Nasopharyngeal carcinoma (NPC) is sensitive to radiotherapy and chemotherapy.Combined chemoradiotherapy improved the survival of the patients with locally advanced NPC.However,a part of these patients did not gain the survival benefit from the combined chemoradiotherapy because of the additional serious adverse reaction.In order to achieve the best therapeutic gain after balancing the benefit and cost,all kinds of influencing factors of individualized chemoradiotherapy including the clinical and biological molecular factors which has a broad developing prospect must also be considered.

Objective To compare and evaluate dose at optic structures (eyeballs, optic nerves and chiasma) between conventional and CT simulated treatment planning for nasopharyngeal carcinoma. Methods Thirty three patients with T1 to T4 nasopharyngeal carcinoma underwent simulated spiral CT with picker PQ 5000 and AcQ plan 4.1.1 software system. At first irradiation portals were delinated by the simulation films taken on the conventional X ray simulator using the digital reconstruction (DRR) of the treatment planning system (TPS) supplemented by the patient's CT (or MRI) and clinical findings. Then, the gross tumor volume (GTV),clinical target volume (CTV) and planned target volume (PTV) were delineated on every section of the CT scans. At the same time, the silhouette of the nearby important organs was drawn out ,paying special attention to the backward passage of the retrobulbar optic nerves up to the optic chiasma. The final portals were designed by the 3 dimensional relation between the tumor and its surrounding organs. Then dose distribution was separately calculated by two independent TPSs,with 100% at the target center. Finally,the maximum dose (D max ),average dose (D ave ) and median dose (D med ) of the tumor target area, eye ball,optic nerve and also the length of optic nerve included within the portal of these two technics were compared.Results The dose distribution in nasopharyngeal GTV and CTV were satisfactory both in CT simulated and conventional planning. However, the D max ,D ave and D med all showed significant differences. Those by CT simulated planning were obviously lower than those by conventional planning. CT simulated planning was able to spare more optic nerve by leaving it out of the irradiation portal,thereby,avoiding unwanted radiation.Conclusion CT simulated treatment planning is able to reduce the superfluous radiation to the optic nerve in external irradiation of nasophargngeal carcinoma.

Objective To investigate the local-regional recurrence of nasopharyngeal carcinoma (NPC) 5 years after conventional radiotherapy and its prognosis.Methods From August 1989 to Decem ber 1999,1384 patients with newly histo-pathologicatly diagnosed NPC were treated with conventional radia tion.350 out of 1277 followed-up patients were diagnosed as local-regional failure.The intervals between completion of radiation and tumor relapse ranged from 6 months to 171 months.There were 62 patients with local-regional recurrence 5 years after the radiotherapy,including 41 in nasopharynx,19 in neck and 2 in na sopharynx and neck simultaneously.Thirty-seven patients with late local-regional recurrence received a sec ond course conventional radiotherapy.Results The median survival time was 44 months(95% CI = 30.4 -57.6) of patients with re-irradiation comparing with 14 months (95% CI = 7.1-20.8) of those without. The 5 year survival rate after re-irradiation was 42%.Conclusions Local-regional recurrence of nasopha ryngeal carcinoma can oeoure 5 years after radiotherapy.Second course converntional radiotherapy possesses good results.

As the first treatment of choice for medically inoperable patients with early stage non-small cell lung cancer,it is demonstrated that the therapeutic outcome of stereotactic body radiation therapy (SBRT)is similar to that of surgery,but the data is mainly from nonrandomized controls and retrospective studies.More cases of randomized prospective clinical trials are needed to confirm the conclusions.The biologically effective dose ＞ 100 Gy is associated with improved local control and overall survival,and the small tumor volume is correlated with higher local control rate.

OBJECTIVETo construct an double-layered tube-shaped poly (lactic-co-glycolic acid) (PLGA) scaffold composited with vascular endothelial growth factor (VEGF)/ platelet-derived growth factor (PDGF), and to evaluate in vivo the axial vascularization from femoral arteriovenous bundle encapsulated.

METHODSEighteen male adult New Zealand rabbits were assigned randomly into 3 groups: Experimental group (n = 8), experimental control group (n = 8), empty control group (n=2). The femoral arteriovenous bundle were separated and encapsulated in double-layered tubeshaped PLGA scaffold prepared by solution casting and particle leaching. According to the way of cell factors being composited to the prepared double-layered scaffold: 1) experimental group: VEGF in inner layer and PDGF in outer layer; 2) experimental control group: VEGF in inner layer with blank outer layer; 3) empty control group: Pure blank. Specimens were retrieved at 7, 10, 14, 21 days postoperatively (7, 10 days in empty control group). The histological evaluation was performed.

RESULTSAt 7 days postoperatively, blood vessel sprouts were observed in experimental group and experimental control group, radially from the central femoral arteriovenous bundle. At 10 days postoperatively, completely penetrations of the double-layered scaffold by abundant new generated blood vessel sprouts were observed, and density descended gradiently from inside to outside. At 14 days postoperatively, new blood vessels in experimental group showed more thickness and layered structure of the wall, while monolayer endothelial cells in experimental control group. At 21 days postoperatively, new blood vessels in experimental group showed more mature characteristics, while less density of blood vessels in experimental control group. There was no obvious blood vessel structure in empty control group.

CONCLUSIONThe double-layered tube-shaped PLGA scaffold composited with VEGF/PDGF could induce early angiogenesis.

OBJECTIVE: To establish a CDDP-resistant cell line from human nasopharyngeal carcinoma and evaluate its biological characteristics. METHOD: By continuously exposing and gradually increasing dose of cisplatin (CDDP), a resistant nasopharyngeal carcinoma cell line (HNE1/CDDP) was established. Drug sensitivity of this cell line was detected by MTT assay; the alterations of its biological characteristics were determined using light microscopy, cell counting and flow cytometry (FCM); its ability of adhesion, migration and invasion were also evaluated. RESULT: HNE1/CDDP cell line was developed after 10 months with stable resistance to cisplatin with the resistance index was 5.83. HNE1/CDDP cell exhibited cross-resistance to many other chemotherapeutic agents (carboplatin, oxaliplatin and etoposide, etc). The morphology of HNE1/CDDP changed; doubling time prolonged; and the cell number of S-phase and G2/M-phase decreased while of G0/G1 phase increased compared with parental cells. The ability of adhesion, migration and invasion had no difference between the parental and the resistant cells. CONCLUSION HNE1/CDDP cell line shows the typical and stable resistant phenotype and can be used as a research model.
Antineoplastic Agents ; pharmacology ; Cell Line, Tumor ; Cisplatin ; pharmacology ; Drug Resistance, Multiple ; Drug Resistance, Neoplasm ; Humans ; Nasopharyngeal Neoplasms

There is increasing interest in the clinical use of flattening filter-free (FFF) beams. In this study, we aimed to investigate the dosimetric characteristics of volumetric modulated arc radiotherapy (VMAT) with FFF beams for nasopharyngeal carcinoma (NPC). Ten NPC patients were randomly selected to undergo a RapidArc plan with either FFF beams (RA-FFF) or conventional beams (RA-C). The doses to the planning target volumes (PTVs), organs at risk (OARs), and normal tissues were compared. The technical delivery parameters for RapidArc plans were also assessed to compare the characteristics of FFF and conventional beams. Both techniques delivered adequate doses to PTVs. For PTVs, RA-C delivered lower maximum and mean doses and improved conformity and homogeneity compared with RA-FFF. Both techniques provided similar maximum doses to the optic nerves and lenses. For the brain stem, spinal cord, larynx, parotid glands, oral cavity, and skin, RA-FFF showed significant dose increases compared to RA-C. The dose to normal tissue was lower in RA-FFF. The monitor units (MUs) were (536 ± 46) MU for RA-FFF and (501 ±25) MU for RA-C. The treatment duration did not significantly differ between plans. Although both treatment plans could meet clinical needs, RA-C is dosimetrically superior to RA-FFF for NPC radiotherapy.
Adult ; Aged ; Feasibility Studies ; Female ; Humans ; Male ; Middle Aged ; Nasopharyngeal Neoplasms ; pathology ; radiotherapy ; Organs at Risk ; radiation effects ; Radiometry ; methods ; Radiotherapy Dosage ; Radiotherapy Planning, Computer-Assisted ; methods ; Radiotherapy, Intensity-Modulated ; methods

Ectoine is an amino acid derivative and an important natural product in halophilic microorganisms. It plays an important role in protecting cells and stabilizing biological macromolecules, and can be widely used in biomedical fields such as drug preparation adjuvants, organ transplantation and preservation, skin wound repair and cosmetics. Due to the medical value and commercial market demand of ectoine, this article summarized the recent advances in the microbial production of ectoine, including the mutation and breeding of hyper-producing strains, construction of genetically and metabolically engineered strains, optimization of fermentation processes, and extraction and purification processes. The application of multi-omics technologies and computational biology to develop an ectoine producing cell factory was prospected, with the aim to provide a reference for ectoine overproduction.
Amino Acids, Diamino/metabolism* ; Fermentation