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Objective: To investigate the potential association between multimorbidity and the handgrip strength of middle-aged and older adults., Methods: The baseline (2011) and second-round follow-up (2015) data of China Health and Retirement Longitudinal Study (CHARLS) were used. Adults≥40 were selected as the subjects of the study. Variables incorporated in the study included handgrip strength, chronic disease prevalence, demographic variables, and health behavior variables. Generalized estimating equations were used to analyze the longitudinal association between handgrip strength and multimorbidity., Results: A total of 28 368 middle-aged and older adults were included in the baseline and follow-up samples, with an average age of (59.1±9.7) years old, the oldest being 96 while the youngest being 40. Among them, 6 239 were male, accounting for 47.3%. In the second-round follow-up, 9 186 baseline respondents and 5 994 new respondents were covered, reaching a total of 15 180 respondents. Compared with the baseline, a higher proportion of the second-round follow-up respondents were female ( P =0.033) and were older ( P <0.001). From the baseline to the second-round follow-up, Q1, the lowest grip strength category, increased from 23.4% to 26.6%, while Q4, the highest grip strength category, decreased from 26.5% to 21.2%. The prevalence of having more than three chronic diseases increased from 18.2% to 24.2% and the prevalence of having more than five chronic diseases increased from 3.3% to 6.2%. After adjusting for confounding variables, the interaction items of handgrip strength and time showed statistical significance. After stratification by gender, the interaction items of male handgrip strength and follow-up time were statistically significant in both models ( P <0.05). The marginal effect graph of the interactive item showed that the multimorbidity prevalence of respondents with lower handgrip levels grew faster with age. Individual effect analysis showed that the correlation between handgrip strength and multimorbidity was not statistically significant at baseline, but the follow-up done four years afterwards showed statistical significant correlation between handgrip strength and multimorbidity., Conclusion: Respondents with lower baseline handgrip strength are associated with increasingly higher risk of multimorbidity over time. Handgrip strength can be used as an effective screening tool for middle-aged and older adults in China to identify those at higher risks of multimorbidity of chronic diseases., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).)

Objective: To understand the level of job satisfaction and work engagement of physicians in public hospitals, to analyze the interaction between job satisfaction and work engagement, and to discuss how each dimension of job satisfaction affects work engagement so as to provide information and reference for improving the level of work engagement of physicians in public hospitals., Methods: Covering 6 public hospitals in Sichuan (3 tertiary-level hospitals and 3 secondary-level hospitals), 638 questionnaires were obtained from physicians through convenient sampling for data description and analysis. Pearson correlation method was used to analyze the correlation between job satisfaction and work engagement, and multiple linear stepwise regression method was used to analyze work engagement and the influencing factors of each dimension., Results: With regard to job satisfaction, physicians showed high levels of satisfaction in personal safety (3.77±0.87), leadership identification and support (3.59±0.77), and job pressure (3.51±0.81). The mean points of work engagement and each dimension were as follows: total mean points of work engagement (4.02±0.99), dedication (4.21±1.13), absorption (4.19±1.08) and vigor (3.63±1.04). In job satisfaction, salary and benefits, work environment, social recognition, organizational management, leadership identification and support are positively correlated to work engagement and all dimensions. In job satisfaction, 5 dimensions, including social recognition, leadership recognition and support, work achievement, personal safety and organizational management, had a significant influence on work engagement and all dimensions., Conclusion: Emphasis on the high-level needs for recognition and self-actualization of doctors, doctor-patient communication, and personal development of doctors may improve doctors' job satisfaction and work engagement., (Copyright© by Editorial Board of Journal of Sichuan University (Medical Sciences).)

Objective: To investigate the seroprevalence of Toxoplasma gondii infection and identify the genotypes of T. gondii isolates from cancer patients in Anhui Province., Methods: Three hundred and fifty-six blood samples were collected from outpatients and hospitalized cancer patients in Hefei, Anhui Province. IgG and gM antibodies specific to T gondii were determined by ELISA. The ELISA positive samples were subjected to detection of Toxoplasma DNA with PCR targeting a 529-bp repeat element of T. gondii. Genotyping of T. gondii isolates was performed using multilocus PCR-RFLP and 10 genetic markers, including 9 nuclear loci, sagl, sag2, sag3, btub, gra6, L358, pkl, c22-8, c29-2, and apico., Results: Among 356 cancer patients, 21 (5.9%) cases were found to be IgG-positive and 8 (2.3%) were IgM-positive, and five of them were found to have both IgG and IgM antibodies. The total seroprevalence of Toxoplasma infection was 6.8%. Six PCR-positive samples were genotyped at 10 loci and two of them obtained all genetic markers and identified as the genotype of Chinese 1 (ToxoDB#9)., Conclusion: In this study, latent and active toxoplasmosis exist in the patients with malignant tumors, and two isolates are genotyped as the type of Chinese 1 (ToxoDB#9) in Anhui, China.

Objective: To establish a model of ER stress-induced apoptosis with tunicamycin and to examine whether Bim is dysregulated and its potential role in resistance of melanoma cells to apoptosis under endoplasmic reticulum (ER) stress., Methods: A model of ER stress-induced apoptosis was established with tunicamycin. Apoptotic cells were quantitated using the annexin V/propidium iodide method by flow cytometry. Hoechst staining was also used to confirm the apoptotic cell death. Western blotting was used to measure the activation of caspase-3 and -9, and the expression of Bim, GRP78, CHOP, and Foxo1 at the protein level. The expression of Bim, CHOP and Foxo1 at the mRNA level was quantitated by qPCR. The siRNA technique was used to inhibit the expression of Bim., Results: Treatment of the melanoma cells with tunicamycin did not induce significant apoptosis and activation of caspase cascade, whereas it caused marked activation of caspase-3 and -9, and apoptosis in HEK293 cells which were used as a control. With exposure to tunicamycin (3 µmol/L) for 12, 24, 36 hours the Bim protein levels were not increased in Mel-RM and MM200 cells. Its mRNA levels were 0.37 ± 0.05, 0.13 ± 0.02 and 0.02 ± 0.01 in Mel-RM cells, while 0.41 ± 0.06, 0.16 ± 0.04 and 0.21 ± 0.03 in MM200 cells, respectively. The expression of Bim mRNA was significantly reduced compared with that in the control groups of the two cell lines (P < 0.01). siRNA knockdown of Bim protected HEK293 cells against activation of caspase-3. The cell apoptosis of Bim siRNA group was (5.69 ± 0.38)%, significantly lower than that of the siRNA control group (40.32 ± 1.64)% and blank control group (35.46 ± 2.01)% (P < 0.01). In the melanoma cells after exposure to tunicamycin (3 µmol/L) for 6, 12, 24, and 36 hours the transcription factor CHOP at mRNA level were significantly increased and the expressions at protein level were also up-regulated. The expressions of another transcription factor Foxo1 at mRNA level significantly decreased and the expressions at protein level were down-regulated, too., Conclusions: The lack of Bim up-regulation contributes to the resistance of melanoma cells to ER stress-induced apoptosis and may be a mechanism by which melanoma cells adapt to ER stress conditions. Transcription factors CHOP and Foxo1 may be responsible for the dysregulation of Bim in melanoma cells upon ER stress.

Aim: To preparation and characterize the rabbit polyclonal antibodies against human PON2 (paraoxonase-2)., Methods: A fragment of human PON2 gene which was of low homology with rabbits but of higher hydrophilicity and immunogenicity was selected for recombinant expression in prokaryotic expression system. The rabbits were immunized with the purified GST fusion protein 3 times. The specificity and sensitivity of the anti-human PON2 polyclonal antibodies were detected by Western blot and indirect immunofluorescence., Results: The GST-PON2 fusion protein was highly expressed in Ecoli with a molecular weight of 46 kDa. Western blot analysis proved the rabbit polyclonal antibodies could specifically recognize 39 kDa native PON2 protein expressed in several cells and tissues, such as HeLa cells, U937 cells, and human liver tissue. Indirect immunofluorescence analysis confirmed that PON2 protein was located in the cytoplasm of SY5Y cells., Conclusion: The rabbit polyclonal antibodies against human PON2 can specifically recognize natural protein expressed in human cells and tissues, Which can be used for further study and clinical detection of human PON2.

Aim: To investigate the amount of CD4+CD25high Treg cells and the expression of Foxp3 in neonatal cord blood, and to analyze the expression of Treg cells in neonates., Methods: The mononuclear cells from cord blood or peripheral blood were isolated from neonatal cord blood (n=15) or healthy adult's peripheral blood (n=12) by density gradient centrifugation. Then they were stained with fluorescence labeled monoclonal antibodies for cell surface and intracellular protein. The amount of CD4+CD25high Treg cells and intercellular transcription factor Foxp3 were measured by flow cytometry., Results: The amount of CD4+CD25high Treg cells in CD3+CD4+ T cells in cord blood was significantly higher than that in adult's peripheral blood (3.86%+/-1.63% vs 0.87%+/-0.74%, P<0.01), whereas the expression of Foxp3 in CD4+CD25high Treg cells in cord blood was markedly lower than in adult's blood (23.21%+/-8.9% vs 71.3%+/-11.6%, P<0.01)., Conclusion: The low expression of Foxp3 in CD4+CD25high Treg cells in cord blood suggests Treg cells in neonates are not mature in suppression.

Objective: To obtain genes encoding the novel molecules for diagnosis of schistosomiasis., Methods: Juvenile S. japonicum cDNA library was immunoscreened to obtain positive clones. By DNA sequencing and sequence analysis, the target gene was amplified by PCR and subcloned into prokaryotic plasmid pET28a. The recombinant plasmid was transformed into E. coli BL21 followed by expression of the protein induced by IPTG. The protein was identified by Western blotting., Results: 34 positive clones were obtained, 24 of which were chosen to be sequenced, 13 of which were Sj22600 gene. The protein were recognized with sera of infected rabbits and patients with acute and chronic schistosomiasis by Western blotting., Conclusion: The gene coding for Sj22600 membrane protein was screened with high frequency in the cDNA library. The E. coli BL21 transformed with the recombinant plasmid can express the fusion protein, which shows immunoactivity.

Background & Objective: Multiple steps and gene expression changes were involved in the development and progression of nasopharyngeal carcinoma (NPC), but the molecular mechanism is not understanding clearly. This study was designed to investigate the profiling of differently expressed genes in nasopharyngeal carcinoma compared with noncancerous nasopharynx tissues to explore the feature of gene expression in NPC and identify new candidate genes related to the development and progression of NPC., Methods: Differently expressed genes of NPC in 21 cases, which were divided into three pools, were investigated by using high density cDNA microarray representing 18,000 cDNA clones. The alterations in gene expression levels were confirmed by reverse-transcription PCR in 2 randomly selected genes., Results: A total of 317 genes were identified to be differently expressed in NPC of three pools as compared with noncancerous controls. Among the 317 genes, 23 genes were found to be consistent in at least two NPC sample pools, including 16 up-regulated genes and 7 down-regulated genes. Six genes were found to be consistent in all the three NPC sample pools. The 6 genes include 2 up-regulated unknown genes, 3 up-regulated unknown genes and 1 down-regulated unknown gene., Conclusion: The present study represents a global view of gene expression of NPC and provides important clues for further study of NPC related genes.