BACKGROUND: Chitosan is commonly prepared using emulsion freeze-drying methods, which is complexly operated. OBJECTIVE: To introduce a simple methods for the preparation of chitosan and analyze its biological characteristic. DESIGN, TIME AND SETTING: Controlled observation experiments were carried out in the Central Laboratory, the Second Affiliated Hospital of Chinese Medical University (Shenyang, Liaoning, China) from April to December in 2007. MATERIALS: Ten Wistar rats of 8 weeks old and SPF grade were adopted. Chitosan powder in separated packs, with 99% purity and 99% deacetylation degree were the product of Shandong Jinan Ocean Bio-Product Co., Ltd. (China). METHODS: Acetic acid solution was added into chitosan to prepare 8% chitosan acetic acid hydrosol, which was then stayed for one day. Flowing the immersion into the hydrosol and immediate dislodgement, plastic tube was soaked in 1 mol/L sodium hydroxide for 3 minutes. Hydrosol out of the tube etiolated and coagulated into jells, the tube was removed when the jells were semi-dried. Subsequent to complete drying, chitosan tubes were prepared as an internal diameter of 5 mm, and were cut into many segmentations (length 2 mm). The prepared tubes were subcutaneously implanted into rat muscular tissues at right McBurney point, while rat left muscular tissues were only incised and sutured, taking as controls. MAIN OUTCOME MEASURES: Gross observation of chitosan tube, degradation percentage of chitosan tubes in rat muscular tissue, and tissue inflammation change around chitosan tube detected by hematoxylin-eosin stain. RESULTS: The surface of chitosan tube was smooth and the tenacity was good. Intramuscular implantation test showed that 50% and 90% chitosan tubes were absorbed by tissues in 4 weeks and 8 weeks postoperatively. Inflammatory reaction surrounding tubes was decreased gradually. CONCLUSION: It gives a new kind of way to prepare chitosan tube, with few materials, low cost, simple operation and short time. The prepared chitosan tubes approve the good histocompatibility and biological degradation.

Perihematomal edema is common after hypertensive intracerebral hemorrhage. It is one of the important causes influencing functional recovery. This article reviews the mechanisms of perihematomal brain edema formation after hypertensive intracerebral hemorrhage, particularly, the potential mechanisms of hypertension in the processes of brain edema formation, as well as therapeutic targets of brain edema.

Objective To analyse the associativity among serum thyroid hormone level,brain injury and neuroethology in preterm infants by testing the thyroid hormone level and neuro-behaviour assessment.Methods Fifty-two preterm infants were continuously admitted in neonatal department of Shanghai Children's Hospital from Dec 2009 to Apr 2010. Radio-immunity was used to determine the serum level of T3,T4, TSH within 6 h after birth. Each case received cranial ultrasonic examination within 3 d after birth and rechecked every week. Before discharge, every infant received a cranial MRI examination. The 52 cases were devided into three groups according to the result of ultrasound and MRI:no brain damage group (33 cases),intraventricular hemorrhage greup (10 cases) ,and white matter injury group (9 cases). At the corrected gestation age 40±2 weeks,every infant received a neonatal behavioral neurological assessment (NBNA). Results The level of serum TSH in all the three groups of preterm infants were normal, which could reject congenital hypothyroidism. Eight preterm infants(15.4% ,8/52) had normal thyroid hormone level,another 44 preterm infants(84. 6% ,44/52) got lower thyroid functions. The levels of T3 and T4 were higher in the no brain damage group than those in intraventricular hemorrhage group and white matter injury group. And the preterm infants who had white mauer injury got the lowest level of thyroine hormone T3 and T4. Thyroxine hormone levels had significant difference among three groups (P ＜ 0. 05). The preterm infants who had no brain damage got higher scores in capability, passive muscle tonus,initiative muscle tonus and total score than the other two groups. Intraventricular hemorrhage group always got higher scores in NBNA than the white matter injury group (P ＜ 0. 05). The NBNA scores had significant difference among three groups (P ＜ 0. 05). Conclusion Premature infant who has more severe brain injury always has lower levels of thyroxine hormone. Premature infants with brain injury get lower scores in NBNA test than those without brain injury.

Selectins are a family of adhesion molecules,including P-,L-,E-selectins.The three adhesion molecules all participate in the inflammatory processes of ischemia-reperfusion injury of brain.P-selectin is expressed on activated platelets as well as on endothelial cells.E-selectin is only expressed on endothelial cells.P-and E-selectin mediate the adhesion of the leukocytes,platelets and endothelial cells.L-selectin is mainly expressed on leukocytes and mediates leukocytes rolling contact with microvascular endothelial cells.

Objective: To design and prepare a field battle "Windbreaker" stretcher for fixation of spinal cord injury using macromolecular material, and to determine its application index and assess its efficacy. Methods: Using shape memory waterborne polyurethaneurea/SiO2 nano-composite, we prepared a field battle "Windbreaker" stretcher for fixation of spinal cord injury according to the physique of the Chinese. The time spent to finish the fixation procedure under different conditions (raining, cold weather, land and rivers) was recorded, and the time of solidification was also observed. Results: The weight of a complete set of the field battle "Windbreaker" stretcher was (7.5±1.4) kg. The time to complete a fixation was (2.1±0.55) min in the water, (1.9±0.35) min under dry environment. The time of solidification was(7.7±1.45) min in the water and was (6.9±1.23) min under dry environment. The maximum strength the stretcher could bear was (80±5.7) kg. Conclusion: Our self-designed "Windbreaker" stretcher can be used for rapid and simple fixation of different spinal cord injuries, and the mechanics intensity meet the requirement for fixation. The stretcher can be used for fixation of spinal cord injury under different conditions of field battle.

Objective: To design a portable real-time monitoring tool for spine surgery and to preliminarily evaluate its application,so as to reduce the iatrogenic injury during the treatment of battle field spinal cord injury. Methods: A portable spine guiding device for spinal fixation was designed and prepared. The spinal specimens were randomly divided into control group (n = 10) and experimental group (n = 10). In the control group the way was cleared for the pedicle according to the doctor's experience; in the experimental group the way was cleared using our self-designed guiding device. The operation time was recorded in the two groups. After manipulation the specimens were opened along the pedicle level; the location and the depth of the needle were compared. Results;The manipulation time of a single vertebral body was (0. 5 + 0. 2) min in the control group and (0. 6 + 0. 1) min in the experimental group (P>0. 05). The edge of the puncture to the pedicle wall in the control group was significantly shorter than that in the experimental group ([1. 1 + 0. 3] vs [1. 8 + 0. 2] mm,P = 0. 037). Conclusion:The designed portable guiding device for spinal fixation is easy to carry, simple to operate; and initial in vitro application is satisfactory and can provide reliable reference for early operation.

Objective To investigate the impact of LY294002 on the proliferation of cancer stem cell-enriched spheroid cells from human hepatocellular carcinoma via regulating phosphatidylinositol-3-kinaseprotein kinase B(PI3K-Akt)signaling pathway. Methods The cancer stem cell-enriched spheroid cells were genera-ted by culturing HepG2 cells in serum-free medium. LY294002(10,20,30 μmol/ L),an inhibitor of PI3K-Akt signaling pathway,was used in the experimental groups,without used in the control group. The impact of LY294002 on the spheroid cells proliferation was confirmed by cell counting kit(CCK-8 kit). The expression of Akt was tested by Western blotting. The expression of PI3K-Akt signaling pathway downstream genes such as decoy receptor 3(DcR3),mammalian target of rapamycin(mTOR),B-cell lymphoma(Bcl)-2 and Cyclin D1 were tested by real-time PCR. Results 30 μmol/ L LY294002 could inhibit the proliferation of spheroid cells, and significant difference in the absorbance(A value)was observed between the experimental group and control group[(0. 14 ± 0. 03)vs(0. 56 ± 0. 01),t = - 8. 915,P = 0. 000]. The expression level of phosphorylated Akt protein increased[(0. 57 ± 0. 08)vs(0. 16 ± 0. 42),t = 6. 027,P = 0. 026]. The mRNA of DcR3 [(0. 38 ± 0. 08)vs 1,t = 13. 060,P = 0. 006],mTOR[(0. 37 ± 0. 04)vs 1,t = 30. 363,P = 0. 001],Bcl-2 [(0. 26 ± 0. 04)vs 1,t = 33. 554,P = 0. 001]and Cyclin D1[(0. 10 ± 0. 02)vs 1,t = 63. 528,P = 0. 000] decreased. Conclusion LY294002 could inhibit the proliferation of cancer stem cell-enriched spheroid cells from human hepatocellular carcinoma via inhibiting PI3K-Akt signaling pathway.

OBJECTIVE Cervical cancer is the third most malignant tumor in the world. Farnesoid X receptor (FXR) is a member of nuclear receptor superfamily. It is highly expressed in liver, kidney and small intestine, while it showed low expression level in other tissues. It not only plays an important role in the metabolism of bile acids and sugars, but also in the production of chronic inflammation in the early stage of cancer, the proliferation and migration of tumor. Compared with the normal tissue, the expression of FXR in most tumor tissues decreased. But there is no correlation between cervical cancer and FXR. So we aimed to find out the relationship between FXR and cervical cancer. METHODS A clinical study using qPCR, western blot and immunohistochemistry detected the expression of FXR in tumor tissues and normal tissues of clinical patients. FXR was activated by agonists or over-expressed by lentivirus. MTT, clone formation and flow cytometry were used to detect the relationship between FXR and proliferation of cervical cell lines. Tumor growth ability of FXR was detected by nude mice tumorigenicity. The interaction between FXR and CDKN2A-p14ARF-MDM2-p53 pathway was detected by qPCR, Western blot and immunohistochemistry. RESULTS FXR was decreased in cancer tissues compared to normal control. Activation of FXR by agonist or constitutively- over- expression of FXR inhibited cervical cell proliferation. Over- expressed FXR attenuated Caski, Hela and Siha xenograft tumor growth in nude mice compared with control. Over-expression of FXR caused G1 cell-cycle arresting and up-regulated CDKN2A-p14ARF-MDM2-p53 pathway. CONCLUSION FXR inhibits cervical cancer cell proliferation and cervical tumorigenicity which is related to CDKN2A-p14ARF-MDM2-p53 pathway. Activation or overexpression of FXR may be a potential target for the treatment of cervical cancer.

Objective To investigate the pathogenesis of brain-type hemodialysis disequilibrium syndrome(DDS) in dogs with acute renal failure. Methods Seventy-two hours after bilateral ureteral ligation,12 uremic dogs were hemodialyzed for 2 hours,yeilding decreases in plasma urea from (66. 76?13.70) mmol/L to (17. 85?5. 84)mmol/L( P

Atherosclerosis is a pathegenesis process involved in the inflammatory and proliferative responses of cells in which endothelial cells have an important function in the regulation of a variety of genes. A variety of molecules have been identified in the atherosclerotic environment that are able to activate NF ?B. Possible functional implications for activated NF ?B in atherogenesis are discussed by protecting endothelial cells selectively, perhaps, it may provide a new method for the therapy of the atherosclerosis.