Age-Related Changes of Material Mechanics and Bone Material Parameters of Rat Skulls / 法医学杂志

Objective To study the relationship between material mechanics and bone material parameters of rat skulls and their correlation with age by examination of the parameters. Methods Forty-eight healthy male SD rats were divided into 2, 4, 6, 8, 17, 26, 52 and 104 week groups according to their age. Each group had six rats. The right cranium was compressed by KD Ⅱ-0.2 microcomputer controlled electronic universal testing machine, and material mechanics parameters （ultimate load, compression strength and compression modulus） were measured, then the skull slices were cut off and scanned by Micro-CT system to detect bone material parameters （skull thickness, bone mineral density, bone volume, and trabecular thickness）. Results The differences in ultimate load, compression strength and compression modulus among all groups had statistical significance （P<0.05）, and were positively correlated with age within 26 weeks （P<0.05）. The differences in skull thickness, bone mineral density, bone volume and trabecular thickness among all groups had statistical significance （P<0.05）, and were positively correlated with age within 52 weeks （P<0.05）. All material mechanics parameters were positively correlated with bone material parameters （P<0.05）. Conclusion There is a positive correlation between bone material parameters （skull thickness, bone mineral density, bone volume, trabecular thickness）, material mechanics parameter （skull ultimate load, compression strength, compression modulus） and age in a certain range, which can be used to infer age.

Effect of HMGB1 expression knockdown on invasion ability of breast cancer cells induced by TNF-α / 中国病理生理杂志

AIM:To investigate the effect of high-mobility group box-1 (HMGB1) expression knockdown on the invasion ability of breast cancer cells induced by tumor necrosis factor-α (TNF-α).METHODS:HMGB1 siRNA was used to transfect into the breast cancer MDA-MB-231 cells.The expression of HMGB1 at mRNA and protein levels was determined by RT-qPCR and Western blot.After the MDA-MB-231 cells with HMGB1 expression knockdown were treated with TNF-α, the apoptosis rate was analyzed by flow cytometry, the cell invasion ability was measured by Transwell assay, and the cell migration ability was detected by cell scratch test.The protein expression of E-cadherin, MMP-2, N-cadherin, MMP-9 and Bax was determined by Western blot.RESULTS:The expression of HMGB1 at mRNA and protein levels in the MDA-MB-231 cells transfected with HMGB1 siRNA was significantly lower than that in the non-transfected cells (P<0.05).The apoptosis rate in the cells was increased after TNF-αtreatment, and the cell invasion and migration abilities were also increased.The protein level of E-cadherin in the cells was decreased, the protein level of N-cadherin was increased, and the protein levels of MMP-2, MMP-9 and Bax were also increased (P<0.05).After the MDA-MB-231 cells with HMGB1 expression knockdown were induced by TNF-α, the apoptotic rate was increased, the invasion and migration abilities were decreased, the protein levels of E-cadherin and Bax were increased, and the protein levels of N-cadherin, MMP-2 and MMP-9 were decreased, as compared with the cells only induced by TNF-αwithout knockdown of HMGB1 expression (P<0.05).CONCLUSION:Knockdown of HMGB1 expression enhances the apoptosis of breast cancer cells induced by TNF-α, and inhibited the cell invasion, migration and epithelial-mesenchymal transition induced by TNF-α.The mechanism may be related with the changes of protein expression of MMP-2, MMP-9 and Bax.

Ubiquitin ligase Smurf1 promotes poly-ubiquitination of PDK1 / 军事医学

Objective To investigate the mechanism of 3-phosphoinositide-dependent protein kinase 1(PDK1)poly-ubiquitination.Methods Co-immunoprecipitation(Co-IP)and Western blot(WB)were used to analyze poly-ubiquitination of PDK1.It was confirmed that ubiquitin ligase smad ubiquitylation regulatory factor 1(Smurf1)inprove PDK1 poly-ubiquitination within MEF cells,site-directed mutagenesis and WB before PDK1 poly-ubiquitination sites were determined.Results We found that PDK1 could undergoes poly-ubiquitination,ubiquitin ligase Smurf1 was found to be a direct E3 ligase for PDK1 poly-ubiquitination and might rely on the ubiquitin ligase Smurf 1 K699 site activity.K304 was PDK1 poly-ubiquitination modification site point.Conclusion The ubiquitin ligase Smurf1 can promate poly-ubiquitination of PDK1.

Survival Analysis of Hepatocellular Carcinoma: A Comparison Between Young Patients and Aged Patients / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>To compare the clinicopathological features and prognosis between younger and aged patients with hepatocellular carcinoma (HCC).</p><p><b>METHODS</b>We analyzed the outcome of 451 HCC patients underwent liver resection, transcatheter arterial chemoembolization and radiofrequency ablation, respectively. Then risk factors for aged and younger patients' survival were evaluated by multivariate analysis, respectively.</p><p><b>RESULTS</b>The patients who were older than 55 years old were defined as the older group. The overall survival for aged patients was significantly worse than those younger patients. The younger patients had similar liver functional reserve but more aggressive tumor factors than aged patients. Cox regression analysis showed that the elevated levels of aspartate aminotransferase (AST) (Wald χ2 = 3.963, P = 0.047, hazard ratio [HR] =1.453, 95% confidence interval [CI]: 1.006-2.098), lower albumin (Wald χ2 = 12.213, P < 0.001, HR = 1.982, 95% CI: 1.351-2.910), tumor size (Wald χ2 = 8.179, P = 0.004, HR = 1.841, 95% CI: 1.212-2.797), and higher alpha-fetoprotein level (Wald χ2 = 4.044, P = 0.044, HR = 1.465, 95% CI: 1.010-2.126) were independent prognostic factors for aged patients, while only elevated levels of AST (Wald χ2 = 14.491, P < 0.001, HR = 2.285, 95% CI: 1.493-3.496) and tumor size (Wald χ2 = 21.662, P < 0.001, HR = 2.928, 95% CI: 1.863-4.604) were independent prognostic factors for younger patients.</p><p><b>CONCLUSIONS</b>Age is a risk factor to determine the prognosis of patients with HCC. Aged patients who have good liver functional reserve are still encouraged to receive curative therapy.</p>

Comparison of two quantitation methods of circulating tumor cells in patients with small cell lung cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To establish a quantitative method to detect circulating tumor cells (CTC) in patients with small cell lung cancer, and analyze its sensitivity and stability.</p><p><b>METHODS</b>A specific primer and probe for prepro-gastrin-releasing peptide (preproGRP) was designed and a quantitative RT-PCR method was established to detect preproGRP mRNA. Cell incorporation method was used to evaluate the sensitivity. Magnetic cell sorting (MACS) was used to isolate and purify CTC from peripheral blood, and the MACS in combination with morphological diagnosis were used for cell counting.</p><p><b>RESULTS</b>The isolation rate of CTC by MACS was 30% and the lower detection limit was 5 cells per ml blood. The sensitivity of quantitative RT-PCR in detection of preproGRP mRNA in CTC was 0.64 cells per reaction, and the lower detection limit was 50 cells per ml blood, which was lower than that of MACS. However, the cell numbers calculated by Ct value was in greater accordance (about 80%) with actual cell numbers than that obtained by MACS.</p><p><b>CONCLUSIONS</b>PreproGRP quantitative RT-PCR and MACS have both advantages and disadvantages in detecting CTC of SCLC patients. MACS has a higher sensitivity, and is more favorable when CTC count is below 50 per ml blood. Meanwhile, preproGRP mRNA quantitative RT-PCR is more reliable in calculating actual cell numbers.</p>

A preliminary study on recombinant expression and function in vitro of proteasome activator REGγ / 军事医学科学院院刊

Objective To study the expression of the fused proteasome activator REGγ(11S regulator complex gamma subunit) using gene recombination technology and to further study the interaction between REGγ and casein kinase-2 interacting protein-1(CKIP-1)in vitro.Methods Firstly, the full length cDNA fragment of REGγ was amplified through PCR using the plasmid pCMV-Myc-REGγ as template and subcloned into the prokaryotic expression vector pGEX-4T-2 before being transformed into E.coli BL21 cells. The protein expression was induced by isopropyl-β-D-thiogalactoside(IPTG) .Secondly, the protein expression was monitored by SDS-PAGE and Western blotting after ultrasonication. Finally, the GST Pull-down assay was performed to investigate the interaction between REGγ and CKIP-1 in vitro.Results The prokaryotic expression construct pGEX-4T-2-REGγ was generated successfully and confirmed by DNA sequencing. Expression analysis showed that the GST-REGγ protein was easily expressed and isolated mainly in the lysate supernatant after sonication and centrifugation. The GST Pull-down assay revealed the strong mutual interaction between REGγ and CKIP-1 in vitro.Conclusion The proteasome activator REGγ could interact with the negative regulator of osteoblastogenesis CKIP-1 in vitro and the current study has shed light on further investigations of their physiological relevance.

Clinical value of CEA and CYFRA21-1 as an assessment indicator of therapeutic efficacy in advanced non-small cell lung cancer patients / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the value of carcinoembryonic antigen (CEA) or cytokeratin 19 fragment (CYFRA21-1) as an assessment indicator of therapeutic efficacy in advanced non-small cell lung cancer (NSCLC) patients.</p><p><b>METHODS</b>228 cases of advanced NSCLC with chemotherapy were enrolled into this retrospective study. The serum CEA or CYFRA21-1 levels of all patients were above the cut-off limit before treatment. The relationship between changes of tumor markers (TMs) and imaging therapeutic efficacy or progression-free survival (PFS) was analyzed, and the value of TMs in therapeutic efficacy assessment was evaluated.</p><p><b>RESULTS</b>According to RECIST criteria, partial response (PR) occurred in 40 cases, stable disease (SD) in 151 and PD (progressive disease) in 37. The cut-off values of the changes of TMs between pre- and post-treatment were determined according to the above mentioned criteria. The CEA down (D), stable (S), above (A) groups were 90, 49 and 66 cases, respectively. CYFRA21-1 down (D), stable (S), above (A) groups were 84, 26 and 37 cases, respectively. PR groups were 68.4% and 88.9% in CEA and cyfra21-1 down groups, respectively, 7.9% and 5.6% in the above groups, respectively. PD groups were 59.4% and 76.2% in CEA and CYFRA21-1 above groups, respectively. No PD cases were in the down groups. The changes of TMs in SD group were between them. Statistically significant correlations were observed between changes of TMs and imaging therapeutic efficacy (r(CEA) = 0.45, P = 0.00; r(CYFRA21-1) = 0.44, P = 0.00). PFS among different TMs groups were significantly different (all P < 0.05), which can be used to further distinguish the prognosis among SD subgroups.</p><p><b>CONCLUSION</b>Changes of TMs can be used to predict the imaging therapeutic effect and PFS of the patients, and if the SD group is divided into subgroups according to different therapeutic efficacy and prognosis, it may help the patients to receive individualized treatment.</p>

The effect of the metallic dental materials on magnetic resonance imaging / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the influence of conventional metal materials in oral cavity on brain magnetic resonance imaging (MRI).</p><p><b>METHODS</b>Four kinds of metal materials (metal ligature wire, forging hard and slotless denture, casting nichrome denture, casting copper alloy denture) in oral cavity were scanned through MRI. FSE sequence T1 weighted imaging (FSE T1), EPI diffusion-weighted imaging (DWI) sequence of ordinary, Propeller DWI imaging were used.</p><p><b>RESULTS</b>In FSE T1 sequence, metal ligature wire and forging hard and slotless denture produced serious false image, casting nichrome denture produced moderate false image, casting copper alloy denture produced only little false image. In EPI DWI sequence, obvious magnetic-sensitive false image were produced in the dissection tissue of the brain by metal ligature wire. While in Propeller DWI sequence, magnetic-sensitive false image were greatly reduced and satisfactory images were formed.</p><p><b>CONCLUSION</b>Different metal materials in oral cavity have different influence on the MRI. The false images produced by different metal materials are closely related to the type of the material. Magnetic-sensitive false images can be eliminated by Propeller DWI technique.</p>

Duration of tau hyperphosphorylation and spatial memory deficit induced by single injection of Forskolin into lateral ventricle of rat / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the duration of tau hyperphosphorylation and spatial memory retentive deficit induced by single injecting with Forskolin, a protein kinase A activator, into lateral ventricle of rats, and the correlation between the two pathological alterations.</p><p><b>METHODS</b>Forskolin (80 micromol/L, 40 microl) was injected into the lateral ventricle by stereotaxic injection. Tau phosphorylation and spatial memory retention were measured by Western blot/immunocytochemistry and Morris-Water-Maze test, respectively.</p><p><b>RESULTS</b>The phosphorylation levels of tau at Tau-1, PHF-1, and pS214 epitopes were significantly elevated at 24, 48 and 72 h after single administration of Forskolin (P < 0.05). The most significant elevation was seen at 48 h (P < 0.01) and it tended to recover at 72 h (P < 0.05) after injection. The correlation between the two pathological alterations was positive at PHF-1 site (r = 0.97, P < 0.05), negative at Tau-1 site (r = -0.963, P < 0.05), and not significant at pS214 site (r = 0.705, P > 0.05).</p><p><b>CONCLUSIONS</b>Forskolin can induce tau hyperphosphorylation and spatial memory retentive deficit within a certain period of time. The level of tau phosphorylation in hippocampus is somehow correlated with the spatial memory deficit in rats.</p>

Inhibition of melatonin biosynthesis activates protein kinase a and induces Alzheimer-like tau hyperphosphorylation in rats / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To investigate effect of inhibiting melatonin biosynthesis on activities of protein kinase A (PKA), glycogen synthase kinase-3 (GSK-3) and tau phosphorylation at PS214 and M4 epitopes using haloperidol, a specific inhibitor of 5-hydroxyindole-O-methyltransferase.</p><p><b>METHODS</b>Brain ventricular and intraperitoneal injections were used for haloperidol administration, Western blots for tau phosphorylation, 32P-labeling for PKA and GSK-3 activity, and high performance liquid chromatograph for detection of serum melatonin levels.</p><p><b>RESULTS</b>Haloperidol injection through the lateral ventricle and intraperitoneal reinforcement significantly stimulated PKA activity with a concurrent hyperphosphorylation of tau at M4 (Thr231/Ser235) and PS214 (Ser214) sites. Prior treatment of the rats using melatonin supplement for one week and reinforcement during the haloperidol administration arrested PKA activity and attenuated tau hyperphosphorylation. GSK-3 activity showed no obvious change after haloperidol injection, however, melatonin supplements and reinforcements during haloperidol infusion inactivated basal activity of GSK-3.</p><p><b>CONCLUSION</b>Decreased melatonin may be involved in Alzheimer-like tau hyperphosphorylation, and overactivation of PKA may play a crucial role in this process.</p>

A motif-based scanning approach for prediction of protein phosphorylation / 生物工程学报

Scansite is a short linear motif-based scanning approach established in the latest two years. It's accessible over the World Wide Web and can be used to identify sequence motifs likely to be phosphorylated by specific protein kinases or likely to bind to specific protein domains such as 14-3-3, SH2 and SH3 domains. The usage and function of the potent approach were reviewed and compared with previously established tools for phosphorylation prediction. The facing problems and application outlook of Scansite in prediction of cell signaling networks within proteomes were also presented.