Pancreatic cancer secondary to intraductal papillary mucinous neoplasm with collision between gastric cancer and B-cell lymphoma: A case report

BACKGROUND Patients with intraductal papillary mucinous neoplasm(IPMN)have an increased risk of pancreatic and extrapancreatic malignancies.Lymphomas are rare extrapancreatic malignancies,and in situ collisions of early gastric cancer and diffuse large B-cell lymphoma(DLBCL)are even rarer.Here,we report the first case of pancreatic cancer comorbid with in situ collision of extrapancreatic malignancies(early gastric cancer and DLBCL)in a follow-up IPMN patient.Furthermore,we have made innovations in the treatment of such cases.CASE SUMMARY An 81-year-old Japanese female diagnosed with IPMN developed elevated carbohydrate antigen(CA)19-9 levels during follow-up.Because her CA19-9 levels continued to rise,endoscopic ultrasound(EUS)was performed and revealed a suspicious lesion at the pancreatic tail.However,lesions in the pancreas were not found by computed tomography,magnetic resonance imaging,or endoscopic retrograde cholangiopancreatography.To make an exact pathological diagnosis,EUS-guided fine needle aspiration was performed.To our supprise,early gastric cancer was found in preoperative gastroscopy.The gastric cancer was completely resected through endoscopic submucosal dissection before postoperative pathology identified early adenocarcinoma collided with DLBCL.Subsequent EUS-guided fine needle aspiration provided pathological support forthe pancreatic cancer diagnosis, and then laparoscopic distal pancreatectomy andsplenectomy were performed. CA19-9 levels returned to normal postoperatively.CONCLUSION Endoscopic submucosal dissection is appropriate for submucosal lymphomas inpatients intoleratant of chemotherapy. EUS can detect small IPMN-relatedpancreatic tumors.

Conventional Radical and RAFT Alternating Copolymerizations of Hydroxyalkyl Vinyl Ethers and Dialkyl Maleates

The alternating copolymerization of hydroxyalkyl vinyl ethers and dialkyl maleates is investigated by conventional radical polymerization and reversible addition-fragmentation chain transfer polymerization(RAFT).The influence of comonomer structure,comonomer feeding ratios,and monomer concentrations on the copolymerization and the copolymer structure have been investigated systematically.With 2-hydroxyethyl vinyl ether(HEVE)and dimethyl maleates(DMM)as comonomers,a well-defined alternating copolymer is prepared with M_(n)=3400 and M_(w)/M_(n)=1.93 up to 71.6% monomer.The alternating sequential chain structure of the copolymers has been proved by both NMR and matrixassisted laser desorption/ionization time-of-flight mass spectrometry(MALDI-TOF MS).The experimental reactivity ratios and theoretical calculated highest occupied molecular orbital and the lowest unoccupied molecular orbital of vinyl ethers and alkyl maleates support that these monomer pairs have tendency to form alternating copolymers.With 2-cyanopropan-2-yl N-methyl-N-(pyridin-4-yl)carbamodithioate as the RAFT agent,the molecular weight of HEVE and DMM copolymer increases with the monomer conversion,demonstrating a controlled radical polymerization feature with well-controlled molecular weight and relatively narrower molecular weight distribution.With alternating copolymer of HEVE and DMM as macro-CTA(M_(n)=5200 and M_(w)/M_(n)=1.46),both the chain extension with HEVE and DMM(M_(n)=10400 and M_(w)/M_(n)=1.72)and block copolymerization with vinyl acetate have been successfully achieved(M_(n)=8500 and M_(w)/M_(n)=1.52).

Polypropylene/Silica Nanocomposites in situ Prepared via Sol-Gel Reactions Using Porous Spherical Poly(propylene-g-(styrene-alt-maleic anhydride)) Granules as Reaction Loci

Using the porous polypropylene （PP） granules consisting of submicroparticles prepared by the reactor granular technology （RGT）, a facile process was developed to synthesize in situ polypropylene/silica nanocomposites where styrene- alt-maleic anhydride copolymers （PSM） were firstly grafted onto both the outer- and the inner-pore surfaces of PP granules via solid-phase grafting polymerization, and then a sol-gel reaction was conducted inside these micro-pores with the carboxyl acid derived from maleic anhydride as catalyst. TEM micrographs demonstrated that the silica nanoparticles obtained by this strategy had a size around 10-20 nm in diameter and uniformly dispersed in the PSM-based nanocomposites. More importantly, the silica nanoparticles could significantly reduce the size of PP spherulites. Consequently, the PP/silica nanocomposites with high transparency and good mechanical performance were achieved.

Facile Construction of Synergistic β-Glucosidase and Cellulase Sequential Co-immobilization System for Enhanced Biomass Conversion

Converting renewable cellulose into glucose via cellulase catalysis for further production of biofuel has been recognized as one of the most promising ways for solving energy crisis.However,the hydrolysis performance of immobilized cellulase was not satisfactory for practical application due to the reduced catalytic efficiency and lack of β-glucosidase(BG)component in cellulase.Here,a facile method was developed to sequentially co-immobilize BG and cellulase by polymeric microparticles with hierarchical structure.In this strategy,BG was firstly entrapped into the cross-linked poly(ethylene glycol)(PEG)microparticles via inverse emulsion polymerization initiated by isopropyl thioxanthone(ITX)under the irradiation of visible light,leaving the formed ITX semi-pinacol(ITXSP)dormant groups on surface of BG-loaded microparticles,which could be further activated by visible light irradiation and initiated a graft polymerization to introduce poly(acrylic acid)(PAA)brush on the PEG core.After that,cellulase was covalently bonded on the PAA chains via carbodiimide reaction.The synergic effect of BG and cellulase was verified in the dual enzyme immobilization system,which led to a better stability at a wide range of temperature and pH than free enzymes.The dual enzymes system exhibited excellent reusability,which could retain 75%and 57%of the initial activity after 10 cycles of hydrolysis of carboxyl methyl cellulose and 5 cycles of hydrolysis of filter paper,respectively,indicative of the potential in biofuel areas in a cost-effective manner.

Synthetic Features and Mechanism for the Preparation of Vinyl Chloride-co-Butyl Acrylate-co-Vinyl Acetate Terpolymer via Precipitation Polymerization

Without any type of su rfactant or dispersing agent,precipitation polymerization has great superiorities in both polymer synthesis and applications.In the present work,the polymerization of vinyl chloride(VC),n-butyl acrylate(BA),and vinyl acetate(VAc)are conducted in the precipitation polymerization system and series of their random terpolymers poly(vinyl chloride-co-n-butyl acrylate-co-vinyl acetate)(PCBV)are synthesized successfully.The effects of various polymerization conditions,including solvent polarity,temperature,initiator concentration,and monomer feed ratios on the polymerization kinetics,number-average molecular weight(M_(n)),and terpolymer composition are investigated systematically.The solvent and the monomer feed ratio are crucial factors not only for the polymer morphology,but also for the reaction kinetic.In the non-polar solvent such as n-hexane,the PCBV displays particle morphology when the composition of BA ratio lower than 10 wt%.Otherwise,the PCBV forms a uniform polymer phase and precipitates out from the mixture.In the polar solvent,e.g.,dimethyl carbonate(DMC)and ethanol,the PCBV polymer maintains a slurry state either in low or in high monomer feed ratio.Impressively,VC based ternary copolymer that obtained in n-hexane has much lower M_(n)(<20 kDa)and much higher BA units mass fraction(>40 wt%)compared with emulsion and suspension polymerization.Additionally,the terpolymer can be easily sepa rated by simple centrifugation.

Preparation of Ultralow Molecular Weight Poly(vinyl chloride) with Submicrometer Particles via Precipitation Polymerization

Poly(vinyl chloride), with ultralow molecular weight, produced by free radical polymerization either at high temperature or in the presence of chain transfer agents, is widely used as special resins and polymer process additives. This paper reports a new process, called self-stabilized precipitation polymerization, in which the polymerization of vinyl chloride monomer (VCM) is conducted in hydrocarbon diluents without addition of any suspending agent or emulsifier. The merits of this novel strategy include:(1) PVC resins with ultra-low number-average molecular weight (Mn) from 4000 to 15000, which is much lower than Mn of those prepared by conventional suspension and emulsion polymerizations,(2) sub-micrometer PVC particles with near spherical morphology, and (3) the very simple post-polymerization separation process. Under mild stirring, polymerization proceeds stably and smoothly. The influences of main process factors, such as solvents, initiator and monomer concentrations, polymerization time, and temperature on both particle morphology and Mn of the polymer products are investigated systematically. The molar ratio of-CH2-CHCl-/-CH=CH-CH2CHCl, a good indicator of structural defects, is about 1000/0.1 which means the low molecular weights do not result from chain transfer to the monomers. Then the mechanism of this polymerization is proposed. In summary, this novel polymerization technology provides a straightforward method for preparing PVC particulate products with low Mn.

A facile method to prepare polypropylene/poly(butyl acrylate)alloy via water–solid phase suspension grafting polymerization

Polypropylene/poly（butyl acrylate） alloy is produced by water-solid phase suspension grafting polymerization with a submicrometer microdomain where graft polymerization occurs within micropores of polypropylene particles prepared by reactor granule technology （RGT）. The results show that the grafting percentage （GP） of butyl acrylate （BA） increases with the increase of the monomer concentration, which could reach 32.6% while the grafting efficiency （GE） is up to 98%. The addition of the crosslinking agent, triethylene glycol diacrylate （TEGDA）, could improve GP up to 36.3%. Transmission electron microscopic （TEM） micrographs demonstrate that PBA microdomains distributed in PP matrix increase in size less than 500 rim. Moreover, TEM images show that the grafting phase exhibits a singlephase behavior with the addition of TEGDA, which implies that the ratio of graft copolymer increased.

The potential prognostic and predictive roles of programmed cell death protein 1 expressed by tumor-infiltrating lymphocytes in solid tumors:a meta-analysis

Aim:Several previous studies have evaluated the potential role of programmed cell death protein 1(PD-1)expressed by tumor-infiltrating lymphocytes(TILs)in various solid tumors and performed its prognosis role in patients’survival with inconsistent results.This study aims to further systematically evaluate the association of PD-1 by TILs with clinicopathological parameters and clinical outcomes in solid tumor patients.Methods:A comprehensive search was conducted in PubMed,Embase,Web of Science,CNKI and Wanfang databases for relevant studies.The potential prognostic and predictive roles of PD-1 were assessed by pooled hazard ratio(HR),odds ratio(OR)and 95%confidence intervals(CI).A total of 1863 patients were selected for in-depth analysis.Results:The results demonstrated that PD-1 by TILs was correlated to overall survival for ovarian cancer(HR=0.40,95%CI:0.26-0.61,P<0.00001).Higher PD-1 expression was associated with lymph node metastasis(OR=2.55,95%CI:1.22-5.29,P=0.01)and tumor grade(OR=3.08,95%CI:2.07-4.57,P<0.00001).Conclusion:The prognostic role of PD-1 by TILs is variant in different tumor types,which highlights the role of PD-1 by TILs as a potential predictive and prognostic biomarker and the development of strategies against the PD-L1/PD-1 axis would be a promising therapeutic target for some solid tumors.