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Objective@#Viscoelasticity is an essential feature of nerves, although little is known about their viscous properties. The discovery of shear wave dispersion (SWD) imaging has presented a new approach for the non-invasive evaluation of tissue viscosity.The present study investigated the feasibility of using SWD imaging to evaluate diabetic neuropathy using the sciatic nerve in a diabetic rat model. @*Materials and Methods@#This study included 11 diabetic rats in the diabetic group and 12 healthy rats in the control group.Bilateral sciatic nerves were evaluated 3 months after treatment with streptozotocin. We measured the nerve cross-sectional area (CSA), nerve stiffness using shear wave elastography (SWE), and nerve viscosity using SWD imaging. The motor nerve conduction velocity (MNCV) was also measured. These four indicators and the histology of the sciatic nerves were then compared between the two groups. The performance of CSA, SWE, and SWD imaging in distinguishing the two groups was assessed using receiver operating characteristic (ROC) analysis. @*Results@#Nerve CSA, stiffness, and viscosity in the diabetic group was significantly higher than those in the control group (all p < 0.05). The results also revealed a significantly lower MNCV in the diabetic group (p = 0.005). Additionally, the density of myelinated fibers was significantly lower in the diabetic group (p = 0.004). The average thickness of the myelin sheath was also lower in the diabetic group (p = 0.012). The area under the ROC curve for distinguishing the diabetic neuropathy group from the control group was 0.876 for SWD imaging, which was significantly greater than 0.677 for CSA (p = 0.030) and 0.705 for SWE (p = 0.035). @*Conclusion@#Sciatic nerve viscosity measured using SWD imaging was significantly higher in diabetic rats. The viscosity measured using SWD imaging performed well in distinguishing the diabetic neuropathy group from the control group.Therefore, SWD imaging may be a promising method for the evaluation of diabetic neuropathy.
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Background Lipid metabolism in liver shows circadian-dependent profiles. The hepatotoxicity of environmental chemicals is dependent on circadian time. Objective To observe the effects of bisphenol A (BPA) exposure at different zeitgeber time (ZT) on hepatic and blood lipid metabolism and decipher the underlying mechanisms related to circadian rhythm in mice. Methods Thirty-five female C57BL/6J mice were sacrificed every 4 h in a light-dark cycle (12 h/12 h). The liver tissues were collected to describe the circadian profiles of hepatic Rev-erba, Bmal1, Clock, Srebp1c, and Chrebp mRNA expression levels within 24 h. Thirty female mice were divided into 6 groups by the timing (ZT3 represents the 3 h after light on, ZT15 represents the 3 h after light off) and dose (50 or 500 μg·kg−1·d−1) of BPA exposure to observe hepatotoxicity. Mice were gavaged with designed doses of BPA once per day for 4 weeks. Mice were maintained with ad libitum access to food and water and measured body weight weekly. After the experiment, mice were euthanatized and liver tissues were separated to determine the biochemical indicators of lipid metabolism and lipid metabolism- and circadian-related gene mRNA expressions. Results Hepatic Rev-erba, Bmal1, Clock, Srebp1c, and Chrebp mRNA expression levels were rhythmic during a 24 h period in mice. At ZT3 and ZT15, BPA did not alter body weight, plasma glucose, plasma total cholesterol, plasma low density lipoprotein cholesterol, and plasma triglycerides (P>0.05). The plasma high density lipoprotein cholesterol decreased in the 50 μg·kg−1·d−1 BPA group at ZT3 by 14.56% compared with the control group (P<0.05). The liver triglycerides increased in the 50 μg·kg−1·d−1 BPA group at ZT15 by 115.20% compared with the control group (P<0.05). BPA decreased Srebp1c mRNA expression level when dosing at ZT3 and increased Chrebp, Srebp1c, and Acc1 mRNA expression levels when dosing at ZT15 compared with the control group (P<0.05). BPA increased Bmal1 mRNA expression level and decreased Rev-erbα mRNA expression level at ZT3 exposure and decreased Bmal1 and increased Rev-erbα mRNA expression level at ZT15 exposure (P<0.05). Conclusion BPA exposure at light or dark period has different effects on hepatic lipid metabolism in mice. Hepatic lipid deposit appears when BPA is dosed at dark period. Rev-erbα-Bmal1 regulation circuits and the subsequent upregulation of Srebp1c and Chrebp and the target gene Acc1 may be involved.
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Objective@#Investigate the effects of inducible ppp2r1a knockout on main physiological function in adult mice and study the mechanism.@*Methods@#Ppp2r1aflox/flox mice and CAGG-CreER mice were hybridized to obtain 20 CAGG-CreER ppp2r1aflox/flox and 20 mice in homozygous group. Two groups of mice were divided into 4 groups respectively, finally we got 8 groups with 5 mice in each group. Tamoxifen was injected intraperitoneally to acquire inducible ppp2r1a knockout mice. The knockout efficiency of PP2A Aα in vital organs was measured by Western blot. At 0, 2, 4 and 6 days after injection, we measured body weight, histopathological change, peripheral blood cell counts and blood biochemical. Real-time PCR was performed to measure expression of liver glucolipid metabolism genes.@*Results@#After tamoxifen injection for 6 days, the knockout efficiency of PP2A Aα in vital organs was 35%, 12%, 15%, 60%, 69% and 72%, respectively in heart, liver, spleen, lung, kidney and brain. After tamoxifen injection for 6 days, the weight of homozygous mice was lower than that of wild type mice, with values of (17.42±1.76) g and (21.69±1.82) g, respectively (P<0.05). Moreover, the activity level, abdominal and renal fat were significantly decreased in homozygous mice. Homozygous mice survived no more than 7 days. Compared with wild type mice, the organ coefficient of spleen of homozygous mice was decreased at the 6th day, with values of (0.59±0.10)% and (0.36±0.05)% respectively (P<0.05). Obvious spleen atrophy and marked decrease of nucleated cells were showed by performing HE staining. Tunel staining revealed increased apoptosis ratio of splenic lymphocytes in homozygous mice. The levels of alanine aminotransferase (ALT) and aspartate transaminase (AST) of homozygous mice were higher than wild type mice (P<0.05). The values of ALT and AST in homozygous mice were (153.68±62.80) U/L and (193.2±44.28) U/L. The corresponding values in wild type mice were (41.02±12.91) U/L and (69.40±9.55) U/L. The above results indicated that ppp2r1a knockout caused liver damage. Blood sugar level of homozygous mice was lower than in wild type mice (P<0.05), with values of (4.20±1.99) mmol/L and (8.88±0.65) mmol/L respectively. Plasma total cholesterol (TC), high density lipoprotein (HDL) and β-hydroxybutyric acid (β-HB) level of homozygous mice were higher than those of wild type mice (P<0.05). The values of TC, HDL and β-HB in homozygous mice were (3.12±0.39), (1.53±0.38) and (2.49±0.89) mmol/L. The corresponding values in wild type mice were (1.69±0.92), (0.78±0.50) and (0.45±0.30) mmol/L respectively. The above results indicated that ppp2r1a loss interfered glucose and cholesterol metabolism. In addition, we also found that the white blood cell count (WBC) and lymphocyte count (LYM) of homozygous mice were lower than in wild type mice (P<0.05). The values of WBC and LYM in homozygous mice were (1.88±0.89)×109/L and (0.92±0.37)×109/L respectively. The corresponding values in wild type mice were (3.91±0.80)×109/L and (2.74±0.52)×109/L respectively. The mRNA levels of glucose-6-phosphatase (G6P) and phosphoenolpyruvate carboxykinase (PEPCK) of homozygous were lower than wild type mice (P<0.05). The fold change of G6P and PEPCK in homozygous mice was 0.46±0.11 and 0.72±0.07 respectively. The corresponding fold change in wild type mice was 1.02±0.07 and 1.02±0.06 respectively.@*Conclusion@#Whole body ppp2r1a is essential for the survival of adult mice, due to the important role in maintaining the metabolism of glucose and cholesterol of liver.
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Objective To study the prevalence and associated factors of loneliness in individuals with speech disability.Methods Using multi-stage stratified random cluster sampling method,170 community-residing ver-bally disabled persons were selected and administered with a general information questionnaire,one single -item loneliness self-rating question and social support scale.A total of 204 study questionnaires were distributed to the subjects;170 subjects(mean age:43.1±13.7 years)completed the survey.Results As high as 46.47% (79/170)of these verbally disabled individuals reported to feel lonely often.Females (OR=2.45),unemployment (OR=2.95), first and second degrees of disability (OR=4.35),co-existence of chronic illnesses (OR=6.50)and low utiliza-tion of social support (OR=2.58)were significantly associated with the increased risk of loneliness in persons with speech disability (P =0.002~0.046).Conclusion Loneliness is highly prevalent in individuals with speech disabili-ty.Verbally disabled persons,who are female,unemployed,severely disabled,and chronically ill and have a low use of social support,are the target population of mental health services.
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<p><b>OBJECTIVE</b>To detect the expression changes of the demethylase TETs (Ten-eleven translocation enzymes) in human embryonic kidney cell (HEK293) exposed to high dose cadmium chloride (CdCl2), and to investigate the regulation effects of TETs on global genomic methylation.</p><p><b>METHODS</b>HEK293 cells were exposed to CdCl2 for 24 h, 48 h and 72 h, the survival rate was tested by CCK-8 (cell counting kit-8) method, and the cell morphology was observed. The levels of TETs mRNA and protein were detected by fluorescence quantitative PCR and Western blot, respectively. The genomic DNA methylation level was detectedby pyro sequencing assay.</p><p><b>RESULTS</b>CdCl2 had toxic effects on HEK293 cells, and the half inhibitory concentration (IC50) was 1.78 µmol/L. After exposure of CdCl2 for 24 h, 48 h and 72 h, the morphology of HEK293 cells was altered, and the high dose group (2.0 µmol/L) showed vacuolar changes and fuzzy appearance. The level of TET1 mRNA in groups of 0.0, 0.5, 1.0, 2.0 µmol/L were 0.23 ± 0.13, 0.48 ± 0.12, 0.59 ± 0.16 and 0.95 ± 0.39, respectively (F = 182.89, P = 0.002); The level of TET2 mRNA in groups of 0.0, 0.5, 1.0, 2.0 µmol/L were 0.23 ± 0.12, 0.32 ± 0.02,0.31 ± 0.10 and 0.34 ± 0.07, respectively (F = 27.94, P < 0.001); The level of TET3 mRNA in groups of 0.0, 0.5, 1.0, 2.0 µmol/L were 0.26 ± 0.10, 0.27 ± 0.11, 0.25 ± 0.11 and 0.28 ± 0.09, respectively (F = 1.76, P = 0.036). The interaction effect existed between exposure time and doses of TET1 mRNA, TET2 mRNA and TET3 mRNA (F values were 32.94, 23.04 and 13.78, respectively; P values were < 0.001, 0.041 and < 0.001, respectively). Western blot showed that in different exposure time and dose, the protein expression levels of TETs had the similar trend as mRNA levels. In 24 h (55.01 ± 3.62)%, 48 h (48.31 ± 8.99)%, 72 h (48.76 ± 6.60)%, the DNA methylation had significant differences (F = 18.50, P < 0.001); In groups of 0.0 µmol/L (55.29 ± 2.83)%, 0.5 µmol/L (55.35 ± 3.11)%, 1.0 µmol/L (48.58 ± 6.40)% and 2.0 µmol/L (43.56 ± 7.89)%, the differences of DNA methylation had significant differences (F = 7.03, P = 0.048); the effect of interaction was also existed (F = 2.73, P = 0.043).</p><p><b>CONCLUSION</b>In the short term exposure to CdCl2, the levels of TETs mRNA and protein showed a trend of increase according to the exposure time and dose, and the methylation level of whole genomic DNA was also altered. The demethylase TETs may play a role in regulating the genomic methylation level of HEK293 exposed to cadmium.</p>
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Humans , Cadmium Chloride , Toxicity , DNA Methylation , Dioxygenases , Genetics , Epithelial Cells , HEK293 Cells , RNA, MessengerABSTRACT
Objective To investigate the influence of age on the perioperative characteristics of posterior lumbar interbody fusion (PLIF). Methods 129 patients (25~91 years old) with spondylolisthesis, lumbar stenosis and/or disc degeneration/herniation with instability, or unsuccessful results after a failed previous PLIF. They were divided into control group (0.05) between 2 groups. Conclusion Age can not in-crease the rate of perioperative complications of PLIF, and the advanced age should not be surgical contraindication.
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Objective To compare the clinical effect of the two surgical methods of posterior pedicle screw fixation decompression in treatment of thoracolumbar burst fractures,and in order to provide the basis for choosing the rational treatment.Methods Retrospectively analyzed the clinical data of 98 patients with thoracolumbar burst fractures underwent surgery of posterior pedicle screw fixation decompression from January 2007 to January 2011.Fifty-six patients were given posterior fixed indirect decompression surgery (indirect decompression group) and 42 patients were given posterior fixed direct decompression (direct decompression group).The patients were followed up for (1.03 ± 0.36) years after surgery,the image,recovery of neurological function,postoperative complications and capacity for independent living of the two groups were compared and evaluated.Results After surgery,the vertebral height ratio,Cobb angle,canal compromise rate in indirect decompression group were (91.67 ± 26.19)％,(10.10 ± 2.89)°,(18.61 ±5.32)％,in direct decompression group were(86.23 ± 24.64)％,(11.98 ± 3.42)°,(22.37 ± 6.39)％.There was significant difference compared with before surgery (P ＜ 0.05) and no significant difference between two groups (P ＞0.05).After surgery,the neurological function of the two groups were improved,and the improvement in indirect decompression group was better than that in direct decompression group (P ＜ 0.05).The postoperative complications ratio in indirect decompression group was 23.2％ (13/56),significantly lower than that in direct decompression group[83.3％(35/42)](x2 =10.370,P＜ 0.01).There was 60.7％(34/56)patients with capacity for independent living in indirect decompression group,significantly higher than that in direct decompression group [40.5％ (17/42)] (x2 =4.329,P ＜ 0.05).Conclusion The posterior pedicle screw fixation indirect decompression in treatment of thoracolumbar burst fractures is a feasible operation method,and is worth to utilize in clinic.