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BACKGROUND: Although clinicians have traditionally used the Finnegan Neonatal Abstinence Scoring Tool to assess the severity of neonatal opioid withdrawal, a newer function-based approach - the Eat, Sleep, Console care approach - is increasing in use. Whether the new approach can safely reduce the time until infants are medically ready for discharge when it is applied broadly across diverse sites is unknown. METHODS: In this cluster-randomized, controlled trial at 26 U.S. hospitals, we enrolled infants with neonatal opioid withdrawal syndrome who had been born at 36 weeks' gestation or more. At a randomly assigned time, hospitals transitioned from usual care that used the Finnegan tool to the Eat, Sleep, Console approach. During a 3-month transition period, staff members at each hospital were trained to use the new approach. The primary outcome was the time from birth until medical readiness for discharge as defined by the trial. Composite safety outcomes that were assessed during the first 3 months of postnatal age included in-hospital safety, unscheduled health care visits, and nonaccidental trauma or death. RESULTS: A total of 1305 infants were enrolled. In an intention-to-treat analysis that included 837 infants who met the trial definition for medical readiness for discharge, the number of days from birth until readiness for hospital discharge was 8.2 in the Eat, Sleep, Console group and 14.9 in the usual-care group (adjusted mean difference, 6.7 days; 95% confidence interval [CI], 4.7 to 8.8), for a rate ratio of 0.55 (95% CI, 0.46 to 0.65; P<0.001). The incidence of adverse outcomes was similar in the two groups. CONCLUSIONS: As compared with usual care, use of the Eat, Sleep, Console care approach significantly decreased the number of days until infants with neonatal opioid withdrawal syndrome were medically ready for discharge, without increasing specified adverse outcomes. (Funded by the Helping End Addiction Long-term (HEAL) Initiative of the National Institutes of Health; ESC-NOW ClinicalTrials.gov number, NCT04057820.).
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Síndrome de Abstinência Neonatal , Síndrome de Abstinência a Substâncias , Humanos , Recém-Nascido , Analgésicos Opioides/efeitos adversos , Analgésicos Opioides/uso terapêutico , Entorpecentes/uso terapêutico , Síndrome de Abstinência Neonatal/terapia , Sono , Síndrome de Abstinência a Substâncias/diagnóstico , Síndrome de Abstinência a Substâncias/tratamento farmacológico , Síndrome de Abstinência a Substâncias/terapia , Ingestão de Alimentos , Estados Unidos , Índice de Gravidade de Doença , Fatores de Tempo , Conforto do PacienteRESUMO
OBJECTIVES: To determine performance of C-reactive protein (CRP) in the diagnosis of early-onset sepsis, and to assess patient outcomes with and without routine use of CRP. STUDY DESIGN: This was a retrospective cohort study of infants admitted to 2 neonatal intensive care units. CRP was used routinely in early-onset sepsis evaluations during 2009-2014; this period was used to determine CRP performance at a cut-off of ≥10 mg/L in diagnosis of culture-confirmed early-onset sepsis. Routine CRP use was discontinued during 2018-2020; outcomes among infants admitted during this period were compared with those in 2012-2014. RESULTS: From 2009 to 2014, 10â134 infants were admitted; 9103 (89.8%) had CRP and 7549 (74.5%) had blood culture obtained within 3 days of birth. CRP obtained ±4 hours from blood culture had a sensitivity of 41.7%, specificity 89.9%, and positive likelihood ratio 4.12 in diagnosis of early-onset sepsis. When obtained 24-72 hours after blood culture, sensitivity of CRP increased (89.5%), but specificity (55.7%) and positive likelihood ratio (2.02) decreased. Comparing the periods with (n = 4977) and without (n = 5135) routine use of CRP, we observed lower rates of early-onset sepsis evaluation (74.5% vs 50.5%), antibiotic initiation (65.0% vs 50.8%), and antibiotic prolongation in the absence of early-onset sepsis (17.3% vs 7.2%) in the later period. Rate and timing of early-onset sepsis detection, transfer to a greater level of care, and in-hospital mortality were not different between periods. CONCLUSIONS: CRP diagnostic performance was not sufficient to guide decision-making in early-onset sepsis. Discontinuation of routine CRP use was not associated with differences in patient outcomes despite lower rates of antibiotic administration.
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Proteína C-Reativa , Sepse , Recém-Nascido , Humanos , Proteína C-Reativa/análise , Estudos Retrospectivos , Sepse/tratamento farmacológico , Antibacterianos/uso terapêutico , BiomarcadoresRESUMO
BACKGROUND: Hyperthermia is a known risk for sudden unexpected infant death. The practice of hat placement at birth to prevent transient hypothermia may not be necessary and sets an early standard for clothing infants that may lead to hyperthermia postnatally. OBJECTIVE: To examine the elimination of hats on thermoregulation (eg, hypothermia, <97.6°F) in full-term newborns with no abnormalities within 24 hours of birth. METHODS: In 2018, an institution guideline discontinued the use of hats at birth. Subsequently, newborn body temperatures were respectively extracted from electronic health records and data were compared from 482 infants (>38 weeks' gestation and newborn birth weight >2500 g) prior to ( n = 257) and following ( n = 225) the practice change. Body temperatures prior to and after the practice change to eliminate hats use were compared. RESULTS: No statistically significant difference was observed: (1) in the proportion of infants experiencing hypothermia with or without hat use, respectively, 23.7% compared with 31.1% ( P = .09) and (2) in the odds of an infant experiencing hypothermia when adjusting for relevant covariates (odds ratio = 1.44; 95% confidence interval 0.89-2.32; P = .14). CONCLUSIONS: Our findings demonstrate that the use of hats on infants at birth had no measurable impact on newborn thermoregulation.
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Hipotermia , Feminino , Gravidez , Criança , Recém-Nascido , Humanos , Hipotermia/prevenção & controle , Assistência Perinatal , Regulação da Temperatura Corporal , Temperatura Corporal , Idade GestacionalRESUMO
INTRODUCTION: Pain assessment is challenging in neonates. Behavioral and physiological pain scales do not assess neocortical nociception, essential to pain encoding and central pain pathway development. Functional near-infrared spectroscopy (fNIRS) can assess neocortical activation to noxious stimuli from changes in oxy-(HbO) and total-hemoglobin concentrations (HbT). This study aims to assess fNIRS nociceptive functional activation in the prefrontal cortex of neonates undergoing circumcision through changes in HbO and HbT, and the correlation between changes in fNIRS and Neonatal Infant Pain Scale (NIPS), a behavioral pain assessment scale. METHODS: In healthy term neonates, HbO, HbT, and NIPS were recorded during sequential circumcision events 1-Prep before local anesthetic injection; 2-Local anesthetic injection; 3-Prep before incision; 4-Oral sucrose; 5-Incision; 6-Gomco (hemostatic device) attached; 7-Gomco twisted on; and 8-Gomco removed. fNIRS and NIPS changes after each event were assessed with Wilcoxon signed-rank test and summarized as median and interquartile range (IQR). Changes in fNIRS vs. NIPS were correlated with Spearman coefficient. RESULTS: In 31 neonates fNIRS increased (median [IQR] µmol/L) with noxious events: Local injection (HbO: 1.1 [0.5, 3.1], p < .001; HbT: 2.3 [0.2, 7.6], p < .001), Gomco attached (HbO: 0.7 [0.1, 1.7], p = .002; HbT: 0.7 [-0.2, 2.9], p = .02), and Gomco twisted on (HbO: 0.5 [-0.2, 1.7], p = .03; HbT: 0.8 [-0.1, 3.3], p = .02). fNIRS decreased with non-noxious event: Prep before incision (HbO: -0.6 [-1.2, -0.2] p < .001; HbT: -1 [-1.8, -0.4], p < .001). Local anesthetic attenuated fNIRS increases to subsequent sharp stimuli. NIPS increased with subsequent sharp stimuli despite local anesthetic. Although fNIRS and NIPS changed in the same direction, there was not a strong correlation between them. CONCLUSIONS: During neonatal circumcision, changes in fNIRS differed between different types of painful stimuli, which was not the case for NIPS, suggesting that fNIRS may complement NIPS to assess the quality of pain.
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Circuncisão Masculina , Espectroscopia de Luz Próxima ao Infravermelho , Anestésicos Locais , Humanos , Lactente , Recém-Nascido , Masculino , Dor , Medição da Dor , Espectroscopia de Luz Próxima ao Infravermelho/métodosRESUMO
OBJECTIVE: To assess decisional conflict and knowledge about prematurity among mothers facing extreme premature delivery when the counseling clinicians were randomized to counsel using a validated decision aid compared with usual counseling. STUDY DESIGN: In this randomized trial, clinicians at 5 level III neonatal intensive care units in the US were randomized to supplement counseling using the decision aid or to counsel mothers in their usual manner. We enrolled mothers with threatened premature delivery at 220/7 to 256/7 weeks of gestation within 7 days of their counseling. The primary outcome was the Decisional Conflict Scale (DCS) score. One hundred mothers per group were enrolled to detect a clinically relevant effect size of 0.4 in the Decisional Conflict Scale. Secondary outcomes included knowledge about prematurity; scores on the Preparedness for Decision Making scale; and acceptability. RESULTS: Ninety-two clinicians were randomized and 316 mothers were counseled. Of these, 201 (64%) mothers were enrolled. The median gestational age was 24.1 weeks (IQR 23.7-24.9). In both groups, DCS scores were low (16.3 ± 18.2 vs 16.8 ± 17, P = .97) and Preparedness for Decision Making scores were high (73.4 ± 28.3 vs 70.5 ± 31.1, P = .33). There was a significantly greater knowledge score in the decision aid group (66.2 ± 18.5 vs 57.2 ± 18.8, P = .005). Most clinicians and parents found the decision aid useful. CONCLUSIONS: For parents facing extremely premature delivery, use of a decision aid did not impact maternal decisional conflict, but it significantly improved knowledge of complex information. A structured decision aid may improve comprehension of complex information. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01713894.
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Cuidadores/psicologia , Aconselhamento/métodos , Técnicas de Apoio para a Decisão , Lactente Extremamente Prematuro , Pais/psicologia , Adulto , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Doenças do Prematuro/diagnóstico , Doenças do Prematuro/enfermagem , Terapia Intensiva Neonatal , Masculino , Gravidez , Taxa de Sobrevida , Resultado do Tratamento , Estados UnidosRESUMO
The premature infant is born into the world unprepared to naturally thrive in a foreign environment. Lung development entails immense growth, structural remodeling and differentiation of specialized cells during the normal term perinatal and postnatal periods. Thus, the premature infant presents with a lung deficient for appropriate respiration. Disruption of lung development seen in bronchopulmonary dysplasia (BPD) and chronic lung disease (CLD) results in not only impaired airway growth but also a deficiency in the accompanying vasculature including the capillary system required for gas exchange. Deficient vascular area can lead to elevated pulmonary vascular resistance and the development of pulmonary hypertension (PH). Unlike PH seen in children and adults with pulmonary arterial hypertension (PAH), treatment with conventional pulmonary vasodilators can be limited in developmental lung disease-associated PH because there are fewer blood vessels to dilate. In this brief review, we highlight some of the knowledge on PH in the premature infant presented at the Proceedings of the 22nd Annual Update on Pediatric and Congenital Cardiovascular Disease.
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BACKGROUND: Moderately preterm infants (MPTI) comprise a large proportion of NICU admissions and are an understudied population. The unique experience of families with MPTIs has yet to be examined in the literature. Describing MPTI parent needs and preferences may inform interventions to improve care and outcomes for this population. METHODS: Semistructured qualitative interviews were performed with English-speaking birth parents of infants born between 32 and 34 weeks gestation to describe their NICU experience and identify areas for improvement specifically surrounding care team inclusion, education, discharge, and communication. Interviews were recorded, transcribed, and analyzed using directed content analysis. Enrollment ceased when the data reached thematic saturation. RESULTS: Sixteen birth parents participated. Four themes emerged around parent-medical team connectedness, parental confusion, discharge readiness, and the desire for a use of a mix of in-person and electronic communication methods (e-mail, texting, apps, etc) for communication. MPTI parents valued a strong connection with the medical team; however, they described a lack of knowledge regarding the reasons for admission and ongoing management. Near discharge, parents desired more information regarding feeding, reflux, and breathing patterns. Parents preferred in-person discussions but described a role for electronic methods to improve their understanding of their infant and discharge readiness. CONCLUSIONS: From the MPTI parent perspective, clinicians can focus improvement efforts on communication, specifically around reasons for admission, discharge planning, and anticipatory guidance. These results may serve as a foundation for initiatives to improve the MPTI parent experience and potentially parent and MPTI outcomes.
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Comunicação , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Pais , Alta do Paciente , Humanos , Pais/psicologia , Recém-Nascido , Feminino , Masculino , Relações Profissional-Família , Pesquisa Qualitativa , Adulto , Entrevistas como AssuntoRESUMO
BACKGROUND: Infants at risk for hypoxic ischemic encephalopathy (HIE) require a time sensitive evaluation and decision-making regarding treatment with therapeutic hypothermia (TH). Prior to this project, there was no standardized approach to evaluating these infants locally. METHODS: Included infants were "at risk for HIE," defined as meeting the "patient characteristics" and "biochemical criteria" per the institutional HIE pathway. Our primary outcome was documentation of an HIE therapeutic hypothermia evaluation (HIETHE) within the first six hours of life which included: (1) recognition of at-risk status, (2) an encephalopathy exam, and (3) a decision regarding TH. Plan-Do-Study-Act cycles included novel clinical decision support. RESULTS: From October 2020 to May 2023, among infants at-risk for HIE, the average percentage with an HIETHE documented improved from 47% to 82%. CONCLUSIONS: We standardized the approach to infants at risk for HIE and improved the presence of a complete and timely evaluation regarding TH eligibility.
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Documentação , Hipotermia Induzida , Hipóxia-Isquemia Encefálica , Humanos , Hipóxia-Isquemia Encefálica/terapia , Hipóxia-Isquemia Encefálica/diagnóstico , Recém-Nascido , Documentação/normas , Feminino , Masculino , Medição de RiscoRESUMO
Importance: Infants with neonatal opioid withdrawal syndrome (NOWS) cared for with the Eat, Sleep, Console (ESC) care approach receive less pharmacologic treatment and have shorter hospital stays compared to usual care with the Finnegan Neonatal Abstinence Scoring Tool, but the effects of these approaches on feeding and weight are unknown. Objective: To evaluate feeding practices and weight trajectories in infants cared for with ESC vs usual care. Design, Setting, and Participants: ESC-NOW is a cluster randomized trial of infants with NOWS born at 36 weeks' gestation or later at 26 US hospitals from September 2020 to March 2022. Each site transitioned from usual care to ESC (the study intervention) at a randomized time. Feeding was per site practice and not specified by the intervention. Feeding and weight outcomes were assessed at hospital discharge. Intervention: ESC vs usual care. Main Outcomes and Measures: Outcomes include prospectively identified secondary end points related to feeding and weight. z Scores were used for growth to account for corrected gestational age at the time of measurement. All analyses were intention to treat and adjusted for study design. Maternal/infant characteristics were included in adjusted models. Results: The analyses included 1305 infants (702 in usual care and 603 in ESC; mean [SD] gestational age, 38.6 [1.3] weeks; 655 [50.2%] male and 650 [49.8%] female). Baseline demographic characteristics were similar between groups. The proportion of breastfed infants was higher in the ESC group (52.7% vs 41.7%; absolute difference, 11%; 95% CI, 1.0-20.9). A higher proportion of infants cared for with ESC received exclusive breast milk (15.1% vs 6.7%; absolute difference, 8.4%; 95% CI, 0.9-5.8) or any breast milk (38.8% vs 27.4%; absolute difference, 11.4%; 95% CI, 0.2-23.1) and were directly breastfeeding at discharge (35.2% vs 19.5%; absolute difference, 15.7%; 95% CI, 4.1-27.3). There was no difference in proportion of infants with weight loss greater than 10% or maximum percentage weight loss, although infants cared for with ESC had a lower weight z score on day of life 3 (-1.08 vs -1.01; absolute difference, 0.07; 95% CI, 0.02-0.12). When pharmacologic treatment was added into the model, no breastfeeding outcomes were statistically significant. Conclusions and Relevance: In this study, infants cared for with ESC were more likely to initiate and continue breastfeeding and had no difference in percentage weight loss. The improvement in breastfeeding with ESC may be driven by reduction in pharmacologic treatment and provision of effective nonpharmacologic care. Trial Registration: ClinicalTrials.gov Identifier: NCT04057820.
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Importance: The function-based eat, sleep, console (ESC) care approach substantially reduces the proportion of infants who receive pharmacologic treatment for neonatal opioid withdrawal syndrome (NOWS). This reduction has led to concerns for increased postnatal opioid exposure in infants who receive pharmacologic treatment. However, the effect of the ESC care approach on hospital outcomes for infants pharmacologically treated for NOWS is currently unknown. Objective: To evaluate differences in opioid exposure and total length of hospital stay (LOS) for pharmacologically treated infants managed with the ESC care approach vs usual care with the Finnegan tool. Design, Setting, and Participants: This post hoc subgroup analysis involved infants pharmacologically treated in ESC-NOW, a stepped-wedge cluster randomized clinical trial conducted at 26 US hospitals. Hospitals maintained pretrial practices for pharmacologic treatment, including opioid type, scheduled opioid dosing, and use of adjuvant medications. Infants were born at 36 weeks' gestation or later, had evidence of antenatal opioid exposure, and received opioid treatment for NOWS between September 2020 and March 2022. Data were analyzed from November 2022 to January 2024. Exposure: Opioid treatment for NOWS and the ESC care approach. Main Outcomes and Measures: For each outcome (total opioid exposure, peak opioid dose, time from birth to initiation of first opioid dose, length of opioid treatment, and LOS), we used generalized linear mixed models to adjust for the stepped-wedge design and maternal and infant characteristics. Results: In the ESC-NOW trial, 463 of 1305 infants were pharmacologically treated (143/603 [23.7%] in the ESC care approach group and 320/702 [45.6%] in the usual care group). Mean total opioid exposure was lower in the ESC care approach group with an absolute difference of 4.1 morphine milligram equivalents per kilogram (MME/kg) (95% CI, 1.3-7.0) when compared with usual care (4.8 MME/kg vs 8.9 MME/kg, respectively; P = .001). Mean time from birth to initiation of pharmacologic treatment was 22.4 hours (95% CI, 7.1-37.7) longer with the ESC care approach vs usual care (75.4 vs 53.0 hours, respectively; P = .002). No significant difference in mean peak opioid dose was observed between groups (ESC care approach, 0.147 MME/kg, vs usual care, 0.126 MME/kg). The mean length of treatment was 6.3 days shorter (95% CI, 3.0-9.6) in the ESC care approach group vs usual care group (11.8 vs 18.1 days, respectively; P < .001), and mean LOS was 6.2 days shorter (95% CI, 3.0-9.4) with the ESC care approach than with usual care (16.7 vs 22.9 days, respectively; P < .001). Conclusion and Relevance: When compared with usual care, the ESC care approach was associated with less opioid exposure and shorter LOS for infants pharmacologically treated for NOWS. The ESC care approach was not associated with a higher peak opioid dose, although pharmacologic treatment was typically initiated later. Trial Registration: ClinicalTrials.gov Identifier: NCT04057820.
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Analgésicos Opioides , Síndrome de Abstinência Neonatal , Humanos , Síndrome de Abstinência Neonatal/tratamento farmacológico , Feminino , Recém-Nascido , Analgésicos Opioides/uso terapêutico , Analgésicos Opioides/administração & dosagem , Analgésicos Opioides/efeitos adversos , Masculino , Tempo de Internação/estatística & dados numéricos , Sono/efeitos dos fármacosRESUMO
The electronic health record (EHR) offers an exciting opportunity for quality improvement efforts. An understanding of the nuances of a site's EHR landscape including the best practices in clinical decision support design, basics of data capture, and acknowledgment of the potential unintended consequences of technology change is essential to ensuring effective usage of this powerful tool.
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Sistemas de Apoio a Decisões Clínicas , Registros Eletrônicos de Saúde , Humanos , Melhoria de QualidadeRESUMO
BACKGROUND: Premature infants have bradycardia and/or desaturation events due to apnea of prematurity that resolve as the infants mature. Despite American Academy of Pediatrics guidelines recommending a standard "event-free" period before discharge, length of observation in our Intensive Care Nursery was variable. By June 2018, for infants born <36 weeks' gestation in the Intensive Care Nursery, we aimed to standardize time to discharge after the last documented event at 5 days, when the baseline mean was 3.6 days (range 0-6 days). METHODS: A quality-improvement team used the Model for Improvement. Plan-do-study-act cycles improved nursing documentation of events and standardized discharge criteria after consensus on operational definitions. The outcome measure was days to discharge after last documented event. Process measures included percentage of events documented completely and correctly in the electronic medical record. Balancing measure was length of stay after 36 weeks' corrected gestational age. We used statistical process control. RESULTS: The baseline event watch ranged from 0 to 6 days. After defining significant events, documentation expectations, and consensus on a 5-day "watch" before discharge, the event watch range narrowed with a mean that shifted from 3.6 to 4.8 days on X-bar S statistical process control chart. Completeness of documentation increased from 38% to 63%, and documentation of significant events increased from 38% to 88%. Length of stay after 36 weeks' corrected gestational age was unchanged, and nursing satisfaction improved. CONCLUSIONS: We found decreasing variation in the management of apnea of prematurity while simultaneously improving staff satisfaction. Next steps include revising electronic medical record flowsheets and spread to network NICUs.
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Apneia/terapia , Documentação/normas , Terapia Intensiva Neonatal/normas , Tempo de Internação , Alta do Paciente/normas , Melhoria de Qualidade , Consenso , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Unidades de Terapia Intensiva Neonatal , Avaliação de Resultados em Cuidados de Saúde , Fatores de Tempo , Sinais VitaisRESUMO
The neuroprotective effects of lithium, a mood stabilizer, against glutamate-induced excitotoxicity in rat cortical neurons were associated with a decrease in Tyr1472 phosphorylation of the N-methyl-D-aspartate (NMDA) receptor NR2B subunit and a loss of receptor activity. Since this receptor tyrosine phosphorylation is mediated by the Src-family tyrosine kinases, we investigated the effects of lithium on the Src kinase activity. Levels of phosphorylated Src kinase at Tyr416, an index of Src activation, were reduced after treatment with LiCl (1 mM) for more than 3 days. Protein levels of Src-family kinases such as Src, Fyn, and Yes were unchanged by lithium treatment. The activities of cytosolic protein tyrosine kinase and protein phosphatase were also unchanged by lithium treatment, indicating the selectivity and the modulation. Moreover, the levels of postsynaptic densities (PSD) and SynGAP, the scaffolding proteins of the NMDA receptor complex, were unaltered by lithium. A Src kinase inhibitor, SU6656, and an NR2B antagonist, ifenprodil, partially blocked glutamate excitotoxicity. Our results suggest that lithium-induced inactivation of Src kinase contributes to this drug-induced NMDA receptor inhibition and neuroprotection against excitotoxicity.
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Córtex Cerebral/efeitos dos fármacos , Lítio/farmacologia , Neurônios/efeitos dos fármacos , Receptores de N-Metil-D-Aspartato/fisiologia , Quinases da Família src/antagonistas & inibidores , Animais , Células Cultivadas , Córtex Cerebral/enzimologia , Neurônios/enzimologia , RatosRESUMO
Mechanisms underlying the therapeutic effects of lithium for bipolar mood disorder remain poorly understood. Recent studies demonstrate that lithium has neuroprotective actions against a variety of insults in vitro and in vivo. This study was undertaken to investigate the role of the brain-derived neurotrophic factor (BDNF)/TrkB signaling pathway in mediating neuroprotection of lithium against glutamate excitotoxicity in cortical neurons. Pretreatment with either lithium or BDNF protected rat cerebral cortical neurons from glutamate excitotoxicity. The duration of treatment required to elicit maximal neuroprotection by BDNF (1 day) was much shorter than that by lithium (6 days). K252a, an inhibitor of Trk tyrosine kinases, and a BDNF neutralizing antibody suppressed the neuroprotective effect of lithium. Treatment of cortical neurons with lithium increased the cellular BDNF content in 3 days and the phosphorylation of TrkB at Tyr490 in 5 days, suggesting that long-term lithium administration enhances BDNF expression/secretion, leading to the activation of TrkB receptor. Lithium failed to protect against glutamate excitotoxicity in cortical neurons derived from homozygous and heterozygous BDNF knockout mice, although lithium fully protected cortical neurons prepared from wild type mice littermates. Taken together, these data suggest that the BDNF/TrkB pathway plays an essential role in mediating the neuroprotective effect of lithium.
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Fator Neurotrófico Derivado do Encéfalo/biossíntese , Ácido Glutâmico/toxicidade , Cloreto de Lítio/farmacologia , Neurônios/efeitos dos fármacos , Receptor trkB/metabolismo , Animais , Células Cultivadas , Córtex Cerebral/efeitos dos fármacos , Córtex Cerebral/metabolismo , Córtex Cerebral/patologia , Agonistas de Aminoácidos Excitatórios/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neurônios/metabolismo , Neurônios/patologia , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Ratos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologiaRESUMO
Lithium has long been one of the primary drugs used to treat bipolar mood disorder. However, neither the etiology of this disease nor the therapeutic mechanism(s) of this drug is well understood. Several lines of clinical evidence suggest that lithium has neurotrophic actions. For example chronic lithium treatment increases the volume of gray matter and the content of N-acetyl-aspartate, a cell survival marker, in bipolar mood disorder patients (Moore et al., 2000). Moreover, treatment with this mood-stabilizer suppresses the decrease in the volume of the subgenual pre-frontal cortex found in bipolar patients (Drevets, 2001). To elucidate molecular mechanisms underlying the neuroprotective and neurotrophic actions of lithium, we employed a preparation of cultured cortical neurons prepared form embryonic rats. We found that treatment with therapeutic doses (0.2-1.2 mM) of lithium robustly protects cortical neurons from multiple insults, notably glutamate-induced excitotoxicity. The neuroprotection against glutamate excitotoxicity is time-dependent, requiring treatment for 5-6 days for maximal effect, and is associated with a reduction in NMDA receptor-mediated Ca2+ influx. The latter is correlated with a decrease in Tyrosine 1472 phosphorylation levels in the NR2B subunit of NMDA receptors and a loss of Src kinase activity which is involved in NR2B tyrosine phosphorylation. Neither the activity of total tyrosine protein kinase nor that of tyrosine protein phosphatase is affected by this drug, indicating the selectivity of the modulation. Lithium neuroprotection against excitotoxicity is inhibited by a BDNF-neutralizing antibody and K252a, a Trk antagonist. Lithium treatment time-dependently increases the intracellular level of BDNF in cortical neurons and activates its receptor, TrkB. The neuroprotection can be completely blocked by either heterozygous or homozygous knockout of the BDNF gene. These results suggest a central role of BDNF and TrkB in mediating the neuroprotective effects of this mood-stabilizer. Finally, long-term lithium treatment of cortical neurons stimulates the proliferation of their progenitor cells detected by co-labeling with BrdU and nestin. Lithium pretreatment also blocks the decrease in progenitor proliferation induced by glutamate, glucocorticoids and haloperidol, suggesting a role in CNS neuroplasticity. We used animal models to investigate further therapeutic potentials for lithium. In the MCAO/reperfusion model of stroke, we found that post-insult treatment with lithium robustly reduced infarct volume and neurological deficits. These beneficial effects were evident when therapeutic concentrations of lithium were injected at least up to 3 h after ischemic onset. The neuroprotection was associated with activation of heat-shock factor-1 and induction of heat-shock protein-70, a cytoprotective protein. In a rat excitotoxic model of Huntington's disease, the excitotoxin-induced loss of striatal medium-sized neurons was markedly reduced by lithium. This lithium protection was correlated with up-regulation of cytoprotective Bcl-2 and down-regulation of apoptotic proteins p53 and Bax, and neurons showing DNA damage and caspase-3 activation. Taken together, our results provide a new insight into the molecular mechanisms involved in lithium neuroprotection against glutamate excitotoxicity. Moreover, these novel molecular and cellular actions might contribute to the neurotrophic and neuroprotective actions of this mood-stabilizer in patients, and could be related to its clinical efficacy for treating mood disorder patients. Clearly, mood-stabilizers may have expanded use for treating excitotoxin-related neurodegenerative diseases.
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Lítio/farmacologia , Neurônios/efeitos dos fármacos , Animais , Técnicas In Vitro , Lítio/uso terapêutico , RatosRESUMO
Maternal obesity during pregnancy increases the risk for offspring obesity, in part through effects on the developing brain. Previous research has shown that perinatal consumption of highly palatable foods by the mother can influence the development of offspring taste preferences and alter gene expression within the central nervous system (CNS) reward system. Opioids stimulate consumption of both fats and carbohydrates, and overconsumption of these energy dense foods increases the risk for obesity. What has remained unclear is whether this risk can be transmitted to the offspring before gestation or if it is wholly the gestational exposure that affects offspring brain development. Utilizing an embryo transfer experimental design, 2-cell embryos were obtained from obese or control dams, and transferred to obese or control gestational carriers. Expression of the mu-opioid receptor (MOR), preproenkephalin (PENK), and the dopamine transporter was evaluated in the hypothalamus and reward circuitry (ventral tegmental area, prefrontal cortex, and nucleus accumbens) in adult and late embryonic brains. Obesity before pregnancy altered expression levels of both MOR and PENK, with males relatively more affected than females. These data are the first to demonstrate that obesity at conception, in addition to during gestation, can program the brain reward system.