Objective To investigate the possible mechanism of gemcitabine resistance in pancreatic cancer chemotherapy. Methods Recent literatures about the genes and signal pathways those play key roles in mediating gemcitabine chemotherapy resistance of pancreatic cancer were collected and reviewed.Results Oncogenes like c-Src and bcl-X-L, inflammation pathway of NF-?B, cytokines like IL-1? and NO are closely related with the chemoresistance; the relationship between multiple drug resistance relevant genes like MDR1/P-gP and the resistance to gemcitabine remains to be clarified. Conclusion Genes and pathways like c-Src, bcl-X-L, NF-?B, etc. might become new targets to increase the chemotherapeutic sensitivity of pancreatic cancer, however, the mechanism of pancreatic cancer chemotherapy resistance still needs further to be studied.

Objective Clutching internal fixtor(CIF)loose and the fixed part weakly heal up are often found in orthopedic clinic.In the present paper,biomechanics methods were used to try to explain and analyze these issues,providing a helpful suggestion for the application of CIF in clinic.Method Commerical finite element models(FEM)Program ANSYS was applied to set up the finite element models of orthopedic CIF and bone tissue to analyze and evaluate the biomechanical performances of the NiTi shape memory alloy CIF.Results There is an interaction force between embracing force of CIF and resistant force of bone tissue during the orthopedic clinical treatment.The embracing force along two semi-circular arms of CIF is increasing from the open position and reached the maximum value at the open symmetry position where the deformation of the bone occurred.Conclusion It is the key to choose the force loading position during the practical treatment,as the concentration force is the main force when there is an interactive force between the bone and the CIF.

Objective Clutching internal fixtor(CIF)loose and the fixed part weakly heal up are often found in orthopedic clinic.In the present paper,biomechanics methods were used to try to explain and analyze these issues,providing a helpful suggestion for the application of CIF in clinic.Method Commerical finite element models(FEM)Program ANSYS was applied to set up the finite element models of orthopedic CIF and bone tissue to analyze and evaluate the biomechanical performances of the NiTi shape memory alloy CIF.Results There is an interaction force between embracing force of CIF and resistant force of bone tissue during the orthopedic clinical treatment.The embracing force along two semi-circular arms of CIF is increasing from the open position and reached the maximum value at the open symmetry position where the deformation of the bone occurred.Conclusion It is the key to choose the force loading position during the practical treatment,as the concentration force is the main force when there is an interactive force between the bone and the CIF.

The glycosylation of platelets may prolong their life-span when being transfused after preservation under 4 degrees C, therefore this study was aimed to investigate the effect of glycosylation on morphology, ultrastructure, function and membrane glycoprotein of platelets. The experiments were divided into 3 groups: group preserved in room temperature (RT group), group preserved in 4 degrees C (4T group) and group UDP-Gal glycosylated and preserved in 4 degrees C (U+4T group). The binding rate of RCA I lectin and expression of platelet surface markers CD62P, CD42b were determined by flow cytometry. Morphology and ultrastructure of platelets were observed by light microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Platelets aggregation was detected by aggregometer. The results showed that the binding rate of RCAI in U+4T group significantly higher than that in RT group (p<0.01), no obvious changes was found in ultrastructure of glycosylated platelets, as compared with fresh platelets. Some morphologic changes, such as pseudopodium could be observed in 4T group. The aggregation rate of platelets in U+4T group reached to 50% of RT group. The expression levels of CD42b and CD62P, and the binding rate of annexin V in U+4T group were not significantly different from that in RT group. It is concluded that UDP-Gal can effectively cause galactosylation of platelets, and the platelets modified with UDP-Gal remain normal morphology, ultrastructure and function.
Blood Platelets ; drug effects ; physiology ; ultrastructure ; Blood Preservation ; methods ; Cryopreservation ; methods ; Galactose ; pharmacology ; Glycosylation ; Humans

This study was aimed to investigate the stability and in vitro function of glycosylated platelets concentrates after long-term refrigeration. The experiments were divided into 4 groups: group preserved at room temperature (RT group), group preserved at 4 degrees C (4T group), group glycosylated and preserved at 4 degrees C (U + 4 group) and group preserved at 4 degrees C and glycosylated (4 + U group). All groups followed for up to 14 days. The binding rate of RCA I lectin and expression of Plt surface markers CD62P, CD42b and Annexin V binding were determined by flow cytometry. pH and mean volume were determined by pH meter and hematotocytometer respectively. Platelet aggregation was detected by aggregometer. The results showed that during storage up to 14 days RCAI binding rate of modified groups was 5 - 6 fold of RT group. The pH of platelets suspension had no significant difference between these two groups (p > 0.05). Mean volumes of both groups (10.6 +/- 1.9 fL and 11.14 +/- 1.1 fL) were also no significant difference (p > 0.05). Furthermore, aggregation responsiveness of modified groups was better than that of RT groups (p < 0.05) although both decreased during the storage. The expression level of CD62P, CD42b and Annexin V binding during 5 days of storage had no significant difference between modified and fresh platelet groups (p > 0.05). While the expression level of CD62P and PS increased and the expression level of CD42b decreased during storage up to 14 days, there was significant difference between modified and fresh platelet groups (p < 0.01). It is concluded that the glycan modification is stable during storage up to 14 days. The glycosylated platelets retain in vitro function better than RT platelets during storage, but it shows activation to varying degrees in vitro after storage for 5 days.
Blood Platelets ; cytology ; metabolism ; Blood Preservation ; Cryopreservation ; methods ; Galactose ; pharmacology ; Glycosylation ; Humans ; Platelet Aggregation ; drug effects

Objective To investigate the optimal concentration and site for ozoneadministration to relieve neuropathic pain in rats. Methods Twenty-four adult male rats with sciaticnerve injury (SNI) were randomized equally into 4 groups, and received ozone injections for analgesia atdifferent sites, namely the operative site, the sciatic nerve, the L5 spinal nerve or the operative site inaddition to the L5 spinal nerve. Another 4 groups of rats with SNI (n=6) had ozone injections at theconcentrations of 40, 50, 60, or 70 μg/mL, all administered at both the operative site and the L5 spinalnerve. The analgesic effects of the ozone injections were evaluated using paw withdrawal threshold test inall the rats. Results In rats with ozone injection at both the operative field and the L5 spinal nerve, themechanical pain threshold was significantly increased in comparison with that in rats with injections atother sites (P<0.05), but different doses of ozone simultaneously injected at the two sites did not producesignificant differences in the pain threshold (P>0.05). Conclusion Ozone produces obvious analgesiceffects in rats with SNI-induced neuropathic pain when injected at both the operative site and thespinal nerve, and ozone within the concentration range from 40 to 70 μg/mL has similar analgesic effect.

To study effect of vitrification state of protective solutions on recovery of red blood cells after lyophilization, four protective solutions composed of isotonic buffers containing 7% DMSO (v/v) and 20%, 30%, 40% or 50% polyvinylpyrrolidone (PVP) (w/v) were adopted. Vitrification state of protective solutions was examined first when white ice crystal appeared in any protective solution during freezing or thawing, if the used solution was not a vitrification solution. Red blood cells were lyophilized in MINILYO45 freeze-dryer after washing, mixing with protective solutions and prefreezing. After lyophilization, the samples were quickly rehydrated by 37 degrees C rehydration solution. The results showed that in vitrification and devitrification experiments, white ice crystal appeared in solution of 20% PVP + 7% DMSO and 30% PVP + 7% DMSO during freezing and thawing; vitrification appeared in solution of 40% PVP + 7% DMSO during freezing, but devitrification appeared during thawing; vitrification appeared in solution of 50% PVP + 7% DMSO during freezing and thawing. After rehydration, the recoveries of red blood cells and hemoglobin in 40% PVP + 7% DMSO group were (81.36 +/- 14.94)% and (77.54 +/- 12.86)%, which were significantly higher than that in 20% PVP + 7% DMSO, 30% PVP + 7% DMSO and 50% PVP + 7% DMSO groups (P < 0.01). The concentration of free hemoglobin in 40% PVP + 7% DMSO group was also significantly lower than that in other three groups (P < 0.01). With increase of PVP concentration in protective solutions, vitrification state and protective effect of these solutions also increased; when concentration of PVP in protective solution was 40% though it was not a vitrification solution, the effect of lyophilization was the best; but when concentration of PVP further increased to 50%, though it was a vitrification solution, the effect decreased. It is concluded that excessive vitrification state could not benefit lyophilization of red blood cells.
Cryoprotective Agents ; pharmacology ; Dimethyl Sulfoxide ; pharmacology ; Dose-Response Relationship, Drug ; Erythrocytes ; cytology ; drug effects ; ultrastructure ; Freeze Drying ; methods ; Humans ; Microscopy, Electron ; Povidone ; pharmacology

Now the clinical preservation methods of human red blood cells mainly include hypothermic storage (4 degrees C) and cryopreservation (-80 degrees C or -196 degrees C). The preservation time of hypothermic storage of red blood cells is relatively short and it is easy to be contaminated by microbes. Cryopreservation greatly prolongs the storage time, but it needs heavy storage equipments. Because the protective solutions in cryopreservation contain glycerol, red blood cells need complicated washing in order to remove glycerol. These shortage methods limit their application to some special conditions, such as war or natural disasters. Compared with conventional preservation methods of red blood cells, lyophilization has many advantages such as less weight, convenient transportation, room temperature preservation, prone to be rehydrated. In this review, the progress and challenge in the development of lyophilization of red blood cells, especially application of trehalose and its mechanism in the lyophilization of red blood cells were systematically discussed. This review can provide some theoretic guidance for developing a safe, simple and efficient preservation approach of red blood cells by lyophilization.
Blood Preservation ; Cryopreservation ; Erythrocytes ; Freeze Drying ; Humans ; Trehalose ; pharmacology

To study the anti-tumor metastatic constituents in Rhodiola wallichiana (HK) S H Fu var Cholaensis (Praeg) S H Fu, chemical constituents were isolated and purified by repeated column chromatography (silica gel, Toyopearl HW-40C and preparative HPLC). Their structures were elucidated on the basis of spectral data analysis. The anti-tumor metastasis assay was applied to evaluate the activities of the isolated compounds. Ten compounds (1-10) were isolated and their structures were identified by comparison of their spectral data with literature as follows: syringic acid (1), salidroside (2), tyrosol (3), scaphopetalone (4), berchemol (5), 2,6-dimethoxyacetophenone (6), rhobupcyanoside A (7), miyaginin (8), chavicol-4-O-β-D-apiofuranosyl-(1 --> 6)-O-β-D-glucopyranoside (9), eugenyol-O-β-D-apiofuranosyl-(1 --> 6)-O-β-D-glucopyranoside (10). Compounds 4-6 and 8-10, were isolated from this genus for the first time, while compound 7 was isolated from this plant for the first time. Compounds 2, 6-8 showed positive anti-tumor metastatic activities, and compounds 2 and 8 showed significant anti-tumor metastatic activities.
Antineoplastic Agents, Phytogenic ; isolation & purification ; pharmacology ; Cell Line, Tumor ; Humans ; Neoplasm Metastasis ; prevention & control ; Rhodiola ; chemistry