Midday Napping, Nighttime Sleep, and Mortality: Prospective Cohort Evidence in China / 生物医学与环境科学（英文）

OBJECTIVE@#In developed countries, midday napping and nighttime sleep duration have been linked to long-term survival; however, little is known about such effects in less developed regions. Therefore, this study aimed to assess the associations of midday napping and nocturnal sleep with mortality in middle-aged and older Chinese adults.@*METHODS@#A nationwide cohort of 15,524 adults aged ≥ 45 years was enrolled from 28 provincial regions across mainland China and followed up from 2011 to 2018, using data from the Chinese Health and Retirement Longitudinal Study. Midday napping and nighttime sleep duration were assessed using standardized questionnaires. Cox proportional hazards models with random intercepts for the surveyed provinces were used to estimate hazard ratios ( HRs) of all-cause mortality, adjusting for sociodemographic characteristics, behavioral factors, and health status.@*RESULTS@#A total of 1,745 deaths occurred during a median follow-up of 7.1 years, and the mean (standard deviation) age was 59 (10.1) years at baseline. Compared with non-nappers, over 60 min nappers had a higher risk of all-cause mortality [ HR: 1.35, 95% confidence interval ( CI): 1.17-1.56], while no significant associations were observed among < 30 min nappers. Compared with sleep duration of 6-8 h/night, both short (< 6 h) and long (≥ 8 h) sleep duration were significantly associated with increased mortality, with corresponding HR (95% CI) estimates of 1.21 (1.05-1.38) and 1.26 (1.10-1.44), respectively. We observed significant patterns for greater risks associated with longer nap duration, with a P trend value < 0.001 for all-cause mortality. No significant evidence of an additive interaction was identified between midday napping and nighttime sleep.@*CONCLUSION@#Long midday napping and inappropriate nighttime sleep were independently associated with an increased risk of all-cause mortality in middle-aged and older Chinese populations. Biological studies are needed to validate our findings and clarify the mechanisms underlying this association.

Progress on the protective effect of heme oxygenase-1 in viral infection / 药学学报

Heme oxygenase-1 (HO-1) is a cytoprotective enzyme that catalyzes the conversion of heme to CO, biliverdin, and iron, which together protect cells from oxidative and inflammatory damage and play an important role in maintaining cell homeostasis. In recent years, HO-1 has also been found to have antiviral biological effects, and the induced expression of HO-1 inhibits the replication of various viruses such as hepatitis C virus, hepatitis B virus, human immunodeficiency virus, dengue virus, ebolavirus, influenza A virus, Zika virus, severe acute respiratory syndrome coronavirus 2, human respiratory syncytial virus, hepatitis A virus and enterovirus 71. The inhibitory effect of HO-1 on these viruses involves three mechanisms, including direct inhibition of virus replication by HO-1 and its downstream products, enhancement of type I interferon responses in host cell, and attenuation of inflammatory damage caused by viral infection. This review focuses on the recent advances in the antiviral effect of HO-1 and its mechanism, which is expected to provide evidence for HO-1 as a potential target for antiviral therapy.

An investigation on serum antibody level of varicella-zoster virus in healthy population in Beijing / 中华预防医学杂志

Objective: To assess the level and trend of varicella-zoster virus (VZV) antibody among healthy population in Beijing in 2017, after the five-year implementation of the two doses varicella vaccination strategy in 2012, and to provide evidence for scientific evaluation of immunization strategy. Methods: A total of 2 144 subjects in ten age groups from 8 districts of Beijing city were recruited in this study using cross-sectional survey based on multi-stage cluster random sampling method. Serum samples were collected and VZV antibody was detected by ELISA. The influencing factors of antibody concentration and positive rate were analyzed and compared with the study in 2012. The antibody concentration and antibody positive rate were analyzed by nonparametric test and χ² test respectively. Results: The ratio of subjects with registered residence in Beijing city to other provinces was 1∶1. The ratio of male to female was 1∶1.08. The median concentration of VZV antibody was 341.4 (78.6, 1 497.8) mIU/ml, and the total antibody positive rate was 71.1% (1 524/2 144). There were significant differences in antibody positive rate (χ²=736.39, P<0.01) and antibody concentration (χ²=740.34, P<0.01) among different age groups. The antibody positive rate generally increased with age (χ²trend=7.32, Ptrend<0.01). Among 862 children under 14 years old, the antibody positive rate of two doses vaccination 72.8% (182/250) was significantly higher than that of one dose vaccination 51.9% (154/297) (χ²=25.14, P<0.01). There was significant difference between 1-4 years old group (χ²=11.71, P<0.01) and 10-14 years old group (χ²=5.95, P=0.02), but not in 5-9 years old group (χ²=3.00, P=0.07). Compared with the study in 2012, the antibody positive rate increased in 5-9 years old group (χ²=14.35, P<0.01) and decreased in 1-4 years old group (χ²=11.51, P=0.01) in 2017. Conclusion: The recommended varicella booster vaccination has significantly improved the VZV antibody level of children in Beijing city. In the future, it is necessary to explore a more optimized two doses varicella vaccination schedule for children in combination with epidemiological evidence.

Cancer Treatment Strategies by Targeting the Oncoprotein c-Myc / 中国生物化学与分子生物学报

c-Myc is a transcription factor involved in the Myc/Max/Mxd signal regulatory network. c-Myc plays important roles in human development and the oncogenesis or progression of different types of tumors. Current studies have shown that c-Myc mutations or expression changes are present in more than 70% of tumors. Therefore, c-Myc-targeted inhibitors might become a new strategy for tumor therapy. Currently, there is no clinical treatment for targeting c-Myc. With the continuous study aiming at the c-Myc targeted clinical application, Omomyc has become a representative c-Myc inhibitor by direct inhibition of c-Myc in tumors, which may be a feasible clinical treatment strategy. Although targeting c-Myc has broad prospects in cancer treatment, direct inhibition of c-Myc still has many risks and challenges. Therefore, in this review, firstly, we will summarize the regulatory network and biological functions of c-Myc in cells. Secondly, the potential significance of targeting c-Myc or its homologues in tumor therapy will be discussed. Additionally, the challenges faced by c-Myc as a potential therapeutic target in clinical application will be summarized. Finally, we will also discuss the advantages and disadvantages of some c-Myc inhibitors that have been discovered to date, such as small molecule inhibitors and protein and peptide inhibitors, therefore providing the theoretical basis for c-Myc targeted clinical therapy in cancer.

Establishment of Metastatic Model of Oral Cancer Using Cal27cell in Nude Mice and Its Significance / 昆明医科大学学报

Objective To establish the orthotopic model of Cal27 tongue squamous carcinoma cells.Me thods 2×106 Cal27 cells suspension was injected into floor of mouth of nude mice. Then the tumor volume was measured periodically and the body weight of the nude mice was recorded. 14 days later, nude mice were killed, and the primary tumor and adjacent tissues, lungs, and liver were harvested. The tissue sections were stained with hematoxylin and eosin. The submandibular lymph nodes and lung, liver metastasis, and statistical metastasis rate were observed. Re s ults The tumor formed after day 3 that nude mice were inoculated with Cal27 cells, and tumor formation rate was 100％ (24/24). HE staining showed tumor tissue had typical performance of squamous carcinom. The squamous carcinoma cells were found in the submandibular lymph nodes, and the metastasis rate was 70％ (17/24). There were no metastasis found in liver and lung. Conclus ions Orthotopic metastatic model of oral cancer in nude mice has been established successfully. This animal model can objectively reflect the biological behavior of human oral cancer, is one of the ideal methods to study the invasion and metastasis of oral squamous cell carcinoma.

Diverse expression of ER-α36, a novel variant of ER-α, in hippocampus and cortex of neonatal and adult rats / 生理学报

ER-α36, a novel variant of ER-α, is expressed in breast, uterus, digestive tract, respiratory tract etc. The aim of the present study was to investigate the distribution and expression of ER-α36 in the central nervous system (CNS). Here, we comparatively analyzed the expression pattern of ER-α36 in the hippocampus and cortex of neonatal (1-day-old) and adult (12-week-old) Sprague-Dawley (SD) rats by using immunohistochemistry/immunocytochemistry analysis and Western blot. The results showed that ER-α36 was expressed both in hippocampus and cortex of adult rats, but mainly distributed in pyramidal neurons. ER-α36 was mainly located on the cytomembrane of hippocampal and cortical neurons from neonatal rats. Compared with the cortical neurons, the hippocampal neurons showed lower ER-α36 protein expression in the neonatal rats, but exhibited higher level of ER-α36 in the adult rats. Furthermore, the adult rats showed higher levels of ER-α36 expression in both hippocampus and cortex compared with the neonatal rats. These results suggest that ER-α36 might be involved in the regulation of membrane-initiated estrogen signaling throughout the postnatal development of diverse brain regions, and thus will be a potential target for the treatment of degenerative diseases in nervous system.

Development of a singleplex PCR assay targeting O-antigen modification genes for molecular serotyping of Shigella flexneri / 中华流行病学杂志

Objective To develop a singleplex PCR assay targeting O-antigen modification genes for molecular serotyping of Shigella (S.)flexneri.Methods Eight pairs of primer for O-antigen synthesis and modification genes of S.flexneriwere designed and used for developing an O-antigen modification gene-specific singleplex PCR assay to serotype 14 most common S.flexneri serotypes (1 a,1 b,1 c,2a,2b,3a,3b,4a,4b,5a,Y,X,Xv and F6).Bacterial pathogens which causing diarrheal disease were used for specificity detection.106 S.flexneri clinical isolates were serotyped by this method and compared with the slide agglutination method.Results An O-antigen modification,gene-specific singleplex PCR was developed.When six singleplex PCR reactions were performed,14 of the 15 recognized S.flexneri serotypes were identified,except for serotype Xv.The detection threshold ranged from 10 pg to 1 ng DNA in a 20 μ l reaction system.A high concordance between the singleplex PCR assay and slide agglutination were observed when 106 S.flexneri strains of various serotypes were analyzed with an exception that 1 serotype Y strain showed that it was carrying the additional defective gtr Ⅱ genes.Conclusion This method showed advantages over the traditional slide agglutination methods,and was promising when under application in the following situations as clinical diagnosis.

Study on the integration site and arrangement of SfII and SfX prophages in Shigella flexneri serotype 2b strains / 中华流行病学杂志

Objective To study the integration site and arrangement of SfII and SfX prophages in Shigella flexneri serotype 2b strains. Methods A series of primers were designed based on potential integration site of SfII and SfX prophages in Shigella flexneri serotype 2b strains, and PCR were performed for 50 serotype 2b strains to amplify special genes located in host and prophages. PCR products were sequenced to identify integration sites and arrangement of SfII and SfX. Results In all the serotype 2b strains, prophage SfII and SfX were adjacent to each other, and integrated into the thrW tRNA gene of the host, which were located between genes proA and yaiC of host. Prophage SfX was located immediately upstream of prophage SfII in all the detected 50 serotype 2b strains exception for strain 51251. Conclusion This was the first report on the integration site and arrangement of serotype-converting prophages SfII and SfX in Shigella flexneri 2b strains.

Secretion expression of cholera toxin B subunit in food-grading Lactococcus lactis expression system / 中华流行病学杂志

<p><b>OBJECTIVE</b>To clone and secretion express cholera toxin B subunit (CTB) in food-grading Lactococcus lactis expression systems.</p><p><b>METHODS</b>ctB fragment that encoding CTB was amplified by polymerase chain reaction (PCR) using the genomic DNA of Vibrio cholera strain 569B as template and was inserted into two secretion expression vector pSQZ and pSQ to construct food-grading expression system L.lactis MBP71/pSQZ-ctB and L.lactis MBP71/pSQ-ctB. The expressed CTB was detected by Western-blot assay.</p><p><b>RESULTS</b>The ctB fragment was successfully amplified from Vibrio cholera strain 569B and inserted into two secretion expression vectors pSQZ and pSQ to construct food-grading expression system L. lactis MBP71/pSQZ-ctB and L. lactis MBP71/pSQ-ctB. Western-blot assay demonstrated that CTB was secretion and expressed from L.lactis MBP71 harboring vectors pSQZ-ctB and pSQ-ctB, and the quantity of CTB secreted by L. lactis MBP71/pSQ-ctB was about 2 microg/ml, higher than that of L. lactis MBP71/pSQZ-ctB.</p><p><b>CONCLUSION</b>CTB was successfully secreted and expressed by food-grading L. lactis expression systems.</p>

The Influence of Reconstruction Algorithm and Heart Rate on Coronary Artery Image Quality and Stenosis Detection at 64-Detector Cardiac CT

OBJECTIVE: We wanted to evaluate the impact of two reconstruction algorithms (halfscan and multisector) on the image quality and the accuracy of measuring the severity of coronary stenoses by using a pulsating cardiac phantom with different heart rates (HRs). MATERIALS AND METHODS: Simulated coronary arteries with different stenotic severities (25, 50, 75%) and different luminal diameters (3, 4, 5 mm) were scanned with a fixed pitch of 0.16 and a 0.35 second gantry rotation time on a 64-slice multidetector CT. Both reconstruction algorithms (halfscan and multisector) were applied to HRs of 40-120 beats per minute (bpm) at 10 bpm intervals. Three experienced radiologists visually assessed the image quality and they manually measured the stenotic severity. RESULTS: Fewer measurement errors occurred with multisector reconstruction (p = 0.05), a slower HR (p < 0.001) and a larger luminal diameter (p = 0.014); measurement errors were not related with the observers or the stenotic severity. There was no significant difference in measurements as for the reconstruction algorithms below an HR of 70 bpm. More nonassessable segments were visualized with halfscan reconstruction (p = 0.004) and higher HRs (p < 0.001). Halfscan reconstruction had better quality scores when the HR was below 60 bpm, while multisector reconstruction had better quality scores when the HR was above 90 bpm. For the HRs between 60 and 90 bpm, both reconstruction modes had similar quality scores. With excluding the nonassessable segments, both reconstruction algorithms achieved a similar mean measured stenotic severity and similar standard deviations. CONCLUSION: At a higher HR (above 90 bpm), multisector reconstruction had better temporal resolution, fewer nonassessable segments, better quality scores and better accuracy of measuring the stenotic severity in this phantom study.