[Expression of SQSTM1 in papillary thyroid carcinoma and its influence on invasion, migration and proliferation of papillary thyroid cancer cells].

Objective: To investigate the expression of SQSTM1 in thyroid papillary carcinoma and its influence on the invasion and migration of thyroid papillary carcinoma cells TPC-1. Methods: From April to June 2019, cancer tissues and adjacent tissues of 21 cases with thyroid papillary carcinoma in the First Affiliated Hospital of Zhengzhou University were collected, and the expression of SQSTM1 was detected by RT-qPCR. SQSTM1 knockdown cell line SQSTM1-KD-TPC-1 was constructed in TPC-1 cells by lentivirus transfection. RT-qPCR was used to detect SQSTM1 expression in TPC-1 cells and SQSTM1-KD-TPC-1 cells. The changes of invasion and migration before and after SQSTM1 knockdown in TPC-1 cells were detected by transwell test. The proliferation of TPC-1 and SQSTM1-KD-TPC-1 cells were detected by MTT and clone formation test. RT-qPCR was used to detect the gene expression of proliferation related proteins. Results: The expression of SQSTM1 in papillary thyroid carcinoma tissues was significantly higher than that in normal adjacent tissues, and 76.2%(16/21) of the petients showed high mRNA expression. Knock down SQSTM1 significantly inhibited the ability of tumor proliferation, invasion and migration, and the expression of proliferation-related proteins were significantly decreased (P<0.01), indicating that SQSTM1 was involved in the regulation of proliferation related pathway mechanism. Conclusion: SQSTM1 significantly promotes invasion, migration and proliferation in thyroid papillary cancer cells TPC-1 and may be a potential gene therapy target.

[Study on Cep63 expression and apoptosis of thyroid papillary carcinoma cell lines TPC-1].

Objective: To investigate the effect of centrosomal protein Cep63 on the apoptosis of papillary thyroid carcinoma (PTC) cell lines TPC-1 and underlying mechanism. Methods: With collected PTC tissues and adjacent tissues, Cep63 expression was detected by RT-qPCR and its relationship with clinicopathological factors was analyzed. The experiment included negative control group (NC), low expression group (Cep63(-)) and overexpression group (Cep63(+)), and wild-type TPC-1 cells were transfected with Cep63 lentivirus. The efficiency of Cep63 was detected by western blot (WB) and qRT-PCR. Cell proliferation ability was detected by plate cloning experiment and MTT assay. Cell apoptotic rate was detected by flow cytometry, and expression levels of apoptosis-related proteins were detected by immunohistochemistry and WB. The t-test was used to compare the differences in the means between the two groups, the one-way analysis of variance was used to compare multiple groups, and the chi-square test was used to analyze the association between gene expression levels and pathological factors. Results: Compared with NC group, cell proliferation ability was significantly decreased in Cep63(-) group (3.18±0.07 vs. 2.14±0.09, t=8.54, P<0.01) and significantly increased in Cep63(+) group (3.18±0.07 vs. 3.58±0.10, t=3.21, P<0.05). Apoptotic rates in NC, Cep63 (-) and Cep63 (+) groups were respectively 3.03%±0.24%, 8.66%±0.44% and 1.17%±0.44%, and the flow cytometry showed that the low expression of Cep63 significantly increased the apoptosis TPC-1 cells (F=157.7, P<0.001). Bcl-2 protein expression levels of NC, Cep63 (-) and Cep63 (+) groups were respectively 1.07±0.03, 0.49±0.01 and 1.99±0.09, and BAX protein expression levels of three groups were respectively 0.64±0.02, 1.06±0.01 and 0.21±0.03. WB showed that the expression level of Bcl-2 decreased (F=183.2, P<0.001), while the expression level of BAX was significantly up-regulated (F=283.7, P<0.001). Conclusion: Cep63 may regulate the apoptotic process of TPC-1 cells through Bcl-2/BAX pathway and Cep63 may be a potential oncogene of PTC.

Determination of pseudocontact shifts of low-populated excited states by NMR chemical exchange saturation transfer.

Despite the critical roles of excited states in protein functions, they remain intractable for most structural studies because of their notably low populations. Chemical shifts for "invisible" states in slow exchange with the ground state are intuitively observed using nuclear magnetic resonance (NMR) chemical exchange saturation transfer (CEST) experiments. Here, we present a CEST NMR spectroscopy study for the observation of protein pseudocontact shifts (PCSs) of excited states, which carry valuable angular and distance information about these states. We first validate this approach, dubbed PCS-CEST, in the slow-exchange system of Abp1p SH3-Ark1p labeled with lanthanide ions, where the PCSs of the minor states resemble those of the holo-form ground state as expected. We further demonstrate that pre-existing folding transitional conformations of an FF domain exhibit remarkably lower PCS values than the ground state, which suggests that the low-populated ensemble is unfolded or largely unfolded. A higher resolution of PCSs of the minor states is achieved using our 1D selective CEST experiments. Thus, PCS-CEST provides an exquisite structural probe into the minor but functionally essential excited states.

The Ihh signal is essential for regulating proliferation and hypertrophy of cultured chicken chondrocytes.

The Indian hedgehog (Ihh) signal plays a vital role in regulating proliferation and hypertrophy of chondrocytes. To investigate its function in postnatal chicken (Gallus gallus) chondrocytes, cyclopamine was used to inhibit Ihh signaling. The MTT and ALP assays revealed the downgrade-proliferation and upgrade-differentiation of chondrocytes. To further elucidate the mechanism, the mRNA expression levels of Ihh, parathyroid hormone related protein (PTHrP), Gli-2, Bcl-2, Bone Morphogenetic Protein 6 (BMP-6), type X collagen (Col X) and type II collagen (Col II) were detected by quantitative real-time RT-PCR analysis, and the protein expressions of Ihh, Col X, and Col II were determined using Western blot analysis. After the Ihh signal was blocked, chondrocytes demonstrated high expression levels of PTHrP and Col X and low levels of Gli-2, BMP-6, Bcl-2 and Col II although Ihh expression was increased. Based on these results, the Ihh signal is essential for balancing chicken chondrocyte proliferation and hypertrophy, and the regulatory function of PTHrP acts in an Ihh-dependent manner. Furthermore, BMP-6 and Bcl-2 played roles in maintaining the development of chondrocytes and may be downstream regulatory factors of Ihh signaling.

Bone response of broiler chickens (Gallus gallus domesticus) induced by corticosterone.

Experiments were conducted with chickens exposed to corticosterone (CORT), with the aim of determining its effects on bone characteristics. At 7 d of age, the experimental birds were injected daily with CORT (4 mg/kg of body mass) for 1 week. CORT administration significantly decreased the body weight while increasing relative liver weight of the chickens and the bone parameters were also decreased. Histology and immunohistochemistry of type X collagen revealed that CORT reduced the lengths of proliferative and prehypertrophic zone in growth plate and the number of positive chondrocytes in the prehypertrophic zone. In conclusion exposure to CORT depressed the growth performance and retarded the longitudinal growth of the long bones by inhibiting the proliferation and differentiation of chondrocytes in growth plate in broilers.

[Locating the impairment of human cognitive function during hypoxia].

Objective. To find the location where the human brain cognitive function impairs under hypoxia. Method. 14 healthy males, aged 18-20 years, performed auditory Oddball test of two different intensities (55 dB, 80 dB) during exposure to 5000 m by breathing low oxygen mixture. EEG and Reaction Time (RT) were recorded. P3, the component of ERP, was extracted from EEG. P3 latency and RT were used as indices of the experiment. Additive Factors Method was used to analyse the result of the experiment. Result. Interaction between hypoxia and stimulus intensity was found for P3 latency and RT. Conclusion. Acute hypoxia influences the preprocessing stage of information processing.

[Effects of sleep deprivation on human performance].

Objective. To investigate the effects of sleep deprivation (SD) on human performance. Method. 8 healthy male college students participated the test. During 26 h of continuous awakeness (from 6:00 to 8:00 the next day), the volunteers were demanded to perform a battery of tests at 9 different time (7:00, 12:00, 16:00, 20:00, 0:00, 2:00, 4:00, 6:00, 8:00). The tests include: (1) single task: aural Oddball response, the response time (RT1) and correct rate (CR1) were recorded; (2) dual tasks: manual tracking and aural Oddball response, the response time (RT2), tracking error (ER) and correct rate (CR2) were recorded; (3) The Stanford sleepiness scale and subjective ratings of task difficulty access. Result. SD had significant effects on CT1, CT2 and ER (P=0.0001, P=0.00001, P=0.0004 respectively); SD increased RT1, RT2, ER at night time. SD had significant effects on SR, SSS score (P=0.0001, P=0.0000 respectively); SD increased SR, SSS score at night time. Since the subjects changed their response strategy, CR1 and CR2 were not influenced by SD at night time. Conclusion. SD has significant effects on response time, tracking error, subjective difficulty of cognitive tasks and subjective sleepiness.

[Comparison of sensitivity of mental load assessment indexes].

Objective. To compare the sensitivities of indexes used in the assessment of mental load. Method. Twenty five indexes belonging to primary task performance, additional task performance, subjective rate and psychophysiological measure were recorded during performance of 11 different difficult tasks. Result. It showed that tracking error (ER), reaction time (RT), correct rate (CR), category scale (CS), multistage evaluation scale (MES), multi-dimensional scale (MDS), latency of P3 (LAT), inter beat interval (IBI), inter respiration interval (IRI) and blink rate (BR) were significantly different among the various tasks. CS, MES and MDS were more sensitive to the total load; ER, LAT, IBI and IRI were more sensitive to the load of primary task, while RT and CR to that of additional task and BR to the visual load. Conclusion. It demonstrated that the sensitivities of the various indexes are different and the information are limited. Multi-indexes may be preferred for mental load assessment.

[Effects of mild and moderate hypoxia on event-related potentials and the comparison of different stimulus paradigms].

OBJECTIVE: To investigate the effects of mild and moderate hypoxia on event-related potentials (ERP), and to compare the sensitivity of different stimulus paradigms to hypoxia. METHODS: Twelve subjects performed visual Oddball and memory set size (MSET) 1 and MSET 3 of Sternberg tasks on the ground and at the simulated altitudes of 2500 m and 4300 m by breathing low oxygen mixtures. P3 latency and amplitude of ERP, reaction time (RT) and response error rate (ER) were recorded. RESULTS: During hypoxia at the altitude of 4300 m, P3 latency significantly delayed, and ER was high when the difficulty of task increased (Sternberg paradigm with MSET 3). In contrast, at the altitude of 2500 m no changes were observed. Sternberg paradigm with MSET 1, in comparison with others, could elicit clearer ERP waves, and P3 latency was slower during hypoxia. CONCLUSION: Hypoxia at the altitude of 4300 m has strong influence on ERP. P3 latency can be used as a sensitive index in evaluating the decrement of brain cognitive capacity during hypoxia. ERP elicited by Sternberg paradigm with MSET 1 was more sensitive to hypoxia.

Catalase Content in Peanut Milk as Affected by Growth of Aspergillus parasiticus.

Changes in catalase content and pH of peanut milk in which Aspergillus parasiticus was cultured were monitored over a 10-d period at 30°C. A 3- to 10-fold increase in catalase content was detected after 6 d of incubation, while the content in uninoculated (control) peanut milk decreased by about 50% after 3 d of incubation. The pH of uninoculated catalase-supplemented peanut milk increased from 6.7 to 9.2, whereas the pH of inoculated peanut milk remained essentially unchanged. Production of catalase by A. parasiticus and perhaps other molds could be a basis for developing a hydrogen peroxide treatment for separating mold-contaminated kernels from sound kernels.

Separation of Aflatoxin-Contaminated Kernels from Sound Kernels by Hydrogen Peroxide Treatment.

Blends (0:1, 1:3, 1:1, and 3:1, wt/wt) of aflatoxin-contaminated and sound peanut kernels were submerged for 1, 2, and 3 min in various concentrations of hydrogen peroxide solution. The effectiveness of these treatments in separating aflatoxin-contaminated kernels from sound kernels was determined. Peanuts that floated (floaters) and those that did not (sinkers) were subjected to aflatoxin analysis. Second order polynomial equations were satisfactorily fitted to the experimental data. Hydrogen peroxide concentrations of 0.075, 0.150, and 0.25% resulted in a reduction in aflatoxin content in the kernels in the sinker fraction by 90% within 1 min, regardless of the initial aflatoxin content. The total aflatoxin content in sinker and floater fractions was approximately the same as that in unfractionated samples, indicating that the low concentrations of hydrogen peroxide in treatment solutions did not degrade aflatoxin. Response surface methodology was used to generate contour plots which revealed optimum treatment conditions for giving a maximum yield of the sinker fraction with low aflatoxin content. For peanuts containing 50 ppb aflatoxin, optimum conditions consist of a 0.08% hydrogen peroxide treatment for 0.7 min. This procedure results in a maximum sinker fraction yield of 85.5% of the original lot with a residual aflatoxin content of ≤5 ppb.