Senescence is one of the most important phenomena in cells' life. It is hold by one of hypothesis for cell senescence that residue DNA damages of a cell will accelerate its senescence.The normal function of surveillance and repair system for DNA damage is highly related with the senescence regulation of a cell. As a result, research of senescence regulation role of enzymes related for surveillance and repair of DNA damage, such as PARP, DNA-PK, ATM, p53, etc., will discover the inner relation between stress response of cell to DNA damage, regulation of DNA damage repair and cell senescence. That may be helpful for research of anti-aging and treatment of tumor by regulation of senescence of tumor cells.

Objective To investigate the effects of a recombinant antisense adeno virus for epidermal growth factor receptor (EGFR) combined with irradiation on b reast cancer cells.Methods Human EGFR cDNA fragment was subcloned in the oppos ite orientation to the cytomegaloviral promoter and inserted into a E1/E3-delet e d type 5 adenoviral vector to obtain AdE5 construct which expresses EGFR antisen se RNA. Combined with ?-ray irradiation, its effects on clonogenicity and cell cycle phase distribution were studied in a human breast cancer line MDA-MB-231 . Results EGFR protein expression was dramatically inhibited in MDA-MB-231 cell s after AdE5 infection. The post-irradiation clonogenicity was reduced by AdE5 in a viral and irradiation dose-dependent manner. Further cytometric analysis show e d that AdE5 infection at a?MOI of 300?pfu/cell induced a cell cycle progre ssion from radio-resistant G 0+G 1 phases to radiosensitive G 2+M phases, resultin g in a synergistic effect after combination of these two treatments. Conclusions The t ransduction of EGFR antisense RNA by adenoviral vector is effective for antisens e strategy targeting EGFR, and increases the cell-killing effect of ionizing radiation on breast cancer cells.

Objective To understand the variation of the DNA double-strand break rejoining capacity among different cultured cancer cell lines and the primary cancer cells from brain cancer patients,and to explore the predictor of radiotherapy responses of cancers. Methods DNA double-strand breaks (DSBs) were induced by 60Co γ-irradiation. Pulsed-field gel electrophoresis was used to analyze the initial production and rejoining of DNA DSBs. Radiosensitivity was determined by in vitro assay of clonogenic-forming capacity. Results A wide variation of radiosensitivity, e.g. The survival parameter of D0 varied from 0.65 to 2.15 Gy, was displayed among the eight cell lines derived from different type of cancers. Although differential level of initial DNA DSBs induced by 20 Gy γ-rays was observed among various cell lines, it was not correlated with the radiosensitivity. The deficiency of DNA DSB rejoining in radiosensitive cell lines was shown either in the early rapid-rejoining phase (SX-10 cells) or in the late slow-rejoining phase (A2780 cells). A significant relationship was observed between the residual level of DNA DSBs measured at 2 h post-20 Gy irradiation and the cellular radioseusitivity (D0 or SF2). The kinetic curves of rejoining DNA DSBs in the primary human brain tumor cells indicated a variation on DSB rejoining capacity among different individual tumor. The residual level of DNA DSBs after 2 h of rejoining post 20 Gy irradiation in primary human brain tumor cells is compatible to the results obtained in vitro culture cancer cell lines. Conclusions The residual level of DNA DSBs is correlated with radioresistance of cancer cells, and the residual DNA damage is a useful parameter in predicting the response of tumor tissue to radiotherapy.

Regulation of gene expression is one of the most importa nt responses of cells to DNA damage induced by radiation. A novel expressed seq u ence tag (EST) fragment had been cloned from human embryo lung cells induced by 50cGy radiation and named RIG1. To clone the full-length cDNA of RIG1, a non-c loned cDNA library of human embryo lung cells induced by low dose irradiation ha d been established. This library was used as template in enchanced nest RACE PCR and biotin-labeled probe was used for further purification. The 3′ flanking s equence of this EST was cloned and sequenced with this set of technology. It was illuminated by homology analysis that this 3′ flanking sequence and the origin al EST are well aligned with a BAC clone of 20th chromosome and the predic ted exons sequence of this chromosome is well consisten ce with the real EST. Thus the RIG1 can be roughly located in 20th chromos ome. By use of the exons sequence predicted from chromosome sequence by GENSCA N, full-length of RIG1 gene has been cloned. Chromosome location of RIG1 gene i s further determined by this successful verification of Bioinformatics predictio n by experiment. By the same step, genome sequence of RIG1 has been determined. Therefore,by the combined use of Bioinformatics analysis，the full-length cDNA sequence and genome sequence of RIG1 gene are obtained and the predicted protei n sequence is determined.

OBJECTIVETo investigate the therapeutic effect of primary reconstruction of skin avulsion injury with bilateral anterolateral thigh flaps combined with thorax umbilicus flap or latissimus dorsi flap.

METHODSFrom June 2005 to Aug. 2011, 4 cases with skin avulsion injury on both feet were treated. The bilateral anterolateral thigh flaps, including with anterolateral thigh cutaneous nerves, were transferred to cover the feet plantar. The thorax umbilicus flap or latissimus dorsi flap were used to cover the feet dorsum.

RESULTSAll the skin avulsion injury were reconstructed primarily. All the flaps survived completely with good cosmetic and functional results. The patients were followed up for 6 months to 2 years with good sensory recovery (two point discrimination: 14-18 mm).

CONCLUSIONThe skin avulsion injury on both feet can be primarily reconstructed by bilateral anterolateral thigh flaps combined with thorax umbilicus flap or latissimus dorsi flap.

Adolescent ; Follow-Up Studies ; Foot Injuries ; surgery ; Humans ; Lacerations ; surgery ; Myocutaneous Flap ; transplantation ; Reconstructive Surgical Procedures ; Skin ; injuries ; innervation ; Surgical Flaps ; innervation ; transplantation ; Thigh ; innervation

OBJECTIVETo investigate the clinical effect of lateral superior genicular composite tissue flap for tissue defect.

METHODSThe axis line of flap is the lateral thigh vertical midline. The cutaneous branch is inserted 4 cm near the femoral lateral epicondylus. The anterior border is the elongation line along patellar lateral border. The posterior margin is the hinder margin of femoral biceps. The lower border is the horizontal line along the upper line of patella. The composite flaps were used in 18 cases with soft tissue defects in extremities, 11 cases with clacaneus tenden defects and 16 cases with bony nonunion. Results From Mar. 2002 to Sept. 2013, 45 cases were treated with the composite tissue flaps. The flaps size ranged from 6 cm x 3 cm to 17cm x 9 cm. All the flaps survived completely. Blood supply crisis happened in 2 cases, which was released by reanastomosis. The patients were followed up for 1 - 2. 5 years with satisfactory aesthetic and functional results. All the bone defect and nonunion were healed. Good healing was also achieved in donor sites. 8 months after operation, knee joint function is evaluated as good by hospital special surgery knee score (HSS).

CONCLUSIONLateral superior genicular compostie tissue flap can be used to reconstruct soft tissue defect, bone defect and tenden calcaneus defect in one stage.

Anatomic Landmarks ; anatomy & histology ; Follow-Up Studies ; Graft Survival ; Humans ; Knee ; anatomy & histology ; Muscle, Skeletal ; anatomy & histology ; Soft Tissue Injuries ; pathology ; surgery ; Surgical Flaps ; transplantation ; Thigh ; Time Factors ; Wound Healing

Objective:Anatomical study of the cross-donor flap pedicled with the peroneal artery and the discussion of the effect of clinical application, so as to describe a new method for the repair of large-area soft tissue defects in the foot and ankle.Methods:From June 2016 to August 2019, 12 specimens of adult lower limbs were studied. The popliteal arteries were perfused with perchloroethylene-ethyl acetate-lead oxide and red perchloroethylene-ethyl acetate. The origin, number, outer diameter, course and distribution of perforating branches of the peroneal artery were anatomically observed. The source, distribution and anastomosis of the skin nutrient vessels in the posterolateral area of the calf were also studied. Relationship of the blood supply between the peroneal arteries and veins and the nutritional vessels of the sural nerve were observed. In 9 patients, the peroneal artery and vein were designed as the pedicle of cross-donor flap in the repair of large soft tissue defects of foot and ankle. The patients were entered follow-up through outpatient visits and telephone interviews.Results:Among the 12 adult specimens of lower limbs, there were 65 perforating branches from the peroneal artery, 4-7 branches on each side, with an average of (5.41±1.00) branches. The diameter of the penetrating deep fascia was(1.07±0.36) mm. The perforator branches were mostly distributed in 3 sections of 4.0-11.0 cm, 16.0-21.0 cm and 24.0-27.0 cm away from the lateral malleolus, accounting for 48%, 24% and 17% of the total number of perforators, respectively. The outer diameters of the perforator vessels were (0.92±0.26)(0.56-1.68) mm, (1.32±0.38)(0.60-2.14) mm, and (0.98±0.28)(0.62-1.36) mm. The length of the pedicle of the perforator vessels were (3.91±0.96)(2.15-5.78) cm, (5.34±0.50)(4.01-5.85) cm, and (3.31±1.15)(2.16-5.66) cm. The perforating branches in the 3 sections appeared constantly. The diameter of the vessels was≥0.5 mm with an average length of at(4.19±1.16)(2.15-5.85) cm. The vascular network of the flap in the posterolateral area of the calf was mainly composed of subdermal vascular network and deep fascial vascular network. The deep fascia vascular network in the posterolateral area of the calf had 3 obvious longitudinal chains, including the medial sural neurotrophic vascular chain, the small saphenous vein-sural nerve communicating branch vascular chain and the lateral sural neurotrophic vascular chain, which took the nutrient blood supply from the perforating branches of the peroneal artery also formed a longitudinal and transverse anastomosis between the perforating branches of the peroneal artery. In the clinical trials performed on 9 patients, all soft tissue defects of foot and ankle were repaired. The composite tissue flap survived without infection or necrosis. The follow-up was lasted for 12 months to 3 years. The postoperative function and the donor site appearance were good and the patients walked normally. According to the American Orthopaedic Foot and Ankle Association(AOFAS) foot scoring standard, the function of affected feet were evaluated. Five patients were excellent and 4 were good.Conclusion:The cross-donor flaps pedicled with peroneal arteries and veins has sufficient blood supply and a large area. It provides a method for the repair of large-area soft tissue defects in the foot and ankle.