The isochronous substitution effect of 24 hour activity behavior on physical health of college students / 中国学校卫生

Objective@#An isochronous substitution model was established to explore the association and substitution effect between college students 24 hour activity behavior and physical health, so as to provide specific activity behavior suggestions for college students to improve their physical health.@*Methods@#A stratified random cluster sampling method was used to conduct physical fitness tests and 24 hour activity behavior surveys among 2 794 college students in 12 colleges and universities in Tianjin.Time spent on sedentary behavior(SB), light intensity physical activity(LPA), moderate to vigorous physical activity(MVPA) and sleep(SLP) time. The isochronous method of components was used to explore the relationship between 24 h activity behavior and physical health.@*Results@#Except for 50 m running, MVPA was negatively correlated with BMI Z ( β =-0.62, P <0.05), but positively correlated with other physical fitness indexes ( β =0.34~274.23, P <0.05). LPA was not associated with lung capacity, sitting forward flexion and 50 m running, and negatively correlated with other physical fitness indexes ( β =-14.30- -0.19, P <0.05). SB was negatively correlated with most physical fitness indexes ( β =-11.57- -0.33, P <0.05), but positively correlated with BMI Z ( β =0.45, P < 0.05 ). In addition to lung capacity, SLP was positively correlated with BMI Z , total physical fitness score,1 minute sit-ups, pull ups, 800/1 000 m running, sitting forward flexion, and 50 m running ( β =0.27-11.21, P <0.05), but negatively correlated with long jump ( β =-0.10, P <0.05）. Isochronous substitution showed that the adverse effects of 30 min/d SB and LPA substitution of MVPA were much greater than the beneficial effects of MVPA substitution for corresponding behaviors (total physical score: SB, -0.58 vs 0.47 points; LPA, -0.50 vs 0.38 points).@*Conclusion@#MVPA and SLP have been found to have a positive effect on physical fitness among college students. Therefore, in the process of improving the physical health of college students, ensuring adequate sleep, improving MVPA and reducing SB as much as possible may be one of the effective methods.

Predictors of colorectal polyps complicating colorectal laterally spreading tumors and the risk factors for malignancy in coexistence / 中华消化内镜杂志

Objective:To investigate the independent predictors of colorectal polyps complicating colorectal laterally spreading tumors (CLST) and the independent risk factors for malignancy in CLST coexisting with colorectal polyps.Methods:Clinical data of 260 patients with CLST who underwent endoscopy and received treatment in the Second Affiliated Hospital of Dalian Medical University from January 2016 to December 2021 were retrospectively collected. Patients were divided into the coexisting group ( n=135) and the non-coexisting group ( n=125) according to the presence or absence of polyps. Differences in clinicopathological characteristics between the two groups were compared and binary logistic regression was used to analyse the predictors of coexistence. Then the coexisting group was further divided into coexisting malignant group ( n=38) and coexisting non-malignant group ( n=97) according to the infiltration depth of CLST, and binary logistic regression was used to analyse the risk factors for malignancy in CLST coexisting with colorectal polyps. Results:Male ( P=0.002, OR=2.355, 95% CI:1.354-4.099), villous tubular adenoma ( P=0.022, OR=3.873, 95% CI: 1.214-12.355) and polyps history ( P=0.001, OR=2.738, 95% CI: 1.527-4.909) were independent predictors for colorectal polyps coexisting with CLST. Area under the curve (AUC) of the predictive model was 0.725 ( P<0.001, 95% CI: 0.664-0.786). Polyp diameter≥10 mm ( P=0.007, OR=6.266, 95% CI:1.634-24.034), CLST diameter≥20 mm ( P<0.001, OR=11.879, 95% CI:4.078-34.601), granular-mixed type CLST ( P=0.003, OR=8.584, 95% CI: 2.126-34.660), flat-elevated type CLST ( P=0.021, OR=4.399, 95% CI: 1.250-15.482) and pseudo-depressed type CLST ( P<0.001, OR=31.426, 95% CI: 4.975-198.509) were independent risk factors for malignancy in CLST coexisting with polyps. AUC of the predictive model was 0.854 ( P<0.001, 95% CI: 0.775-0.933). Conclusion:Male CLST patients with polyps history and a pathological type of villous tubular adenoma are more likely to develop coexistence. In patients with CLST which is granular-mixed type, flat-elevated type and pseudo-depressed type coexisting with colorectal polyps, the larger the diameter of the polyp and the diameter of the CLST, the more likely it is to be malignant.

ATP1 promotes Candida albicans to escape from macrophage killing through regulating oxidative stress / 中华皮肤科杂志

Objective:To investigate the physiological role of F1Fo-ATP synthase α-subunit encoding gene (ATP1) in promoting Candida albicans ( C. albicans) to escape from macrophage killing through eliminating intracellular reactive oxygen species (ROS) by using a reverse genetics approach. Methods:An ATP1 deletion strain and a parental strain of C. albicans were cultured on the YPD media, and the number of formed colonies on the plates was counted to evaluate in vitro viability of C. albicans. To evaluate their in vivo viability, the ATP1 deletion strain and parental strain of C. albicans were inoculated into mice through the caudal vein, kidney tissues were taken out from the mice 1-7 days after the infection, and inoculated onto the YPD medium followed by numeration of colonies after 48 hours of culture. After co-culture of overnight-cultured C. albicans suspensions with macrophages, some of the C. albicans suspensions were inoculated onto the YPD solid medium followed by numeration of colonies and determination of survival rate, and some culture supernatants were inoculated into the 96-well plate for detection of the level of lactate dehydrogenase (LDH) released by macrophages by LDH release assay. A model mimicking oxidative stress in macrophages was established by using hydrogen peroxide. After treatment with hydrogen peroxide, the number of colonies was counted to compare the viability of the C. albicans strains. DCFH-DA staining was conducted to detect the intracellular ROS level in C. albicans after co-culture with macrophages or treatment with hydrogen peroxide, and real-time fluorescence-based quantitative PCR to measure mRNA expression of catalase 1 (CAT1) , superoxide dismutase 4 (SOD4) and SOD5 genes in C. albicans after treatment with hydrogen peroxide. Statistical analysis was carried out by using two-way analysis of variance or Student t test. Results:In vitro, the colony number in both the parental strain group and ATP1 deletion strain group gradually increased over time; after 24 hours, the colony number of the ATP1 deletion strain group was only 10% of that in the parental strain group ( F = 481.84, P < 0.001) . The number of colony formed by the parental strain-infected mouse kidney tissues gradually increased over time, but that by the ATP1 deletion strain-infected mouse kidney tissues gradually decreased, and there was a significant difference between the two groups ( F = 78.27, P = 0.001) . After in vitro co-culture of C. albicans with macrophages, the survival rate in the ATP1 deletion strain group (62.67% ± 3.51%) was significantly lower than that in the parental strain group (82.33% ± 2.52%, t = 7.88, P = 0.001) , and the percentage of LDH released by macrophages was also significantly lower in the ATP1 deletion strain group (27.80% ± 3.54%) than in the parental strain group (87.78% ± 0.17%, t = 33.89, P < 0.001) , which were consistent with the in vivo results. In the model mimicking oxidative stress, the viability of the ATP1 deletion strain group was significantly lower than that of the parental strain group ( F = 3 440.65, P < 0.001) . Both in the co-culture model with macrophages and in the model mimicking oxidative stress in macrophages, the intracellular ROS levels were significantly higher in the ATP1 deletion strain group than in the parental strain group (both P < 0.001) . Furthermore, the mRNA expression of CAT1, SOD4 and SOD5 genes was significantly lower in the ATP1 deletion strain group than in the parental strain group after treatment with hydrogen peroxide (all P < 0.001) . Conclusion:ATP1 deletion may reduce the capabilities of C. albicans to counteract oxidative stress and eliminate ROS, likely by down-regulating the expression of oxidative stress- and ROS clearance-related genes respectively, which may prevent C. albicans from escaping from the macrophage killing and lead it to be eliminated by the host ultimately.

Cloning of human adiponectin gene by PCR-driven overlap extension and expression in Pichia pastoris / 生物工程学报

Gene of human adiponectin (ADPN) was cloned by PCR-driven overlap extension. The ADPN gene was linked into pGEM-T vector. After the sequence was determined, the ADPN gene was subcloned into expression vector pPIC3.5K to yield the recombinant expression vector pPIC3.5K-ADPN. The recombinant plasmid was transformed into Pichia pastoris GS115 by electroporation, then the recombinant strain was identified by PCR and Southern blotting. After induction by methanol, ADPN was expressed in GS115, then the protein was identified by Western blotting. The results showed that the ADPN was expressed successfully. The optimum conditions of expression were 30 degrees C and 1% methanol inducing 48 h.