Objective To evaluate the accuracy of dose-length product (DLP) values in CT dose reports by comparing them with the DLP values measured using a pencil-type ionization chamber. Methods Experiments were conducted using four CT scanners with different detector row numbers from two manufacturers (A and B), along with a head phantom and a pencil-type ionization chamber. Other scanning parameters were fixed, while pairwise combinations of kV and mAs were tested. The DLP values were measured under various scanning conditions using the pencil-type ionization chamber (DLP_measured) and the corresponding DLP values in CT dose reports were recorded (DLP_reported). All data were subjected to statistical analysis. Results Differences were observed between DLP_reported and DLP_measured values. The smallest mean absolute value of ΔDLP was approximately 2.526 mGy·cm observed on the 40-row CT scanner of manufacturer A. There was a difference between the ΔDLPs of the four CT scanners. Both DLP_reported and DLP_measured exhibited a linear relationship with mAs. Conclusion The percentage errors between DLP_reported and DLP_measured values for all four CT scanners were within the national standard tolerance of 15%. DLP values in CT dose reports can serve as a reference for assessing patient radiation dose during scanning. However, for radiation dose-related research, data measured using dosimetric instruments such as pencil-type ionization chamber are recommended.

One of the basic questions in the aging field is whether there is a fundamental difference between the aging of lower invertebrates and mammals. A major difference between the lower invertebrates and mammals is the abundancy of noncoding RNAs, most of which are not conserved. We have previously identified a noncoding RNA Terc-53 that is derived from the RNA component of telomerase Terc. To study its physiological functions, we generated two transgenic mouse models overexpressing the RNA in wild-type and early-aging Terc-/- backgrounds. Terc-53 mice showed age-related cognition decline and shortened life span, even though no developmental defects or physiological abnormality at an early age was observed, indicating its involvement in normal aging of mammals. Subsequent mechanistic study identified hyaluronan-mediated motility receptor (Hmmr) as the main effector of Terc-53. Terc-53 mediates the degradation of Hmmr, leading to an increase of inflammation in the affected tissues, accelerating organismal aging. adeno-associated virus delivered supplementation of Hmmr in the hippocampus reversed the cognition decline in Terc-53 transgenic mice. Neither Terc-53 nor Hmmr has homologs in C. elegans. Neither do arthropods express hyaluronan. These findings demonstrate the complexity of aging in mammals and open new paths for exploring noncoding RNA and Hmmr as means of treating age-related physical debilities and improving healthspan.
Animals ; Mice ; RNA, Untranslated/metabolism* ; Aging/genetics* ; Mice, Transgenic ; Telomerase/metabolism* ; RNA/genetics* ; Hippocampus/metabolism* ; Humans ; Mice, Inbred C57BL

Objective To investigate the effects of acute sleep deprivation on the behavior and synaptic protein expression of rats.Methods Seventy healthy male Wistar rats were randomly divided into seven groups,a Control group and sleep deprivation groups(24,48,72,96,120 and 144 hours).The sleep deprivation rat model was established by the modified multiplatform water environment sleep deprivation method.Spatial learning and memory were assessed by the Morris water maze.Anxiety was assessed by the open field test.The morphology and quantity of hippocampal neurons were observed by Nissl staining.Western blot and Real-time PCR were used to determine the expression of synaptophysin(SYN),post-synaptic density protein-95(PSD-95),and brain-derived neurotrophic factor(BDNF)in rats.Results Compared with the Control group,the numbers of standing and modification were significantly increased by prolongation of the sleep deprivation time(P＜0.05).The escape latency and path length were significantly increased in 120 and 144 h groups(P＜0.05),whereas the number of platform crossings and the percentage of the target quadrant time were significantly decreased(P＜0.01)and negatively correlated to the sleep deprivation time.The expression levels of BDNF,SYN,and PSD-95 were significantly decreased with the prolongation of sleep deprivation time(P＜0.01).Conclusions With the increase in sleep deprivation time,cognitive dysfunction and anxiety gradually deteriorated,which may be related to decreases in the expression of synaptic biomarkers.

Objective:To analyze the influences of leukocytes on improving blood glucose control in patients with type 2 diabetes mellitus (T2DM) and periodontitis after periodontal mechanical therapy.Methods:Thirty-five patients visiting Peking University Third Hospital from March 2011 to August 2012, as well as thirty-four patients visiting Peking University School and Hospital of Stomatology from March 2011 to August 2012 and December 2016 to December 2018 were selected in this research. These subjects were non-smokers, and with moderate to severe chronic periodontitis and T2DM. The full set of periodontal examinations including probing depth (PD), attachment loss (AL), bleeding index (BI) and plaque index (PLI) were conducted. Besides, counts of white blood cells (WBC), parameters of glucose and lipids metabolites such as fasting blood glucose (FBG), glycosylated hemoglobin (HbA 1c), total cholesterol (TC), triglyceride (TG), high density lipoprotein (HDL) and low density lipoprotein (LDL) in serum were examined before treatment. Then, oral hygiene instruction, scaling and root planing (SRP) were carried out. Three months after SRP, the baseline examinations were repeated in all patients. According to the baseline leukocyte counts, the patients were divided into subgroups: low WBC group (WBC<6.19×10 9/L) and high WBC group (WBC≥6.19×10 9/L). Paired t-test for comparison of changes after treatment, analysis of co-variance for comparing the intervention effects between subgroups, and multifactor Logistic regression analysis were performed. Results:Three months after SRP, all periodontal indexes were significantly improved in both groups. Leukocyte counts decreased significantly in high WBC group (6.89±1.53 vs. 7.64±1.51, P=0.008). In high WBC group, HbA 1c (7.18±1.09 vs. 7.67±1.35, P=0.001) and LDL (2.67±0.85 vs. 3.28±0.76, P=0.042) decreased significantly, while there were no such differences in low WBC group. Influence of leukocyte level on HbA 1c ( OR=0.12, P=0.038) and LDL ( OR=0.15, P=0.001) improvement was statistically significant. Hierarchical analysis showed such improvement notably perform in female [HbA 1c ( OR=0.30, P=0.021), LDL ( OR=0.34, P=0.001)] and severe periodontitis group [HbA 1c ( OR=0.15, P=0.025), LDL ( OR=0.24, P=0.017)]. Through interaction test, female and leukocyte counts at baseline had relative excess risk affecting the effect of periodontal intervention on HbA 1c ( P=0.036) and LDL ( P=0.005). Conclusions:SRP could significantly improve the blood glucose and lipid control in patients who had T2DM and chronic periodontitis with relative higher leukocytes level. Female patients with severe periodontitis showed more obviously effects.