RESUMEN
In vitro fertilization (IVF) is associated with DNA methylation abnormalities and a higher incidence of adverse pregnancy outcomes. However, which exposure(s), among the many IVF interventions, contributes to these outcomes remains unknown. Frozen embryo transfer (ET) is increasingly utilized as an alternative to fresh ET, but reports suggest a higher incidence of pre-eclampsia and large for gestational age infants. This study examines DNA methylation in human placentas using the 850K Infinium MethylationEPIC BeadChip array obtained after 65 programmed frozen ET cycles, 82 fresh ET cycles and 45 unassisted conceptions. Nine patients provided placentas following frozen and fresh ET from consecutive pregnancies for a paired subgroup analysis. In parallel, eight mouse placentas from fresh and frozen ET were analyzed using the Infinium Mouse Methylation BeadChip array. Human and mouse placentas were significantly hypermethylated after frozen ET compared with fresh. Paired analysis showed similar trends. Sex-specific analysis revealed that these changes were driven by male placentas in humans and mice. Frozen and fresh ET placentas were significantly different from controls, with frozen samples hypermethylated compared with controls driven by males and fresh samples being hypomethylated compared with controls, driven by females. Sexually dimorphic epigenetic changes could indicate differential susceptibility to IVF-associated perturbations, which highlights the importance of sex-specific evaluation of adverse outcomes. Similarities between changes in mice and humans underscore the suitability of the mouse model in evaluating how IVF impacts the epigenetic landscape, which is valuable given limited access to human tissue and the ability to isolate specific interventions in mice.
Asunto(s)
Metilación de ADN , Transferencia de Embrión , Embarazo , Femenino , Humanos , Masculino , Ratones , Animales , Metilación de ADN/genética , Transferencia de Embrión/efectos adversos , Criopreservación , Fertilización In Vitro/efectos adversos , Placenta , Estudios RetrospectivosRESUMEN
OBJECTIVES: Hippocampal sclerosis (HS) is a common cause of temporal lobe epilepsy. Neuroradiological practice relies on visual assessment, but quantification of HS imaging biomarkers-hippocampal volume loss and T2 elevation-could improve detection. We tested whether quantitative measures, contextualised with normative data, improve rater accuracy and confidence. METHODS: Quantitative reports (QReports) were generated for 43 individuals with epilepsy (mean age ± SD 40.0 ± 14.8 years, 22 men; 15 histologically unilateral HS; 5 bilateral; 23 MR-negative). Normative data was generated from 111 healthy individuals (age 40.0 ± 12.8 years, 52 men). Nine raters with different experience (neuroradiologists, trainees, and image analysts) assessed subjects' imaging with and without QReports. Raters assigned imaging normal, right, left, or bilateral HS. Confidence was rated on a 5-point scale. RESULTS: Correct designation (normal/abnormal) was high and showed further trend-level improvement with QReports, from 87.5 to 92.5% (p = 0.07, effect size d = 0.69). Largest magnitude improvement (84.5 to 93.8%) was for image analysts (d = 0.87). For bilateral HS, QReports significantly improved overall accuracy, from 74.4 to 91.1% (p = 0.042, d = 0.7). Agreement with the correct diagnosis (kappa) tended to increase from 0.74 ('fair') to 0.86 ('excellent') with the report (p = 0.06, d = 0.81). Confidence increased when correctly assessing scans with the QReport (p < 0.001, η2p = 0.945). CONCLUSIONS: QReports of HS imaging biomarkers can improve rater accuracy and confidence, particularly in challenging bilateral cases. Improvements were seen across all raters, with large effect sizes, greatest for image analysts. These findings may have positive implications for clinical radiology services and justify further validation in larger groups. KEY POINTS: ⢠Quantification of imaging biomarkers for hippocampal sclerosis-volume loss and raised T2 signal-could improve clinical radiological detection in challenging cases. ⢠Quantitative reports for individual patients, contextualised with normative reference data, improved diagnostic accuracy and confidence in a group of nine raters, in particular for bilateral HS cases. ⢠We present a pre-use clinical validation of an automated imaging assessment tool to assist clinical radiology reporting of hippocampal sclerosis, which improves detection accuracy.
Asunto(s)
Epilepsia del Lóbulo Temporal , Epilepsia , Adulto , Epilepsia/patología , Epilepsia del Lóbulo Temporal/diagnóstico por imagen , Epilepsia del Lóbulo Temporal/patología , Hipocampo/diagnóstico por imagen , Hipocampo/patología , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Esclerosis/diagnóstico por imagen , Esclerosis/patologíaRESUMEN
BACKGROUND: Relevant information on health research must be made publicly available in an accurate, timely and accessible manner if evidence is to inform practice and benefit patient care. Failure to publish research information represents a significant waste of research funds. However, recent studies have demonstrated that non-publication and selective or biased reporting remains a significant problem. The role of online publications in rectifying these issues by providing open access to study information is increasingly recognised. OBJECTIVE: This paper details a novel approach to publishing research information developed by the National Institute for Health Research (NIHR), a major funder of health research in the United Kingdom. The NIHR has enhanced its Journals Library ( www.journalslibrary.nihr.ac.uk ), providing an online repository of information from research funded through five programmes. We describe how the NIHR Journals Library provides a 'thread' of relevant information for each study, including protocols, participant information sheets, data linkages, final reports, publications and diverse knowledge products. We also discuss the Library as a 'living' resource, one that is updated as each study progresses from inception to completion. Finally, we consider the implications of the Library for the NIHR, other journals and research teams submitting information. CONCLUSION: Openly publishing information from funded research in the NIHR Journals Library serves as a model of knowledge sharing, maximising return on investment and enhancing the usability and replicability of research findings for different evidence-user communities. The Library also supports wider 'research on research' ambitions, enabling users to interrogate the repository of NIHR-funded studies, enhancing the understanding of research commissioning, design, dissemination and impact. Video abstract: www.youtube.com/watch?v=8H03uxN_iTE .
Asunto(s)
Investigación Biomédica , Medicina Basada en la Evidencia , Programas de Gobierno , Difusión de la Información , Internet , Bibliotecas , Edición , Atención a la Salud , Financiación Gubernamental , Humanos , Reino UnidoRESUMEN
AIM AND OBJECTIVES: To describe the lived experience of young adults with perinatally acquired HIV (PaHIV). BACKGROUND: With the advancement of the highly active antiretroviral treatment, PaHIV infection has transformed into a chronic lifelong illness that is faced by young adults who grew up with HIV. The known challenges that are associated with HIV are poverty, stigma and social and emotional isolation. DESIGN: This was a qualitative single-interview study of a convenience sample of PaHIV-infected young adults receiving care at a large metropolitan pediatric hospital. METHODS: The participants had individual face-to-face interviews which were audio-taped and transcribed verbatim. Themes were developed to describe their living space, and Max Van Manen's lifeworld guide was used to describe their lived experience. FINDINGS: Seventeen participants (eight males/nine females) were enrolled. Four major themes emerged: (i) limited social capital, especially when orphaned participants reflected on a life void of parental guidance; (ii) incomplete education and unemployment, participants described an idle existence; (iii) a harsh life, described as participants facing difficulties meeting their life's milestones; (iv) unanticipated adult issues, where participants described their limited ability to care for themselves and their children. Van Manen lifeworld themes also described the space they occupied, their memories growing up with PaHIV, their health care and relationships. CONCLUSION: Our study provides a valuable insight into the social and emotional difficulties faced by youth with PaHIV. The findings underscore the importance of extensive support and coordination of services between adult and pediatric providers to optimize long-term outcomes among young adults with PaHIV. RELEVANCE TO CLINICAL PRACTICE: The young adults with PaHIV require close attention and support from the healthcare providers, who can offer them a safe space to discuss lived experiences and support their ability to achieve full lives.
Asunto(s)
Infecciones por VIH/congénito , Infecciones por VIH/psicología , Calidad de Vida/psicología , Adolescente , Adulto , Enfermedad Crónica , Femenino , Humanos , Masculino , Pobreza , Investigación Cualitativa , Estigma Social , Factores Socioeconómicos , Adulto JovenRESUMEN
The NHS was founded 69 years ago on the principles of compassion and commitment to providing free healthcare to those who require it, regardless of age, gender, ethnicity, economic status or any other characteristic.
Asunto(s)
Actitud del Personal de Salud , Atención a la Salud , Empatía , Personal de Salud/psicología , Medicina Estatal/organización & administración , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Reino UnidoRESUMEN
BACKGROUND: Chalmers and Glasziou's paper published in 2014 recommends research funding bodies should mandate that proposals for additional primary research are built on systematic reviews of existing evidence showing what is already known. Jones et al. identified 11 (23%) of 48 trials funded during 2006-8 by the National Institute for Health Research Health Technology Assessment (NIHR HTA) Programme did not reference a systematic review. This study did not explore the reasons for trials not referencing a systematic review or consider trials using any other evidence in the absence of a systematic review. Referencing a systematic review may not be possible in certain circumstances, for instance if the systematic review does not address the question being proposed in the trial. The current study extended Jones' study by exploring the reasons for why trials did not reference a systematic review and included a more recent cohort of trials funded in 2013 to determine if there were any changes in the referencing or use of systematic reviews. METHODS: Two cohorts of NIHR HTA randomised controlled trials were included. Cohort I included the same trials as Jones et al. (with the exception of one trial which was discontinued). Cohort II included NIHR HTA trials funded in 2013. Data extraction was undertaken independently by two reviewers using full applications and trial protocols. Descriptive statistics was used and no formal statistical analyses were conducted. RESULTS: Five (11%) trials of the 47 funded during 2006-2008 did not reference a systematic review. These 5 trials had warranted reasons for not referencing systematic reviews. All trials from Cohort II referenced a systematic review. A quarter of all those trials with a preceding systematic review used a different primary outcome than those stated in the reviews. CONCLUSIONS: The NIHR requires that proposals for new primary research are justified by existing evidence and the findings of this study confirm the adherence to this requirement with a high rate of applications using systematic reviews.
Asunto(s)
Ensayos Clínicos Controlados Aleatorios como Asunto , Humanos , Programas Nacionales de Salud , Proyectos de Investigación , Estudios Retrospectivos , Literatura de Revisión como AsuntoRESUMEN
PURPOSE: Hippocampal sclerosis, a common cause of refractory focal epilepsy, requires hippocampal volumetry for accurate diagnosis and surgical planning. Manual segmentation is time-consuming and subject to interrater/intrarater variability. Automated algorithms perform poorly in patients with temporal lobe epilepsy. We validate and make freely available online a novel automated method. METHODS: Manual hippocampal segmentation was performed on 876, 3T MRI scans and 202, 1.5T scans. A template database of 400 high-quality manual segmentations was used to perform automated segmentation of all scans with a multi-atlas-based segmentation propagation method adapted to perform label fusion based on local similarity to ensure accurate segmentation regardless of pathology. Agreement between manual and automated segmentations was assessed by degree of overlap (Dice coefficient) and comparison of hippocampal volumes. KEY FINDINGS: The automated segmentation algorithm provided robust delineation of the hippocampi on 3T scans with no more variability than that seen between different human raters (Dice coefficients: interrater 0.832, manual vs. automated 0.847). In addition, the algorithm provided excellent results with the 1.5T scans (Dice coefficient 0.827), and automated segmentation remained accurate even in small sclerotic hippocampi. There was a strong correlation between manual and automated hippocampal volumes (Pearson correlation coefficient 0.929 on the left and 0.941 on the right in 3T scans). SIGNIFICANCE: We demonstrate reliable identification of hippocampal atrophy in patients with hippocampal sclerosis, which is crucial for clinical management of epilepsy, particularly if surgical treatment is being contemplated. We provide a free online Web-based service to enable hippocampal volumetry to be available globally, with consequent greatly improved evaluation of those with epilepsy.
Asunto(s)
Epilepsia/patología , Hipocampo/patología , Adulto , Algoritmos , Atrofia , Femenino , Humanos , Interpretación de Imagen Asistida por Computador/métodos , Imagen por Resonancia Magnética/métodos , Masculino , Neuroimagen/métodos , Tamaño de los Órganos , EsclerosisRESUMEN
Children and adolescents with obesity who present for weight loss surgery are a unique subset of patients. A thorough understanding of the perioperative needs of these individuals is essential to avoid deleterious complications. This review illustrates the necessity for specialized care, including the continued need of specified drug dosing and a systematic approach in the management of the pediatric bariatric patient.
Asunto(s)
Anestésicos , Cirugía Bariátrica , Humanos , Adolescente , Niño , Obesidad/cirugía , Cirugía Bariátrica/efectos adversosRESUMEN
Background: When health-related research funding agencies choose to fund research, they balance a number of competing issues: costs, stakeholder views and potential benefits. The REWARD Alliance, and the related Lancet-REWARD Campaign, question whether those decisions are yielding all the value they could. Methods: A group of health-related research funding agencies, organisations that represent health-related research funding agencies and those that inform and set health-related-research funding policy from around the world have come together since 2016 to share, learn, collaborate and influence emerging practice. This group meets under the name of the Ensuring Value in Research Funders' Forum (EViR Funders' Forum). The EViR Funders' Forum worked together to develop a set of ten Guiding Principles, that if funders adhered to would reduce research waste and ensure value in research. Results: The EViR Funders' Forum has previously agreed and published a Consensus Statement. The Forum has agreed on a set of ten Guiding Principles to help health-research funders to maximise the value of research by ensuring that: research priorities are justifiable; the design, conduct and analysis of research minimise bias; regulation and management are proportionate to risks; methods and findings are accessible in full; and findings are appropriately and effectively disseminated and used. Conclusions: When setting research funding policy, we must balance multiple stakeholders' needs and expectations. When funders do this well, they maximise the probability of benefits to society from the research they support - when funders do this badly, they passively allow or actively contribute to research waste. These challenges must be resolved by funders either working together or in conjunction with other actors in the research ecosystem.
Asunto(s)
Investigación Biomédica , Humanos , Investigación Biomédica/economía , Apoyo a la Investigación como Asunto/economía , Investigación/economíaRESUMEN
Adolescents seeking bariatric surgery may present with pre-existing psychiatric diagnoses for which they use chronic medications. To heighten awareness concerning perioperative polypharmacy in adolescents with extreme obesity, we conducted a retrospective review of patients undergoing laparoscopic sleeve gastrectomy between February 2010 and May 2017 at Children's National Health System (CNHS). A total of 167 adolescent patients had pre-existing psychiatric diagnoses which included depression (50%), anxiety (23%), ADHD (23%), and binge eating disorder (11%). Medications prescribed to treat these diagnoses included selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs). Additionally, all patients were given fentanyl, ondansetron, morphine, and acetaminophen perioperatively. Although no life threatening symptoms of drug-drug interactions (DDIs) were appreciated, the combined use of many different potent drugs in these patients warrants attention.
Asunto(s)
Cirugía Bariátrica , Obesidad Mórbida , Adolescente , Niño , Humanos , Obesidad Mórbida/cirugía , Polifarmacia , Estudios Retrospectivos , Inhibidores Selectivos de la Recaptación de SerotoninaRESUMEN
INTRODUCTION: Severe obesity predisposes youth to a higher risk of venous thromboembolism (VTE). This study evaluates a BMI-stratified prophylactic dosing regimen of enoxaparin in adolescents with severe obesity undergoing surgery. METHODS: Adolescents aged 12-20 years received prophylactic enoxaparin at 40 mg SC (for a BMI < 50 kg/m2) and 60 mg SC (for a BMI ≥ 50 kg/m2) every 12 h until discharge. Blood samples were drawn at pre-dose, 1, 2, 4, 6, and 12 h. Plasma Anti-Factor Xa (Anti-FXa) activity was used as a surrogate marker for enoxaparin pharmacokinetics. RESULTS: Ten female and two male obese adolescents (age range 14-19 years) had a mean BMI of 49.9 kg/m2 (38.4-58 kg/m2). Four patients had a BMI of less than 50 kg/m2 and received 40 mg enoxaparin, resulting in a mean dosage of 0.352 ± 0.070 mg/kg body weight. Eight patients were dosed with 60 mg enoxaparin every 12 h, resulting in a mean dosage of 0.395 ± 0.028 mg/kg. Peak plasma anti-FXa activity (Cmax) ranged from 0.14 to 0.30 IU/mL, median Cmax was 0.205 IU/mL. Median Tmax was 5.67 h (range 3.78-7.52 h). Median AUCi was 1.00 h IU/mL (range 0.42-1.67 h IU/mL). Ten out of 12 patients (83%) reached the primary endpoint with anti-FXa activity in the range for VTE prevention (0.1-0.3 IU/mL). CONCLUSIONS: Our dosing scheme of 40 mg vs. 60 mg enoxaparin stratified according to BMI proved to be effective in reaching prophylactic anti-FXa activity in 83% of adolescent patients.
Asunto(s)
Cirugía Bariátrica , Quimioprevención/métodos , Enoxaparina/administración & dosificación , Obesidad Mórbida/cirugía , Obesidad Infantil/cirugía , Tromboembolia Venosa/prevención & control , Adolescente , Adulto , Anticoagulantes/administración & dosificación , Anticoagulantes/efectos adversos , Cirugía Bariátrica/efectos adversos , Cirugía Bariátrica/métodos , Niño , Relación Dosis-Respuesta a Droga , Esquema de Medicación , Enoxaparina/efectos adversos , Enoxaparina/farmacocinética , Femenino , Humanos , Masculino , Obesidad Mórbida/metabolismo , Obesidad Infantil/metabolismo , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Cuidados Preoperatorios/efectos adversos , Cuidados Preoperatorios/métodos , Estudios Prospectivos , Tromboembolia Venosa/etiología , Adulto JovenRESUMEN
AIM: To examine the impact of preexisting psychiatric/psychological diagnoses on perioperative analgesic requirements in adolescents with morbid obesity undergoing bariatric surgery. METHODS: A retrospective cohort study of adolescents with morbid obesity undergoing bariatric surgery. Primary and secondary outcomes included perioperative analgesic intake and pain scores (Numerical Rating Scale (0-10) NRS) throughout the hospital stay. RESULTS: From our Bariatric Surgery Research Registry, we identified 17 adolescents with psychiatric/psychological diagnoses prior to undergoing bariatric surgery. Fifteen patients from the same registry and without such diagnosis undergoing bariatric surgery during the same time interval served as controls. In both groups, there was a predominance of female patients. During the perioperative period, in both groups, oral morphine equivalent and ketorolac and acetaminophen intake were similar. Notably, the perioperative median pain scores at the times examined were below 5 for all patients. The median pain scores in the PACU, day of surgery, and first postoperative day were similar. Conversely, on postoperative day 2, pain scores were higher in patients with diagnoses of psychiatric/psychological disorders (p = 0.004) compared to those without. CONCLUSION: In this cohort of morbidly obese adolescents undergoing bariatric surgery, patients with and without preexisting psychiatric/psychological diagnoses had similar analgesic requirements during the perioperative period. This finding appears contrary to those suggesting that preexisting depression and/or anxiety might be associated with increased analgesic requirements during the perioperative period.
Asunto(s)
Analgésicos/uso terapéutico , Cirugía Bariátrica , Obesidad Mórbida/cirugía , Dolor Postoperatorio/tratamiento farmacológico , Adolescente , Ansiedad/complicaciones , Cirugía Bariátrica/psicología , Depresión/complicaciones , Femenino , Humanos , Masculino , Obesidad Mórbida/complicaciones , Obesidad Mórbida/psicología , Dolor Postoperatorio/diagnóstico , Dolor Postoperatorio/psicología , Estudios RetrospectivosRESUMEN
INTRODUCTION: Medial temporal lobe epilepsy (mTLE) is the most common refractory focal epilepsy in adults. Around 30%-40% of patients have prominent memory impairment and experience significant postoperative memory and language decline after surgical treatment. BDNF Val66Met polymorphism has also been associated with cognition and variability in structural and functional hippocampal indices in healthy controls and some patient groups. AIMS: We examined whether BDNF Val66Met variation was associated with cognitive impairment in mTLE. METHODS: In this study, we investigated the association of Val66Met polymorphism with cognitive performance (n = 276), postoperative cognitive change (n = 126) and fMRI activation patterns during memory encoding and language paradigms in 2 groups of patients with mTLE (n = 37 and 34). RESULTS: mTLE patients carrying the Met allele performed more poorly on memory tasks and showed reduced medial temporal lobe activation and reduced task-related deactivations within the default mode networks in both the fMRI memory and language tasks than Val/Val patients. CONCLUSIONS: Although cognitive impairment in epilepsy is the result of a complex interaction of factors, our results suggest a role of genetic factors on cognitive impairment in mTLE.
Asunto(s)
Factor Neurotrófico Derivado del Encéfalo/genética , Disfunción Cognitiva/etiología , Disfunción Cognitiva/psicología , Epilepsia Refractaria/genética , Epilepsia Refractaria/psicología , Epilepsias Parciales/genética , Epilepsias Parciales/psicología , Epilepsia del Lóbulo Temporal/genética , Epilepsia del Lóbulo Temporal/psicología , Red Nerviosa/fisiopatología , Polimorfismo Genético/genética , Adulto , Epilepsia Refractaria/fisiopatología , Inglaterra/epidemiología , Epilepsias Parciales/fisiopatología , Epilepsia del Lóbulo Temporal/fisiopatología , Femenino , Frecuencia de los Genes , Genotipo , Hipocampo/fisiopatología , Humanos , Imagen por Resonancia Magnética , Masculino , Memoria , Pruebas Neuropsicológicas , Procedimientos Neuroquirúrgicos , Desempeño PsicomotorRESUMEN
PLAIN ENGLISH SUMMARY: There is a need for the authors of research reports to be able to communicate their work clearly and effectively to readers who are not familiar with the research area. The National Institute for Health Research (NIHR), along with a number of other funding bodies and journals, require researchers to write short lay summaries, often termed plain English summaries (PESs), to make research accessible to the general public. Because many researchers write using technical, specialised language, particularly in scientific reports, writing PESs can be challenging. In this study we looked at how to improve the quality of PESs. We took PESs which had been submitted to the NIHR Journals Library and asked authors to rewrite them using new guidance. We also asked an independent medical writer to edit the summaries. We measured the quality of these three versions (original summary, rewritten summary and edited summary) in two ways. First, we asked a group of people who were not specialists in the subject area to read and rate how easy the summaries were to understand. Secondly, we used a well-known measure called the Flesch reading ease score to assess how easy the PESs were to read. We found that there was no difference in how easy people found the summaries to understand across the three versions. However, the PESs that were rewritten by the authors and that were edited by the independent medical writer were both easier to read than the originals. This shows that PESs can be improved and for organisations who feel that employing an independent writer to edit summaries, providing clear, practical guidance to authors may be a cost-effective alternative. BACKGROUND: Plain English summaries (PES) or lay summaries are often included as part of research reports and journal articles. These summaries are vital to ensure that research findings are accessible and available to non-specialist audiences, for example patients and members of the public. Writing a PES requires the adoption of a different style than is generally used in a traditional scientific report, and researchers can find this challenging. This study explored two possible ways to improve the quality of PESs in the NIHR Journals Library: 1) Providing enhanced guidance to authors and asking them to rewrite the PES and 2) Employing an independent medical writer to edit the PES. METHODS: We compared the three versions of the PES (original, author rewritten and independent writer edited) to assess 1) how easy they were to understand and 2) how easy they were to read. In order to establish how easy PESs were to understand, a group of 60 public reviewers read a set of summaries and rated them on a four point scale from "Did not understand" to "Understood all". The Flesch reading ease score was used to measure how easy the summaries were to read. RESULTS: Results indicated no significant difference across the three versions of the PES in terms of ease of understanding. However, both the author rewritten and independent writer edited versions were significantly easier to read than the original. There was no significant difference in ease of reading between these two versions. CONCLUSION: These findings suggest that employing independent medical writers to edit PESs and providing clear, practical guidance to authors are two ways in which the readability of PESs could be improved. Results have implications for journal editors and publishers seeking to enhance accessibility and availability of research findings.
RESUMEN
[This corrects the article DOI: 10.1186/s40900-017-0064-0.].
RESUMEN
BACKGROUND: The hippocampus plays a central role in cognition, and understanding the specific contributions of its subregions will likely be key to explaining its wide-ranging functions. However, delineating substructures within the human hippocampus in vivo from magnetic resonance image scans is fraught with difficulties. To our knowledge, the extant literature contains only brief descriptions of segmentation procedures used to delineate hippocampal subregions in magnetic resonance imaging/functional magnetic resonance imaging studies. METHODS: Consequently, here we provide a clear, step-by-step and fully illustrated guide to segmenting hippocampal subregions along the entire length of the human hippocampus on 3T magnetic resonance images. RESULTS: We give a detailed description of how to segment the hippocampus into the following six subregions: dentate gyrus/Cornu Ammonis 4, CA3/2, CA1, subiculum, pre/parasubiculum and the uncus. Importantly, this in-depth protocol incorporates the most recent cyto- and chemo-architectural evidence and includes a series of comprehensive figures which compare slices of histologically stained tissue with equivalent 3T images. CONCLUSION: As hippocampal subregion segmentation is an evolving field of research, we do not suggest this protocol is definitive or final. Rather, we present a fully explained and expedient method of manual segmentation which remains faithful to our current understanding of human hippocampal neuroanatomy. We hope that this 'tutorial'-style guide, which can be followed by experts and non-experts alike, will be a practical resource for clinical and research scientists with an interest in the human hippocampus.
RESUMEN
BACKGROUND: The number of obese pediatric patients requiring anesthesia is rapidly increasing. Although fentanyl is a commonly used narcotic during surgery, there are no pharmacokinetic (PK) data available for optimal dosing of fentanyl in adolescents with clinically severe obesity. MATERIALS AND METHODS: An institutional review board-approved exploratory pilot study was conducted in six adolescents aged 14-19 years undergoing bariatric surgery. Mean total body weight (TBW) and mean BMI were 137.4 ± 14.3 kg and 49.6 ± 6.4 kg/m2 (99.5th BMI percentile), respectively. Fentanyl was administered intravenously for intraoperative analgesia based on ideal body weight per standard of care. PK blood samples were drawn over a 24-h post-dose period. Fentanyl PK parameters were calculated by non-compartmental analysis. RESULTS: Mean fentanyl AUC0-∞ was 1.5 ± 0.5 h·ng/mL. Systemic clearance of fentanyl was 1522 ± 310 mL/min and 11.2 ± 2.6 mL/min·kg TBW. Volume of distribution was 635 ± 282 L and 4.7 ± 2.1 L/kg TBW. While absolute clearance was increased, absolute volume of distribution was comparable to previously established adult values. CONCLUSIONS: These results suggest that fentanyl clearance is enhanced in adolescents with clinically severe obesity while volume of distribution is comparable to previously published studies. STUDY REGISTRATION: NCT01955993 (clinicaltrials.gov).
Asunto(s)
Anestésicos Intravenosos , Fentanilo , Obesidad Mórbida/cirugía , Administración Intravenosa , Adolescente , Anestésicos Intravenosos/efectos adversos , Anestésicos Intravenosos/farmacocinética , Cirugía Bariátrica , Femenino , Fentanilo/efectos adversos , Fentanilo/farmacocinética , Humanos , Proyectos Piloto , Estudios Prospectivos , Adulto JovenRESUMEN
OBJECTIVES: The aims of this study were to develop a population pharmacokinetic model for intravenous paracetamol in preterm and term neonates and to assess the generalizability of the model by testing its predictive performance in an external dataset. METHODS: Nonlinear mixed-effects models were constructed from paracetamol concentration-time data in NONMEM 7.2. Potential covariates included body weight, gestational age, postnatal age, postmenstrual age, sex, race, total bilirubin, and estimated glomerular filtration rate. An external dataset was used to test the predictive performance of the model through calculation of bias, precision, and normalized prediction distribution errors. RESULTS: The model-building dataset included 260 observations from 35 neonates with a mean gestational age of 33.6 weeks [standard deviation (SD) 6.6]. Data were well-described by a one-compartment model with first-order elimination. Weight predicted paracetamol clearance and volume of distribution, which were estimated as 0.348 L/h (5.5 % relative standard error; 30.8 % coefficient of variation) and 2.46 L (3.5 % relative standard error; 14.3 % coefficient of variation), respectively, at the mean subject weight of 2.30 kg. An external evaluation was performed on an independent dataset that included 436 observations from 60 neonates with a mean gestational age of 35.6 weeks (SD 4.3). The median prediction error was 10.1 % [95 % confidence interval (CI) 6.1-14.3] and the median absolute prediction error was 25.3 % (95 % CI 23.1-28.1). CONCLUSIONS: Weight predicted intravenous paracetamol pharmacokinetics in neonates ranging from extreme preterm to full-term gestational status. External evaluation suggested that these findings should be generalizable to other similar patient populations.