Cationic colloidal gold (CCG) nanoparticles were used for labeling on the anioinic sites of living cells under two-photon fluorescence (TPF) microscope,and for delivering macromolecules into the target cells when irradiated by focused femtosecond laser pulses. 15 nm CCG nanoparticles which were made by conjugation with poly-L-Lysine,were attached on the anionic sites,especially on the membrane,of CHO-K1 cells because of their strong positive charge at physiological pH. Target cells labeled with cationic gold nanoparticles were imaged under TPF microscope,and lifetime images of the same targets were taken by time correlated single photon counting (TCSPC) technique in order to verify the fluorescence of the marker and the luminescence of the gold particles. The results shown that CCG nanoparticles first accumulated on the negatively charged sites of the membrane,then entered via endocytic pathway and attached anionic sites in plasma. A macromolecular 10 ku fluorescein isothiocyanate dextran (FITC-D) was added into the sample and the focused femtosecond laser of TPL microscope was employed to scan the target cells layer by layer. Typical laser power level used in biological imaging is about 3～5 mW. Here the laser power of scanning was below 5 mW in order to prevent photochemical damage of the fs-pulses alone and to localize effects to the nanoparticles on a nano-scale. After scanning the target cells under stack mode,macromolecular fluoresceins surrounding the cells was observed to cross the membrane and to diffuse in the cytoplasma. Comparing with the images before scanning,the two-photon fluorescence and fluorescence lifetime images revealed the delivery of FITC-D into target cells. Photothermal effects,which may be responsible for the permeabilisation,are highly localized in nanoscale and are not expected to cause damage exceeding the cell membrane. After extensive of laser scanning also cell death occurred. The ratio of the uptake of FITC-D and cellular death under different conditions were measured by flow cytometer. The results shown: with the increased scanning times or ratio of particles to cells,transfer efficiency increased first and decreased afterwards,but the ratio of cellular death went up all along.

Objective To optimize experimental parameters for the photosensitization of 5-aminolevulinic acid (ALA) in promyelocytic leukemia cell HL60 and compare them with normal human peripheral blood mononuclear cell (PBMC). Methods ALA incubation time, wavelength applied to irradiate, concentration of ALA incubated, irradiation fluence may modulate the effect of 5-aminolevulinic acid based Photodynamic Therapy (ALA-PDT).The high-pressure mercury lamps of 400W served as light source, the interference filter of 410nm, 432nm, 545nm, 577nm were used to select the specific wavelength. Fluorescence microscope was used to detect the fluorescence intensity and location of protoporphyrin IX (PpIX) endogenously produced by ALA. MTT assay was used to measure the survival of cell. Flow cytometry with ANNEXIN V FITC kit (contains annexin V FITC, binding buffer and PI) was used to detect the mode of cell death. Results ① 1mmol/L ALA incubated 1×105/mL HL60 cell line for 4 hours, the maximum fluorescence of ALA induced PpIX was detected in cytomembrane. ② Irradiated with 410nm for 14.4J/cm2 can result in the minimum survivability of HL60 cell. ③ The main mode of HL60 cell death caused by ALA-PDT is necrosis. Conclusion ALA for 1mmol/L, 4 hours for dark incubation time, 410nm for irradiation wavelength, 14.4J/cm2 for irradiation fluence were the optimal parameters to selectively eliminate promyelocytic leukemia cell HL60 by ALA based PDT. The photosensitization of ALA based PDT caused the necrosis of HL60 cell, so it could be used for inactivation of certain leukemia cells.

Objective To study ischemic effects on reentrant activities and cardiac arrhythmias using a computational approach. Method The Noble 98 mathematical model of ventricular cell was used in the study. The operator splitting and adaptive time step methods were utilized to integrate the partial differential equations in cardiac conduction models. The ischemic cells were simulated by decreasing the intracellular ATP concentration, reducing the Na+ conductance, and increasing the extracellular K+ concentration in a two-dimensional tissue. Spiral waves were initiated by the cross field technique. Result The results showed that spiral waves in local severe ischemia displayed three different morphologies,whereas in moderate ischemia only two kinds of wave forms exhibited. When the degree of ischemia reached a critical value, the reentrant wave could break. But for larger areas of ischemia spiral wave formed a typical functional reentry around the obstacle. Conclusion The study demonstrates that size and level of ischemia have effects on VTs and VFs. Large ischemic area is beneficial for maintenance of spiral wave and can provide a high probability in the genesis of VTs. Spiral waves can easily break up and degenerate into VFs under critical area or level of ischemia.

BACKGROUND:Recently, glucocorticoid-induced necrosis of femoral head has been much studied. However, the precise Wnt signaling pathway by which puerarin suppresses adipogenic differentiation of glucocorticoid-induced bone marrow mesenchymal stem cells adipogenic differentiation of glucocorticoid-induced bone marrow mesenchymal stem cells remains unconfirmed. OBJECTIVE:To investigate the expression of Wnt signaling pathway related genes and the key factor protein,β-catenin, during adipogenic differentiation of glucocorticoid-induced rat bone marrow mesenchymal stem cells treated by puerarin. METHODS:The third generation of bone marrow mesenchymal stem cells were cultured with Dulbecco’s modified Eagle’s medium containing blank serum (blank control group), dexamethasone (hormone group), dexamethasone with puerarin low dose group, the middle dose group and high dose group. After 6 days of culture, in the above five groups, the expressions of Wnt/β-catenin signaling pathway members, Wnt10b mRNA, GSK3βmRNA,β-catenin mRNA, were detected using RT-PCR assay, and the expression ofβ-catenin protein was detected using western blot assay.
RESULTS AND CONCLUSION:Compared with the control group, the Wnt10b mRNA,β-catenin mRNA andβ-catenin protein expressions were significantly higher in puerarin groups, but GSK3βmRNA expression was significantly lower in the puerarin groups. These findings suggest that puerarin effects on inhibition of adipogenic differentiation of glucocorticoid-induced bone marrow mesenchymal stem cells probably are realized through the activation of Wnt/β-catenin signal pathway and regulation of the key factor Wnt10b mRNA, GSK3βmRNA,β-catenin mRNA, andβ-catenin protein expressions. The mechanism by which puerarin prevents glucocorticoid-induced necrosis of femoral head not only improves local microcirculation of the femoral head, but also relates to its inhibitory effects on adipogenic differentiation of glucocorticoid-induced bone marrow mesenchymal stem cells.

Objective:To analyse the methord and effects of intermaxillary traction(IMT)screws used in the treatment of jaw frac-ture.Methods:In the treatment of 1 68 cases of jaw fracture IMT screws were used for the restoration of normal and stable occlusion. The screw number,position,traction effect and postoperative complications of the treatment were analysed.Results:705 screws were used in 168 patients,4 screws were used in each of 147 cased (88%),6 in 12(7%),5 in 9(5%).336(47.7%)screws were fixed between the roots of first and second premolar,292(41 .4%)between the roots of canine and first premolar,50 (7.1%)be-tween the roots of second premolar and first molar,27(3.8%)between the other tooth roots.Normal postoperative occlusion relation was achived by the use of screws in 92 cases without traction.Occlusion disharmony or deviation was found in 76 cases by the used of screws and was restored to normlal by 1 4-day traction in 71 cases.The total efficiency of the treatment was 97%.Pain of the mucosa surrounding the screws was observed in 23 cases (1 3.7%).Root damage,traction screw loosening and adjacent tooth dislocation were observed in 1 3(1 .8%),1 1 (1 .6%)and 2(0.3%)cases respectively.Conclusion:For the fixation of IMT screws,the posi-tions between tooth root from canine to first molar were most common and safe.The fixation point should be in 5 ~8mm below the gin-gival margin.Use of 4-6 screws can meet treatment need.

Objective:To analyse the effects of mandibular swing approach in the treatment of the tumors in infratemporal fossa. Methods:11 patients with tumors in infratemporal fossa treated by the surgical operation with mandibular swing approach. The mandi-ble cut was at the front of foramina mentale in 5 cases, at the front of mandible angle in 4 cases and at the middle of chin in 2 cases re-spectively. Results:According to the nature, location, size and the relationship of the tumors with peripheral nerve and blood vessels, flexible selection of the position of mandibular cut could fully expose and completely remove the infratemporal fossa tumor. Conclusion:Surgical treatment of the tumors in infratemporal fossa by mandibular swing approach is safe and effective.

Objective:To study the effects of the surgical treatment of nerve avulsion inside and outside the mandibular cannel.Methods:34 patients with trigeminal neuralgia of the third division,received neurotomy and avulsion of inferior alveolar nerve in the mandibular cannel above the lingual or through the mental foramen,concurrently with the avulsion of buccal nerve.Patients were fol-lowed up for 2-4 years.Results:All the operations were successfully completed,The wounds were well-healed.All patients felt that pain disappeared in the area innervated by inferior alveolar nerve.During the 2-4 years of follow-up,no recurrence was found.Conclusion:Inferior alveolar nerve neurotomy and avulsion in the mandibular cannel is simple,safe and effective in the treatment of trigeminal neuralgia of the third division.

As exogenous ALA (5-aminolevulinic acid) esters can induce the production and accumulation of endogenous photosensitizer PpIX (protoporphyrin IX) in tumor tissues more effectively, they have been the most active photosensitizer prodrug in PDT(photodynamic therapy) field. In this article, along with the procedure of ALA esters based PDT, some primary mechanism and experimental results were considered, which include: first, cellular uptake of ALA esters and its conversion into ALA; second, the production and accumulation of endogenous photosensitizer PpIX induced by eNdogenous ALA esters; last, the photosensitization of PpIX.
Aminolevulinic Acid ; pharmacology ; Esters ; pharmacology ; Photochemotherapy ; Photosensitizing Agents ; pharmacology ; Prodrugs ; Protoporphyrins ; pharmacology

Objective To study the toxic effects of 5-amionlevulinic acid-based photodynamic therapy (ALA-PDT) on human peripheral blood mononuclear cells (PBMCs), cord blood mononuclear cells (CBMCs) and peripheral blood stem cells (PBSCs), and furthermore, to understand the possible causes of this response. Methods We used MTT assay to detect the survival rate of PBMCs, CBMCs and PBSCs after treated by ALA-PDT under the optimum experiment conditions with U937 as control;Annexin V-FITC/PI was used to detect the pattern of cell death induced by ALA-PDT. By using flow cytometry, we detected intracellular PpIX fluorescence intensity. Results After ALA-PDT treatment the survival rate of PBMCs had no significant change;however in PBSCs and CBMCs, the survival rate reduced to 70%, and the survival rate of leukemia cell U937 was the lowest, about 30%. After incubation with ALA,except for PBMCs, intraceUuiar PplX fluorescence intensity of the other two kinds of normal haemocytes and U937 increased obviously. These results combined with the flow cytometry suggested that the main pattern of cell death here was apoptosts. Conclusion Under the optimum experiment conditions, ALA-PDT has a slight effect on normal haemocytes but excellent depletions of leukemia cells. Therefore, it can effectively purify autologons bone marrow or stem cell grafts.

The macroporous structure of human bone allows the ingrowth of the soft tissues and organic cells into the bone matrix, profits the development and metabolism of bone tissue, and adapts the bone to the change of load. There is great requirement for artificial biomimic porous bioactive ceramics with the similar structure of bone tissue that can be used clinically for repairing lost bone. Fine hydroxyapatite (HAp) powder produced by wet chemical reaction was mixed with hydrogen peroxide (H2O2), polyvinyl alcohol, methyl cellulose or other pores-making materials to form green cake. After drying at low temperature (below 100 degrees C) and decarbonizing at about 300 degrees C-400 degrees C, the spongy ceramic block was sintered at high temperature, thus, macroporous HAp bioceramic with interconnected pores and reasonable porosity and pore-diameter was manufactured. This kind of porous HAp bioceramics were intrinsically osteoinductive to a certain degree, but its outstanding property was that they can absorb human bone morphogenetic proteins and other bone growth factors to form composites, so that the macroporous HAp bioactive ceramic has appropriate feasibility for clinical application. From the point of biomedical application, the recent developments in synthesis and characteristics investigation of macroporous HAp are reviewed in this paper.
Biocompatible Materials ; chemical synthesis ; chemistry ; Bone and Bones ; Ceramics ; chemical synthesis ; chemistry ; Durapatite ; chemical synthesis ; chemistry ; Hot Temperature ; Humans ; Porosity ; Powders