Endoscopic resection for calcifying fibrous tumors of the gastrointestinal tract

BACKGROUND Calcifying fibrous tumors(CFTs)are rare mesenchymal lesions that can occur in various sites throughout the body,including the tubular gastrointestinal(GI)tract.AIM To analyze the clinical findings of 36 patients with GI tract CFTs to provide guidance for diagnosis and treatment.METHODS This retrospective study included 36 patients diagnosed with CFTs of the GI tract.We collected demographic and clinical information and conducted regular follow-ups to assess for local recurrence.RESULTS The stomach was the most commonly involved site,accounting for 72.2%of the 36 CFTs.Endoscopic mucosal resection(n=1,2.8%),endoscopic submucosal dissection(n=14,38.9%),endoscopic full-thickness resection(n=16,44.4%),and submucosal tunneling endoscopic resection(n=5,13.9%)were used to resect calcifying fibrous tumors.Overall,34(94.4%)CFTs underwent complete endoscopic resections with a mean procedure time of 39.8±29.8 min.The average maximum diameter of the tumors was 10.6±4.3 cm.No complications,such as bleeding or perforation,occurred during an average hospital stay of 2.9±1.2 d.In addition,two patients developed new growth of CFTs near the primary tumor sites,and none of the patients developed distant metastases during the follow-up period.CONCLUSION GI tract CFTs are rare and typically benign tumors that can be effectively managed with endoscopic procedures.

Structure optimization of the organ-pipe cavitating nozzle and its erosion ability test on hydrate-bearing sediments

Cavitating jet is a promising drilling rate improvement technology in both the marine natural gas hydrate (NGH) fluidization exploitation method and the integrated radial jet drilling and completion method. In present study, we aim to improve the efficiency of jet erosion and extracting NGH. With a computational fluid dynamics (CFD) method, the pressure, velocity and cavitation field characteristics of organ-pipe cavitating jet (OPCJ) are analysed. The divergent angle, throat length, and divergent length of OPCJ nozzle are preferred to obtain stronger jet cavitation erosion effect. Laboratory experiments of gas hydrate-bearing sediments (GHBS) erosion by OPCJ and conical jet (CJ) are conducted to compare and validate the jet erosion performance. The impinging models of OPCJ and CJ are constructed to study the impact characteristics. Results show that the preferred values of divergent angle, throat length, and divergent length are 15°, 1d, and 3d, respectively, in present simulation conditions. For GHBS, the OPCJ possesses the advantages of high efficiency and low energy consumption. Moreover, the OPCJ has higher penetration efficiency, while showing equivalent penetration ability compared to CJ. During the impinging process, the OPCJ can induce stronger impact pressure and turbulence effect, and also shows stronger chambering effect and bottom cleaning ability compared to CJ. This study presents the erosion performance of OPCJ and CJ on GHBS, and provides preliminary insights on the potential field applications in NGH exploitation.

内镜黏膜下剥离术治疗巨大结直肠侧向发育型肿瘤的临床研究

目的评价内镜黏膜下剥离术(ESD)治疗巨大结直肠侧向发育型肿瘤(LST)中的疗效和安全性。方法对150例病灶直径>4 cm的结直肠LST的临床资料进行回顾性总结,分析LST形态分型、部位、病理结果、整块切除率、完全切除率和并发症。结果 150例患者中,颗粒型87例(58.0%),非颗粒型63例(42.0%)。部位分别为直肠109例(72.7%),乙状结肠13例(8.7%),降结肠5例(3.3%),横结肠8例(5.3%),升结肠13例(8.7%),盲肠2例(1.3%)。低级别上皮内瘤变23例,高级别上皮内瘤变104例,黏膜内癌7例,黏膜下癌16例。整块切除率为92.7%(139/150),完全切除率89.3%(134/150)。术中出血8.0%(12/150),术后出血1.3%(2/150),穿孔率为2.0%(3/150),术后狭窄2.0%(3/150)。结论非颗粒型巨大结直肠LST恶变率大。ESD治疗巨大结直肠LST是安全有效的。

Endoscopic submucosal dissection for foregut neuroendocrine tumors:An initial study

AIM:To evaluate the feasibility and efficacy of endoscopic submucosal dissection(ESD) for foregut neuroendocrine tumors(NETs).METHODS:From April 2008 to December 2010,patients with confirmed histological diagnosis of foregut NETs were included.None had regional lymph node enlargement or distant metastases to the liver or lung on preoperative computerized tomography scanning or endoscopic ultrasonography(EUS).ESD was attempted under general anesthesia.After making several marking dots around the lesion,a mixture solution was injected into the submucosa.The mucosa was incised outside the marking dots.Dissection of the submucosal layer beneath the tumor was performed under direct vision to achieve complete en bloc resection of the specimen.Tumor features,clinicopathological characteristics,complete resection rate,and complications were evaluated.Foregut NETs were graded as G1,G2,or G3 on the basis of proliferative activity by mitotic count or Ki-67 index.All patients underwent regular follow-up to evaluate for any local recurrence or distant metastasis.RESULTS:Those treated by ESD included 24 patients with 29 foregut NETs.The locations of the 29 lesions are as follows:esophagus(n = 1),cardia(n = 1),stomach(n = 23),and duodenal bulb(n = 4).All lesions were found incidentally during routine upper gastrointestinal endoscopy for other indications,and none had symptoms of carcinoid syndrome.Preoperative EUS showed that all tumors were confined to the submucosa.Among the 24 gastric lesions,16 lesions in 11 patients were type I gastric NETs arising in chronic atrophic gastritis with hypergastrinemia,while the other 8 solitary lesions were type Ⅲ because of absence of atrophic gastritis in these cases.All of the tumors were removed in an en bloc fashion.The average maximum diameter of the lesions was 9.4 mm(range:2-30 mm),and the procedure time was 20.3 min(range:10-45 min).According to the World Health Organization 2010 classification,histological evaluation determined that 26 lesions were NET-G1,2 gastric lesions were NET-G2,and 1 esophageal lesion was neuroendocrine carcinoma(NEC).Complete resection was achieved in 28 lesions(28/29,96.6%),and all of them were confined to the submucosa in histopathologic assessment with no lymphovascular invasion.The remaining patient with NEC underwent additional surgery because the resected specimens revealed angiolymphatic and muscularis invasion,as well as incomplete resection.Delayed bleeding occurred in 1 case 3 d after ESD,which was managed by endoscopic treatment.There were no procedure-related perforations.During a mean follow-up period of 24.4 mo(range:12-48 mo),local recurrence occurred in only 1 patient 7 mo after initial ESD.This patient successfully underwent repeat ESD.Metastasis to lymph nodes or distal organs was not observed in any patient.No patients died during the study period.CONCLUSION:ESD appears to be a safe,feasible,and effective procedure for providing accurate histopathological evaluations and curative treatment for eligible foregut NETs.

Curative effect of BCG-polysaccharide nuceic acid on atopic dermatitis in mice

Objective:To explore the effect of bacilli Galmette-Gurin(BCG)-polysaccharide nuceic acid on atopic dermatitis in mice and its mechanism.Methods:Forty NC/Nga mice were selected and randomly divided into Group A(model group),Group B(dexamethasone treatment group),Group C(BCG polysaccharide nucleic acid treatment group) and Group D(control group) with 10 mice in each group.Atopic dermatitis model were constructed by applying 2,4-dinitrochlorobenzene on the skin of the mice.Mice in Group D were treated with acetone solution(100 μ L) on the foot pad and abdomen after hair removal at the age of 7 weeks.then on ear skin at the age of 8-13 weeks.For mice in A,B and C groups,100 μL of acetone solution containing 2,4-dinitrochlorobenzene was applied to the foot pad and the abdomen at the age of 7 weeks,then on ear skins at the age of8 to 13 weeks.At the age of 7-13 weeks,mice in Group A and Group D were treated with 100 μL saline(i.p.);mice were given dexamethasone(0.1 mL/kg,i.p.) every other day for 7 weeks in Group B;mice were treated with BCG polysaccharide nucleic acid(0.5 mg/kg,i.p.) every other day for7 weeks in Group C.The ear thickness was measured every week and the scratching frequency was recorded 1 times for 10 min a week.The mice were sacrificed after the last administration of drugs,IgE,IL-4,IL-10,IL-I2 and IFN- γ in the plasma were detected using ELISA,and RT-PCR method was employed to detect the concentrations of IL-4,IL-10,IL-12 and IFN- γ proteins.After IIK staining,the lesion degree of inflammation in ear tissue was observed microscopically.Results:The ear thickness and scratching frequency of Group A were significantly higher than those in group B,C and D(P<0.05),and there was no significant difference between Group B and C(P>0.05);the concentrations of IgE,IL-4 and IL-10 in the plasma and the expression of IL-4,IL-10 mRNA in the spleen tissues of Group A,B and C were all significantly higher than those of Group D(P<0.05);the concentrations of plasma IL-12 and IFN- γ,and spleen protein expression of IL-12 and IFN- γ in Group C mice were significantly higher than those of Group A(P<0.05).Histological observation showed obvious ear tissue exudation,erythema,swelling,desquamation of skin,and scabbing in Group A.Histopathology of the skin lesion also showed hyperkeratosis,focal-parakeratosis,stratum spinosum hypertrophy,mild sponge-like edema,a large number of lymphocytes along with plasma cell infiltration in dermis,angiectasis and hyperemia in Group A,while degree of ear skin lesion in Group B and D mice was significandy lighter than that of Group A.Conclusions:BCC polysaccharide nucleic acid can significandy reduce the serum IgE concentrations,increase the expression of IL-12,IFN- γ protein,correct the imbalance of Th1/Th2 in atopic dermatitis mice,and has obvious inhibitory effect on atopic dermatitis in NC/Nga mice.

Endoscopic biliary drainage for biliary obstruction

OBJECTIVE: To improve the successful rate of endoscopic biliary drainage. METHODS: Three hundred and fifty-two patients with biliary obstruction were given biliary drainage via duodenoscope from January 1998 to December 2002. 258 patients received endoscopic naso-biliary drainage (ENBD), 51 endoscopic retrograde biliary drainage (ERBD), and 43 endoscopic metal biliary endoprothesis (EMBE). RESULTS: Of the 352 patients with biliary obstruction, 337 succeeded in drainage by endoscopy and 15 failed. Ten ENBD failed patients were handled successfully by readjustment of the site of the naso-biliary tube. In 3 ERBD failed patients, 2 were given plastic stents with appropriate length and got a fluent drainage. Percutaneous transhepatic biliary drainage (PTBD) was performed in one patient after failure of endoscopic management. In 2 patients with failed EMBE, one stent could not exceed the site of tumor stricture and one was obstructed by tumor implantation only one month after EMBE. Placement of another metallic stent and a plastic stent through the previous prothesis for each patient ensured a successful drainage. CONCLUSIONS: The effect of endoscopic biliary drainage for biliary obstruction is definite. Drainage failure can be avoided or remedied as early as possible by taking some active measures.

Endoscopic sphincterotomy or papillary balloon dilatation for choledocholithiasis

Objective: To assess the safety and effect of endoscopicsphincterotomy (EST) and endoscopic papillary bal-loon dilatation (EPBD) for choledocholithiasis.Methods: 328 patients with choledocholithiasis weresubjected to EST or EPBD; they included 174 patientswith single stone, 112 patients with two stones and 42patients with three stones (one patient with 20 stones).Patients with stones less than 10 mm in diameter un-derwent EPBD and those with stones larger than 11mm in diameter underwent EST.Results: EST and EPBD succeeded in 323 patients(98.5%), and failed in 5. Stones in 98 patients wereexcluded spontaneously after endoscopic therapy. 207patients were subjected to basket or balloon stone ex-traction. Stones in 14 patients were discharged bybasket lithotripsy. Four patients were given wavelithotripsy. Stones in 22 of the 323 patients were ex-tracted thoroughly after 2-3 times attempts. Totalcomplications were noted in 2.5% of the patients.Hemorrhage from the gastrointestinal tract was seenin one patient, cholangitis in 4 patients, and pancre-atitis in 3 patients. In 92 patients receiving digestivetract barium X-ray examination, 86 developed nobarium reflux to the baliary tract, 2 pneumobilia, 4barium reflux to the biliary tract.Conclusion: EST and EPBD are relatively safe and effec-tive in treatment of choledocholithiasis, and have fewcomplications.

Flow-visualization and numerical investigation on the optimum design of cavitating jet nozzle

Cavitating jet is widely used in drilling,rock cutting and ocean re source exploitation because of its stro ng erosion ability.The analysis of the relationship between the flow characteristics and the structure of cavitating jet nozzle is critical.Here,we utilized 3 D printed technology and high-speed photography to design visualization experime nts to analyse the impact of the variation of resonator and throat size of the organ-pipe self-resonating cavitating nozzles on the cavitation characteristics through image processing.The velocity field,pressure field and vapor volume fraction injected by the nozzle were taken as the objective functions to study the influence of different structural parameters on the cavitation effect based on FLUENT 19.0 software,and the results were compared with the experimental results.The results show that increasing the length and diameter of the resonator contributes to the occurrence of cavitation and the structure stability of the flow field.However,excessive size affects self-resonant of the nozzle and makes it difficult to form resonance effect.In this study,the optimal values of nozzle throat length and divergent angle are twice the throat diameter and 40°,respectively.This research provides an integrated research method to study the optimization of self-resonating nozzle and cavitating jet characteristics.

Deficiency of Autophagy-Related Gene 5 in Keratinocytes Leads to Aggravation of Epidermal Damage in 2,4-Dinitrochlorobenzene-Induced Allergic Contact Dermatitis

Objective:The interrelationship between apoptosis and autophagy plays an important role in many pathophysiological processes,however,whether their interplay is involved in allergic contact dermatitis(ACD)has not yet been elucidated.So,we conducted this study to determine whether keratinocyte-specific autophagy-related gene 5(ATG5)deficiency can regulate apoptosis to inhibit skin damage in mice with 2,4-dinitrochlorobenzene(DNCB)-induced ACD.Methods:This study involved keratinocyte-specificAtg5 conditional knockout(cKO)mice(Krt14cre/+-Atg5flox/flox)and control mice(Krt14+/+-Atg5flox/flox).We painted DNCB on the right ear of each mouse to induce ACD.Dermatitis scoring and measurements of ear weight and thickness were performed to evaluate inflammation levels.An immunohistochemical assay was performed to analyze immune cell infiltration.Histological study and TUNEL staining were performed to compare the differences in skin lesions betweenAtg5 cKO mice and control mice.Immunofluorescence and western blotting were used to examine the levels of ATG5 and apoptosis-related protein.The results were statistically analyzed byt test.Results:After DNCB stimulation of mice ears,we observed a more severe phenotype inAtg5 cKO mice than in control mice(dermatitis score:7.500±2.588vs.3.250±0.822,P=0.003).Further analysis of ATG5 protein confirmed keratinocyte-specific ablation ofAtg5 in cKO mice and showed that DNCB did not influence ATG5 expression.Immunohistochemistry assay revealed that the infiltrated immune cells were not involved in aggravation of the phenotype of DNCB-stimulatedAtg5 cKO mice.However,the histological study(P=0.024),TUNEL staining(P=0.024),immunofluorescence(P=0.036),and western blotting showed that the increase in keratinocyte death,especially apoptosis,contributed to aggravation of the phenotype of DNCB-stimulatedAtg5 cKO mice.Conclusion:Deficiency ofAtg5 in keratinocytes increases apoptosis,aggravating skin damage in DNCB-induced ACD mice.This has no relationship with the involvement of immune cells.

Long-term outcomes of endoscopic submucosal dissection for high-grade dysplasia and early-stage carcinoma in the colorectum

Background:Colorectal carcinomas(CRCs)arise from premalignant precursors in an adenoma-carcinoma sequence,in which adenoma with high-grade dysplasia(HGD)and early-stage carcinoma are defined as advanced neoplasia.A limited number of studies have evaluated the long-term outcomes of endoscopic submucosal dissection(ESD)for advanced colorectal neoplasia.This study aimed to assess the efficacy and safety of ESD for advanced colorectal neoplasia as well as the long-term outcomes,including local recurrence and metastasis.Methods:We analyzed data collected from 610 consecutive patients with 616 advanced colorectal neoplasia lesions treated with ESD between January 2007 and December 2013.Clinical,endoscopic,and histological data were col-lected over a median follow-up period of 58 months to determine tumor stage and type,resection status,complica-tions,tumor recurrence,and distant metastasis.Results:The overall rates of en bloc resection,histological complete resection,and major complications were 94.3%,89.4%,and 2.3%,respectively.Hybrid ESD was an independent factor of piecemeal resection.Tumor location in the colon was associated with increased risk of ESD-related complications.During the follow-up period,all patients remained free of metastasis.However,local recurrence occurred in 4 patients(0.8%);piecemeal resection was a risk factor.Conclusions:ESD is effective and safe for resection of advanced colorectal neoplasia,with a high en bloc resection rate and favorable long-term outcomes.ESD is indicated for the treatment of HGD and early-stage CRC to obtain cura-tive resection and reduce local recurrence rate.

Optimal two-impulse space interception with multiple constraints

We consider optimal two-impulse space interception problems with multiple constraints.The multiple constraints are imposed on the terminal position of a space interceptor,impulse and impact instants,and the component-wise magnitudes of velocity impulses.These optimization problems are formulated as multi-point boundary value problems and solved by the calculus of variations.Slackness variable methods are used to convert all inequality constraints into equality constraints so that the Lagrange multiplier method can be used.A new dynamic slackness variable method is presented.As a result,an indirect optimization method is developed.Subsequently,our method is used to solve the two-impulse space interception problems of free-flight ballistic missiles.A number of conclusions for local optimal solutions have been drawn based on highly accurate numerical solutions.Specifically,by numerical examples,we show that when time and velocity impulse constraints are imposed,optimal two-impulse solutions may occur;if two-impulse instants are free,then a two-impulse space interception problem with velocity impulse constraints may degenerate to a one-impulse case.

Hohmann transfer via constrained optimization

Inspired by the geometric method proposed by Jean-Pierre MAREC, we first consider the Hohmann transfer problem between two coplanar circular orbits as a static nonlinear programming problem with an inequality constraint. By the Kuhn-Tucker theorem and a second-order sufficient condition for minima, we analytically prove the global minimum of the Hohmann transfer. Two sets of feasible solutions are found: one corresponding to the Hohmann transfer is the global minimum and the other is a local minimum. We next formulate the Hohmann transfer problem as boundary value problems, which are solved by the calculus of variations. The two sets of feasible solutions are also found by numerical examples. Via static and dynamic constrained optimizations, the solution to the Hohmann transfer problem is re-discovered, and its global minimum is analytically verified using nonlinear programming.