Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 238
Filtrar
Más filtros

Intervalo de año de publicación
1.
Pediatr Crit Care Med ; 25(6): 538-546, 2024 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-38299930

RESUMEN

OBJECTIVES: Postoperative hypertension frequently occurs after surgery for congenital heart disease. Given safety concerns when using calcium channel blockers in infants along with the cost and side-effect profile of nitroprusside, we retrospectively assessed our experience of using nicardipine and nitroprusside for postoperative blood pressure control in infants who underwent surgery for congenital heart disease. We also investigated the cost difference between the medications. DESIGN: This study was a single-center retrospective, pre-post chart review of patients who had surgery for congenital heart disease between 2016 and 2020. The primary aim was a noninferiority comparison of achievement of blood pressure goal at 1-hour post-initiation of an antihypertensive agent. Secondary comparisons included achievement of blood pressure goal at 2 hours after medication initiation, Vasoactive-Inotropic Score (VIS), and blood transfusion, crystalloid volume, and calcium needs. SETTING: Academic quaternary-care center. PATIENTS: Infants under 1 year old who required treatment for hypertension with nitroprusside ( n = 71) or nicardipine ( n = 52) within 24 hours of surgery for congenital heart disease. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We failed to identify any difference in proportion of patients that achieved blood pressure control at 1-hour after medication initiation (nitroprusside 52% vs. nicardipine 54%; p = 0.86), with nicardipine noninferior to nitroprusside within a 15% margin. Of patients who did not achieve control at 1-hour post-medication initiation, receiving nicardipine was associated with blood pressure control at 2 hours post-medication initiation (79% vs. 38%; p = 0.003). We also failed to identify an association between antihypertensive types and mean VIS scores, blood transfusion volumes, crystalloid volumes, and quantities of calcium administered. Index cost of using nitroprusside was 16 times higher than using nicardipine, primarily due to difference in wholesale cost. CONCLUSIONS: In our experience of achieving blood pressure control in infants after surgery for congenital heart disease (2016-2020), antihypertensive treatment with nicardipine was noninferior to nitroprusside. Furthermore, nicardipine use was significantly less expensive than nitroprusside. Our contemporary practice is therefore to use nicardipine in preference to nitroprusside.


Asunto(s)
Antihipertensivos , Cardiopatías Congénitas , Hipertensión , Nicardipino , Nitroprusiato , Complicaciones Posoperatorias , Humanos , Nicardipino/uso terapéutico , Nicardipino/administración & dosificación , Nicardipino/economía , Estudios Retrospectivos , Nitroprusiato/uso terapéutico , Nitroprusiato/administración & dosificación , Nitroprusiato/economía , Lactante , Cardiopatías Congénitas/cirugía , Femenino , Masculino , Recién Nacido , Antihipertensivos/economía , Antihipertensivos/uso terapéutico , Antihipertensivos/administración & dosificación , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/economía , Hipertensión/tratamiento farmacológico , Bloqueadores de los Canales de Calcio/uso terapéutico , Bloqueadores de los Canales de Calcio/economía , Bloqueadores de los Canales de Calcio/administración & dosificación , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Presión Sanguínea/efectos de los fármacos , Vasodilatadores/uso terapéutico , Vasodilatadores/administración & dosificación , Vasodilatadores/economía , Costos y Análisis de Costo
2.
J Biomech Eng ; 146(1)2024 01 01.
Artículo en Inglés | MEDLINE | ID: mdl-37916891

RESUMEN

Performing a small bowel anastomosis, or reconnecting small bowel segments, remains a core competency and critical step for the successful surgical management of numerous bowel and urinary conditions. As surgical education and technology moves toward improving patient outcomes through automation and increasing training opportunities, a detailed characterization of the interventional biomechanical properties of the human bowel is important. This is especially true due to the prevalence of anastomotic leakage as a frequent (3.02%) postoperative complication of small bowel anastomoses. This study aims to characterize the forces required for a suture to tear through human small bowel (suture pullout force, SPOF), while analyzing how these forces are affected by tissue orientation, suture material, suture size, and donor demographics. 803 tests were performed on 35 human small bowel specimens. A uni-axial test frame was used to tension sutures looped through 10 × 20 mm rectangular bowel samples to tissue failure. The mean SPOF of the small bowel was 4.62±1.40 N. We found no significant effect of tissue orientation (p = 0.083), suture material (p = 0.681), suture size (p = 0.131), age (p = 0.158), sex (p = .083), or body mass index (BMI) (p = 0.100) on SPOF. To our knowledge, this is the first study reporting human small bowel SPOF. Little research has been published about procedure-specific data on human small bowel. Filling this gap in research will inform the design of more accurate human bowel synthetic models and provide an accurate baseline for training and clinical applications.


Asunto(s)
Fenómenos Mecánicos , Suturas , Humanos , Anastomosis Quirúrgica
3.
Int J Mol Sci ; 25(7)2024 Mar 31.
Artículo en Inglés | MEDLINE | ID: mdl-38612701

RESUMEN

The amyloid cascade hypothesis for Alzheimer's disease is still alive, although heavily challenged. Effective anti-amyloid immunotherapy would confirm the hypothesis' claim that the protein amyloid-beta is the cause of the disease. Two antibodies, aducanumab and lecanemab, have been approved by the U.S. Food and Drug Administration, while a third, donanemab, is under review. The main argument for the FDA approvals is a presumed therapy-induced removal of cerebral amyloid deposits. Lecanemab and donanemab are also thought to cause some statistical delay in the determination of cognitive decline. However, clinical efficacy that is less than with conventional treatment, selection of amyloid-positive trial patients with non-specific amyloid-PET imaging, and uncertain therapy-induced removal of cerebral amyloids in clinical trials cast doubt on this anti-Alzheimer's antibody therapy and hence on the amyloid hypothesis, calling for a more thorough investigation of the negative impact of this type of therapy on the brain.


Asunto(s)
Enfermedad de Alzheimer , Anticuerpos Monoclonales Humanizados , Estados Unidos , Humanos , Enfermedad de Alzheimer/terapia , Cubierta de Hielo , Proteínas Amiloidogénicas , Radioinmunoterapia
4.
Br J Sports Med ; 57(12): 810-821, 2023 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-37316187

RESUMEN

OBJECTIVE: Concern exists about possible problems with later-in-life brain health, such as cognitive impairment, mental health problems and neurological diseases, in former athletes. We examined the future risk for adverse health effects associated with sport-related concussion, or exposure to repetitive head impacts, in former athletes. DESIGN: Systematic review. DATA SOURCES: Search of MEDLINE, Embase, Cochrane, CINAHL Plus and SPORTDiscus in October 2019 and updated in March 2022. ELIGIBILITY CRITERIA: Studies measuring future risk (cohort studies) or approximating that risk (case-control studies). RESULTS: Ten studies of former amateur athletes and 18 studies of former professional athletes were included. No postmortem neuropathology studies or neuroimaging studies met criteria for inclusion. Depression was examined in five studies in former amateur athletes, none identifying an increased risk. Nine studies examined suicidality or suicide as a manner of death, and none found an association with increased risk. Some studies comparing professional athletes with the general population reported associations between sports participation and dementia or amyotrophic lateral sclerosis (ALS) as a cause of death. Most did not control for potential confounding factors (eg, genetic, demographic, health-related or environmental), were ecological in design and had high risk of bias. CONCLUSION: Evidence does not support an increased risk of mental health or neurological diseases in former amateur athletes with exposure to repetitive head impacts. Some studies in former professional athletes suggest an increased risk of neurological disorders such as ALS and dementia; these findings need to be confirmed in higher quality studies with better control of confounding factors. PROSPERO REGISTRATION NUMBER: CRD42022159486.


Asunto(s)
Esclerosis Amiotrófica Lateral , Conmoción Encefálica , Demencia , Deportes , Humanos , Conmoción Encefálica/epidemiología , Conmoción Encefálica/etiología , Estudios de Cohortes , Estudios de Casos y Controles
5.
Sensors (Basel) ; 23(19)2023 Sep 22.
Artículo en Inglés | MEDLINE | ID: mdl-37836847

RESUMEN

This pilot feasibility study aimed to evaluate the effects of transcranial magnetic stimulation (TMS) on chemotherapy-related cognitive impairment (CRCI), and we report here on the first patient. BACKGROUND: Deleterious cognitive changes due to chemotherapy or CRCI are commonly referred to as "chemo brain". With the increasing survival of cancer patients, this poorly understood and inadequately treated condition will likewise have an increasing toll on individuals and society. Since there is no approved treatment for chemo brain, we have initiated a therapeutic trial using transcranial magnetic stimulation (TMS), a non-invasive brain stimulation technique approved in many countries for the treatment of neurologic and psychiatric conditions like migraine and depression. CASE PRESENTATION: A 58-year-old woman, diagnosed 7 years prior with left breast cancer, underwent partial mastectomy with sentinel lymph node biopsy. She then received four cycles of adjuvant chemotherapy followed by radiation therapy. Afterwards, she was on tamoxifen for 4 years and then switched to aromatase inhibitors. The patient's CRCI started during chemotherapy and severely impaired her quality of life for an additional two years. In the third year after chemotherapy, the CRCI partially cleared to stabilize to the level at the time of presentation for this trial. The patient continues to have memory difficulties and decreased concentration, which makes multi-tasking very difficult to impossible. She is reliant on memory aids at work and at home. The participant underwent 10 consecutive sessions of TMS during weekdays for 2 weeks. Stimulation was directed to the left dorsolateral prefrontal cortex. After TMS, the participant significantly improved in memory function on neuropsychological testing. While she reported no subjective differences in concentration or memory, she did report an improvement in her sleep. Functional magnetic resonance imaging of the brain before and after TMS showed increased resting-state functional connectivity between the stimulation site and several brain regions. Remarkably, after 6 years of chemo brain and remaining in the same position at work due to her inability to concentrate and multi-task, she applied for and received a promotion 5-6 months after her TMS treatments. CONCLUSIONS: This first patient in the phase 1 clinical trial testing of TMS for the treatment of "chemo brain" provided important lessons for feasibility and insights into mechanisms of potential benefit.


Asunto(s)
Neoplasias de la Mama , Estimulación Magnética Transcraneal , Femenino , Humanos , Persona de Mediana Edad , Encéfalo/diagnóstico por imagen , Neoplasias de la Mama/tratamiento farmacológico , Imagen por Resonancia Magnética , Mastectomía , Calidad de Vida , Estimulación Magnética Transcraneal/métodos
6.
Acta Neuropathol ; 144(1): 27-44, 2022 07.
Artículo en Inglés | MEDLINE | ID: mdl-35697880

RESUMEN

Limbic-predominant age-related TDP-43 encephalopathy neuropathologic change (LATE-NC) and Alzheimer's disease neuropathologic change (ADNC) are each associated with substantial cognitive impairment in aging populations. However, the prevalence of LATE-NC across the full range of ADNC remains uncertain. To address this knowledge gap, neuropathologic, genetic, and clinical data were compiled from 13 high-quality community- and population-based longitudinal studies. Participants were recruited from United States (8 cohorts, including one focusing on Japanese-American men), United Kingdom (2 cohorts), Brazil, Austria, and Finland. The total number of participants included was 6196, and the average age of death was 88.1 years. Not all data were available on each individual and there were differences between the cohorts in study designs and the amount of missing data. Among those with known cognitive status before death (n = 5665), 43.0% were cognitively normal, 14.9% had MCI, and 42.4% had dementia-broadly consistent with epidemiologic data in this age group. Approximately 99% of participants (n = 6125) had available CERAD neuritic amyloid plaque score data. In this subsample, 39.4% had autopsy-confirmed LATE-NC of any stage. Among brains with "frequent" neuritic amyloid plaques, 54.9% had comorbid LATE-NC, whereas in brains with no detected neuritic amyloid plaques, 27.0% had LATE-NC. Data on LATE-NC stages were available for 3803 participants, of which 25% had LATE-NC stage > 1 (associated with cognitive impairment). In the subset of individuals with Thal Aß phase = 0 (lacking detectable Aß plaques), the brains with LATE-NC had relatively more severe primary age-related tauopathy (PART). A total of 3267 participants had available clinical data relevant to frontotemporal dementia (FTD), and none were given the clinical diagnosis of definite FTD nor the pathological diagnosis of frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP). In the 10 cohorts with detailed neurocognitive assessments proximal to death, cognition tended to be worse with LATE-NC across the full spectrum of ADNC severity. This study provided a credible estimate of the current prevalence of LATE-NC in advanced age. LATE-NC was seen in almost 40% of participants and often, but not always, coexisted with Alzheimer's disease neuropathology.


Asunto(s)
Enfermedad de Alzheimer , Demencia Frontotemporal , Enfermedades del Sistema Nervioso , Anciano de 80 o más Años , Enfermedad de Alzheimer/genética , Amiloide , Autopsia , Proteínas de Unión al ADN , Humanos , Masculino , Placa Amiloide/patología
7.
Am J Forensic Med Pathol ; 43(2): 195-198, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-34907999

RESUMEN

ABSTRACT: Central pontine myelinolysis is most commonly associated with rapid correction of hyponatremia and has historically been associated with alcoholism. In this case report, 2 deaths with gross findings of central pontine lesions led to the possibility that CPM may have been a potential mechanism of death. Subsequent analysis revealed that these lesions were incidental findings. This case report discusses the importance of appropriate microscopic and immunohistochemical analysis of suspected CPM cases.


Asunto(s)
Alcoholismo , Hiponatremia , Mielinólisis Pontino Central , Alcoholismo/complicaciones , Alcoholismo/patología , Humanos , Hiponatremia/complicaciones , Hiponatremia/patología , Imagen por Resonancia Magnética/efectos adversos , Mielinólisis Pontino Central/complicaciones , Mielinólisis Pontino Central/patología , Puente/patología
8.
Brain ; 142(12): 3672-3693, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31670780

RESUMEN

In the 20th century, chronic traumatic encephalopathy (CTE) was conceptualized as a neurological disorder affecting some active and retired boxers who had tremendous exposure to neurotrauma. In recent years, the two research groups in the USA who have led the field have asserted definitively that CTE is a delayed-onset and progressive neurodegenerative disease, with symptoms appearing in midlife or decades after exposure. Between 2005 and 2012 autopsy cases of former boxers and American football players described neuropathology attributed to CTE that was broad and diverse. This pathology, resulting from multiple causes, was aggregated and referred to, in toto, as the pathology 'characteristic' of CTE. Preliminary consensus criteria for defining the neuropathology of CTE were forged in 2015 and published in 2016. Most of the macroscopic and microscopic neuropathological findings described as characteristic of CTE, in studies published before 2016, were not included in the new criteria for defining the pathology. In the past few years, there has been steadily emerging evidence that the neuropathology described as unique to CTE may not be unique. CTE pathology has been described in individuals with no known participation in collision or contact sports and no known exposure to repetitive neurotrauma. This pathology has been reported in individuals with substance abuse, temporal lobe epilepsy, amyotrophic lateral sclerosis, multiple system atrophy, and other neurodegenerative diseases. Moreover, throughout history, some clinical cases have been described as not being progressive, and there is now evidence that CTE neuropathology might not be progressive in some individuals. Considering the current state of knowledge, including the absence of a series of validated sensitive and specific biomarkers, CTE pathology might not be inexorably progressive or specific to those who have experienced repetitive neurotrauma.


Asunto(s)
Lesiones Encefálicas/patología , Encefalopatía Traumática Crónica/patología , Lesiones Encefálicas/complicaciones , Encefalopatía Traumática Crónica/etiología , Progresión de la Enfermedad , Humanos
9.
Acta Astronaut ; 159: 499-507, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31086425

RESUMEN

The modal response of a liquid-filled tank to external acoustic excitation can be used to infer with high resolution the mass of contained liquid, the mass flow rate of liquids into and out of the tank, and changes in tank pressure. Both contained liquid mass and internal ullage pressure affect the modal response of the tank walls through fluid mass-loading of the tank walls and pressure-induced wall stiffening, respectively. Modal Propellant Gauging refers to the technology that exploits these shifts in modal frequencies to infer the mass of propellant in a tank. MPG is a non-invasive gauging technology that has demonstrated gauging resolutions of 1% for settled propellants and 2-3% for unsettled, sloshing propellants. Extensive parabolic flight testing of the MPG system on model tanks has been conducted to validate the technology in reduced gravity. MPG testing on a qualification tank for the Orion Program's European Service Module has also been conducted and is reported here. Finite element modeling of the Orion ESM ″upper" tank is discussed and compared with measurement data. Three computational approaches to mass determination, Peak Tracking, Point Sensor, and Spectral Density methods, are described here. Use cases are defined and analyzed in the context of the Orion ESM Qualification tank data, and an implementation scheme for continuous mass gauging on the Orion ESM is discussed.

10.
Environ Sci Technol ; 52(19): 11094-11101, 2018 10 02.
Artículo en Inglés | MEDLINE | ID: mdl-30169962

RESUMEN

Compound specific carbon isotopic measurements (δ13C) of levoglucosan were carried out for ambient aerosol sampled during an intensive biomass burning period at different sites in Guangdong province, China. The δ13C of ambient levoglucosan was found to be noticeably heavier than the average δ13C of levoglucosan found in source C3-plant-combustion samples. To estimate the photochemical age of sampled ambient levoglucosan, back trajectory analyses were done. The origin and pathways of the probed air masses were determined, using the Lagrangian-particle-dispersion-model FLEXPART and ECMWF meteorological data. On the other hand, the isotopic hydrocarbon clock concept was applied to relate the changes in the field-measured stable carbon isotopic composition to the extent of chemical processing during transport. Comparison of the photochemical age derived using these two independent approaches shows on average good agreement, despite a substantial scatter of the individual data pairs. These analyses demonstrate that the degree of oxidative aging of particulate levoglucosan can be quantified by combining laboratory KIE studies, observed δ13C at the source and in the field, as well as back trajectory analyses. In this study, the chemical loss of levoglucosan was found to exceed 50% in one-fifth of the analyzed samples. Consequently, the use of levoglucosan as a stable molecular tracer may underestimate the contribution of biomass burning to air pollution.


Asunto(s)
Contaminantes Atmosféricos , Material Particulado , Aerosoles , Biomasa , China , Monitoreo del Ambiente , Glucosa/análogos & derivados , Estaciones del Año
11.
Nature ; 492(7428): 225-8, 2012 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-23235875

RESUMEN

Highly charged iron (Fe(16+), here referred to as Fe XVII) produces some of the brightest X-ray emission lines from hot astrophysical objects, including galaxy clusters and stellar coronae, and it dominates the emission of the Sun at wavelengths near 15 ångströms. The Fe XVII spectrum is, however, poorly fitted by even the best astrophysical models. A particular problem has been that the intensity of the strongest Fe XVII line is generally weaker than predicted. This has affected the interpretation of observations by the Chandra and XMM-Newton orbiting X-ray missions, fuelling a continuing controversy over whether this discrepancy is caused by incomplete modelling of the plasma environment in these objects or by shortcomings in the treatment of the underlying atomic physics. Here we report the results of an experiment in which a target of iron ions was induced to fluoresce by subjecting it to femtosecond X-ray pulses from a free-electron laser; our aim was to isolate a key aspect of the quantum mechanical description of the line emission. Surprisingly, we find a relative oscillator strength that is unexpectedly low, differing by 3.6σ from the best quantum mechanical calculations. Our measurements suggest that the poor agreement is rooted in the quality of the underlying atomic wavefunctions rather than in insufficient modelling of collisional processes.

12.
Can J Anaesth ; 65(9): 1057-1065, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-29704223

RESUMEN

PURPOSE: Severe postoperative pain following spine surgery is a significant cause of morbidity, extended length of facility stay, and marked opioid usage. The erector spinae plane (ESP) block anesthetizes the dorsal rami of spinal nerves that innervate the paraspinal muscles and bony vertebra. We describe the use of low thoracic ESP blocks as part of multimodal analgesia in lumbosacral spine surgery. CLINICAL FEATURES: We performed bilateral ESP blocks at the T10 or T12 level in six cases of lumbosacral spine surgery: three lumbar decompressions, two sacral laminoplasties, and one coccygectomy. Following induction of general anesthesia, single-injection ESP blocks were performed in three patients while bilateral continuous ESP block catheters were placed in the remaining three. All six patients had minimal postoperative pain and very low postoperative opioid requirements. There was no discernible motor or sensory block in any of the cases and no interference with intraoperative somatosensory evoked potential monitoring used in two of the cases. CONCLUSIONS: The ESP block can contribute significantly to a perioperative multimodal opioid-sparing analgesic regimen and enhance recovery after lumbosacral spine surgery.


Asunto(s)
Bloqueo Nervioso/métodos , Dolor Postoperatorio/prevención & control , Columna Vertebral/cirugía , Anciano , Anciano de 80 o más Años , Potenciales Evocados Somatosensoriales , Femenino , Humanos , Región Lumbosacra , Masculino , Persona de Mediana Edad
13.
Br J Sports Med ; 51(12): 969-977, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28455362

RESUMEN

OBJECTIVE: Systematic review of possible long-term effects of sports-related concussion in retired athletes. DATA SOURCES: Ten electronic databases. STUDY SELECTION: Original research; incidence, risk factors or causation related to long-term mental health or neurological problems; individuals who have suffered a concussion; retired athletes as the subjects and possible long-term sequelae defined as >10 years after the injury. DATA EXTRACTION: Study population, exposure/outcome measures, clinical data, neurological examination findings, cognitive assessment, neuroimaging findings and neuropathology results. Risk of bias and level of evidence were evaluated by two authors. RESULTS: Following review of 3819 studies, 47 met inclusion criteria. Some former athletes have depression and cognitive deficits later in life, and there is an association between these deficits and multiple prior concussions. Former athletes are not at increased risk for death by suicide (two studies). Former high school American football players do not appear to be at increased risk for later life neurodegenerative diseases (two studies). Some retired professional American football players may be at increased risk for diminishment in cognitive functioning or mild cognitive impairment (several studies), and neurodegenerative diseases (one study). Neuroimaging studies show modest evidence of macrostructural, microstructural, functional and neurochemical changes in some athletes. CONCLUSION: Multiple concussions appear to be a risk factor for cognitive impairment and mental health problems in some individuals. More research is needed to better understand the prevalence of chronic traumatic encephalopathy and other neurological conditions and diseases, and the extent to which they are related to concussions and/or repetitive neurotrauma sustained in sports.


Asunto(s)
Traumatismos en Atletas/complicaciones , Conmoción Encefálica/complicaciones , Síndrome Posconmocional/epidemiología , Atletas , Encéfalo/patología , Conmoción Encefálica/diagnóstico , Trastornos del Conocimiento/epidemiología , Trastornos del Conocimiento/etiología , Depresión/epidemiología , Depresión/etiología , Fútbol Americano/lesiones , Humanos , Incidencia , Neuroimagen , Síndrome Posconmocional/etiología , Factores de Riesgo
14.
BMC Neurol ; 16: 72, 2016 May 21.
Artículo en Inglés | MEDLINE | ID: mdl-27206499

RESUMEN

BACKGROUND: Primary central nervous system lymphoma (PCNSL) may rarely be preceded by "sentinel demyelination," a pathologic entity characterized by histologically confirmed demyelinating inflammatory brain lesions that mimic multiple sclerosis (MS) or acute disseminated encephalomyelitis (ADEM). Interpreting the overlapping radiologic and clinical characteristics associated with each of these conditions-contrast-enhancing demyelination of white matter and relapsing and remitting steroid-responsive symptoms respectively-can be a significant diagnostic challenge. CASE PRESENTATION: We describe a 57-year-old woman with an unusual clinical course who presented with multi-focal enhancing white matter lesions demonstrated to be inflammatory demyelination by brain biopsy. Despite a good initial response to steroids and rituximab for treatment of presumed tumefactive multiple sclerosis, the patient's condition rapidly deteriorated, and a repeat brain biopsy six months later was consistent with a diagnosis of diffuse large B-cell lymphoma. CONCLUSIONS: Early clinical suspicion for PCNSL and awareness that biopsied lesions may initially show sentinel demyelination suggestive of alternate diagnoses may be essential for early initiation of appropriate therapies and mitigation of disease progression. Clinical, pathophysiological, and diagnostic aspects of sentinel demyelination and PCNSL are discussed.


Asunto(s)
Neoplasias del Sistema Nervioso Central/patología , Enfermedades Desmielinizantes/patología , Linfoma de Células B/patología , Corticoesteroides/uso terapéutico , Neoplasias del Sistema Nervioso Central/complicaciones , Enfermedades Desmielinizantes/complicaciones , Enfermedades Desmielinizantes/diagnóstico por imagen , Enfermedades Desmielinizantes/tratamiento farmacológico , Progresión de la Enfermedad , Femenino , Humanos , Linfoma de Células B/complicaciones , Linfoma de Células B/diagnóstico por imagen , Imagen por Resonancia Magnética , Persona de Mediana Edad , Rituximab/uso terapéutico , Sustancia Blanca/patología
15.
Phys Chem Chem Phys ; 18(47): 32466-32476, 2016 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-27869257

RESUMEN

Understanding the dynamics of electron-ion energy transfer in warm dense (WD) matter is important to the measurement of equation of state (EOS) properties and for understanding the energy balance in dynamic simulations. In this work, we present a comprehensive investigation of nonadiabatic electron relaxation and thermal excitation dynamics in aluminum under high pressure and temperature. Using quantum-classical trajectory surface hopping approaches, we examine the role of nonadiabatic couplings and electronic decoherence in electron-nuclear energy transfer in WD aluminum. The computed timescales range from 400 fs to 4.0 ps and are consistent with existing experimental studies. We have derived general scaling relationships between macroscopic parameters of WD systems such as temperature or mass density and the timescales of energy redistribution between quantum and classical degrees of freedom. The scaling laws are supported by computational results. We show that electronic decoherence plays essential role and can change the functional dependencies qualitatively. The established scaling relationships can be of use in modelling of WD matter.

17.
J Alzheimers Dis Rep ; 8(1): 501-516, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38549627

RESUMEN

Background: Cumulative effects of traumatic brain injury is of increasing concern, especially with respect to its role in the etiology and pathogenesis of neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Objective: Compare regional brain volume and connectivity between athletes with a history of concussion and controls. Methods: We evaluated whole-brain volumetric effects with Bayesian regression models and functional connectivity with network-based statistics, in 125 retired athletes (a mean of 11 reported concussions) and 36 matched controls. Results: Brain regions significantly lower in volume in the concussed group included the middle frontal gyrus, hippocampus, supramarginal gyrus, temporal pole, and inferior frontal gyrus. Conversely, brain regions significantly larger included the hippocampal and collateral sulcus, middle occipital gyrus, medial orbital gyrus, caudate nucleus, lateral orbital gyrus, and medial postcentral gyrus. Functional connectivity analyses revealed increased edge strength, most marked in motor domains. Numerous edges of this network strengthened in athletes were significantly weakened with concussion. Aligned to meta-analytic neuroimaging data, the observed changes suggest functional enhancement within the motor, sensory, coordination, balance, and visual processing domains in athletes, attenuated by concussive head injury with a negative impact on memory and language. Conclusions: These findings suggest that engagement in sport may benefit the brain across numerous domains, but also highlights the potentially damaging effects of concussive head injury. Future studies with longitudinal cohorts including autopsy examination are needed to determine whether the latter reflects tissue loss from brain shearing, or the onset of a progressive Alzheimer's disease like proteinopathy.

18.
Neurotrauma Rep ; 5(1): 337-347, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38595792

RESUMEN

There are no validated diagnostic criteria for traumatic encephalopathy syndrome (TES). During the early and middle 20th century, TES was described as a clinical condition that was experienced by some high-exposure boxers-and it was believed to reflect chronic traumatic brain injury. Consensus criteria for the diagnosis of TES were published in 2021. We applied the consensus criteria for TES retrospectively to cases of chronic brain damage in boxers described in articles published in the 20th century that were obtained from narrative and systematic reviews. The sample included 157 boxers identified in 21 articles published between 1929 and 1999. Two authors reviewed each case description and coded the criteria for TES. For the core clinical features, cognitive impairment was noted in 63.1%, and in 28.7% of cases the person's cognitive functioning appeared to be broadly normal. Neurobehavioral dysregulation was present in 25.5%. One third (34.4%) were identified as progressive, 30.6% were not progressive, and the course could not be clearly determined in 35.0%. In total, 29.9% met the TES consensus criteria, 28.0% did not, and 42.0% had insufficient information to make a diagnostic determination. TES, in the 20th century, was described as a neurological condition, not a psychiatric disorder-and this supports the decision of the 2021 consensus group to remove primary and secondary psychiatric diagnoses from being a core diagnostic feature. Future research is needed to determine whether, or the extent to which, cognitive impairment or neurobehavioral dysregulation described as characterizing TES are associated with chronic traumatic encephalopathy neuropathological change.

19.
J Neurosurg Spine ; 40(3): 375-388, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38100766

RESUMEN

Tarlov perineurial spinal cysts (TCs) are an underrecognized cause of spinal neuropathic symptoms. TCs form within the sensory nerve root sleeves, where CSF extends distally and can accumulate pathologically. Typically, they develop at the sacral dermatomes where the nerve roots are under the highest hydrostatic pressure and lack enclosing vertebral foramina. In total, 90% of patients are women, and genetic disorders that weaken connective tissues, e.g., Ehlers-Danlos syndrome, convey considerable risk. Most small TCs are asymptomatic and do not require treatment, but even incidental visualizations should be documented in case symptoms develop later. Symptomatic TCs most commonly cause sacropelvic dermatomal neuropathic pain, as well as bladder, bowel, and sexual dysfunction. Large cysts routinely cause muscle atrophy and weakness by compressing the ventral motor roots, and multiple cysts or multiroot compression by one large cyst can cause even greater cauda equina syndromes. Rarely, giant cysts erode the sacrum or extend as intrapelvic masses. Disabling TCs require consideration for surgical intervention. The authors' systematic review of treatment analyzed 31 case series of interventional percutaneous procedures and open surgical procedures. The surgical series were smaller and reported somewhat better outcomes with longer term follow-up but slightly higher risks. When data were lacking, authorial expertise and case reports informed details of the specific interventional and surgical techniques, as well as medical, physical, and psychological management. Cyst-wrapping surgery appeared to offer the best long-term outcomes by permanently reducing cyst size and reconstructing the nerve root sleeves. This curtails ongoing injury to the axons and neuronal death, and may also promote axonal regeneration to improve somatic and autonomic sacral nerve function.


Asunto(s)
Quistes de Tarlov , Humanos , Axones , Raíces Nerviosas Espinales/diagnóstico por imagen , Raíces Nerviosas Espinales/cirugía , Columna Vertebral , Quistes de Tarlov/complicaciones , Quistes de Tarlov/diagnóstico por imagen , Quistes de Tarlov/cirugía
20.
Nat Commun ; 15(1): 1709, 2024 Feb 24.
Artículo en Inglés | MEDLINE | ID: mdl-38402242

RESUMEN

With the advent of serial X-ray crystallography on microfocus beamlines at free-electron laser and synchrotron facilities, the demand for protein microcrystals has significantly risen in recent years. However, by in vitro crystallization extensive efforts are usually required to purify proteins and produce sufficiently homogeneous microcrystals. Here, we present InCellCryst, an advanced pipeline for producing homogeneous microcrystals directly within living insect cells. Our baculovirus-based cloning system enables the production of crystals from completely native proteins as well as the screening of different cellular compartments to maximize chances for protein crystallization. By optimizing cloning procedures, recombinant virus production, crystallization and crystal detection, X-ray diffraction data can be collected 24 days after the start of target gene cloning. Furthermore, improved strategies for serial synchrotron diffraction data collection directly from crystals within living cells abolish the need to purify the recombinant protein or the associated microcrystals.


Asunto(s)
Rayos Láser , Sincrotrones , Cristalografía por Rayos X , Cristalización , Proteínas Recombinantes/genética
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA