Abstract
Oligodendrocyte progenitor cells (OPCs) account for approximately 5% of the adult brain and have been historically studied for their role in myelination. In the adult brain, OPCs maintain ...their proliferative capacity and ability to differentiate into oligodendrocytes throughout adulthood, even though relatively few mature oligodendrocytes are produced post-developmental myelination. Recent work has begun to demonstrate that OPCs likely perform multiple functions in both homeostasis and disease and can significantly impact behavioral phenotypes such as food intake and depressive symptoms. However, the exact mechanisms through which OPCs might influence brain function remain unclear. The first step in further exploration of OPC function is to profile the transcriptional repertoire and assess the heterogeneity of adult OPCs. In this work, we demonstrate that adult OPCs are transcriptionally diverse and separate into two distinct populations in the homeostatic brain. These two groups show distinct transcriptional signatures and enrichment of biological processes unique to individual OPC populations. We have validated these OPC populations using multiple methods, including multiplex RNA in situ hybridization and RNA flow cytometry. This study provides an important resource that profiles the transcriptome of adult OPCs and will provide a toolbox for further investigation into novel OPC functions.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Hypothalamic-pituitary axis dysfunction is a common complication in post-operative craniopharyngioma(CP) patients, and it greatly impacts the long-term quality of life of such patients. To better ...understand the effects of postoperative hypothalamic-pituitary dysfunction and long-term hormone replacement therapy in patients with childhood CP, we assessed approximately 200 patients with childhood-onset CP postoperatively.
Clinical details of patients with childhood-onset CP who underwent sellar tumor resection in Beijing Children's Hospital and Beijing Tiantan Hospital from 2018 to 2019 were retrieved retrospectively. The participants were followed up to assess the effects of post-operative long-term hormone replacement therapy and assess the tumor recurrence rate.
The median age of admission was 8.1 (1.8, 14.3) years. Headache (45.5%), visual impairment (39.5%), and nausea (33.0%) were the most common clinical manifestations. ACP accounted for 95% of all CP cases. The incidence of central adrenal insufficiency and central hypothyroidism within the first week after surgery was 56.2% and 70.3%, respectively. At the same time 85.5% of the patients required at least one dose of desmopressin to control urine output. Total survival and tumor recurrence rates were 98.6% and 26.1%, respectively, with a median follow-up time of 29.7 (19.0, 40.3) months. During the follow-up period, 28.1% patients met the diagnostic criteria for short stature, while 54.4% fit the criteria for obesity. In addition, 94.4% of the patients were taking at least one kind of hormone substitution, and 74.7% were taking three or more. The prevalence of levothyroxine, glucocorticoid, desmopressin, and growth hormone replacement therapy was 87.3%, 77.5%, 78.9% and 31.0%, respectively. The proportion of patients treated with the substitutive combination of levothyroxine, hydrocortisone, and desmopressin was 54.9%.
This study is a large-sample systematic postoperative endocrine function evaluation of patients with childhood-onset CP. Due to the high prevalence of post-operative hypothalamic-pituitary dysfunction, patients with CP usually require long-term multiple hormone substitution therapy. Individualized management and accurate hormone replacement dosage for postoperative childhood-onset CP patients are of great importance.
The aim of the present study was to evaluate the status of glycemic control, and assess the effects of the disease course and comprehensive management measures on the blood glucose level in children ...and adolescents with type 2 diabetes mellitus.
The study collected the clinical data of type 2 diabetes patients in Beijing Children's Hospital from January 2015 to September 2020. Patients were grouped based on the disease course to compare their glycated hemoglobin (HbA1c) level, islet β-cell function, insulin resistance and comprehensive management measures.
Of the 170 participants, the median disease course was 2.0 years (interquartile range IQR 1.0-4.0 years). The baseline HbA1c was 11.2% (IQR 9.2-12.4%). According to the grouping by the disease course, the median HbA1c was the lowest (5.7% IQR 5.3-6.1%) in the half-year course group and the highest in the 4-year course group (9.0 IQR 6.8%-11.3%). Compared with the group with a disease duration <2 years, patients in the >4 years group had a lower proportion of patients with HbA1c <7% (29.2% vs 66.2%), a lower homeostasis model assessment of β-cell function, and a lower proportion with a controlled diet, moderate-intensity exercise, regular follow up and no drug treatment. We deemed HbA1c as the dependent variable, and found that disease duration, homeostasis model assessment of β-cell function at follow up, continuous moderate-intensity exercise, regular review and treatment regimen were significant influencing factors for glycemic control.
Children and adolescents with type 2 diabetes and a prolonged disease course showed poor glycemic control and decreased islet β-cell function. A good lifestyle, especially moderate-intensity exercise, can help such cases better control their blood glucose level.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Abstract
Neuroinflammation is associated with neurodegenerative diseases, including Alzheimer’s and Parkinson’s. The cytokine interleukin-12 activates signal transducer and activator of transcription ...4 (Stat4), and consumption of a high-fat, high-cholesterol diet (HFD-C) and Stat4 activity are associated with inflammation, atherosclerosis, and a diabetic metabolic phenotype. In studies of in vitro hippocampal slices from control
Stat4
fl/fl
Ldlr
−/−
mice fed a HFD-C diabetogenic diet, we show that Schaffer collateral-CA1 synapses exhibited larger reductions in activity-dependent, long-term potentiation (LTP) of synaptic transmission, compared to mice fed a standard diet. Glucose tolerance and insulin sensitivity shifts produced by HFD-C diet were reduced in
Stat4
ΔLysM
Ldlr
−/−
mice compared to
Stat4
fl/fl
Ldlr
−/−
controls.
Stat4
ΔLysM
Ldlr
−/−
mice, which lack Stat4 under control of the
LysM
Cre
promoter, were resistant to HFD-C induced impairments in LTP. In contrast, Schaffer collateral-CA1 synapses in
Stat4
ΔLysM
Ldlr
−/−
mice fed the HFD-C diet showed
larger
LTP than control
Stat4
fl/fl
Ldlr
−/−
mice. Expression of a number of neuroinflammatory and synaptic plasticity genes was reduced by HFD-C diet in control mice, and less affected by HFD-C diet in
Stat4
ΔLysM
Ldlr
−/−
mice. These data suggest that suppression of Stat4 activation may protect against effects of Western diet on cognition, type 2 diabetes, and reduce risk of Alzheimer’s disease and other neurodegenerative disorders associated with neuroinflammation.
Ageing is a major risk factor for many neurological pathologies, but its mechanisms remain unclear. Unlike other tissues, the parenchyma of the central nervous system (CNS) lacks lymphatic ...vasculature and waste products are removed partly through a paravascular route. (Re)discovery and characterization of meningeal lymphatic vessels has prompted an assessment of their role in waste clearance from the CNS. Here we show that meningeal lymphatic vessels drain macromolecules from the CNS (cerebrospinal and interstitial fluids) into the cervical lymph nodes in mice. Impairment of meningeal lymphatic function slows paravascular influx of macromolecules into the brain and efflux of macromolecules from the interstitial fluid, and induces cognitive impairment in mice. Treatment of aged mice with vascular endothelial growth factor C enhances meningeal lymphatic drainage of macromolecules from the cerebrospinal fluid, improving brain perfusion and learning and memory performance. Disruption of meningeal lymphatic vessels in transgenic mouse models of Alzheimer's disease promotes amyloid-β deposition in the meninges, which resembles human meningeal pathology, and aggravates parenchymal amyloid-β accumulation. Meningeal lymphatic dysfunction may be an aggravating factor in Alzheimer's disease pathology and in age-associated cognitive decline. Thus, augmentation of meningeal lymphatic function might be a promising therapeutic target for preventing or delaying age-associated neurological diseases.
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KISLJ, NUK, SBMB, UL, UM, UPUK
Source radiation analysis frequently involves characterization or identification of sound sources and fields. In order to effectively perform source radiation analysis, an integrated acoustical ...imaging system including software and hardware was developed based on spatial transformation. This system utilizes measurements of the complex sound field over a two-dimensional hologram surface with the one-microphone sequential sampling method. Four spatial transformation techniques, i.e. direct convolution, two-dimensional fast Fourier transform, Gauss-Hermite decomposition, and singular value decomposition, were implemented to project the hologram data to desired locations in the three-dimensional space. In addition, four new approaches based on feedback iteration concepts, with the variations of optimization and constraints, were developed to deal particularly with the ill-posed nature encountered in the backward reconstruction of source images. The theoretical background, numerical or experimental investigations, and applicational considerations of the previously mentioned aspects are thoroughly discussed in the dissertation. The conclusions detail the significance of the research results and the future prospects for radiation analysis based on spatial transformation. The technical aspects of the experimental implementation such as a computerized data acquisition system are also included in the appendix.
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