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1.
J Pediatr Hematol Oncol ; 46(6): e448-e452, 2024 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-39051638

RESUMEN

Infection is a major cause of treatment-related morbidity and mortality in pediatric acute lymphoblastic leukemia (ALL). Most children with ALL who develop life-threatening bacterial infections do so during induction therapy. We describe a rare case of ALL presenting simultaneously with Streptococcus agalactiae group B Streptococcus bacteremia and meningitis in a 3-year-old girl. She received appropriate antimicrobial therapy and a 2-drug early induction regimen consisting of vincristine and dexamethasone, leading to slow neurologic recovery and a favorable initial response to anti-neoplastic therapy as evidenced by minimal residual disease of 1.12% on day 15 of induction.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica , Dexametasona , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Infecciones Estreptocócicas , Streptococcus agalactiae , Humanos , Femenino , Preescolar , Infecciones Estreptocócicas/tratamiento farmacológico , Infecciones Estreptocócicas/microbiología , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras B/complicaciones , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Dexametasona/uso terapéutico , Dexametasona/administración & dosificación , Meningitis Bacterianas/tratamiento farmacológico , Meningitis Bacterianas/microbiología , Meningitis Bacterianas/diagnóstico , Vincristina/administración & dosificación , Vincristina/uso terapéutico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamiento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Bacteriemia/tratamiento farmacológico , Bacteriemia/microbiología
2.
Emerg Infect Dis ; 30(6): 1245-1248, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38782142

RESUMEN

Choanephora infundibulifera is a member of the Mucorales order of fungi. The species is associated with plants as a saprophyte or parasite and may be responsible for spoilage or disease but is an uncommon cause of human infection. We describe C. infundibulifera rhinosinusitis in a young man with leukemia in Tennessee, USA.


Asunto(s)
Sinusitis , Humanos , Masculino , Tennessee , Sinusitis/microbiología , Sinusitis/diagnóstico , Sinusitis/parasitología , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicaciones , Mucormicosis/diagnóstico , Mucormicosis/microbiología , Mucormicosis/tratamiento farmacológico , Mucorales/aislamiento & purificación , Mucorales/clasificación , Rinitis/microbiología , Rinitis/diagnóstico , Adulto , Antifúngicos/uso terapéutico , Rinosinusitis
3.
Exp Neurol ; 378: 114808, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38750949

RESUMEN

Low-dose (< 2 h/day), acute intermittent hypoxia (AIH) elicits multiple forms of serotonin-dependent phrenic motor plasticity and is emerging as a promising therapeutic strategy to restore respiratory and non-respiratory motor function after spinal cord injury (SCI). In contrast, high-dose (> 8 h/day), chronic intermittent hypoxia (CIH) undermines some forms of serotonin-dependent phrenic motor plasticity and elicits pathology. CIH is a hallmark of sleep disordered breathing, which is highly prevalent in individuals with cervical SCI. Interestingly, AIH and CIH preconditioning differentially impact phrenic motor plasticity. Although mechanisms of AIH-induced plasticity in the phrenic motor system are well-described in naïve rats, we know little concerning how these mechanisms are affected by chronic SCI or intermittent hypoxia preconditioning. Thus, in a rat model of chronic, incomplete cervical SCI (lateral spinal hemisection at C2 (C2Hx), we assessed serotonin type 2A, 2B and 7 receptor expression in and near phrenic motor neurons and compared: 1) intact vs. chronically injured rats; and 2) the impact of preconditioning with varied "doses" of intermittent hypoxia (IH). While there were no effects of chronic injury or intermittent hypoxia alone, CIH affected multiple receptors in rats with chronic C2Hx. Specifically, CIH preconditioning (8 h/day; 28 days) increased serotonin 2A and 7 receptor expression exclusively in rats with chronic C2Hx. Understanding the complex, context-specific interactions between chronic SCI and CIH and how this ultimately impacts phrenic motor plasticity is important as we leverage AIH-induced motor plasticity to restore breathing and other non-respiratory motor functions in people with chronic SCI.


Asunto(s)
Hipoxia , Neuronas Motoras , Nervio Frénico , Receptores de Serotonina , Traumatismos de la Médula Espinal , Animales , Masculino , Ratas , Médula Cervical/lesiones , Médula Cervical/metabolismo , Vértebras Cervicales , Enfermedad Crónica , Hipoxia/metabolismo , Neuronas Motoras/metabolismo , Plasticidad Neuronal/fisiología , Nervio Frénico/metabolismo , Ratas Sprague-Dawley , Receptores de Serotonina/metabolismo , Receptores de Serotonina/biosíntesis , Traumatismos de la Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/fisiopatología
4.
Beilstein J Org Chem ; 20: 830-840, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38655556

RESUMEN

Linear nitramines (R-N(R')NO2; R' = H or alkyl) are toxic compounds, some with environmental relevance, while others are rare natural product nitramines. One of these natural product nitramines is N-nitroglycine (NNG), which is produced by some Streptomyces strains and exhibits antibiotic activity towards Gram-negative bacteria. An NNG degrading heme enzyme, called NnlA, has recently been discovered in the genome of Variovorax sp. strain JS1663 (Vs NnlA). Evidence is presented that NnlA and therefore, NNG degradation activity is widespread. To achieve this objective, we characterized and tested the NNG degradation activity of five Vs NnlA homologs originating from bacteria spanning several classes and isolated from geographically distinct locations. E. coli transformants containing all five homologs converted NNG to nitrite. Four of these five homologs were isolated and characterized. Each isolated homolog exhibited similar oligomerization and heme occupancy as Vs NnlA. Reduction of this heme was shown to be required for NnlA activity in each homolog, and each homolog degraded NNG to glyoxylate, NO2- and NH4+ in accordance with observations of Vs NnlA. It was also shown that NnlA cannot degrade the NNG analog 2-nitroaminoethanol. The combined data strongly suggest that NnlA enzymes specifically degrade NNG and are found in diverse bacteria and environments. These results imply that NNG is also produced in diverse environments and NnlA may act as a detoxification enzyme to protect bacteria from exposure to NNG.

5.
Emerg Infect Dis ; 29(8)2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37486155

RESUMEN

Mycolicibacterium neoaurum is a rapidly growing mycobacterium and an emerging cause of human infections. M. neoaurum infections are uncommon but likely underreported, and our understanding of the disease spectrum and optimum management is incomplete. We summarize demographic and clinical characteristics of a case of catheter-related M. neoaurum bacteremia in a child with leukemia and those of 36 previously reported episodes of M. neoaurum infection. Most infections occurred in young to middle-aged adults with serious underlying medical conditions and commonly involved medical devices. Overall, infections were not associated with severe illness or death. In contrast to other mycobacteria species, M. neoaurum was generally susceptible to multiple antimicrobial drugs and responded promptly to treatment, and infections were associated with good outcomes after relatively short therapy duration and device removal. Delays in identification and susceptibility testing were common. We recommend using combination antimicrobial drug therapy and removal of infected devices to eradicate infection.


Asunto(s)
Infección Hospitalaria , Mycobacteriaceae , Infecciones por Mycobacterium , Mycobacterium , Niño , Humanos , Persona de Mediana Edad , Atención a la Salud , Infecciones por Mycobacterium/microbiología , Adulto Joven
6.
Am J Drug Alcohol Abuse ; 49(4): 481-490, 2023 07 04.
Artículo en Inglés | MEDLINE | ID: mdl-36880708

RESUMEN

Background: Alcohol is the most abused substance among adults in the United States. The COVID-19 pandemic impacted patterns of alcohol use, but data are conflicting, and previous studies are largely limited to cross-sectional analyses.Objective: This study aimed to longitudinally assess sociodemographic and psychological correlates of changes in three patterns of alcohol use (number of alcoholic drinks, drinking regularity, and binge drinking) during COVID-19.Methods: We studied changes in self-reported drinking behaviors in 222,195 Mayo Clinic patients over 21 years of age (58.1% female and 41.9% male) between April 1, 2019, and March 30, 2021. Logistic regression models were used to estimate associations between patient characteristics and change in alcohol consumption.Results: Sociodemographically younger age, White race, having a college degree, and living in a rural area were associated with increased alcohol use regularity (all p < .05). Younger age, male, White, high-school education or less, living in a more deprived neighborhood, smoking, and living in a rural area were associated with increases in number of alcohol drinks (all p ≤ .04) and binge drinking (all p ≤ .01). Increased anxiety scores were associated with increased number of drinks, while depression severity was associated with both increased drinking regularity and increased number of drinks (all p ≤ .02) independent of sociodemographic characteristics.Conclusion: Our study showed that both sociodemographic and psychological characteristics were associated with increased alcohol consumption patterns during the COVID-19 pandemic. Our study highlights specific target groups previously not described in the literature for alcohol interventions based on sociodemographic and psychological characteristics.


Asunto(s)
Consumo Excesivo de Bebidas Alcohólicas , COVID-19 , Humanos , Masculino , Adulto , Femenino , Estados Unidos , Consumo Excesivo de Bebidas Alcohólicas/epidemiología , Consumo Excesivo de Bebidas Alcohólicas/psicología , Estudios Transversales , Pandemias , COVID-19/epidemiología , Consumo de Bebidas Alcohólicas/epidemiología , Etanol
7.
J Am Chem Soc ; 145(8): 4589-4600, 2023 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-36795004

RESUMEN

Metal-organic frameworks (MOFs) that display photoredox activity are attractive materials for sustainable photocatalysis. The ability to tune both their pore sizes and electronic structures based solely on the choice of the building blocks makes them amenable for systematic studies based on physical organic and reticular chemistry principles with high degrees of synthetic control. Here, we present a library of eleven isoreticular and multivariate (MTV) photoredox-active MOFs, UCFMOF-n, and UCFMTV-n-x% with a formula Ti6O9[links]3, where the links are linear oligo-p-arylene dicarboxylates with n number of p-arylene rings and x mol% of multivariate links containing electron-donating groups (EDGs). The average and local structures of UCFMOFs were elucidated from advanced powder X-ray diffraction (XRD) and total scattering tools, consisting of parallel arrangements of one-dimensional (1D) [Ti6O9(CO2)6]∞ nanowires connected through the oligo-arylene links with the topology of the edge-2-transitive rod-packed hex net. Preparation of an MTV library of UCFMOFs with varying link sizes and amine EDG functionalization enabled us to study both their steric (pore size) and electronic (highest occupied molecular orbital-lowest unoccupied molecular orbital, HOMO-LUMO, gap) effects on the substrate adsorption and photoredox transformation of benzyl alcohol. The observed relationship between the substrate uptake and reaction kinetics with the molecular traits of the links indicates that longer links, as well as increased EDG functionalization, exhibit impressive photocatalytic rates, outperforming MIL-125 by almost 20-fold. Our studies relating photocatalytic activity with pore size and electronic functionalization demonstrate how these are important parameters to consider when designing new MOF photocatalysts.

8.
J Public Health (Oxf) ; 45(2): 442-449, 2023 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-36194073

RESUMEN

BACKGROUND: In this longitudinal cohort study, we examined the socio-demographic and psychological predictors of alcohol use initiation during the COVID-19 pandemic in a sample of never alcohol users aged ≥21 prior to COVID-19. METHODS: Our study population consisted of 56 930 patients aged ≥21, as of 30 March 2019 were collected from a pre-COVID period of 1 year before 31 March 2020, and during-COVID, a period between 1 April 2020 and 30 March 2021. Univariable and multivariable logistic regression models were utilized to examine the roles of socio-demographic variables (gender, age, education, Area Deprivation Index and rural residence) changes in anxiety and depression severity as predictors of alcohol use initiation. RESULTS: Age, gender, race, ethnicity, education and rural status were significant predictors in multivariable analysis. A subgroup analysis showed neither anxiety nor depression had a significant association with alcohol use initiation. CONCLUSION: Women, younger individuals, those living in a rural area and people who smoke cigarettes were more likely to initiate alcohol use during the pandemic. Our study has public health and clinical implications such as the need for targeted alcohol use screening and intervention for vulnerable individuals.


Asunto(s)
COVID-19 , Humanos , Femenino , COVID-19/epidemiología , Estudios Longitudinales , Pandemias , Consumo de Bebidas Alcohólicas/epidemiología , Consumo de Bebidas Alcohólicas/psicología , Ansiedad/epidemiología , Ansiedad/psicología , Demografía , Depresión/epidemiología , Depresión/psicología
9.
Neuroscience ; 506: 38-50, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36273657

RESUMEN

Cervical spinal cord injury (cSCI) impairs neural drive to the respiratory muscles, causing life- threatening complications such as respiratory insufficiency and diminished airway protection. Repetitive "low dose" acute intermittent hypoxia (AIH) is a promising strategy to restore motor function in people with chronic SCI. Conversely, "high dose" chronic intermittent hypoxia (CIH; ∼8 h/night), such as experienced during sleep apnea, causes pathology. Sleep apnea, spinal ischemia, hypoxia and neuroinflammation associated with cSCI increase extracellular adenosine concentrations and activate spinal adenosine receptors which in turn constrains the functional benefits of therapeutic AIH. Adenosine 1 and 2A receptors (A1, A2A) compete to determine net cAMP signaling and likely the tAIH efficacy with chronic cSCI. Since cSCI and intermittent hypoxia may regulate adenosine receptor expression in phrenic motor neurons, we tested the hypotheses that: 1) daily AIH (28 days) downregulates A2A and upregulates A1 receptor expression; 2) CIH (28 days) upregulates A2A and downregulates A1 receptor expression; and 3) cSCI alters the impact of CIH on adenosine receptor expression. Daily AIH had no effect on either adenosine receptor in intact or injured rats. However, CIH exerted complex effects depending on injury status. Whereas CIH increased A1 receptor expression in intact (not injured) rats, it increased A2A receptor expression in spinally injured (not intact) rats. The differential impact of CIH reinforces the concept that the injured spinal cord behaves in distinct ways from intact spinal cords, and that these differences should be considered in the design of experiments and/or new treatments for chronic cSCI.


Asunto(s)
Síndromes de la Apnea del Sueño , Traumatismos de la Médula Espinal , Ratas , Animales , Neuronas Motoras , Receptores Purinérgicos P1 , Hipoxia , Adenosina
10.
Appl Environ Microbiol ; 88(16): e0102322, 2022 08 23.
Artículo en Inglés | MEDLINE | ID: mdl-35916514

RESUMEN

Linear nitramines are potentially carcinogenic environmental contaminants. The NnlA enzyme from Variovorax sp. strain JS1663 degrades the nitramine N-nitroglycine (NNG)-a natural product produced by some bacteria-to glyoxylate and nitrite (NO2-). Ammonium (NH4+) was predicted as the third product of this reaction. A source of nonheme FeII was shown to be required for initiation of NnlA activity. However, the role of this FeII for NnlA activity was unclear. This study reveals that NnlA contains a b-type heme cofactor. Reduction of this heme-either by a nonheme iron source or dithionite-is required to initiate NnlA activity. Therefore, FeII is not an essential substrate for holoenzyme activity. Our data show that reduced NnlA (FeII-NnlA) catalyzes at least 100 turnovers and does not require O2. Finally, NH4+ was verified as the third product, accounting for the complete nitrogen mass balance. Size exclusion chromatography showed that NnlA is a dimer in solution. Additionally, FeII-NnlA is oxidized by O2 and NO2- and stably binds carbon monoxide (CO) and nitric oxide (NO). These are characteristics shared with heme-binding PAS domains. Furthermore, a structural homology model of NnlA was generated using the PAS domain from Pseudomonas aeruginosa Aer2 as a template. The structural homology model suggested His73 is the axial ligand of the NnlA heme. Site-directed mutagenesis of His73 to alanine decreased the heme occupancy of NnlA and eliminated NNG activity, validating the homology model. We conclude that NnlA forms a homodimeric heme-binding PAS domain protein that requires reduction for initiation of the activity. IMPORTANCE Linear nitramines are potential carcinogens. These compounds result from environmental degradation of high-energy cyclic nitramines and as by-products of carbon capture technologies. Mechanistic understanding of the biodegradation of these compounds is critical to inform strategies for their remediation. Biodegradation of NNG by NnlA from Variovorax sp. strain JS 1663 requires nonheme iron, but its role is unclear. This study shows that nonheme iron is unnecessary. Instead, our study reveals that NnlA contains a heme cofactor, the reduction of which is critical for activating NNG degradation activity. These studies constrain the proposals for NnlA reaction mechanisms, thereby informing mechanistic studies of degradation of anthropogenic nitramine contaminants. In addition, these results will inform future work to design biocatalysts to degrade these nitramine contaminants.


Asunto(s)
Hemo , Dióxido de Nitrógeno , Compuestos Ferrosos/metabolismo , Hemo/metabolismo , Proteínas de Unión al Hemo , Hierro/metabolismo , Óxido Nítrico/metabolismo , Dióxido de Nitrógeno/metabolismo
11.
JMIR Form Res ; 6(5): e37012, 2022 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-35452401

RESUMEN

BACKGROUND: During the COVID-19 pandemic, to prevent the spread of the virus, federal regulatory barriers around telemedicine were lifted, and health care institutions encouraged patients to use telemedicine, including video appointments. Many patients, however, still chose face-2-face (f2f) appointments for nonemergent clinical care. OBJECTIVE: We explored patients' personal and environmental barriers to the use of video appointments from April 2020 to December 2020. METHODS: We conducted qualitative telephone interviews of Mayo Clinic patients who attended f2f appointments at the Mayo Clinic from April 2020 to December 2020 but did not utilize Mayo Clinic video appointment services during that time frame. RESULTS: We found that, although most patients were concerned about preventing COVID-19 transmission, they trusted Mayo Clinic to keep them safe when attending f2f appointments. Many expressed that a video appointment made it difficult to establish rapport with their providers. Other common barriers to video appointments were perceived therapeutic benefits of f2f appointments, low digital literacy, and concerns about privacy and security. CONCLUSIONS: Our study provides an in-depth investigation into barriers to engaging in video appointments for nonemergent clinical care in the context of the COVID-19 pandemic. Our findings corroborate many barriers prevalent in the prepandemic literature and suggest that rapport barriers need to be analyzed and problem-solved at a granular level.

12.
WMJ ; 121(1): E1-E4, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35442585

RESUMEN

INTRODUCTION: Phenibut is a psychoactive drug with GABAB agonism. It remains unregulated and easily attainable in the United States, where it has become a novel drug of abuse. CASE PRESENTATION: We present the case of a 34-year-old man who used phenibut consistently for 3 years. After 6 months of use, he developed signs of dependence and failed outpatient detoxification. While taking high doses, he experienced parasomnia-like symptoms and periods of dysexecutive function. After abrupt cessation, he developed severe withdrawal symptoms, was hospitalized, and required intubation. His condition improved after 1 week of treatment. After recovery and discharge, he remains stable utilizing an extended taper of acamprosate and baclofen. DISCUSSION: Phenibut is not detected on urine drug screen and withdrawal symptoms are nonspecific. Optimal treatment of withdrawal remains unknown. Baclofen and phenobarbital have been successful for treatment of dependence. CONCLUSION: Clinicians should be aware of phenibut abuse and the potential for dependence and withdrawal.


Asunto(s)
Baclofeno , Síndrome de Abstinencia a Sustancias , Adulto , Baclofeno/uso terapéutico , Humanos , Masculino , Síndrome de Abstinencia a Sustancias/tratamiento farmacológico , Ácido gamma-Aminobutírico/análogos & derivados , Ácido gamma-Aminobutírico/uso terapéutico
13.
J Biol Chem ; 298(3): 101696, 2022 03.
Artículo en Inglés | MEDLINE | ID: mdl-35150744

RESUMEN

The hemerythrin-like protein from Mycobacterium kansasii (Mka HLP) is a member of a distinct class of oxo-bridged diiron proteins that are found only in mycobacterial species that cause respiratory disorders in humans. Because it had been shown to exhibit weak catalase activity and a change in absorbance on exposure to nitric oxide (NO), the reactivity of Mka HLP toward NO was examined under a variety of conditions. Under anaerobic conditions, we found that NO was converted to nitrite (NO2-) via an intermediate, which absorbed light at 520 nm. Under aerobic conditions NO was converted to nitrate (NO3-). In each of these two cases, the maximum amount of nitrite or nitrate formed was at best stoichiometric with the concentration of Mka HLP. When incubated with NO and H2O2, we observed NO peroxidase activity yielding nitrite and water as reaction products. Steady-state kinetic analysis of NO consumption during this reaction yielded a Km for NO of 0.44 µM and a kcat/Km of 2.3 × 105 M-1s-1. This high affinity for NO is consistent with a physiological role for Mka HLP in deterring nitrosative stress. This is the first example of a peroxidase that uses an oxo-bridged diiron center and a rare example of a peroxidase utilizing NO as an electron donor and cosubstrate. This activity provides a mechanism by which the infectious Mycobacterium may combat against the cocktail of NO and superoxide (O2•-) generated by macrophages to defend against bacteria, as well as to produce NO2- to adapt to hypoxic conditions.


Asunto(s)
Hemeritrina , Mycobacterium kansasii , Peroxidasas , Hemeritrina/metabolismo , Peróxido de Hidrógeno , Cinética , Mycobacterium kansasii/enzimología , Nitratos/metabolismo , Óxido Nítrico/metabolismo , Nitritos/metabolismo , Dióxido de Nitrógeno/metabolismo , Oxidorreductasas/metabolismo
14.
PEC Innov ; 1: 100044, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37213726

RESUMEN

Objectives: Federal hemp legalization and ongoing shifts in US marijuana laws have led to increased population-wide use of cannabidiol (CBD) supplements, often without the knowledge of primary healthcare providers (PCPs). Given the potential risks related to CBD use, especially in vulnerable subgroups, improved communication is warranted. This study aimed to examine PCP attitudes, experiences, and practice behaviors related to CBD and provider-reported barriers to communication with patients about CBD use. Methods: Fourteen PCPs were recruited and participated in semi-structured interviews. Transcripts were digitally analyzed using inductive thematic analysis. Results: Analyses identified that most PCPs had neutral views about CBD use by their patients. The study found that discussions about CBD use were initiated by patients. Most PCPs cited lack of time, discomfort, low-quality evidence, and low prioritization as reasons for not discussing CBD with patients. Conclusion: PCPs rarely screen for or discuss CBD use with their patients and most of them had neutral views about CBD use by their patients. A number of barriers exist to open dialogue about CBD. Innovation: Our study is the first in-depth report on PCP attitudes, experiences, and practice behaviors related to CBD. The findings of our study have the potential to significantly impact future PCP practice behaviors. These results can inform healthcare system policies around screening for CBD use and PCP communication training. In doing so, these efforts may mitigate risk and optimize benefits related to the expanding CBD market.

15.
Dev Psychol ; 57(4): 548-556, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34594056

RESUMEN

The role of early child care experiences on the development of the mother-child attachment relationship has been studied extensively. However, no prospective studies of early child care have addressed how these experiences might be reflected in the content of attachment representations during adolescence and beyond. The goal of this study was to estimate relatively precise associations between child care quality, child care quantity, and type of care in the first 54 months of life and the content of adolescents' attachment representations around age 18 years (N = 857; 51% female; 78% White, non-Hispanic; M income-to-needs ratio = 4.13), leveraging data from the longitudinal NICHD Study of Early Child Care and Youth Development (SECCYD). We identified a small positive association between the observed quality of early child care (but not quantity or type of care) and secure attachment states of mind as measured by the Adult Attachment Interview (but not the Attachment Script Assessment) at age 18 years that was robust to demographic covariates and observations of maternal and paternal sensitivity during childhood. We observed no significant interactions among child care variables. Associations between early child care experiences and indicators of adolescent attachment were likewise not moderated by maternal sensitivity from infancy to mid-adolescence or by maternal reports of child temperament in early childhood.


Asunto(s)
Cuidado del Niño , National Institute of Child Health and Human Development (U.S.) , Adolescente , Adulto , Niño , Desarrollo Infantil , Preescolar , Femenino , Humanos , Masculino , Relaciones Madre-Hijo , Apego a Objetos , Estados Unidos
16.
Exp Neurol ; 346: 113832, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34363808

RESUMEN

Cervical spinal cord injury (cSCI) severs bulbospinal projections to respiratory motor neurons, paralyzing respiratory muscles below the injury. C2 spinal hemisection (C2Hx) is a model of cSCI often used to study spontaneous and induced plasticity and breathing recovery post-injury. One key assumption is that C2Hx dennervates motor neurons below the injury, but does not affect their survival. However, a recent study reported substantial bilateral motor neuron death caudal to C2Hx. Since phrenic motor neuron (PMN) death following C2Hx would have profound implications for therapeutic strategies designed to target spared neural circuits, we tested the hypothesis that C2Hx minimally impacts PMN survival. Using improved retrograde tracing methods, we observed no loss of PMNs at 2- or 8-weeks post-C2Hx. We also observed no injury-related differences in ChAT or NeuN immunolabeling within labelled PMNs. Although we found no evidence of PMN loss following C2Hx, we cannot rule out neuronal loss in other motor pools. These findings address an essential prerequisite for studies that utilize C2Hx as a model to explore strategies for inducing plasticity and/or regeneration within the phrenic motor system, as they provide important insights into the viability of phrenic motor neurons as therapeutic targets after high cervical injury.


Asunto(s)
Médula Cervical/lesiones , Neuronas Motoras/fisiología , Nervio Frénico/fisiología , Traumatismos de la Médula Espinal/fisiopatología , Animales , Supervivencia Celular/fisiología , Médula Cervical/química , Masculino , Neuronas Motoras/química , Nervio Frénico/química , Ratas , Ratas Sprague-Dawley , Traumatismos de la Médula Espinal/patología
17.
J Neurophysiol ; 126(3): 777-790, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-34260289

RESUMEN

Plasticity is a hallmark of the respiratory neural control system. Phrenic long-term facilitation (pLTF) is one form of respiratory plasticity characterized by persistent increases in phrenic nerve activity following acute intermittent hypoxia (AIH). Although there is evidence that key steps in the cellular pathway giving rise to pLTF are localized within phrenic motor neurons (PMNs), the impact of AIH on the strength of breathing-related synaptic inputs to PMNs remains unclear. Furthermore, the functional impact of AIH is enhanced by repeated/daily exposure to AIH (dAIH). Here, we explored the effects of AIH versus 2 wk of dAIH preconditioning on spontaneous and evoked phrenic responses in anesthetized, paralyzed, and mechanically ventilated rats. Evoked phrenic potentials were elicited by respiratory cycle-triggered lateral funiculus stimulation at the C2 spinal level delivered before and 60 min post-AIH (or the equivalent in time controls). Charge-balanced biphasic pulses (100 µs/phase) of progressively increasing intensity (100-700 µA) were delivered during the inspiratory and expiratory phases of the respiratory cycle. Although robust pLTF (∼60% from baseline) was observed after a single exposure to moderate AIH (3 × 5 min; 5-min intervals), there was no effect on evoked phrenic responses, contrary to our initial hypothesis. However, in rats preconditioned with dAIH, baseline phrenic nerve activity and evoked responses were increased, suggesting that repeated exposure to AIH enhances functional synaptic strength when assessed using this technique. The impact of daily AIH preconditioning on synaptic inputs to PMNs raises interesting questions that require further exploration.NEW & NOTEWORTHY Two weeks of daily acute intermittent hypoxia (dAIH) preconditioning enhanced stimulus-evoked phrenic responses to lateral funiculus stimulation (targeting respiratory bulbospinal projection to phrenic motor neurons). Furthermore, dAIH preconditioning enhanced baseline phrenic motor output responses to maximal chemoreflex activation in intact rats.


Asunto(s)
Hipoxia/fisiopatología , Neuronas Motoras/fisiología , Plasticidad Neuronal , Nervio Frénico/fisiología , Animales , Potenciales Evocados , Masculino , Nervio Frénico/citología , Nervio Frénico/fisiopatología , Ratas , Ratas Sprague-Dawley
19.
Exp Neurol ; 338: 113609, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33460645

RESUMEN

Although cervical spinal cord injury (cSCI) disrupts bulbo-spinal serotonergic projections, partial recovery of spinal serotonergic innervation below the injury site is observed after incomplete cSCI. Since serotonin contributes to functional recovery post-injury, treatments to restore or accelerate serotonergic reinnervation are of considerable interest. Intermittent hypoxia (IH) was reported to increase serotonin innervation near respiratory motor neurons in spinal intact rats, and to improve function after cSCI. Here, we tested the hypotheses that spontaneous serotonergic reinnervation of key respiratory (phrenic and intercostal) motor nuclei: 1) is partially restored 12 weeks post C2 hemisection (C2Hx); 2) is enhanced by IH; and 3) results from sprouting of spared crossed-spinal serotonergic projections below the site of injury. Serotonin was assessed via immunofluorescence in male Sprague Dawley rats with and without C2Hx (12 wks post-injury); individual groups were exposed to 28 days of: 1) normoxia; 2) daily acute IH (dAIH28: 10, 5 min 10.5% O2 episodes per day; 5 min normoxic intervals); 3) mild chronic IH (IH28-5/5: 5 min 10.5% O2 episodes; 5 min intervals; 8 h/day); or 4) moderate chronic IH (IH28-2/2: 2 min 10.5% O2 episodes; 2 min intervals; 8 h/day), simulating IH experienced during moderate sleep apnea. After C2Hx, the number of ipsilateral serotonergic structures was decreased in both motor nuclei, regardless of IH protocol. However, serotonergic structures were larger after C2Hx in both motor nuclei, and total serotonin immunolabeling area was increased in the phrenic motor nucleus but reduced in the intercostal motor nucleus. Both chronic IH protocols increased serotonin structure size and total area in the phrenic motor nuclei of uninjured rats, but had no detectable effects after C2Hx. Although the functional implications of fewer but larger serotonergic structures are unclear, we confirm that serotonergic reinnervation is substantial following injury, but IH does not affect the extent of reinnervation.


Asunto(s)
Médula Cervical/fisiopatología , Hipoxia , Regeneración Nerviosa/fisiología , Serotonina/metabolismo , Traumatismos de la Médula Espinal/fisiopatología , Animales , Médula Cervical/metabolismo , Vértebras Cervicales , Nervios Intercostales/metabolismo , Nervios Intercostales/fisiopatología , Masculino , Neuronas Motoras/fisiología , Nervio Frénico/metabolismo , Nervio Frénico/fisiopatología , Ratas , Ratas Sprague-Dawley , Recuperación de la Función/fisiología , Traumatismos de la Médula Espinal/metabolismo
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