Objective To investigate the impact of tube current and tube voltage on CT attenuation,the correlation between CT attenuation and iodine concentration,as well as the percentage of reducing dosage for contrast agent while reducing the tube voltage.Methods A total of 100 saline solutions with decreasing dilution of contrast medium,in which concentration was between 0.5 to 50.0 mg/ml with the interval of 0.5 mg/ml,was produced.Each of the 25 syringes with a 4 ml sample was fixed on a cylindrical CT calibrated water phantom with an equal distance used the tape.CT scans were performed with a total of 15 scanning methods of the combination of the different tube voltages (70,80,100,140 kV) and tube current (100,200,280 mA).All of the CT attenuations were measured and recorded.The differences of CT attenuations under different scanning tube currents and tube voltages were compared with one-way ANOVA.The Pearson correlation analysis was used to analyze the relationship between CT attenuation and iodine concentration,and linear correlation equations were calculated and shown by regression analysis.According to the equations,the changes of contrast medium dosage were calculated with the changes of tube voltage.Results There was no significant difference in CT attenuations on different tube currents when the tube voltage was fixed (all P＞0.05),while when the tube current was fixed,the difference of CT attenuations on different tube voltages was statistically significant (all P＜0.05).Under different scanning conditions,the CT attenuations was linearly related to the iodine concentration (r2 was 0.953 to 0.997,all P＜0.01).While the tube voltage was reduced from 140 kV to 120 kV,100 kV,80 kV,70 kV,respectively,the iodine concentration of the samples were reduced by 15.4％,33.7％,53.4％,64.7％ respectively.While the voltage was reduced from 120 kV to 100 kV,80 kV,70 kV,respectively,the iodine concentration were rednced by 21.6％,44.9％,58.2％,respectively.While the voltage was reduced from 100 kV to 80 kV and 70 kV,the iodine concentration was reduced by 29.7％ and 46.7％,respectively.While the voltage was reduced from 80 kV to 70 kV,the iodine concentration was reduced by 24.1％.Conclusion CT attenuation can keep constant in low tube voltage setting by reducing the dosage of contrast agent,which can achieve a low radiation dose and low contrast agent dosage.

To date, multiple genetic susceptible genes/loci associated with rheumatoid arthritis (RA) have been identified and confirmed through large-scale genetic association studies and genome-wide association study (GWAS). However, the heritability of RA could be not fully explained by these genetic factors, and gene-gene interaction might account for part of the missing heritability. Indeed, genetic interaction study is a critical research direction in the field of genetic epidemiology of RA, and these studies have provided novel insights into the genetic basis and pathogenesis of RA. Additionally, these studies have also provided scientific reference for risk prediction and prevention of RA. This review is aimed to present a summary of recent progress in genetic interaction study of RA, thus implicate further research in this field.

AIMTo synthesize four water-soluble metal porphyrins [5, 10, 15, 20-tetra[4-(4'-pyridine-1) butyloxy phenyl] metalloporphyrins bromide, metal = Zn (I), Cu (II), Mn (III) and Co (IV)] as analogous enzyme having two anti-active oxygen functions.

METHODSThe first function, scavenging O2-, has been proved by using riboflavine-methionine photoreduction methods. The second function, scavenging H2O2, has been demonstrated by using the oxidating Vit C. The third function, scavenging HO*, has been demonstrated by using Fenton reaction. The complexes were measured by the mice liver homogenate technique of mice.

RESULTSFour model compounds could scavenge O2- in the concentration range of 1.0 x 10(-5) - 1.0 x 10(-6) mol x L(-1), decompose H2O2 in the concentration of 1.5 x 10(-6) - 1.0 x 10(-6) mol x L(-1), scavenge HO* in the concentration of 2.0 x 10(-8) - 1.0 x 10(-8) mol x L(-1). All showed that they had obvious action of decreasing the lipid peroxidation in the concentration of 1.0 x 10(-7) mol x L(-1).

CONCLUSIONAll above-mentioned complexes were considered to be qualified analogous enzymes of anti-active oxygen.

Animals ; Cobalt ; Copper ; Free Radical Scavengers ; chemical synthesis ; pharmacology ; Hydrogen Peroxide ; metabolism ; Hydroxyl Radical ; metabolism ; In Vitro Techniques ; Lipid Peroxidation ; drug effects ; Liver ; metabolism ; Malondialdehyde ; metabolism ; Manganese ; Metalloporphyrins ; chemical synthesis ; pharmacology ; Mice ; Reactive Oxygen Species ; metabolism ; Zinc

OBJECTIVETo investigate the possible pathways for ovarian injury after administration of cyclophosphamide in rats.

METHODSAdult SD rats received a single injection of saline vehicle or chemotherapeutic agent cyclophosphamide, and 8 weeks later, the ovaries were removed, fixed and serially sectioned for pathological examination and ovarian follicle counting. The expression of stem cell factor (SCF) protein was evaluated by immunohistochemistry and immunoreactive score, and SCF mRNA expression determined by RT-PCR in rat ovaries.

RESULTSCyclophosphamide had a detrimental effect on ovarian stromal function and lead to primordial follicle loss. Immunoreactive SCF antigens were expressed on the oocytes in the primordial and primary follicles of rat ovaries, and also in the granulosa cells of the secondary follicles and early antral follicles. There was a higher granulosa SCF, lower oocyte SCF and higher SCF mRNA level in the ovaries of the rats exposed to cyclophosphamide as compared with those in control rat ovaries (P <0.05).

CONCLUSIONAltered SCF expression in the ovaries of rats exposed to cyclophosphamide can be helpful for understanding the mechanisms for chemotherapeutic drug-induced ovarian damage.

Animals ; Cyclophosphamide ; adverse effects ; Female ; Gene Expression ; drug effects ; Granulosa Cells ; drug effects ; metabolism ; Oocytes ; drug effects ; metabolism ; Ovary ; cytology ; drug effects ; injuries ; metabolism ; Rats ; Rats, Sprague-Dawley ; Stem Cell Factor ; genetics ; metabolism

[Objective]To explore the effects of family cohesion and child-teacher dependency on children's attention-deficit/hy?peractivity behaviors at one year after their kindergarten entry.[Methods]Based on a cohort of 7465 first-year preschoolers in Long?hua district of Shenzhen in 2014,the information about social-demographic characteristics,family cohesion(assessed with Family Environment Scale-Chinese Version)were collected from their primary-caregivers at kindergarten entry. The teacher rating scores of child-teacher dependency(assessed with Student-Teacher Relationship Scale)and parental rating scores of attention-deficit/hyperac?tivity behaviors(assessed with Conners'Parent Symptom Questionnaire)were examined at one year after their kindergarten entry. Lo?gistic regression were performed to analyze the relationship and interaction between family cohesion and child-teacher dependency in attention-deficit/hyperactivity behaviors,after adjusting for potential confounders.[Results]Children's attention-deficit/hyperactivity behaviors at one year after kindergarten entry were negatively associated with family cohesion (OR=0.85,95% CI=0.75~0.97,P=0.01),but were not significantly associated with child-teacher dependency(OR=1.00,95%CI=0.93~1.08,P=0.98). Furthermore, family cohesion moderated the impact of child-teacher dependency on children ' s attention-deficit/hyperactivity behaviors at one year after kindergarten entry(OR=0.96,95% CI=0.92~0.99,P=0.03). In addition,neither family cohesion(OR=1.08,95%CI=0.88~1.34,P=0.47)nor child-teacher dependency(OR=1.03,95%CI=0.93~1.15,P=0.53)could protect preschoolers from persistence of attention-deficit/hyperactivity behaviors in the first year of kindergarten.[Conclusion]The association of child-teacher dependency and onset of attention-deficit/hyperactivity behaviors is modified by the level of family cohesion in preschool children.

Objective:To assess the cardiac autonomic nervous function in elderly patients with frailty.Methods:Patients aged ≥ 65 years old admitted in Beijing Hospital from September 2018 to August 2019 were enrolled in this study. Clinical frailty score was used to assess the frailty. The cardiac autonomic modulation was evaluated by sinus heart rate turbulence analysis through 24 h electrocardiogram recording.Results:A total of 129 elderly patients were finally enrolled in this study with a mean age of (77.5±6.4) years, 58.1% of them were male. There were 53 patients in frail group and 76 patients in non-frail group. The age of the frailty group was significantly higher than that of the non-frailty group [(80.5±5.5) vs.(75.3±6.2)]; the prevalence of hypertension [84.9%(45/53)], heart failure [32.1%(17/53)] and peripheral vascular diseases [32.1%(17/53)] in the frailty group was significantly higher than that in the non-frailty group [65.8%(50/76), 1.3%(1/76), 17.1%(13/76); t=5.001, χ 2=5.879, 24.606, 3.921; all P<0.05]. Compared with non-frailty group, turbulence onset (TO) [-0.05(-0.92, 0.82)% vs. -0.74(-1.58, 0)%; Z=2.616, P=0.009] was significantly higher in frailty group, while turbulence slope (TS) [2.34(1.30, 5.00)ms/RR vs. 4.34(2.66, 6.39)ms/RR; Z=-3.048, P=0.002] was significantly lower. The rate of TO abnormality [49.1% (26/53) vs. 26.3%(20/76), χ 2=7.038, P=0.008] and TS abnormality [34.7%(29/53) vs. 21.0%(16/76); χ 2=15.579, P<0.001] in the frailty group was significantly higher than that in the non-frailty group. Multivariate logistic regression analysis showed that TO abnormality( OR=2.970, P=0.010, 95 %CI:1.300-6.785) and TS abnormality( OR=3.618, P=0.003, 95 %CI:1.565-8.364) were correlated with frailty. Conclusion:Cardiac autonomic nerve function may be impaired in elderly frail patients, and decreased vagal nerve tension may be presented.

Objective To evaluate the effectiveness of single nucleotide polymorphism （SNP） genoty-ping in combination with identity by state （IBS） strategy in full sibling testing. Methods Thirty-five blood samples were collected from a four-generation family. Ninety autosomal SNPs were genotyped using Precision ID Identity Panel. The distribution of IBS scores for full siblings and other relationships were calculated and compared. The relationships were determined using Fisher discriminant function and threshold method, respectively. Results Based on family members and previous research, 44, 30, 111, 71 and 1 000 pairs of full siblings （FS）, grandparent-grandchild （GG）, uncle/aunt-nephew/niece （UN）, first cousins （FC） and unrelated individuals （UI） were obtained, respectively. The average IBS scores were 148, 130, 132, 124 and 120, respectively. Except for the GG and UN pairs, the distribution differences among the other relationships had statistical significance （P<0.05）. The false rates of Fisher discriminant function to determine relationships were 1.3%, 22.3%, 17.0% and 38.7% for FS, GG, UN and FC, respectively. Based on the simulation data, the thresholds t₁=128 and t₂=141 were recommended to determine full sibling relationships （the false rate ≤0.05%）. Conclusion The 90 SNP genetic markers included in the Precision ID Identity Panel meet the testing requirements for full sibling relationships. The threshold method based on IBS has a relatively lower false rate and is more flexible.
Genotype ; Genotyping Techniques/methods* ; Humans ; Polymorphism, Single Nucleotide/genetics* ; Siblings

Objective: To clarify correlation between lipoprotein subfraction and different age of coronary heart disease. Methods: A total of 1217 patients with coronary angiography (CAG) confirmed CAD were consecutively enrolled. According to onset age, the patients were divided into 3 groups: Very early CAD group, n=135 patients, ≤45 years, Early CAD group, n=505 patients, male at (45-55) years and female at (45-65) years, Late CAD group, n=577 patients, male>55 years and female>65 years. Meanwhile, there was a Control group, n=72 subjects, ≤45 years with normal CAG. The Lipoprotein system was used to classify lipoprotein subfractions and to analyze the distributions of different particles of high-density lipoprotein (HDL) subfraction and low-density lipoprotein (LDL) subfraction in above 4 groups; to explore the relationship between HDL subfraction and very early CAD occurrence. Results: Compared with other groups, Very early CAD group had decreased large particle of HDL subfraction and increased small particle of LDL subfraction, P<0.05. Logistic regression analysis found that the large particle of HDL subfraction was negatively related to very early CAD occurrence (OR=0.872, 95% CI 0.825-0.922), small particle of LDL subfraction was positively related to very early CAD occurrence (OR=1.038, 95% CI 1.008-1.069). Further multivariate Logistic regression analysis indicated that only large particle of HDL subfraction was obviously negatively related to very early CAD occurrence (OR=0.899, 95% CI 0.848-0.954). Conclusion: Large particle of HDL subfraction was negatively related to very early CAD occurrence which implied it played an important role in very early CAD process.

Objective:To assess the correlation between frailty and cardiac autonomic nervous system function in elderly patients.Methods:Elderly hospitalized patients aged 65 years and over were enrolled and assessed for frailty by using the clinical frailty scale.Cardiac autonomic modulation was evaluated by heart rate variability analysis through 24 h electrocardiogram recording.Results:A total of 180 elderly patients were enrolled in this study, including 66 patients with frailty and 114 patients without frailty.The mean age of the frailty group was higher than that of the non-frailty group(79.8±6.0 vs.75.0±6.3, t=5.030, P<0.001). The proportions of patients with hypertension, stroke/transient cerebral ischemia attack(TIA), heart failure and osteoarthritis were higher in the frailty group than in the non-frailty group(all P<0.05). Compared with the non-frailty group, the standard deviation of normal-to-normal intervals(SDNN)[103.0(76.0, 121.2) vs.107.5(92.0, 136.0), Z=-2.108, P=0.035], the standard deviation of the averages of NN intervals in all 5-min segments(SDANN)[86.0(67.7, 106.5) vs.97.5(78.0, 126.0), Z=-2.694, P=0.007], normalized low frequency(LFnorm)(53.1±13.0 vs.59.3±13.9, t=-3.024, P=0.003)and low frequency/high frequency(LF/HF)ratio[1.2(1.0, 1.4) vs.1.4(1.1, 1.7), Z=-3.041, P=0.002]were decreased and normalized high frequency(HFnorm)(36.8±9.2 vs.32.2±10.7, t=3.033, P=0.003)was increased in the frailty group.HFnorm in the frailty group was significantly higher than that in the non-frailty group.The incidents of SDANN<92 ms, LFnorm<50 nU, HFnorm>32 nU and LF/HF ratio<1.5 were higher in the frailty group than in the non-frailty group(59.1% or 39/66 vs.41.2% or 47/114, 42.4% or 28/66 vs.22.8% or 26/114, 72.7% or 48/66 vs.49.1% or 56/114, 84.8% or 56/66 vs.65.8% or 75/114, χ2=5.346, 7.660, 9.547, 7.664, P=0.021, 0.006, 0.002, 0.006). Logistic multivariate regression analysis showed that LFnorm, HFnorm and LF/HF ratio were correlated with frailty( OR=0.971, 1.039 and 0.333, all P<0.05), and HFnorm>32 nU and LF/HF ratio<1.5 were risk factors for frailty( OR=2.401 and 2.773, both P<0.05). Conclusions:Cardiac autonomic nerve system function is impaired in elderly frail patients, with the imbalance between the sympathetic and vagus nerves.Therefore particular attention should be paid to heart rate variability in elderly patients with frailty.

Objective: To study the effects of regenerated tissue extracts after liver injury on the proliferation, differentiation, migration and invasion of SK-HEP1 cells. Methods: Regenerated tissue extracts after liver injury were used to induce SK-HEP1 cells after enrichment, their effects on the proliferation, differentiation, migration and invasion of SK-HEP1 cells were observed through in vitro cell culture, MTT, flow cytometry and transwell assays. Results: In response to the action of regenerated tissue extracts after liver injury, SK-HEP1 cells were blocked in G