación de las recomendaciones. Resultados. Se desarrollaron 7 recomendaciones y 6 principios generales para osteoporosis inducida por GC en población pediátrica. Conclusión. Estas recomendaciones proporcionan orientación para los médicos que deben tomar decisiones en pacientes pediátricos bajo tratamiento con GC.


Objective. To provide a framework for healthcare professionals managing pediatric patients who are on active glucocorticoid (GC) therapy and to develop recommendations for the prevention and treatment of GC-induced osteoporosis in the pediatric population. Methods. A panel of experts on bone and pediatric diseases developed a series of PICO questions that address issues related to the prevention and treatment of osteoporosis in patients on GC therapy. In accordance with the GRADE approach, we conducted a systematic review of the literature, summarized effect estimations, and classified the quality of the evidence. Then, voting and the formulation of recommendations followed. Results. Seven recommendations and six general principles were developed for GC-induced osteoporosis in the pediatric population. Conclusion. These recommendations provide guidance for clinicians who must make decisions concerning pediatric patients undergoing treatment with GC.


Assuntos
Humanos , Criança , Osteoporose/induzido quimicamente , Osteoporose/prevenção & controle , Osteoporose/tratamento farmacológico , Glucocorticoides/efeitos adversos
3.
Arch Argent Pediatr ; 122(2): e202202948, 2024 04 01.
Artigo em Inglês, Espanhol | MEDLINE | ID: mdl-37382585

RESUMO

Objective. To provide a framework for healthcare professionals managing pediatric patients who are on active glucocorticoid (GC) therapy and to develop recommendations for the prevention and treatment of GC-induced osteoporosis in the pediatric population. Methods. A panel of experts on bone and pediatric diseases developed a series of PICO questions that address issues related to the prevention and treatment of osteoporosis in patients on GC therapy. In accordance with the GRADE approach, we conducted a systematic review of the literature, summarized effect estimations, and classified the quality of the evidence. Then, voting and the formulation of recommendations followed. Results. Seven recommendations and six general principles were developed for GC-induced osteoporosis in the pediatric population. Conclusion. These recommendations provide guidance for clinicians who must make decisions concerning pediatric patients undergoing treatment with GC.


Objetivo. Proporcionar un marco para profesionales de la salud que tratan a pacientes pediátricos bajo terapia con glucocorticoides (GC) y desarrollar recomendaciones para la prevención y el tratamiento de la osteoporosis inducida por GC en la población pediátrica. Métodos. Un panel de expertos en enfermedades óseas y pediátricas generó una serie de preguntas PICO que abordan aspectos relacionados con la prevención y el tratamiento de osteoporosis en pacientes bajo tratamiento con GC. Siguiendo la metodología GRADE, se realizó una revisión sistemática de la literatura, se resumieron las estimaciones del efecto y se calificó la calidad de la evidencia. Luego se procedió a la votación y a la formulación de las recomendaciones. Resultados. Se desarrollaron 7 recomendaciones y 6 principios generales para osteoporosis inducida por GC en población pediátrica. Conclusión. Estas recomendaciones proporcionan orientación para los médicos que deben tomar decisiones en pacientes pediátricos bajo tratamiento con GC.


Assuntos
Glucocorticoides , Osteoporose , Humanos , Criança , Glucocorticoides/efeitos adversos , Osteoporose/induzido quimicamente , Osteoporose/tratamento farmacológico , Osteoporose/prevenção & controle
4.
Eye (Lond) ; 38(1): 168-172, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37491441

RESUMO

BACKGROUND: Ophthalmology outpatient attendances have significantly increased recently with rising pressure from backlogs arising from the pandemic. Medical retina digital surveillance clinics for stable follow-up appointments are well established. We present a model for assessing new referrals and evaluating clinical outcomes and long-term sustainability in a complex high-volume medical retina service. METHODS: Suitable routine new patient referrals were identified from electronic referrals and referred to this new pathway. Structured history, visual acuities, and intraocular pressures were recorded, and widefield colour fundus and optical coherence tomography imaging were performed at a imaging hub for asynchronous consultant-led review. RESULTS: 1458 patients were invited to attend over four months, with a 13.2% did-not-attend (DNA) rate. Common diagnoses included stable diabetic retinopathy (19.9%), early age-related macular degeneration (6.7%), central serous retinopathy (8.8%), and retinal vein occlusion (6.3%). 7 patients (0.05%) required urgent same-day review. 61 (5.0%) required urgent face-to-face (F2F) assessment within two weeks. A total of 727 (59.0%) were either discharged or remained in the virtual pathway following their first visit. CONCLUSION: This study encourages the use of a digital model that efficiently assesses suitable newly referred medical retina patients in both complex and local eye unit settings. This decreased the need for F2F clinics and resources. Further patient satisfaction surveys for digital services are currently being evaluated to guide long-term sustainability of this model.


Assuntos
Retinopatia Diabética , Retina , Humanos , Retina/diagnóstico por imagem , Encaminhamento e Consulta , Retinopatia Diabética/diagnóstico , Instituições de Assistência Ambulatorial , Tomografia de Coerência Óptica/métodos
5.
Eye (Lond) ; 38(1): 118-126, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37402864

RESUMO

BACKGROUND/OBJECTIVES: To examine prevalence of failed visual assessment at 8-10 years in children born to methadone-maintained opioid dependent (MMOD) mothers and relate this to known in utero substance exposure. SUBJECTS/METHODS: Follow up of observational cohort study of methadone-exposed and comparison children matched for birthweight, gestation and postcode of residence at birth. Participants were 144 children (98 exposed, 46 comparison). Prenatal drug exposure was previously established via comprehensive maternal and neonatal toxicology. Children were invited to attend for visual assessment and casenotes were reviewed. Presence of acuity poorer than 0.2 logMAR, strabismus, nystagmus and/or impaired stereovision constituted a 'fail'. Fail rates were compared between methadone-exposed and comparison children after adjusting for known confounding variables. RESULTS: 33 children attended in person: data were also derived from casenote review for all children. After controlling for maternal reported tobacco use, methadone-exposed children were more likely to have a visual 'fail' outcome, adjusted odds ratio 2.6, 95% CI 1.1-6.2; adjusted relative risk 1.8 (95% CI 1.1-3.4). Visual 'fail' outcome rates did not differ between methadone-exposed children who had (n = 47) or had not (n = 51) received pharmacological treatment for neonatal abstinence/opioid withdrawal syndrome (NAS/NOWS); fail rate 62% vs 53% (95% CI of difference-11-27%). CONCLUSIONS: Children born to MMOD mothers are almost twice as likely as unexposed peers to have significant visual abnormalities at primary school age. Prenatal methadone exposure should be considered in the differential diagnosis of nystagmus. Findings support visual assessment prior to school entry for children with any history of prenatal opioid exposure. TRIAL REGISTRATION: The study was prospectively registered on ClinicalTrials.gov (NCT03603301), https://clinicaltrials.gov/ct2/show/NCT03603301 .


Assuntos
Síndrome de Abstinência Neonatal , Nistagmo Patológico , Complicações na Gravidez , Efeitos Tardios da Exposição Pré-Natal , Recém-Nascido , Criança , Feminino , Gravidez , Humanos , Metadona/efeitos adversos , Analgésicos Opioides/efeitos adversos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/diagnóstico , Estudos de Coortes , Síndrome de Abstinência Neonatal/epidemiologia , Síndrome de Abstinência Neonatal/tratamento farmacológico , Complicações na Gravidez/tratamento farmacológico
6.
BMJ Open Ophthalmol ; 8(Suppl 3): A2, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37797984

RESUMO

This feasibility study aimed to investigate the feasibility of collecting and analysing tear proteins from preterm infants at risk of retinopathy of prematurity (ROP). Additionally, we sought to identify any tear proteins which might be implicated in the pathophysiology of ROP.Eligible infants were those undergoing ROP screening without other ocular pathology. Tear samples were obtained by Schirmer's test strips coincident with routine ROP screening. Mass spectrometry was used for proteomic analysis. All participants' parents gave written, informed consent.Samples were collected from 12 infants, including two sets of twins. Gestation ranged from 25+6 to 31+1 weeks. Median postnatal age at sampling was 30.5 days (range 19 to 66). One infant developed self-limiting ROP. An adequate sample for protein analysis was obtained from each infant. 701 proteins were identified; 261 proteins identified in the majority of tear samples, including several common tear proteins, were used for analyses.Increased risk of ROP as determined by G-ROP prediction criteria was associated with an increase in lactate dehydrogenase B (LDH-B) chain protein in tears. Older, more mature infants demonstrated increased concentration of immunoglobulin complexes within their tear samples and two sets of twins in the cohort showed exceptionally similar proteomes, supporting validity of the analysis.Tear sampling by Schirmer test strips and subsequent proteomic analysis in preterm infants is feasible. A larger study is required to investigate the potential use of tear proteomics in early identification of ROP.


Assuntos
Recém-Nascido Prematuro , Retinopatia da Prematuridade , Lactente , Recém-Nascido , Humanos , Retinopatia da Prematuridade/diagnóstico , Proteômica , Idade Gestacional
7.
J Opt Soc Am A Opt Image Sci Vis ; 40(3): 573-582, 2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37133040

RESUMO

Wide-field image correction in systems that look through the atmosphere generally requires a tomographic reconstruction of the turbulence volume to compensate for anisoplanatism. The reconstruction is conditioned by estimating the turbulence volume as a profile of thin homogeneous layers. We present the signal to noise ratio (SNR) of a layer, which quantifies how difficult a single layer of homogeneous turbulence is to detect with wavefront slope measurements. The signal is the sum of wavefront tip and tilt variances at the signal layer, and the noise is the sum of wavefront tip and tilt auto-correlations given the aperture shape and projected aperture separations at all non-signal layers. An analytic expression for layer SNR is found for Kolmogorov and von Kármán turbulence models, then verified with a Monte Carlo simulation. We show that the Kolmogorov layer SNR is a function of only layer Fried length, the spatio-angular sampling of the system, and normalized aperture separation at the layer. In addition to these parameters, the von Kármán layer SNR also depends on aperture size, and layer inner and outer scales. Due to the infinite outer scale, layers of Kolmogorov turbulence tend to have lower SNR than von Kármán layers. We conclude that the layer SNR is a statistically valid performance metric to be used when designing, simulating, operating, and quantifying the performance of any system that measures properties of layers of turbulence in the atmosphere from slope data.

8.
Brain Stimul ; 16(3): 748-755, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37028756

RESUMO

BACKGROUND: Transcranial alternating current stimulation (tACS)-a noninvasive brain stimulation technique that modulates cortical oscillations through entrainment-has been demonstrated to alter oscillatory activity and enhance cognition in healthy adults. TACS is being explored as a tool to improve cognition and memory in patient populations with mild cognitive impairment (MCI) and Alzheimer's disease (AD). OBJECTIVE: To review the growing body of literature and current findings obtained from the application of tACS in patients with MCI or AD, highlighting the effects of gamma tACS on brain function, memory, and cognition. Evidence on the use of brain stimulation in animal models of AD is also discussed. Important parameters of stimulation are underscored for consideration in protocols that aim to apply tACS as a therapeutic tool in patients with MCI/AD. FINDINGS: The application of gamma tACS has shown promising results in the improvement of cognitive and memory processes that are impacted in patients with MCI/AD. These data demonstrate the potential for tACS as an interventional stand-alone tool or alongside pharmacological and/or other behavioral interventions in MCI/AD. CONCLUSIONS: While the use of tACS in MCI/AD has evidenced encouraging results, the effects of this stimulation technique on brain function and pathophysiology in MCI/AD remains to be fully determined. This review explores the literature and highlights the need for continued research on tACS as a tool to alter the course of the disease by reinstating oscillatory activity, improving cognitive and memory processing, delaying disease progression, and remediating cognitive abilities in patients with MCI/AD.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Estimulação Transcraniana por Corrente Contínua , Animais , Estimulação Transcraniana por Corrente Contínua/métodos , Doença de Alzheimer/terapia , Disfunção Cognitiva/terapia , Cognição/fisiologia , Encéfalo
9.
Parasite Immunol ; 45(5): e12979, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-36971331

RESUMO

We demonstrate that CD193, the eotaxin receptor, is highly expressed on circulating B cells in paediatric schistosomiasis mansoni. CD193 plays a role in directing granulocytes into sites of allergic-like inflammation in the mucosa, but little is known about its functional significance on human B cells. We sought to characterize CD193 expression and its relationship with S. mansoni infection. We found that CD193+ B cells increased with the intensity of schistosome infection. In addition, a significant negative association was observed between CD193 expression by B cells and IgE production. Decreased IgE levels are generally associated with susceptibility to re-infection. B cell stimulation with eotaxin-1 increased CD193 levels whereas IL-4 led to a reduction. This was supported by plasma levels of eotaxin-1 correlating with CD193 levels on B cells and other cells. In contrast, CD193 expression was induced on naive B cells with a combination of IL-10 and schistosome antigens. Whereas T cells had a modest increase in CD193 expression, only B cell CD193 appeared functionally chemotactic to eotaxin-1. Thus, CD193+ B cells, which co-express CXCR5, may be enroute to sites with allergic-like inflammation, such as gastrointestinal follicles, or even to Th2 granulomas, which develop around parasite eggs. Overall, our results suggest that schistosome infection may promote CD193 expression and suppress IgE via IL-10 and other undefined mechanisms related to B cell trafficking. This study adds to our understanding of why young children may have poor immunity. Nonetheless, praziquantel treatment was shown to reduce percentages of circulating CD193+ B cells lending hope for future vaccine efforts.


Assuntos
Interleucina-10 , Esquistossomose mansoni , Animais , Criança , Pré-Escolar , Humanos , Quimiocina CCL11 , Imunoglobulina E , Inflamação , Receptores CCR3 , Schistosoma mansoni , Linfócitos B/imunologia
10.
J Robot Surg ; 16(2): 369-375, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33982173

RESUMO

The role of retroperitoneal lymph node dissection (RPLND) in testicular cancer is well established in both the primary and post-chemotherapy setting. The aim of this study was to report our 2 years oncological outcomes of robotic RPLND. A retrospective review was performed of all patients undergoing robotic RPLND by a single surgeon at Princess Margaret Cancer Centre. Demographic, perioperative, and oncologic data were analyzed using descriptive statistics. Between September 2014 and June 2020, 141 patients underwent an RPLND [33 (23.4%) were primary, 108 (76.6%) were post-chemotherapy]. 27 (19.1%) patients underwent a robotic bilateral template nerve-sparing RPLND. RPLND indication was primary (i.e. pre-chemotherapy) in 18 (66.7%), and post-chemotherapy in 9 (33.3%) patients. Stage at RPLND was 2A (n = 15, 55.6%), 2B (n = 9, 33.3%), 2C (n = 1, 3.7%) and 3 (n = 2, 7.4%). Median OR time (incision to closure) was 525 min and blood loss was 200 ml. Nerve sparing was performed in all but one case. Six (22.2%) adjuvant procedures were performed including two (7.4%) vascular repairs. Median length of stay was 2 days. Viable tumor was detected in 17 (63%) and teratoma in 9 (33.3%). Median follow-up was 31.3 months. No adjuvant chemotherapy was given. Three patients (11.1%) relapsed: 2 out-of-field and 1 with both in-field and out-of-field disease. Robotic RPLND can be performed safely. Long-term follow-up of series such as ours, enriched with patients with viable disease and/or teratoma, and not treated with adjuvant chemotherapy is required to ensure oncological outcomes are comparable to the open approach.


Assuntos
Neoplasias Embrionárias de Células Germinativas , Procedimentos Cirúrgicos Robóticos , Neoplasias Testiculares , Humanos , Excisão de Linfonodo/métodos , Masculino , Neoplasias Embrionárias de Células Germinativas/tratamento farmacológico , Neoplasias Embrionárias de Células Germinativas/cirurgia , Espaço Retroperitoneal/cirurgia , Estudos Retrospectivos , Procedimentos Cirúrgicos Robóticos/métodos , Neoplasias Testiculares/tratamento farmacológico , Neoplasias Testiculares/patologia , Neoplasias Testiculares/cirurgia , Resultado do Tratamento
11.
Sci Total Environ ; 803: 149577, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34487896

RESUMO

Forested coastal wetlands are globally important systems sequestering carbon and intercepting nitrogen pollution from nutrient-rich river systems. Coastal wetlands that have suffered extensive disturbance are the target of comprehensive restoration efforts. Accurate assessment of restoration success requires detailed mechanistic understanding of wetland soil biogeochemical functioning across restoration chrono-sequences, which remains poorly understood for these sparsely investigated systems. This study investigated denitrification and greenhouse gas fluxes in mangrove and Melaleuca forest soils of Vietnam, using the 15N-Gas flux method. Denitrification-derived N2O was significantly higher from Melaleuca than mangrove forest soils, despite higher potential rates of total denitrification in the mangrove forest soils (8.1 ng N g-1 h-1) than the Melaleuca soils (6.8 ng N g-1 h-1). Potential N2O and CO2 emissions were significantly higher from the Melaleuca soils than from the mangrove soils. Disturbance and subsequent recovery had no significant effect on N biogeochemistry except with respect to the denitrification product ratio in the mangrove sites, which was highest from the youngest mangrove site. Potential CO2 and CH4 fluxes were significantly affected by restoration in the mangrove soils. The lowest potential CO2 emissions were observed in the mid-age plantation and potential CH4 fluxes decreased in the older forests. The mangrove system, therefore, may remove excess N and improve water quality with low greenhouse gas emissions, whereas in Melaleucas, increased N2O and CO2 emissions also occur. These emissions are likely balanced by higher carbon stocks observed in the Melaleuca soils. These mechanistic insights highlight the importance of ecosystem restoration for pollution attenuation and reduction of greenhouse gas emissions from coastal wetlands. Restoration efforts should continue to focus on increasing wetland area and function, which will benefit local communities with improved water quality and potential for income generation under future carbon trading.


Assuntos
Gases de Efeito Estufa , Dióxido de Carbono/análise , Desnitrificação , Ecossistema , Monitoramento Ambiental , Gases de Efeito Estufa/análise , Metano/análise , Óxido Nitroso/análise , Solo , Áreas Alagadas
13.
Phys Chem Chem Phys ; 23(21): 12309-12320, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34018524

RESUMO

Quasiclassical trajectory analysis is now a standard tool to analyze non-minimum energy pathway motion of organic reactions. However, due to the large amount of information associated with trajectories, quantitative analysis of the dynamic origin of reaction selectivity is complex. For the electrocyclic ring opening of cyclopropyl radical, more than 4000 trajectories were run showing that allyl radicals are formed through a mixture of disrotatory intrinsic reaction coordinate (IRC) motion as well as conrotatory non-IRC motion. Geometric, vibrational mode, and atomic velocity transition-state features from these trajectories were used for supervised machine learning analysis with classification algorithms. Accuracy >80% with a random forest model enabled quantitative and qualitative assessment of transition-state trajectory features controlling disrotatory IRC versus conrotatory non-IRC motion. This analysis revealed that there are two key vibrational modes where their directional combination provides prediction of IRC versus non-IRC motion.

14.
Prostate Cancer Prostatic Dis ; 24(1): 69-76, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-32152437

RESUMO

BACKGROUND: Although 5-alpha-reductase inhibitors (5ARIs) have been shown to benefit men with prostate cancer (PCa) on active surveillance (AS), their long-term safety remains controversial. Our objective is to describe the long-term association of 5ARI use with PCa progression in men on AS. MATERIALS/SUBJECTS AND METHODS: The cohort of men with low-risk PCa was derived from a prospectively maintained AS database at the Princess Margaret (1995-2016). Pathologic, grade, and volume progression were the primary end points. Kaplan-Meier time-to-event analysis was performed and Cox proportional hazards regression was used to determine predictors of progression where 5ARI exposure was analyzed as a time-dependent variable. Patients who came off AS prior to any progression events were censored at that time. RESULTS: The cohort included 288 men with median follow-up of 82 months (interquartile range: 37-120 months). Among non-5ARI users (n = 203); 114 men (56.2%) experienced pathologic progression compared with 24 men (28.2%) in the 5ARI group (n = 85), (p < 0.001). Grade and volume progression were higher in the non-5ARI group compared with the 5ARI group (n = 82; 40.4% vs. n = 19; 22.4% respectively, p = 0.003 for grade progression; n = 87; 43.1% and n = 15; 17.7%, respectively for volume progression p < 0.001). Lack of 5ARI use was independently positively associated with pathologic progression (HR: 2.65; CI: 1.65-4.24), grade progression (HR: 2.75; CI: 1.49-5.06), and volume progression (HR: 3.15; CI: 1.78-5.56). The frequency of progression to high-grade (Grade Group 4-5) tumors was not significantly different between the groups. CONCLUSIONS: Use of 5ARIs diminished both grade and volume progression without an increased risk of developing Grade Groups 4-5 disease.


Assuntos
Inibidores de 5-alfa Redutase/uso terapêutico , Estadiamento de Neoplasias , Próstata/patologia , Neoplasias da Próstata/tratamento farmacológico , Conduta Expectante/métodos , Idoso , Biomarcadores Tumorais/sangue , Biópsia , Progressão da Doença , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Antígeno Prostático Específico/sangue , Neoplasias da Próstata/sangue , Neoplasias da Próstata/patologia , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
15.
Sci Rep ; 10(1): 18782, 2020 11 02.
Artigo em Inglês | MEDLINE | ID: mdl-33139823

RESUMO

Antibiotic overprescribing is a global challenge contributing to rising levels of antibiotic resistance and mortality. We test a novel approach to antibiotic stewardship. Capitalising on the concept of "wisdom of crowds", which states that a group's collective judgement often outperforms the average individual, we test whether pooling treatment durations recommended by different prescribers can improve antibiotic prescribing. Using international survey data from 787 expert antibiotic prescribers, we run computer simulations to test the performance of the wisdom of crowds by comparing three data aggregation rules across different clinical cases and group sizes. We also identify patterns of prescribing bias in recommendations about antibiotic treatment durations to quantify current levels of overprescribing. Our results suggest that pooling the treatment recommendations (using the median) could improve guideline compliance in groups of three or more prescribers. Implications for antibiotic stewardship and the general improvement of medical decision making are discussed. Clinical applicability is likely to be greatest in the context of hospital ward rounds and larger, multidisciplinary team meetings, where complex patient cases are discussed and existing guidelines provide limited guidance.


Assuntos
Gestão de Antimicrobianos , Simulação por Computador , Prescrição Inadequada/prevenção & controle , Prescrição Inadequada/estatística & dados numéricos , Tomada de Decisões , Humanos , Comunicação Interdisciplinar , Equipe de Assistência ao Paciente , Guias de Prática Clínica como Assunto
16.
Mol Syst Biol ; 16(7): e9723, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32692486

RESUMO

The fast-paced field of synthetic biology is fundamentally changing the global biosecurity framework. Current biosecurity regulations and strategies are based on previous governance paradigms for pathogen-oriented security, recombinant DNA research, and broader concerns related to genetically modified organisms (GMOs). Many scholarly discussions and biosecurity practitioners are therefore concerned that synthetic biology outpaces established biosafety and biosecurity measures to prevent deliberate and malicious or inadvertent and accidental misuse of synthetic biology's processes or products. This commentary proposes three strategies to improve biosecurity: Security must be treated as an investment in the future applicability of the technology; social scientists and policy makers should be engaged early in technology development and forecasting; and coordination among global stakeholders is necessary to ensure acceptable levels of risk.


Assuntos
Contenção de Riscos Biológicos/métodos , Desenvolvimento Industrial , Formulação de Políticas , Biologia Sintética/métodos , Contenção de Riscos Biológicos/normas , DNA Recombinante/genética , DNA Recombinante/metabolismo , DNA Recombinante/farmacologia , Humanos , Internacionalidade , Medicina , Organismos Geneticamente Modificados , Fatores de Risco , Ciências Sociais , Virulência/efeitos dos fármacos , Virulência/genética
18.
J Phys Chem A ; 124(23): 4813-4826, 2020 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-32412755

RESUMO

Experimentally, the thermal gas-phase deazetization of 2,3-diazabicyclo[2.2.1]hept-2-ene (1) results in the loss of N2 and the formation of bicyclo products 3 (exo) and 4 (endo) in a nonstatistical ratio, with preference for the exo product. Here, we report unrestricted M06-2X quasiclassical trajectories initialized from the concerted N2 ejection transition state that were able to replicate the experimental preference to form 3. We found that the 3:4 ratio results from the relative amounts of very fast (ballistic) exotype trajectories versus trajectories that lead to the 1,3-diradical intermediate 2. These quasiclassical trajectories provided a set of transition-state vibrational, velocity, momenta, and geometric features for the machine learning analysis. A selection of popular supervised classification algorithms (e.g., random forest) provided poor prediction of trajectory outcomes based on only transition-state vibrational quanta and energy features. However, these machine learning models provided more accurate predictions using atomic velocities and atomic positions, attaining ∼70% accuracy using initial conditions and between 85 and 95% accuracy at later reaction time steps. This increased accuracy allowed the feature importance analysis to reveal that, at the later-time analysis, the methylene bridge out-of-plane bending is correlated with trajectory outcomes for the formation of either the exo product or toward the diradical intermediate. Possible reasons for the struggle of machine learning algorithms to classify trajectories based on transition-state features is the heavily overlapping feature values, the finite but very large possible vibrational mode combinations, and the possibility of chaos as trajectories propagate. We examined this chaos by comparing a set of nearly identical trajectories that differed by only a very small scaling of the kinetic energies resulting from the transition-state reaction coordinate.

19.
Urology ; 138: 76, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32252958
20.
Urol Oncol ; 38(6): 605.e19-605.e24, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32284257

RESUMO

INTRODUCTION: Radical orchiectomy (RO) is the standard treatment for a testis cancer. Organ sparing surgery can be considered in the setting of a solitary functioning testis or bilateral tumors. It has also been suggested as an alternative to RO for small lesions. In this study we report our partial orchiectomy (PO) experience. METHODS: We performed a retrospective review using our prospectively maintained database analyzing PO. RESULTS: Between 1983 and 2018, 77 patients underwent PO. Mean age was 31.3 years (range 17-56). A lesion was palpable in 70 (90.9%) and median lesion size 14.1 mm (range 3-35 mm). Reasons for PO included ``small lesion" in 39 (50.6%); solitary functioning testis in 30 (39%); bilateral lesions in 6 (7.8%); or assumed benign lesion in 1 (1.3%). Median follow-up was 43.5 months (range 1-258). Lesion histology was benign in 25 (32.5%). A positive surgical margin was noted in 6 (7.8%) with none developing local or distant recurrence. Sixteen (20.8%) patients underwent salvage ipsilateral RO at a median of 3 months (range 0-46). Reasons for salvage RO included a radiologically detected lesion in 7, palpable lesion in 4, positive surgical margin in 3 and adverse pathology in 2 patients. Malignant histology was present in 12 (75%) of the salvage RO specimens. There were no reported Clavien-Dindo Grade 3 to 5 complications. CONCLUSION: Organ sparing surgery is a safe and feasible approach to small testis lesions. For the third with benign disease, and even those with malignant histology, a RO can be avoided in carefully selected patients.


Assuntos
Orquiectomia/métodos , Neoplasias Testiculares/cirurgia , Adolescente , Adulto , Institutos de Câncer , Humanos , Masculino , Pessoa de Meia-Idade , Ontário , Estudos Retrospectivos , Resultado do Tratamento , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...