Investigation into perturbed nucleoside metabolism and cell cycle for elucidating the cytotoxicity effect of resveratrol on human lung adenocarcinoma epithelial cells / 中国天然药物

In an effort to understand the molecular events contributing to the cytotoxicity activity of resveratrol (RSV), we investigated its effects on human lung adenocarcinoma epithelial cell line A549 at different concentrations. Cellular nucleoside metabolic profiling was determined by an established liquid chromatography-mass spectrometry method in A549 cells. RSV resulted in significant decreases and imbalances of deoxyribonucleoside triphosphates (dNTPs) pools suppressing subsequent DNA synthesis. Meanwhile, RSV at high concentration caused significant cell cycle arrest at S phase, in which cells required the highest dNTPs supply than other phases for DNA replication. The inhibition of DNA synthesis thus blocked subsequent progression through S phase in A549 cells, which may partly contribute to the cytotoxicity effect of RSV. However, hydroxyurea (HU), an inhibitor of RNR activity, caused similar dNTPs perturbation but no S phase arrest, finally no cytotoxicity effect. Therefore, we believed that the dual effect of high concentration RSV, including S phase arrest and DNA synthesis inhibition, was required for its cytotoxicity effect on A549 cells. In summary, our results provided important clues to the molecular basis for the anticancer effect of RSV on epithelial cells.

A targeting photodynamic drug vehicle composed of neural stem cells and mesoporous silica nanoparticles for tumor therapy / 中国组织工程研究

BACKGROUND:Neural stem cells (NSCs),which exert no promoting effect on tumor growth and break through the blood brain barrier to deliver drugs into tumor tissues,are considered as a promising tumor targeted drug delivery vehicle.OBJECTIVE:To develop a hybrid delivery system composed of NSCs and moseporous silica nanoparticles for photosensitizer delivery,and to test if the system can be used for tumor therapy.METHODS:The photosensitizer,zinc phthalocyanine,was encapsulated in mesoporous silica nanoparticles.(1) Cytophagy experiment:NSCs were incubated with mesoporous silica nanoparticles (0,10,50,100,200 mg/L) loaded with zinc phthalocyanine for 6 hours,and fluorescence microscope was employed to observe the nanoparticles inside the cells.(2) Cytotoxicity test:NSCs incubated with mesoporous silica nanoparticles at various concentrations (0,10,50,100,200 mg/L) which loaded with or without zinc phthalocyanine for 6 hours,followed by 3 days of normal culture.Then,the cells were harvested for MTT assay.(3) Retention of nanoparticles within the NSCs:100 mg/L mesoporous silica nanoparticles loaded with zinc phthalocyanine were co-cultured with NSCs for 6 hours.Then,the cells were normally cultured for 12,24,and 72 hours,and observed with fluorescence microscope.(4) Zinc phthalocyanine excitation in vitro:100 mg/L mesoporous silica nanoparticles loaded with or without zinc phthalocyanine were co-cultured with NSCs for 6 hours.The cells were then normally cultured for 12 hours and irradiated with laser.Microscope was employed to observe cell morphology.(5)Tumor cell killing experiment:NSCs cells were cultured with 100 mg/L mesoporous silica nanoparticles loaded with zinc phthalocyanine,then mixed with MCF7 cells for 12 hours,and irradiated with laser.After that,the cells were cultured for another 12 hours and cell death was observed under fluorescence microscopy.RESULTS AND CONCLUSION:(1) After co-cultured with the calls for 6 hours,nanoparticies could be found in the cytoplasm and the number was increased with the concentration of nanoparticles.(2) The nanoparticles with or without zinc phthalocyanine loaded at the concentration of ＜ 100 mg/L showed no toxicity to NSCs.(3) After 72 hours of co-culture,the nanoparticles in the cytoplasm was decreased in number,but still could be found.(4) Laser irradiation could damage the cell membrane of NSCs co-cultured with mesoporous silica nanoparticles loaded with zinc phthalocyanine.(5) A large number of MCF7 cells died after tumor cells were co-cultured with NSCs that were cultured with mesoporous silica.To conclude,the hybrid system composed of NSCs and mesoporous silica nanoparticles loaded with zinc phthalocyanine can serve as a great potential tumor-targeted delivery vehicle for photodynamic therapy.

TaqMan Real-time RT-PCR Assay for Detecting and Differentiating Japanese Encephalitis Virus / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To detect Japanese encephalitis virus (JEV) rapidly and distinguish its genotypes, a TaqMan-based reverse transcriptase quantitative polymerase chain reaction (RT-PCR) detection system was developed.</p><p><b>METHODS</b>By aligning the full-length sequences of JEV (G1-G5), six sets of highly specific TaqMan real-time RT-PCR primers and probes were designed based on the highly conserved NS1, NS2, and M genes of JEV, which included one set for non-specific JEV detection and five sets for the detection of specific JEV genotypes. Twenty batches of mosquito samples were used to evaluate our quantitative PCR assay.</p><p><b>RESULTS</b>With the specific assay, no other flavivirus were detected. The lower limits of detection of the system were 1 pfu/mL for JEV titers and 100 RNA copies/µL. The coefficients of variation of this real-time RT-PCR were all < 2.8%. The amplification efficiency of this method was between 90% and 103%.</p><p><b>CONCLUSION</b>A TaqMan real-time RT-PCR detection system was successfully established to detect and differentiate all five JEV genotypes.</p>

The application of external fixator for complex tissue defect in the forearm / 中华外科杂志

<p><b>OBJECTIVE</b>To discuss the curative effect of the external fixator for complex tissue defect in the forearm.</p><p><b>METHODS</b>From May, 2005 through December, 2008, the external fixators were used in 17 patients to treat the complex tissue defect in the forearm caused by trauma. There were 11 male and 6 female, with a mean age of 25.6. All patients were accompanied with the exposure of tendon, muscle or screw. The skin defect ranged from 7 cm x4 cm to 19 cm x9 cm. All patients underwent pedicle flap repair. The flap ranged from 10 cm x 6 cm to 20 cm x 15 cm. The proximal pedicle of the flap was sutured into a tubular. The position of the pedicle was fixed by the external fixator. The pin was at the ulnar and the iliac (n=5), and the radius and the iliac (n=12). The immobilization lasted 3 to 8 weeks, 5.1 weeks in average.</p><p><b>RESULTS</b>All patients were followed up for 3 to 20 months, 11.3 in average. All pedicle flaps survived with no pressure ulcer, or no erosion in the axilla. No compartment syndrome or osteomyelitis occurred. Four to six week after surgery, the pedicle was cut. Infection occurred at the cutting end in 1 patient. The wound healed after addressing. The wound in the other 16 patients healed successfully. The fracture of the ulnar and the radius healed 8.5 or 15 weeks after surgery, 13.5 weeks in average. Eleven patients underwent second stage reshape and function restoration. The function of the hands and forearms recovered satisfactorily. Eleven patients returned to their work. Six patients can live with basic function for living.</p><p><b>CONCLUSIONS</b>The external fixator used for complex tissue defect in the forearm can keep the position of the pedicle, replacing plaster fixation. It can reduce the incidence of flap and vessel spasm, and get good outcomes.</p>

Transplantation of large anterior latissimus dorsi muscular flap combination with musculus rectus abdominis flap / 中华外科杂志

<p><b>OBJECTIVE</b>To study the value and surgical techniques of transplantation of large anterior latissimus dorsi muscular flap combination with musculus rectus abdominis flap.</p><p><b>METHODS</b>Three cases (2 male and 1 female) with skin defect and bone exposed were reviewed from May 2005 to January 2007. Two patients suffered from trauma, and 1 suffered from tumor resection. Flaps size were: 60 cm x 32 cm, 55 cm x 30 cm and 50 cm x 25 cm, flaps pattern including: 1 free flap with 2 ends of vascular, 1 flap with pedicle and free vascular end, 1 flap with 2 ends of pedicle.</p><p><b>RESULTS</b>Two flaps survived completely, 1 flap with necrosis edge eventually healed after change of dressing. The infection had been effectively controlled and ready for function recovered. One case caused by trauma recovered with fracture healing, full weight-bearing and restore the original work.</p><p><b>CONCLUSIONS</b>Large anterior latissimus dorsi muscular flap combination with musculus rectus abdominis flap can be used for repair of large skin defect. For the difficulty and technical requirements, surgical indications should be strictly controlled.</p>

Vascularized pedicle iliac crest for the repair of bone and soft tissue defect of lower extremity / 中华外科杂志

<p><b>OBJECTIVE</b>To study the role of transplantation of the vascularized pedicle iliac crest for the repair of bone and soft tissue defect of lower extremity.</p><p><b>METHODS</b>The vascularized pedicle iliac crest was designed for the repair of bone and soft tissue defect of lower extremity according to anatomic feature of leg and foot. Skin graft was used for coverage of the iliac flap.</p><p><b>RESULTS</b>Skin survival could demonstrate the survival of the vascularized pedicle iliac crest indirectly one week postoperatively. Skin survived completely in 4 cases and partly in 3 cases. Callus was seen at the transplantation site one month postoperatively, and K-wires were removed 4 months later in the cases of metatarsal defect. The external fixators were removed in the cases of tibia defect 6 to 8 months postoperatively. The functions of lower extremities were restored in 2 to 4 months. The bone and soft tissue defects were repaired, and ultimate function and cosmetic effects were satisfied after the mean follow up of 10 months (ranged from 6 to 15 months).</p><p><b>CONCLUSION</b>Transplantation of the vascularized pedicle iliac crest is an ideal method for the repair of bone and soft tissue defect of lower extremity. The operation can be performed in one stage. The functions and cosmetic effects are better than the traditional methods.</p>

Unilateral external fixator in the treatment of lower third humeral shaft fractures / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To retrospectively analyze the effect of unilateral external fixators in the treatment of lower third humeral shaft fractures.</p><p><b>METHODS</b>From October 1997 to October 2003, 33 patients aged 15 -70 years (average 31 years) with lower third humeral shaft fractures were treated with unilateral external fixators. There were 9 spiral fractures (type A1), 1 oblique fracture (type A2), 3 transverses fractures (type A3) and 20 comminuted fractures (11 type B1, 9 type B2) according to AO classification. Fifteen cases were treated with open reduction and limited internal fixation and fixation with external fixators, 10 cases treated with open reduction and fixation with external fixators, and 8 cases treated with closed reduction and fixation with external fixators. Nerve exploration was undertaken in 9 cases with preoperative radial nerve injury. External fixators were removed after bone healing. The average follow-up was 18 months with a range from 8 to 24 months.</p><p><b>RESULTS</b>The time of bone healing ranged 11-22 weeks (average 14 weeks). The latest follow-up showed the functions of 9 cases of preoperative radial nerve injury and of 2 cases postoperative radial nerve injury and the function of elbow were recovered to normal. There were only 7 cases of superficial infection at pin hole, which was subsided by using oral antibiotics and pin-hole care with mild disinfectants.</p><p><b>CONCLUSIONS</b>Fixation with unilateral external fixators combined with open reduction and limited internal fixation has a good effect in the treatment of lower third humeral shaft fractures.</p>

The use of dynamic axial external fixator with modified technique in Pilon fractures of tibial / 中华外科杂志

<p><b>OBJECTIVE</b>To retrospectively analyses the results of dynamic axial external fixator with modified technique in the treatment of severely Pilon fractures.</p><p><b>METHODS</b>From July 2000 to February 2003, 14 patients with severely Pilon fractures were treated with dynamic axial external fixator inserted with modified technique combined with limited open reduction and internal fixation with screws and Kirschner wires, with two distal external pins inserted into talus and calcaneus respectively so that the rotation axis of distal clamp was coincided with that of ankle joint. All patients were young or middle-aged people from 20 y to 52 y (average 38 y). All fractures were Rüedi-Allg were type II or type III. External fixators were removed after bone healing. Duration of follow-up was 5 - 36 m (average 18 m).</p><p><b>RESULTS</b>The time of bone healing was 12 - 24 weeks (average 14 weeks). At the latest follow-up, results include 5 excellent, 6 good and 3 fair according to ankle scoring system (ASS). There was only one case of superficial pin site infection settled with oral antibiotics and pin site care with mild disinfectants. There was no wound breakdown, superficial and deep infection, osteomyelitis, fracture fragments redisplacement and collapse.</p><p><b>CONCLUSION</b>Dynamic axial external fixator with modified technique combined with limited internal fixation is an effective method for the treatment of severely Pilon fractures.</p>

Mechanism of radiculopathy induced by experimentally herniated nucleus pulposus in rats / 中华外科杂志

<p><b>OBJECTIVE</b>To determine the effects of the autologous nucleus pulposus on the pain-related behaviors of hind paws in rats.</p><p><b>METHODS</b>The nucleus pulposus harvested from autologous coccygeal vertebra was applied beside the unilateral L4 and L5 nerve roots without compression. The mechanical withdrawal threshold of both paws were measured in different times after surgery. And hematoxylin and eosin (HE) staining was applied to observe the changes of nucleus pulposus and nerve roots.</p><p><b>RESULTS</b>Mechanical sensitivity of the operated side in paws obviously increased after application of autologous nucleus pulposus beside the lumbar nerve roots without compression. And HE staining showed obviously inflammatory changes in the nucleus pulposus and vacuolation in the nerve roots.</p><p><b>CONCLUSIONS</b>Inflammation resulted from nucleus pulposus may contribute to the development of mechanical hyperalgesia. The results suggest that in addition to mechanical compression, inflammation may be an important factor in the pathogenesis of sciatica.</p>