Study on biocompatibility of carbon-based composites / 生物医学工程学杂志

Silicon carbide (SiC) film and silicon dioxide (SiO ) film were deposited on the surface of carbon/carbon composite (C/C) by low pressure chemical vapor deposition (LPCVD). The biocompatibility of the three carbon-based composites, e. g. C/C, C/C-SiC, C/C-SiO were investigated by cytotoxicity test, cell direct contact and cell adhesion experiments. Cytotoxicity, cell direct contact and cell adhesion showed that the three materials had no toxic effect on mouse fibroblasts (L929 cells). However, the particles dropped off from the three materials had a great impact on evaluation accuracy of the thiazolyl blue (MTT) test. More the particles were lost, more growth inhibition to L929 cells. The evaluation accuracy of MTT method can be kept with the filtered extract of materials. Furthermore, the results of surface particles shedding experiment showed that the amount of surface particles shed from C/C-SiO was the most, followed by C/C and C/C-SiC in 72 hours. Particles shedding curves showed there was a peak reached at eighth hour and then declined to the thirty-sixth hour. The filtrate analysis showed that there was no ion exchange between the three materials and simulated body fluid (SBF) solution. The results of this study on biocompatibility of carbon-based composites have certain guiding significance for their future application in clinical filed.

Serum transthyretin in patients with different stages of diabetic retinopathy / 中华眼底病杂志

Objective To measure the concentration of serum transthyretin (TTR) of patients with different stages of diabetic retinopathy (DR).Methods A total of 176 patients with diabetes mellitus were included in this study.There were 104 males and 72 females.The patients aged from 21 to 74 years,with the mean age of(56± 11) years.The diabetes duration raged from 1 to 30 years,with the mean diabetes duration of (10 ± 7) years.The HbA 1C was 5.2％-14.1％,with the mean HbA 1C of (8.6 ± 2.0)％.According to the fundus examination,58 patients had DR (33.0％),but the other 118 patients not (67.0％).For these DR patients,10 patients were in stage Ⅰ (5.7％),26 patients in stage Ⅱ (14.8％),8 patients in stage Ⅲ (4.5％),and 14 patients in stage Ⅳ (8.0％).The concentration of serum TTR was measured by enzyme-linked immunosorbentassay kit.The differences in the concentration of serum TTR between different DR stages were compared.Bivariate analysis was used to analyze the influencing factors of TTR.Results The concentrations of serum TTR of the patients without DR or with DR of stage Ⅰ to Ⅳ were (224.96±65.47),(383.68± 102.99),(247.44±63.21),(228.2 ± 45.89),(189.34± 70.12) mg/L,respectively.The difference between different DR stages was statistically significant (F=14.690,P＜ 0.001).Bivariate analysis showed that the concentration of TTR was correlation to DR (r=0.179,P=0.017).There was no correlation between the concentration of TTR and diabetes duration (r=-0.027,P=0.727),hypertension (r=0.018,P=0.810),hyperlipoidemia (r=0.101,P=0.182),and the use of insulin (r=-0.032,P=0.675).Conclusion The concentration of serum TTR was increased in early DR patients,and gradually decreased with the progression of DR.The concentration of TTR is correlated to DR.

Application of Icare rebound tonometer in children after congenital cataract surgery / 中南大学学报(医学版)

OBJECTIVE@#To compare the difference in intraocular pressure (IOP) readings as well as the tolerability between Icare rebound tonometer (Icare RBT) and Goldmann applanation tonometer (GAT), and to evaluate the application of Icare RBT in monitoring the intraocular pressure in children after congenital cataract surgery.@*METHODS@#The IOP was measured with the Icare RBT and GAT respectively in 150 children (262 eyes) after congenital cataract surgery by two experienced ophthalmologists. Correlation and Bland-Altman analysis were used to assess the agreement in IOP readings between the two instruments. The influence of the central corneal thickness (CCT) adjusted for age on IOP readings was analyzed by linear regression analysis. The tolerance of the patients to Icare RBT and GAT measurement were surveyed.@*RESULTS@#The mean age was (44.82 ± 11.56) months in 150 children, including 81 boys and 69 girls. The mean IOP readings by the Icare RBT and GAT were (16.08 ± 5.72) mmHg and (14.17 ± 5.05) mmHg, respectively. The mean difference between the Icare RBT and GAT was (1.91 ± 2.04) mmHg, which was significantly correlated with CCT (r=0.409, P<0.001). The IOP readings by Icare RBT was significantly correlated with that measured by GAT(r= 0.936, P<0.001). The 95% confidence interval of the difference between the two instruments was ?2.10 to 5.91 mmHg. The Icare RBT examination was well tolerated by the children compared to the GAT examination.@*CONCLUSION@#The Icare RBT is easy to use and well tolerated by the children after congenital cataract surgery. Compared to GAT, the value measured by the IOPs trends to be overestimated. The difference in readings between the 2 tonometers will magnify with the increase in CCT.

The value of virtual touch tissue quantification in the diagnosis of pancreas early damage of patients with hyperuricemia / 中华超声影像学杂志

Objective To explore the value of virtual touch tissue quantification (VTQ ) in the diagnosis of pancreas early damage of patients with hyperuricemia(HUA) .Methods Sixty‐five cases of patients with normal glucose tolerance and HUA (HUA group) and 42 cases of patients with HUA and impaired glucose tolerance (IGT group) were included in the study ,and other 150 health subjects were taken as control group .After routine ultrasound examination ,the pancreas shear wave velocity values (Vs) of different groups were measured by VTQ technology ,and the results were analyzed .Results Compared with the control group ,the rate of the abnormai ultrasonogram of pancreas in IGT group showed obvious increasing trend but there was no significantly difference between the other groups(both P >0 0.5) .The Vs of the normal control group ,HUA group ,and IGT group were (1 2.1 ± 0 1.5)m/s ,(1 4.1 ± 0 1.3)m/s and (1 5.9 ± 0 1.5)m/s ,respectively .The Vs of HUA group and IGT group were higher than that of the control group (both P <0 0.5) ,and the Vs of IGT group was significantly higher than that of HUA group ( P <0 0.5) .Conclusions Hyperuricemia may cause pancreas damage ,and with the disease progress ,the pancreas damage became more serious ,and VTQ technology may play an important role on the diagnosis of pancreas early damage in HUA patients .

EEG-EMG coherence analysis of different hand motions in healthy subjects / 生物医学工程学杂志

It is the functional connectivity between motor cortex and muscle that directly relates to the rehabilitation of the dysfunction in upper limbs and neuromuscular activity status, which can be detected by electroencephalogram-electromyography (EEG-EMG) coherence analysis. In this study, based on coherence analysis method, we process the acquisition signals which consist of 9 channel EEG signal from motor cortex and 4 channel EMG signal from forearm, by using 4 groups of hand motions in the healthy subjects, including flexor digitorum, extensor digitorum, wrist flexion, and wrist extension. The results showed that in the β-band, the coherence coefficients between C3 and flexor digitorum (FD) was greater than extensor digitorum (ED) in the right hand flexor digitorum movement; the coherence coefficients between C3 and ED was greater than FD in the right hand extensor digitorum movement; the coherence coefficients between C3 and flexor carpi ulnaris (FCU) was greater than extensor carpi radialis (ECR) in the right hand wrist flexion movement; the coherence coefficients between C3 and ECR was greater than FCU in the right hand wrist extension movement. This analysis provides experimental basis to explore the information decoding of hand motion based on corticomuscular coherence (CMC).

Quantitative evaluation of carotid elasticity in patients with hyperuricemia by echo-tracking technology / 中华超声影像学杂志

Objective To investigate the clinical value of echo-tracking(ET) technique in evaluating the carotid elasticity in patients with hyperuricemia and hyperuricemia combined with hyperlipidemia.Methods One hundred and twenty patients with hyperuricemia were divided into two group:group of hyperuricemia (group A) and group of hyperuricemia combined with hyperlipidemia (group B).Sixty normal persons were served as the control group.ET was used to measure the carotid artery elastic modulus including stiffness parameters (β),pressure-strain elastic modulus (Ep),arterial compliance (AC),augmentation index (AI) and pulse wave conducting velocity (PWVβ).Then the statistical data were analyzed to observe the changes of each parameter.Results In the comparison of three groups,elastic function index β,Ep,PWVβ and AI in group A and group B were higher than those of control group (P ＜0.05) ;however,AC was lower than that of control group (P ＜ 0.05).Compared with group A,elastic function index β,Ep,PWVβ,AI was higher in group B,while the AC was lower than that of group B (P ＜0.05).Conclusions ET may be helpful to prevent atherosclerotic changes and to provide the basis for the clinical diagonosis and treatment atherosclerotic changes.

Pattern visual evoked potentials in normal-vision eyes of post-therapy amblyopia / 中南大学学报(医学版)

Objective:To evaluate the clinical significance of pattern visual evoked potential (P-VEP) parameters on amblyopic patients with normal-vision atfer pleoptic therapy. Methods:We investigated 60 amblyopic children (8-12 years old) who gained normal-vision atfer pleoptic therapy. hTese patients were assigned to a unilateral amblyopia group (40 patients)and a bilateral amblyopia group (20 patients). Another 20 healthy children served as a control group. All patients underwent a full initial ophthalmologic and orthoptic evaluation. P-VEP test was performed in all. Amplitude and latencies were analyzed and compared among groups. The latencies of P100 waves in the amblyopic eyes were used to generate a multiple linear regression formula from sex, ifrst treatment age, baseline visual acuity, and cycloplegic refraction. Results:hTere was no signiifcant difference in the mean levels of best-corrected visual acuity among groups (P>0.05). A signiifcant prolongation of the latency and a decrease of amplitude of P100 waves were observed in the unilateral amblyopia group and the bilateral amblyopia group compared with the healthy control group (P<0.05). Amplitude and latencies of the fellow eyes in the unilateral amblyopia group were abnormal compared with the healthy control group (P<0.05). Multiple linear regression analysis revealed that the latencies of P100 waves were signiifcantly correlated with the ifrst treatment age, baseline visual acuity, and cycloplegic refraction (R2=0.52, P<0.05). Conclusion:Deifcits exist in the fellow eyes and in normal-vision eyes atfer pleoptic therapy. hTe delayed P100 latency is affected by the ifrst treatment age, baseline visual acuity, and cycloplegic refraction. Traditional amblyopic therapy may be not enough for vision function recovery.

Comparison of growth of human fetal RPE cells on electrospun nanofibers and etched pore polyester membranes / 中南大学学报(医学版)

OBJECTIVE@#To investigate and compare the growth of human fetal retinal pigment epithelial (RPE) cells seeded onto electrospun polyamide nanofibers (EPN) or etched pore polyester (EPP), and, further, to explore their possible use as prosthetic Bruch's membrane.@*METHODS@#Human fetal RPE cells were planted onto the EPN, EPP and plastic (control) substrates in Transwells. The cultures were assessed with respect to cell attachment at 2, 4, 8 hours and proliferation at 1, 4, 8 days after seeding. Growth and morphology of the cells were monitored under the phase contrast microscope, and the phenotype was identified by immunofluorescence staining with antibodies against tight junction protein ZO-1. Strips of single EPP coated with nothing or EPP coated with EPN was differently implanted into the subretinal space of two P21 RCS rats for two weeks and the histologic slides of the retina were assessed.@*RESULTS@#Cultured human fetal RPE cells were attached to either EPN or EPP substrates (with seeding on plastic substrate as control). After 8 h, the numbers of adherent cells in the EPN, EPP and control groups were 1.23*10(5)/cm(2), 1.70*10(5)/cm(2), and 1.64*10(5)/cm(2), respectively. The number of RPE cells attached to EPN was obviously less than that to both EPP and control (P<0.05). On the first day, the proliferation of cells on EPN was less than that of EPP and control (P<0.05); but by the 8th day in culture, the proliferation of cells on EPN had increased and was higher than proliferation on both EPP and control (P<0.05). All of the RPE cells cultured on EPN and EPP substrates were in monolayer, and the EPN-attached cells resembled the inner collagenous layer of Bruch's membrane. Immunofluorescence staining showed that the RPE cells cultured on EPN and EPP substrates adopted a higher expression of ZO-1 than that on the plastic control substrate. Subretinal implantation of either EPP alone or EPP as a carrier for free EPN for 2 weeks in P21RCS rats resulted in an expected encapsulation and loss of photoreceptor layer. No toxicity or other adverse reaction was observed in the vicinity of the transplant.@*CONCLUSION@#EPN and EPP could maintain human fetal RPE cell attachment and proliferation. Both EPN and EPP appeared to be grossly tolerance and biocompatible with subretinal implantation. EPN represents an intriguing prospect for prosthetic Bruch's membrane replacement because of its similarity in structure to native Bruch's membrane.

Analysis of scientific research awards in Xi'an health organizations during 1980-2009 / 中华医学科研管理杂志

Based on the released statistics from 1980 to 2009,this article summarized the scientific research awards gained by Xi' An health-related organizations. The analysis was mainly focused on the achievements of subordinate organizations of the city Health Bureau.In the end,the author discussed about the awards in aspects of quantity,level,institution,descipline,specialty and talents.

The effect of hypoxia on proliferation of cultured bovine retinal pigment epithelial cells and expression of the antiapoptotic protein bcl-2 / 中华眼底病杂志

Objective To study the effect of hypoxia on proliferation of cultured bovine retinal pigment epithelium (RPE) cells and expression of the antiapoptotic protein bcl-2. Methods The bovine RPE cells were cultured under normal and hypoxic chamber respectively. After 24 hours, the proliferation of RPE cells was evaluated by[3-(4,5-dimethylthiazole-2yl)-2,5-diphenyl tetrazolium bromide, MTT]-test. At the same time, anti-bcl-2 protein antibody was examined by immuno-histochemistry method. Results The A value in the hypoxia group was higher than that in the normal group after 24 hours (P

Effects of pulse pressure on coronary artery disease / 西安交通大学学报(医学版)

Objective To study the effects of pulse pressure (PP) on coronary artery disease. Methods High and low systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) were measured in 221 cases with coronary heart disease diagnosed by coronary artery radiography, and the differences of coronary artery count, score, and clinic features were analyzed. Results ① Compared with low SBP group \[81mmHg)) were older in age, with higher percentage of females and lower incidence of unstable angina pectoris(UA) and acute myocardial infarction(AMI). ② Compared with low PP group(