Objective To optimize the application principles of gradient factors(GFs) in decompression algorithm by analyzing its law of regulation.Methods The saturated value of compartments was listed and the limits of decompression were calculated to evaluate the effect of GFs on safety and efficiency of decompression.The anchor point of GFs was changed.Results and Conclusion A higher GF was recommended in shallow and short dives, while in deep and long dives a moderate low GF and decompression by oxygen was preferred.The modification of the anchor points of GFs can increase the risk of decompression sickness and should be used with caution.

Background and purpose:Indensity modulated radiotherapy(IMRT) is an advanced method in radiotherapy field.Divect machine optimization technique is an good aritmetic for IMRT optimization.The purpose of this study was to compare the dosimetric differences between traditional technique and direct machine parameter optimization(DMPO) technique in the treatment of nasopharyngeal carcinoma(NPC) using step and shoot IMRT.Methods:Eleven patients of(NPC) were treated with step and shoot IMRT in Cancer Hospital,Fudan University from Feb.2005 to May 2006.Their plans(original plan,defined as treat) were archived for comparing with four kinds of IMRT plans(defined as DMPO100,DMPO90,DMPO80,DMPO70) with different predefined maximum number of segments(100,90,80,70,respectively),which were designed to use direct machine parameter optimization(DMPO) technique.We compared the total monitor units(MU),total segments,dose distribution and conformity index among the plans.Results:All the plans showed similar target coverage.Compared with traditional technique,IMRT plans with DMPO technique showed higher conformity index,and had similar uniformity except plan DMPO70.The dose distributions of DMPO100 and DMPO90 were similar or superior to the original plan(treat) in terms of critical organs.Without sacrificing plan quality,the total segments were about half of traditional plan if DMPO technique was used for planning.Moreover,the total monitor units(MUs) and the radiation time were decreased.Conclusions:Compared with traditional technique,plans designed with DMPO technique show sharp decrease in total segments without sacrificing plans quality in the treatment of nasopharyngeal carcinoma(NPC).The DMPO technique can also decrease the total MUs and radiation time.

Objective To study the oxidative stress state of mice before and after air simulated diving. Methods Forty-eight mice were divided into 6 groups randomly. Every group was exposed to corresponding pressure for 60 minutes, twice a day for consecutive 3 days. Blood was obtained at the corresponding time to observe the changes of maleic dialdehyde, glutathione, glutathione-s-transferase, glutathione peroxidase, superoxide dismutase and catalase. Results Compared with the control, the activity of glutathione-s-transferase, glutathione peroxidase, superoxide dismutase, catalase and the level of glutathione were markedly inhibited and maleic dialdehyde increased in HO group and HA1 group (P

Background and purpose:There is controversial about dissecting the laryngeal nerve in operation of thyroid tumour in clinic. We adopted the methods of exposure of recurrent laryngeal nerve(RLN) to study their deficiencies and benefits. Methods:We reviewed review 456 cases of thyroid tumour who were operated. In 266 cases, RLN was unveiled generally. In 190 cases that RLN was not exposed, had subtotal thyroidectomy with protection of amatomical region.Results:RLN injury did not occur in the exposure group. 4 cases occurred in non-exposure group(3 cases of temporary RLN injury and 1 case of permanent RLN injury). Among the 3 cases of temporary RLN injury, one was caused by the large size of tumour, the other two were caused by the location of thyroid tumor. One case of permanent RLN injury was a case of reoperation for recurrence.Conclusions:The familiarity of the anatomy and variation of RLN, and the exposure of RLN in thyroid operation, can reduce the rate of the RLN injury.

Through teaching on diving site,teachers can help students strengthen the un-derstanding and memory on theoretical knowledge,translate the knowledge into practical skills,and obtain primary medical supervisal capabilities. Scene teaching in diving unites can help students learn about the great achievements in the past and the present situations. Such understandings would be good for the students’fostering the responsibility and mission sense as a diving physician. In conclusion,it is very necessary to teach on diving site in the teaching of diving medicine,and such teaching should be kept as an essential part.

Objective To investigate the role of mitochondrial respiratory chain (MRC) in induction of reactive oxygen species (ROS) by hyperbaric oxygen (HBO).Methods Superoxide anion (O·-2) specific fluorescence probe DHE and mitochondrial O·-2 probe Mito-SOX were used to label ROS in human umbilical vein endothelium cells(HUVEC) microscopically after HBO exposure.Results After HBO exposure, O·-2 increased (31±8)% and (137±19) % in whole cells and in mitochondria, respectively (P<0.01).These increments were suppressed by MRC complex Ⅱ inhibitor TTFA for (55±11)% in whole cells (P<0.05)and (61±8) % in mitochondria(P<0.01).Conclusion MRC may be the main source of ROS induced by HBO in HUVECs.

Background and purpose:The radiation should move at the same direction in accordance with the position of the couch during radiotherapy due to the different location of gross target volume. However, under the condition of the long distance movement of the couch, collisions between the gantry and the couch (or the patients) may happen. To avoid the collisions between the gantry and the couch, the motion area conlfiction between the gantry and the couch was analyzed.Methods:The distance from isocenter to the surface center of linear accelerator head, and the width and the thickness of treatment bed were measured when the treatment bed was empty, and gantry and collimator were at zero position. Forty sets of bed movement data were collected. The sum of squares ofX-andY-coordinates of reference point was calculated and compared with squares of rotation radius. Then, it was anticipated whether the linear accelerator head will collide with treatment bed. Finally, practical veriifcation was made.Results:Whether linear accelerator head collides with treatment bed depends on the difference between the sum of squares ofX-andY-coordinates and the squares of rotation radius. No collisions will happen when the sum of squares ofX-andY-coordinates is less than that of the squares of rotation radius.Conclusion:It is feasible to avoid collisions of linear accelerator head with treatment bed by comparing the sum of squares ofX-andY-coordinates of reference point with squares of rotation radius.

Objective To explore clinicopathologic features,diagnosis,treatment and prognosis of von Hippel-Lindau (VHL) type 2B mixed cutaneous leukocytoclastic vasculitis. Methods A 22-Year-Old Man who presented with constitutional symptoms,severe hypertension,and purpuric lesions over the knees.Clinical features,histopathological,IHC and anti-angiogenesis therapy of this case with VHL syndrome-2B mixed cutaneous leukocytoclastic vasculitis was studied based on the available follow-up data.He underwent laparoscopic adrenalectomy and nephron sparing nephrectomy.Clinical evaluation included ophthalmologic examination as well as imaging exams and endocrinal hormone test for tumors markers ; molecular analysis consisted of PCR amplification of the complete VHL gene coding sequence (three exons) and automated nucleotide sequencing. Results 24 h urine Norepinephrine was 295.84 μg and octreotide scan was positive.The VHL-2B patient suffered from leukocytoclastic vasculitis,a retinal hole,pancroatic tumors (endocrine tumor and microcystic cystadenoma),bilateral pheochromocyoma,clear renal cell carcinoma,renal cysts,hepatic hemangioma and epididymal cyst.The patient developed 5 different tumors related to VHL within a period of 6 years.The cutaneous vasculitis persisted despite treatment with high-dose systemic corticosteroids,but rapidly resolved after treatment with phenoxybenzamine and removal of bilateral pheochromocytomas.Tumor cells of resected PHEO samples stained positive for CgA and S-100,but negative for Melan-A.,and with less than 1％ Ki-67. Conclusions Cutaneous leukocytoclastic vasculitis is one of paraneoplastic syndrome of pheochromocytoma.Because new lesions may develop during the patient's lifetime,regular clinical inspection is recommended in order to check up the development of any new lesions.

AIM: To evaluate the changes of serum total prostate specific antigen (T-PSA), free prostate specific antigen (F-PSA) and the ratio of F-PSA to T-PSA (F/T) in patients with prostate cancer (PCa) and its clinical significance. METHODS: The concentrations of T-PSA and F-PSA in serum were measured by micropartical enzyme immunoassay (MEIA) using AxSYM System, and the F/T ratio was calculated. RESULTS: Before operation, the concentrations of T-PSA and F-PSA in patients with PCa were much higher and F/T ratio was significantly lower than that in patients with benign prostate hyperplasia (BPH). T-PSA and F-PSA levels decreased, but F/T ratio increased after operation in PCa and BPH. F/T ratio in 83.5% PCa and 6.5% BPH was less than 0.16. To diagnosis PCa, the sensitivity of F/T ratio was 83.5%, and the specificity was 86.7%. CONCLUSION: Serum T-PSA, F-PSA and F/T ratio are important parameters for the early diagnosis of prostate cancer. [

ObjectiveTo discuss the safety and feasibility of transumbilical laparoendoscopic single-site resection of postperitoneal paraganglioma. MethodsFive patients with postperitoneal paraganglioma accepted transumbilical laparoendoscopic single-site surgery from October 2010 to October 2011.Four patients were male and 1 patient was female aged from 24 to 52 years with the average age of 38 years.Three patients presented with paroxysmal hypertension,1 patient with persistent hypertension,and the other with no symptom.The tumors were located on left postperitoneum in 3 cases (2 adjacent to left renal vessels,the other para-aortic),and right postperitoneum in 2 cases (1 adjacent to right renal vessels,the other between inferior vena cava and aorta).The diameter of tumors ranged from 2.5 cm to 6.0 cm.or-blocker was given for preoperational preparation.After 2 -4 weeks,transumbilical laparoendoscopic single-site resection of tumors were administered.Transparacolic route was selected in 4 cases and the other was operated through mesentery. ResultsAll the operations were successful.None was converted to conventional laparoscopic surgery or open surgery.The operative time ranged from 80 to 190 min,the mean was 150 min.The blood loss ranged from 50 to 150 ml,the average blood loss was 85 ml. No operation-related complications ocurred.Four cases with hypertension returned to normal blood pressure.All cases recovered uneventfully and discharged in 3 to 6 d after operation.Postoperational pathologic result proved the diagnosis of paraganglioma.The wound healed very well and the scars were occult.Follow-up was performed in all cases for 3 to 15 months.No recurrence was found.ConclusionTransumbilical laparoendoscopic single-site resection of postperitoneal paraganglioma could be safe and effective,and has good cosmetic effect.