Objective To study absorption characteristic of dioscin from Dioscorea nipponica Makino extract in rat intestine.Methods Single-pass intestinal perfusion (SPIP) model was used for rat in situ and HPLC was used to determine the concentrations of dioscin.The effects of different intestinal segments,drug concentration and P-glycoprotein (P-gp) inhibitor on intestinal absorption were investigated.Results Dioscin could be absorbed in the whole intestine,the absorption rate constant (Ka) and the apparent coefficient (Papp) of dioscin decreased following the sequence of ileum > duodenum =jejunum > colon.Absorption parameters of dioscin had no significant difference at different concentrations (40,80,120 mg·L-1).There were significant differences in Ka and Papp values between P-gp inhibitor group and no P-gp inhibitor group(P<0.05).Conclusion The saturate phenomena was not observed under the test range of drug concentration,and the absorption mechanism may be passive diffusion transport.Dioscin in Dioscorea nipponica Makino extract may be the substrate of P-gp.

Air Pollutants, Occupational ; analysis ; Chromatography, Gas ; methods ; Fluorocarbon Polymers ; analysis ; Workplace

BACKGROUND: Research has showed that the abnormal expression of some proteins closely relates to the occurrence and development of cerebral glioma. However, the relationship between the abnormal expression of CyelinD1protein and the occurrence, development and prognosis of glioma is still uncertain which needs further study.OBJECTIVE: To study the expression of CyclinD1 protein in cerebral glioma and relationship between it and the impact of tumor DESIGN: Control study based on pathological specimens.SETTING: Neurosurgery department of a university hospital.PARTICIPANTS: Totally 48 glioma specimens of different malignaut degree were collected from the patients who accepted surgery treatment in Neurosurgery Department of Second Hospital of Xi' an Jiaotong University during January 1990 and December 1995. Twelve normal cerebral specimens were from the non-tumor patients who were conducted intracranial pressure reducing in Neurosurgery Department of Second Hospital of Xi' an Jiaotong University during January 1990 and December 1995.METHODS: S-P immunohistochemical technique was used to detect the abnormal expression of Cyclin D1 protein. Simultaneously, the dyeing results and clinical characters of patients were associated in order to conduct comparison.RESULTS: The positive expression rate of CyclinD1 protein in human cerebral glioma was 54. 12% while in normal cerebral tissue it was about 8.33%. There was significant difference between them(x2 =8. 148 1,P = 0. 004 3 ) . And the positive expression rate in cerebral glioma of low malignancy was 37.04% while in specimens of high malignancy it was 76.19%, there was significant difference (x2 = 7. 294 0, P = 0. 006 9). The positive expression rate of CyclinD1 protein in specimens of patients with long survival period and short survival period after surgery was 70. 37% and 33.33% respectively with significant difference between them (x2 = 6. 5268,P =0.010 6).CONCLUSION: CyclinD1 is closely related to the occurrence and development of human cerebral glioma. It has provided experimental evidence for the prevention to the occurrence of glioma and the estimation of its prognosis by studying the abnormal proliferation of glioma cells targeted on CyclinD1.

AIM: To observe the effects of Salvia miltiorrhiza Bunge.f.alba. (Sal) on the mitochondrial ultra-structure, oxidative stress and apoptosis induced by ischemia injury in a rat model of focal cerebral ischemia and reperfusion.METHODS: The middle cerebral artery occlusion/reperfusion (MCAO/R) rat model was established by a modified Longa occlusion method. Adult male SD rats were randomly divided into control group, simple ischemia reperfusion group, Sal with ischemia reperfusion group and butylphthalide with ischemia reperfusion group. To study the protective effects of Sal and its mechanism, the intervention of Sal was given and the ultra-structure of mitochondria, functions of mitochondria under oxidative stress and the incidence of apoptosis of brain cells were determined.RESULTS: Many electron dense toxic granulation and vacuolus in mitochondria were observed in the rat brain of focal cerebral ischemia and reperfusion. Under the condition of ischemia and reperfusion, the mitochondria membrane was disaggregative, and the tubular cristae of mitochondrion disappeared. MDA content was obviously increased and the activity of glutathione peroxidase decreased significantly. The apoptosis of brain cells were observed in a great quantity. The changes of ultra-structure of mitochondria and the activity of GSH-Pxase were significantly improved by the treatment of Sal. Furthermore, treatment with Sal delayed the decrease of GSH-Pxase activity, and inhibited the increase in MDA content in brain tissue after ischemia and reperfusion. The incidence of apoptosis of brain cells was also decreased.CONCLUSION: Sal protects the brain tissue from ischemia injury.

Objective To investigate the predictive value of dose?volume histograms ( DVHs ) of organs at risk ( OARs ) including the bladder, rectum, and small intestine in volumetric modulated arc therapy ( VMAT) plans for cervical cancer. Methods A total of 100 VMAT plans for cervical cancer were assigned into the learning group. The correlation of the anatomical information with the V30 , V40 , and V50 values of the bladder, rectum, and small intestine was evaluated in the group. The support vector regression ( SVR) algorithm was used to establish the correspondence between the anatomical information and the DVHs of OARs. The DVHs of OARs in the verification group containing 20 VMAT plans were predicted based on the anatomical information. Results The DVHs of the bladder, rectum, and small intestine were likely to be influenced mainly by the spatial relationship between these OARs and target volume. In the verification group, the prediction errors of V30,V40 and V50 by SVR algorithm were-2.4%±3. 5%,-2.5%±3. 8%, and-1.5%±4. 9% for the bladder, 0.5%±2. 6%,-1.5%±5. 1%, and-2.0%±7. 4% for the rectum, and-2.9%± 5. 3%, 2.7%±7. 7%, and 5.3%±11. 1% for the small intestine, respectively. Conclusions After learning the correlation between the anatomical information and the DVHs of OARs from prior VMAT plans for cervical cancer, SVR algorithm can precisely predict the DVHs of the bladder, rectum, and small intestine based on the anatomical information.

Objective To find an efficient and practical reconstruction algorithm for the fluorescence molecular tomography basing on total leastsquares rule as well as the normalized conjugate gradient method.Methods The finite element method was used to get the weighting matrix from the forward diffusion model.For the inverse reconstruction problem,the total least-squares rule was employed.The normalized conjugate gradient method was applied to find the fluorochrome information in the objective area.Results The simulation experiments showed that images reconstructed by the total least-squares rule were more accurate than those reconstructed by the least-squares rule under the same circumstances when noise existed.The presented algorithm could also give consistent results when the initial guesses varied in a wide range.Conclusion The algorithm presented in this paper offers a practical and efficient reconstruction for the fluorescence molecular tomography.

By introducing the stage management of ethics review for medical research protocols,this paper try to explain the submission requirement,the review procedures,the key points for focusing on,and analyze the issues found in ethical reviewing of research protocols,help to guide the procedures of ethical review,as well as improve the supervision of ethical review for research protocols.

Objective To investigate the effect of pyrrolidine dithiocarbamate(PDTC) on monocyte chemotactic protein1 (MCP-1) in rejection of cardiac allograft and its mechanisms.Methods Heterotopic cervical heart transplantation was performed by cuff-technique.The SD rat recipients were randomly divided into 3 groups:AR group (Acute rejection,n =12),both the recipients and donors were without any treatment.CsA group(n =12),the recipients were treated with 10 mg/kg cyclosporine A after transplantation.PDTC group(n =12),the recipients were treated with 100 mg/kg PDTC after transplantation.All the cardiac allografts were harvested at different time post transplantation according to requirements.We studied allograft myocardial fibrosis wih the help of Masson stain,immuno-histo-chemistry and western blot also were used to detect the expression of MCP-1.Results The survival time of the cardiac allografts was significantly longer in PDTC group than in acute rejection group and CsA group(P ＜ 0.01),and myocardial fibrosis of cardiac allografts in PDTC group was significantly decreased (P ＜ 0.01).The IOD in PDTC group was markedly lower than in CsA group (P ＜ 0.01).Conclusion As the inhibitor of NF-κB,PDTC can significantly relieve rejection of cardiac allograft by inhibiting the expression of MCp-1.

Objective To prepare a redox-responsive doxorubicin-loaded nanoparticle,and to study its in vitro realease behavior and targeting effect on heptoma cells.Methods Cystamine was grafted on the side chains of hyaluronic acid with 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide catalyst,and then β-cyclodextrin (β-CD) was conjugated on the amine groups of the cystamine by Schiff's base reaction to prepare β-CD modified hyaluronic acid (HACD).The HACD/DOX nanoparticles were prepared by encapsulating DOX into HACD using dialysis method.The drug loading,encapsulation efficiency,particle size and distribution,zeta potential and other physical and chemical properties,as well as in vitro drug release behavior of the HACD/DOX nanoparticles were characterized.The cytotoxicity of HACD/DOX nanoparticles to HepG2 cells was studied by cell counting kit-8 (CCK-8) method.The targeting effect of HACD/DOX nanoparticles on HepG2 cells was studied using flow cytometry and confocal laser scanning microscopy (CLSM).Results HACD were successfully synthesized,which could carry DOX to form uniform homogeneous nanoparticles.The drug loading of DOX in the nanoparticles was (16.1±0.2)％ and the encapsulation efficiency was (64.2±0.9)％.The transmission electron microscope images indicated that the shape of the HACD/DOX nanoparticles was homogeneous sphere.The results of granularity analysis showed that the average size of the HACD/DOX nanoparticles was (203.1 ±2.5) nm with a narrow size distribution (PDI =0.202).The zeta potential of the HACD/DOX nanoparticles was (-29.1±0.8) mV.The in vitro release behavior of the nanoparticles exhibited obvious redox-sensitivity.The results of in vitro cytotoxicity showed that the blank carrier material HACD had no obvious toxicity to hepatoma cells,and the HACD/DOX nanoparticles could effectively kill hepatoma cells with the 0.38 μg/ml half maximal inhibitory concentration (IC50) value at 48 h.Flow cytometry and CLSM results demonstrated that the HACD/DOX nanoparticles could target hepatoma cells through the mediating effect of hyaluronic acid.Conclusions The prepared HACD/DOX nanoparticles have suitable particle size,high drug loading and encapsulation efficiency,and can release DOX under the stimulation of reducing agent.These nanoparticles have obvious targeting effect on hepatoma cells,which is expected to be applied as the drug delivery system of hepatocellular carcinoma (HCC) therapy.

Objective To explore application value of blood flow ratio indexes in the diagnosis of Hashimoto's thyroiditis(HT) with different thyroid functions.Methods One hundred and four patients who were diagnosed clinically as HT were enrolled in the study.The patients were classified into three groups according to thyroid functions:the hyperthyroidism group,the hypothyroidism group and the euthyroidism group.Thirty-two volunteers with normal thyroid functions were enrolled as control group.All the cases were examined with ultrasound and five blood flow ratio indexes were calculated automatically.Their differences in the four groups were compared.Results ①Among the five blood flow ratio indexes,three indexes(mean ratio,maxratio and minratio) had significant differences between each two groups(P ＜ 0.001),the other two indexes didn't have any differences among the four groups.②Two receiver operating characteristic (ROC) curves on meanratio were drew:a)HT with hyperthyroidism and HT with euthyroidism;b) HT with euthyroidism and HT with hypothyroidism.The cutoff value as a result of the ROC analysis of HT with hyperthyroidism and HT with euthyroidism was 0.235 with the maxim of specificity and sensitivity.The cutoff value of HT with euthyroidism and HT with hypothyroidism was 0.113 with the maxim of specificity and sensitivity.Both Bland-Altamn scatter diagrams and high intraclass correlation coefficient(ICC) showed that blood flow ratio indexes have high repeatability.Conclusions Blood flow ratio indexes are promising quantitative indexes in reflecting the vascularity of thyroid parenchyma,and they are helpful in the differential diagnosis of HT with different thyroid functions.