OBJECTIVE: 1H-NMR (Nuclear Magnetic Resonance Method) was used to quantitatively determine the MePEG (me-thoxy polyethylene glycol) content and chain density on MePEG-PLGA-NP surface, and study the influences of MePEG molecular weights and proportion on the chemical and physical properties of MePEG-PLGA-NP surface. METHODS: MePEG-PLGA-NP were prepared by self-emulsion solvent diffusion method with methoxy polyethylene glycol-poly(lactic acid-hydroxyl acid) copolymer (Me-PEG-PLGA) as the carriers. And the particle average size and Zeta potential were characterized. 1H-NMR method were used to ascertain the composition of the MePEG-PLGA copolymer and determine the MePEG content and chain density on the MePEG-PLGA-NP surface, and compared with colorimetric assay. RESULTS: The composition of MePEG-PLGA copolymer are basically the same with the labelled amount. When the Molecular weight is at the same, along with the increase of proportion of MePEG, the average size of MePEG-PLGA-NP decrease, the absolute value of the Zeta potential also decrease gradually, MePEG content on particles surface (α) increase gradually, the MePEG chain density on nanoparticles surface (δ) increase gradually, the distance between two adjacent MePEG chains on the surface of the particles (D) decrease; When there is the same proportions, with MePEG chain length increases, nanoparticles are not significantly different on the particle average size and the Zeta potential, whereas α increase gradually, the δ decreases, and D increases; Theavalue of the same MePEG-PLGA-NP determined by colorimetric assay is higher than which is determined by 1H-NMR. CONCLUSION: 1H-NMR method can be used to quantitatively determine the MePEG content and chain density on MePEG-PLGA-NP surface; Compared with the traditional method, the results determined by 1H-NMR method are more accurate. With the experimental limits, MePEG molecular weighs and proportion have influences on the chemical and physical properties of MePEG-PLGA NP surface, such as mean size, Zeta potential and the MePEG content and chain density on nanoparticles surface. Copyright 2012 by the Chinese Pharmaceutical Association.

Objective To analyze sampling frequency and grid density frequency on the computed radiography(CR)system and to develop an effective method to suppress or eliminate grid artifacts.Methods To test grids with different grid-density in combination with IP boards of different specifications. Radiographic images with various qualities were obtained by simulating two kinds of signaling frequencies (namely two kind of grids with different grid densities),and utilizing three kinds of sampling frequencies (6,8,10 pixels/mm).A variety of different simulation images were obtained.Results By comparing simulation images with actual images,it was discovered that correct signaling frequency could be achieved if the sampling frequency were equal to twice the signaling frequency.The obtained image was clear and free of grid artifact.A grid density of

Diabetic retinopathy is one of the most common and serious microvascular complications of diabetes, and it is a very complex pathological process, displaying multi-factor, multi-stage characteristic in the outcome. Recent studies have shown that the pathogenesis of diabetic retinopathy is closely related to oxidative stress, and antioxidant therapy can effectively improve the condition. Heme oxygenase-1(HO-1)is a widely existing antioxidant defense enzyme, which can reduce the injury caused by oxidative stress and plays an important physiological role. Studies have indicated that in retina HO-1 can be highly induced by hyperglycemia. Moreover, the expression level of HO-1 by man-made changes can accelerate or postpone the diseases progression. That means HO-1 for the diagnosis and treatment of diabetic retinopathy has satisfactory applied foreground. In this article we would like to review the role of HO-1 in diabetic retinopathy.

Objective To propose the concept of “Diffusion Index”to replace Oxygenation Index as independent indicators to evaluate prognosis on ARDS patients under mechanical ventilation treatments,and comparison carried out between them preliminarily.Methods Calculation of “1 000 × (PaO2 /FiO2 /PEEP)”was taken as “Diffusion Index”.A total of 130 ARDS patients under mechanical ventilation support (MVS)were admitted to Peking Union Medical College Hospital ICU from July 2013 to July 2014.The data of these patients were retrospectively analyzed.Of them,15 patients were excluded because these patients refused invasive ventilation support.Respirator parameter setting and haemogas figures were recorded accordingly. Both Diffusion Index and Oxygenation Index were used separately to predict detachment of MVS from patients in 28 days,and the correlation between these two indexes and ARDS prognosis were determined.Results According to the outcomes of patients in 28 days,patients were divided into 3 groups:detached group (n =44),failed to detach group (n =14)and death group (n =57).There was obvious difference in trend diagrams observed among three groups between diffusion index and oxygenation index.COX regression analysis of survival curve demonstrated that if Diffusion Index kept greater than 405.8,probability of detachment of MVS from patients was higher and the correlation was significant (P =0.009 ).Conclusions Compared with Oxygenation Index,“Diffusion Index” is a comprehensive indicator for ARDS prognosis with better reliability and validity.

Objective To investigate the characteristics of coronary's pathological changes in patients with impaired glucose tolerance. Methods Four-hundred and ninety patients who were suspected with ischemic chest pain were divided into three groups according to their OGTT results: (1) IGT group: n = 161,(2) 12DM group:n = 159, (3) NGT group: n = 170. Serum levels of triglyceride (TG) , total cholesterol (TC) , highdensity lipoprotein cholesterol (HDL-C) , low-density lipoprotein cholesterol (LDL-C) and high sensitive Creactive protein (hs-CRP) were detected, their body mass indexes (BMI) were calculated. General clinical information (including gender, age, history of smoking, history of hypertension) were collected. All the CAG results were analyzed and Gensini scores were assessed as well. Results The TG levels in the T2DM group and IGT group ([2. 41 ± 1.70] mmol/L and [2. 26 ± 1. 20] mmol/L) were significantly higher than that of the NGT group (1.95 ± 1.14) mmol/L, the differences were significant (t=0.4610,0.3124, P<0. 01 and 0.05,respectively),whereas there was no significant difference between the IGT group and T2DM group (P >0.05);No significant difference was found among the three groups about TC, HDL-C, LDL-C levels (either P > 0.05). The levels of hs-CRP in T2DM group ([2. 38 ± 1. 76] mg/L and IGT group [2. 33 ± 2. 03] mg/L) were higher compared with the NGT group ([1. 54 ± 1. 32] mg/L), the differences were significant (t = 0. 8391,0. 7815, Ps < 0. 01), whereas there was no significant difference between the IGT group and T2 DM group (P >0.05). BMIs of the IGT group ([25.50 ± 3.04]kg/m2) and T2DM group ([26.09 ± 2.86]kg/m2) were higher than that of the NGT group ([24. 70 ± 3. 27] kg/m2), the differences were significant (t = 0. 8063,1. 3947, P<0. 05 and <0.01, respectively),whereas no significant difference was found between the T2DM group and IGT group (P > 0. 05). The incidence of single coronary pathological changes was 44.7% in the NGT group,it was higher than that of the IGT group (23. 6%) and T2DM group (18. 9%) (x2 = 16. 310,25. 116,Ps < 0. 05), whereas there was no significant difference between the IGT group' and T2DM group (P > 0. 05);The incidences of 2 branches pathological changes in the T2DM group (37. 1%) and IGT group (39. 8%) were higher compared with NGT group (23. 5%) ,the differences were significant (x2 =1. 200,10. 099,Ps <0. 05),whereas there was no significant difference between the IGT group and T2DM group (P >0. 05) ;The incidences of 3 vessels pathological changes in the T2DM group (40.9%) and IGT group (33. 5%) were higher than that of the NGT group (20. 0%) , the differences were significant (x2 = 7. 767,17. 028, Ps < 0.05), there was no significant difference between the IGT group and T2DM group (P > 0. 05). The incidence of subtotal or total occlusion of the T2DM group and IGT group were 22. 6% and 18.0% respectively,both were higher than that of the NGT group(7. 6%) (x2 = 14. 573,8. 019 ,Pa < 0.05) , whereas no significant difference was found between the T2DM group and IGT group (P > 0. 05). The incidences of vascular diffusing pathological change in the IGT group (24. 8%) and T2DM group (30. 8%) were higher compared with the NGT group (12.4%) (x2 =8.583,16.724, Ps < 0.05), whereas there was no significant difference between the IGT group and T2DM group (P >0.05). The Gensini scores in the IGT group (55. 05 ± 22. 99) and T2DM group(56. 15 ± 24. 87) were significnatly higher than that of the NGT group (38. 03 ± 17. 38), the differences were significant ((t =17.0142,18. 1186,Ps <0.01),whereas there was no significant difference between the IGT group and T2DM group (P>0.05). Conclusion The incidences of 2 and 3 vessels pathological changes increase significantly in patients with IGT. Moreover, the incidences of occlusion and diffuse stenosis increase significantly. This is similar to the coronary artery pathological charactersitics in patients with diabetes, which indicates that IGT is closely related to the pathological severity of coronary artery. We should pay much attention to those patients with IGT in the clinical work.

Objective To dynamically observe stenosis and wall thickness of carotid artery with endothelium injury in mouse using 7T micro-MR imaging in vivo. Methods A mouse model of carotid artery intimal injury was established by removing endothelium with a flexible wire. The lumen diameter, lumen area, wall thickness and wall area of the injured arteries were observed, and serial MR scanning was performed in different time points after operation. Results The injured arteries and perivascular parenchyma were clearly observed by MR imaging. Before and 1, 5, 10 and 15 days after artery injury, the lumen diameter were (0.57±0.07)mm,(0.41±0.19)mm, (0.44±0.10)mm, (0.43±0.10)mm and (0.47±0.11)mm respectively, and the lumen area were (0.30±0.06)mm2, (0.18±0.11)mm2, (0.18±0.06)mm2, (0.18±0.06)mm2 and (0.22±0.07)mm2. The thickness of artery wall was(0.23±0.12)mm, and the area of artery wall was (0.35±0.24)mm2 15days after artery injury. Conclusions Stenosis and wall thickening of carotid artery after the artery intimal injury of mouse can be dynamically observed on MR imaging in vivo.

Background：In April 2013, a hospital in Suzhou City notified authorities of a patient with nitrite poisoning with two other family members who had similar toxic symptoms five days prior. We investigated the event to identify the cause, source and possible route of contamination.Methods：A case was defined as any person living in the Yang Shan Hua Yuan community who had been diagnosed with cyanoderma and food poisoning symptoms from 15 to 25 April 2013. Active case finding was conducted by interviewing community residents and reviewing medical records from local clinics; information was then retrospectively collected on the patient’s food history, cooking procedures and food sources.Results：We identified three nitrite poisoning cases, one male and two females, from the same family. The time between dinner and onset of illness was less than an a hour. A retrospective survey showed that a substance presumed to be sugar mixed with asparagus on 17 April and with stir-fried asparagus on 21 April was the suspected contaminant. The presumed sugar came from a clean-up of a neighbouring rental house. Nitrite was detected in a vomitus sample, the sugar substance and two leftover food samples.Conclusion：This family cluster of nitrite poisoning resulted from the mistaken use of nitrite as sugar to cook dishes. We recommend that sodium nitrite be dyed a bright colour to prevent such a mistake and that health departments strengthen food hygiene education to alert people about the danger of eating unidentified food from an unknown source.

Objective To investigate the role of phosphatase and tensin homologue deleted on chromosome 10 (PTEN) protein in the spinal cord neurons in diabetic neuropathic pain (DNP) in rats.Methods Male Sprague-Dawley rats,aged 2 months,weighing 180-200 g,were studied.Diabetes mellitus was induced by single intraperitoneal injection of streptozotocin (STZ) 60 mg/kg.Sixteen rats with DNP were randomly divided into 2 groups (n =8 each) using a random number table:DNP group and DNP+PTEN inhibitor bpv (pic) group (DPN-bpv group).Another 16 rats were equally and randomly divided into either control group (group C) or bpv group.In DNP-bpv and bpv groups,bpv (pic) 0.2mg/kg was injected intraperitoneally once a day within 14-28 days after injection of STZ.Before STZ injection (T1),and at 2,7,14,21 and 28 days after STZ injection (T2-6),the mechanical paw withdrawal threshold (MWT) was measured.After measurement of MWT,the rats were sacrificed,and the lumbar segments of the spinal cord (L4.5) were removed for determination of PTEN protein activity (by ELISA) and Akt (s473) phosphorylation (by Western blot).Results Compared with group C,the MWT was significantly decreased at T4-6,and the PTEN protein activity and Akt (s473) phosphorylation were significantly increased in DNP and DNP-bpv groups (P＜0.05 or 0.01).Compared with group DNP,the MWT was significantly increased at T6,and the PTEN protein activity and Akt (s473) phosphorylation were significantly decreased in group DNP-bpv (P＜0.05).Conclusion PTEN protein in the spinal cord neurons is involved in the maintenance of DNP in rats.

Background and purpose:Lymph node metastasis commonly occurs in papillary thyroid carcino-ma (PTC). The object of this study was to investigate the relationship between the rate of involved lymph nodes (LR) and distant metastasis (DM) in PTC, and its potential value in predicting the risk of DM.Methods:PTC patients were divided into two groups as M0 (121 cases) and M1 (41 cases) according to the presence of distant metastases or not. The t-text andχ2 test were used to evaluate the statistical differences in basic clinicopathological features between the two groups. Multivariate analysis was used to quantify LR as an independent factor of DM. The receiver operating charac-teristic (ROC) curve was employed to evaluate the clinical value of LR and the number of involved lymph node (LNs) for predicting DM and optimal cut-off point respectively. The cumulative risk of distant metastasis curves according to the LR and LNs status were constructed with the Kaplan-Meier method, and the Log-rank test was used to compare these curves.Results:There were no statistical differences in age and multifocality between two groups (P>0.05), while signiifcant differences in gender, extrathyroidal invasion and tumor size were observed. LR is an independent indicator for predicting DM (OR=1.133,P=0.000). An increase in LR was signiifcantly associated with DM. Patients with more than 15 involved LNs had the steepest increasing pattern in the cumulative risk of DM compared with those who had less than 15 involved LN (P=0.002).Conclusion:LR may be an independent predictive marker for distant metastases in PTC, and its combination with LNs might better predict the risk of DM.