[A clinical study of mental stress-induced myocardial ischemia in patients with stable coronary artery disease and depression/anxiety].

Objectives: Exploring the association between depression/anxiety and mental stress-induced myocardial ischemia (MSIMI) in patients with stable coronary artery disease (CAD). Methods: A total of 178 subjects was enrolled according to the inclusion and exclusion criterion with 88 men and 90 women at age of (54±12)years. The subjects were divided into four groups including CAD with depression/anxiety, CAD without depression/anxiety, depression/anxiety without CAD, and control group based on the state of coronary artery, the scores of Patient Health Questionnaire 9-item (PHQ-9) and Generalized Anxiety Disorder 7-item (GAD-7) . MSIMI was diagnosed by echocardiography. Data were analyzed by SPSS19.0. Results: The incidence of MSIMI in all CAD patients was 17.24%. Within each group, 35.00% patients were MSIMI in CAD with depression/anxiety, 2.13% were in CAD without depression/anxiety, 14.29% were in depression/anxiety without CAD, and 2.38% were in control group. The risks of MSIMI in depression/anxiety without CAD and with CAD groups were 6.83 (P>0.05) and 22.08 times (P<0.05) higher than that in control group, respectively. Logistic regression showed that a 1-point increment in the GAD-7 score, but not PHQ-9 score [OR=0.95, 95% CI (0.77-1.17), P=0.63], was associated with 1.22-fold increase in the likehood of MSIMI [95% CI (1.07-1.38), P=0.00]. Conclusions: The MSIMI rate is much higher in patients with CAD comorbid depression/anxiety compared with CAD without depression/anxiety. Anxiety, but not depression, is an independent risk factor of MSIMI in CAD patients.

[Coronary microvascular resistance and its relevant factors in patients with moderate coronary stenosis and chest pain].

Objective: To evaluate the impact of cardiovascular risk factors on index of microvascular resistance (IMR) and coronary flow reserve (CFR) and to explore the characteristics of IMR and CFR and the relationship between IMR and angiographic features in patients with intermediate coronary stenosis and chest pain. Methods: Fractional flow reserve (FFR), CFR, and IMR were measured in patients who underwent invasive coronary angiography with 40%-70% stenosis by visual assessment. All patients with FFR>0.75 were enrolled and grouped with the cut-off points of IMR≥25 and CFR≤2.0. Patients with IMR≥25 were group H, including two sub-groups (high IMR-low CFR, group H1 and high IMR-high CFR, group H2), while those with IMR<25 were group N. The thrombolysis in myocardial infarction (TIMI) frame were counted. Results: A total of 34 patients with FFR>0.75 were enrolled with 61.8%(21 cases) of males and 38.2% (13 cases) of females. The mean age was (57.3±8.1) years old. High IMR accounted for 47.1% of all cases. There was significant difference between group H and N in TIMI frame (33.0 vs. 20.8, P=0.031). There were significant differences between group H1 and H2 in homocysteine (17.8 µmol/L vs. 12.0 µmol/L, P=0.005) and IMRcorr (58.0 vs. 36.1, P=0.002). IMRcorr was correlated to TIMI frame (r=0.40, P=0.012) for all cases. The sensitivity and specificity of inferring IMR≥35.3 by TIMI frame were 0.75 and 0.65 (P=0.049) with TIMI frame over 40.5. Conclusions: High IMR may be one of the reasons for chest pain in patients with intermediate coronary stenosis. There is no correlation between vascular risk factors and IMR or CFR, while there is positive correlation between TIMI frame and IMR. The specificity is 65% for inferring IMR rise with TIMI frame over 40.5.

Promoter and first exon methylation regulate porcine FASN gene expression.

DNA methylation is a stable epigenetic mark mediating gene expression. Methylation is crucial for diverse biological processes, including aging and embryo development. FASN (fatty acid synthase) plays an important role in de novo lipogenesis, through catalyzing the reductive synthesis of long-chain fatty acids. In this study, we investigated the FASN gene expression pattern and corresponding DNA methylation status in the inner layer of backfat from Jinhua pigs at different developmental stages. Our results showed that FASN gene expression increases with age and is positively associated with adipocyte volume (r = 0.98, P < 0.01). In addition, the DNA methylation level for the first exon (0.11, CGI 3) of the FASN gene is approximately 8-fold lower than levels for its promoter (0.94, CGI 1&2) (two-way ANOVA, PCGI < 0.01). The association analysis revealed that both promoter (r = -0.944, P < 0.01) and first exon methylation (r = -0.774, P < 0.01) are significantly and negatively correlated with FASN gene expression. Our results will benefit future investigations of the epigenetic mechanism underlying FASN gene expression.

[Effects of interleukin-4-modified gold nanozymes on the full-thickness skin defects in diabetic mice].

Objective: To investigate the effects and mechanism of interleukin-4-modified gold nanoparticle (IL-4-AuNP) on the wound healing of full-thickness skin defects in diabetic mice. Methods: Experimental research methods were adopted. Gold nanoparticle (AuNP) and IL-4-AuNP were synthesized by improving the methods described in published literature. The morphology of those two particles were photographed by transmission electron microscopy, and their particle sizes were calculated. The surface potential and hydration particle size of the two particles were detected by nanoparticle potentiometer and particle size analyzer, respectively. The clearance rate of IL-4-AuNP to hydrogen peroxide and superoxide anion was measured by hydrogen peroxide and superoxide anion kits, respectively. Mouse fibroblast line 3T3 cells were used and divided into the following groups by the random number table (the same below): blank control group, hydrogen peroxide alone group treated with hydrogen peroxide only, hydrogen peroxide+IL-4-AuNP group treated with IL-4-AuNP for 0.5 h and then treated with hydrogen peroxide. After 24 h of culture, the reactive oxygen species (ROS) levels of cells were detected by immunofluorescence method; cell count kit 8 was used to detect relative cell survival rate. The macrophage Raw264.7 mouse cells were then used and divided into blank control group and IL-4-AuNP group that treated with IL-4-AuNP. After 24 h of culture, the expression of arginase 1 (Arg-1) in cells was observed by immunofluorescence method. Twelve male BALB/c mice (mouse age, sex, and strain, the same below) aged 8 to 10 weeks were divided into IL-4-AuNP group and blank control group, treated accordingly. On the 16th day of treatment, whole blood samples were collected from mice for analysis of white blood cell count (WBC), red blood cell count (RBC), hemoglobin level, or platelet count and the level of aspartate aminotransferase (AST), alanine transaminase (ALT), urea, or creatinine. The inflammation, bleeding, or necrosis in the heart, liver, spleen, lung, and kidney tissue of mice were detected by hematoxylin-eosin (HE). Another 36 mice were selected to make diabetic model, and the full-thickness skin defect wounds were made on the back of these mice. The wounds were divided into blank control group, AuNP alone group, and IL-4-AuNP group, with 12 mice in each group, and treated accordingly. On the 0 (immediately), 4th, 9th, and 15th day of treatment, the wound condition was observed and the wound area was calculated. On the 9th day of treatment, HE staining was used to detect the length of neonatal epithelium and the thickness of granulation tissue in the wound. On the 15th day of treatment, immunofluorescence method was used to detect ROS level and the number of Arg-1 positive cells in the wound tissue. The number of samples was 6 in all cases. Data were statistically analyzed with independent sample t test, corrected t test, Tukey test, or Dunnett T3 test. Results: The size of prepared AuNP and IL-4-AuNP were uniform. The particle size, surface potential, and hydration particle size of AuNP and IL-4-AuNP were (13.0±2.1) and (13.9±2.5) nm, (-45.8±3.2) and (-20.3±2.2) mV, (14±3) and (16±4) nm, respectively. For IL-4-AuNP, the clearance rate to hydrogen peroxide and superoxide anion were (69±4)% and (52±5)%, respectively. After 24 h of culture, the ROS level of 3T3 in hydrogen peroxide alone group was significantly higher than that in blank control group (q=26.12, P<0.05); the ROS level of hydrogen peroxide+IL-4-AuNP group was significantly lower than that in hydrogen peroxide alone group (q=25.12, P<0.05) and close to that in blank control group (P>0.05). After 24 h of culture, the relative survival rate of 3T3 cells in hydrogen peroxide+IL-4-AuNP group was significantly higher than that in hydrogen peroxide alone group (t=51.44, P<0.05). After 24 h of culture, Arg-1 expression of Raw264.7 cells in IL-4-AuNP group was significantly higher than that in blank control group (t'=8.83, P<0.05).On the 16th day of treatment, there were no significant statistically differences in WBC, RBC, hemoglobin level, or platelet count and the level of AST, ALT, urea, or creatinine of mice between blank control group and IL-4-AuNP group (P>0.05). No obvious inflammation, bleeding or necrosis was observed in the heart, liver, spleen, lung, and kidney of important organs in IL-4-AuNP group, and no significant changes were observed compared with blank control group. On the 0 and 4th day of treatment, the wound area of diabetic mice in blank control group, AuNP alone group, and IL-4-AuNP group had no significant difference (P>0.05). On the 9th day of treatment, the wound areas both in AuNP alone group and IL-4-AuNP group were significantly smaller than that in blank control group (with q values of 9.45 and 14.87, respectively, P<0.05), the wound area in IL-4-AuNP group was significantly smaller than that in AuNP alone group (q=5.42, P<0.05). On the 15th day of treatment, the wound areas both in AuNP alone group and IL-4-AuNP group were significantly smaller than that in blank control group (with q values of 4.84 and 20.64, respectively, P<0.05), the wound area in IL-4-AuNP group was significantly smaller than that in AuNP alone group (q=15.80, P<0.05); moreover, inflammations such as redness and swelling were significantly reduced in IL-4-AuNP group compared with the other two groups. On the 9th day of treatment, compared with blank control group and AuNP alone group, the length of neonatal epithelium in the wound of diabetic mice in IL-4-AuNP group was significantly longer (all P<0.05), and the thickness of the granulation tissue in the wound was significantly increased (with q values of 11.33 and 9.65, respectively, all P<0.05). On the 15th day of treatment, compared with blank control group, ROS levels in wound tissue of diabetic mice in AuNP alone group and IL-4-AuNP group were significantly decreased (P<0.05). On the 15th day of treatment, the number of Arg-1 positive cells in the wounds of diabetic mice in IL-4-AuNP group was significantly more than that in blank control group and AuNP alone group, respectively (all P<0.05). Conclusions: IL-4-AuNP is safe in vivo, and can improve the oxidative microenvironment by removing ROS and induce macrophage polarization towards M2 phenotype, thus promote efficient diabetic wound healing and regeneration of full-thickness skin defects in diabetic mice.

Development of eddy current testing system for inspection of combustion chambers of liquid rocket engines.

An eddy current testing (ECT) system using a high sensitive anisotropic magnetoresistive (AMR) sensor was developed. In this system, a 20 turn circular coil with a diameter of 3 mm was used to produce the excitation field. A high sensitivity AMR sensor was used to measure the magnetic field produced by the induced eddy currents. A specimen made of copper alloy was prepared to simulate the combustion chamber of liquid rocket. Scanning was realized by rotating the chamber with a motor. To reduce the influence of liftoff variance during scanning, a dual frequency excitation method was used. The experimental results proved that ECT system with an AMR sensor could be used to check liquid rocket combustion chamber.

Note: A hand-held high-Tc superconducting quantum interference device operating without shielding.

By improving the compensation circuit, a hand-held high-Tc rf superconducting quantum interference devices (SQUID) system was developed. It could operate well when moving in unshielded environment. To check the operation, it was used to do eddy-current testing by hand moving the SQUID, and the artificial defect under 6 mm aluminum plate could be successfully detected in shielded environment.

An anisotropic magneto resistive sensor with set/reset field.

Using a set/reset magnetic field, an anisotropic magneto resistive (AMR) magnetic field sensing system was developed to reduce the low frequency noise of an AMR sensor. The magnetic field resolution of the AMR sensor was improved by about three times at the frequencies below 30 Hz and a magnetic field resolution of about 150 pT/√Hz was obtained at 1 Hz. For magnetic particle detection using an AMR sensor with set/reset method, the thermal disturbance effect was canceled well and the signal-to-noise ratio was improved by about three times.

Highly sensitive anisotropic magnetoresistance magnetometer for Eddy-current nondestructive evaluation.

Using a commercially available anisotropic magnetoresistance (AMR) sensor of HMC1001, we developed a sensitive magnetometer. It could operate in amplifier mode or feedback mode. The magnetic field sensitivity of the AMR sensor was about 3.2 mV/V G. When the AMR sensor was biased by a voltage of 24 V, the magnetic field resolutions of the AMR magnetometer were about 12 pT/square root(Hz) at 1 kHz and 20 pT/square root(Hz) at 100 Hz. We used the AMR magnetometer for Eddy-current nondestructive evaluation in unshielded environment.

Lepidopteran cell variants resistant to 5-bromodeoxyuridine and their use for transfection of the HSV-TK gene.

Following mutagenesis of cultured lepidopteran cells (Spodoptera frugiperda) by ethylmethanesulfonate, three variants resistant to 5-bromodeoxyuridine (BrdUrd) were isolated. These clones were 100- to 200-fold more resistant to BrdUrd than the parental cells and were shown to be deficient in thymidine kinase (TK). The drug-resistant phenotype was stable for up to three years of culture under nonselective conditions. It was also found that the S. frugiperda cell line was highly resistant to aminopterin. A selective medium was formulated and used to select herpes simplex virus thymidine kinase (HSV-TK) transfectants from the TK-deficient cells.

Expression of hepatitis B virus surface antigen gene in insect baculovirus vector systems.

The gene coding for the hepatitis B virus surface antigen (HBsAg) under the control of Autographa californicanuclear polyhedrosis virus polyhedrin promoter was successfully inserted into the genome of the Trichoplusia ni nuclear polyhdrosis virus. Infection of Spodoptera frugiperda cells with this recombinant virus produced a significant amount of HBsAg protein and secreted 22 nm particles containing the HBsAg. The expression of HBsAg gene was also obtained both in Trichoplusia ni larvae and in Philosamia cynthia ricini prepupae when infected with the recombinant virus. The HBsAg proteins expressed by baculovirus vector systems have morphological and antigenic properties identical to the 22 nm particles secreted by human cells.