To evaluate the measurement uncertainty of 23 items of clinical biochemistry. Internal quality control and external quality assessment were used to determine the uncertainty and standard uncertainty for the 23 items detected by Hitachi 7600 automatic biochemical analyzer. The uncertainties met the requirements of CLIA'88 for allowable error before correction except those of Cl-, P, TCH and TG, and correction made those of P, TCH and TG satisfy the requirements. The top-down method contributes to the understanding of the uncertainty of clinical biochemical items, while further efforts have to be performed for the uncertainty assessment standard.

In-depth application of the combination of theory and practice is one of the keys to improve the clinical undergraduate teaching quality of clinical laboratory diagnosis.Xuanwu Hospital used ISO15189 standards as a guide to make students fully participate in establishing performance verification and recording registration form,partly participate in the gage calibration,external quality assessment and inter-laboratory comparison etc.It also used the combined form of practice with teaching to make students learn the file writing and the equipment calibration.An orderly teaching model composed of knowledge reserve,file learning,calibration and verification was established,which was a closed-loop system that enabled students to become more deeply and extensively involved in the system and more deeply understand the connotation of clinical laboratory quality.

Objective To investigate the expression level and diagnostic value of serum DNA polymerase α(DNA pol α)in Alzheimer's disease(AD),and analyze its diagnostic efficacy in AD.Methods A total of 100 patients of dementia of Alzheimer's type(DAT)and 43 patients of mild cognitive impairment(MCI)from Xuanwu Hospital Capital Medical University from March 2019 to April 2023 were included in this study,and 68 healthy individuals of the same age group were collected as the HC group.The expression level of DNA pol α was detected in each group,and the diagnostic value of DNA pol α in AD was analyzed by receiver oper-ating characteristic(ROC)curve.Results The expression level of DNA pol α in DAT group was higher than those in the MCI group(P＜0.05)and the HC group(P＜0.001).The expression level of DNA pol α showed an increasing trend as AD progressed.The expression level of DNA pol α was negatively correlated with Mini Intelligent Mental State Examination Scale(MMSE)score and Montreal Cognitive Assessment Scale(MoCA)score(r=-0.155 3,-0.203 7,P＜0.05).The area under the curve(AUC)of DNA pol α for diagnosing DAT was 0.682,and the sensitivity was 0.900.The AUC for diagnosing MCI was 0.546,and the sensitivity was 0.977.The AUC for differential diagnosis of MCI and DAT was 0.664,the sensitivity was 0.780,and the specificity was 0.535.Conclusion The expression level of DNA pol α is significantly increased in AD patients with DAT,and its expression level is related to the progression of AD,suggesting that DNA pol α has the pos-sibility to be a potential blood biomarker for the diagnosis of AD.

OBJECTIVE To reveal the role of the basal forebrain(BF)GABAergic neurons in the regulation of isoflurane anesthesia and to elucidate the underlying neural pathways.METHODS The activity of BF GABAer-gic neurons was monitored during isoflurane anesthesia using a genetically encoded calcium indicator in Vgat-Cre mice of both sexes.The activity of BF GABAer-gic neurons was manipulated by chemogenetic and opto-genetic approaches.Sensitivity,induction time and emer-gence time of isoflurane anesthesia were estimated by righting reflex.The electroencephalogram(EEG)power and burst-suppression were monitored by EEG recording.The effects of activation of GABAergic BF-thalamic reticu-lar nucleus(TRN)pathway on isoflurane anesthesia were investigated with optogenetics.RESULTS The activity of BF GABAergic neurons was generally inhibited during isoflurane anesthesia,obviously decreased during the induction of anesthesia and gradually restored during the emergence from anesthesia.Activation of BF GABAergic neurons with chemogenetics and optogenetics promoted behavioral emergence from isoflurane anesthesia,with decreased sensitivity to isoflurane,delayed induction and accelerated emergence from isoflurane anesthesia.Optogenetic activation of BF GABAergic neurons prom-oted cortical activity during isoflurane anesthesia,with decreased EEG delta power and burst suppression ratio during 0.8%and 1.4%isoflurane anesthesia,respectively.Similar to the effects of activating BF GABAergic cell bod-ies,photostimulation of BF GABAergic terminals in the TRN also strongly promoted cortical activation and behav-ioral emergence from isoflurane anesthesia.CONCLU-SION The GABAergic neurons in the BF is a key neural substrate for general anesthesia regulation that facilitates behavioral and cortical emergence from general anesthe-sia via the BF-TRN pathway.

Aging increases the risk of various diseases. The main goal of aging research is to find therapies that attenuate aging and alleviate aging-related diseases. In this study, we screened a natural product library for geroprotective compounds using Werner syndrome (WS) human mesenchymal stem cells (hMSCs), a premature aging model that we recently established. Ten candidate compounds were identified and quercetin was investigated in detail due to its leading effects. Mechanistic studies revealed that quercetin alleviated senescence via the enhancement of cell proliferation and restoration of heterochromatin architecture in WS hMSCs. RNA-sequencing analysis revealed the transcriptional commonalities and differences in the geroprotective effects by quercetin and Vitamin C. Besides WS hMSCs, quercetin also attenuated cellular senescence in Hutchinson-Gilford progeria syndrome (HGPS) and physiological-aging hMSCs. Taken together, our study identifies quercetin as a geroprotective agent against accelerated and natural aging in hMSCs, providing a potential therapeutic intervention for treating age-associated disorders.