Structural shift of gut microbiota during chemopreventive effects of epigallocatechin gallate on colorectal carcinogenesis in mice

AIM To investigate the effect of epigallocatechin gallate(EGCG) on structural changes of gut microbiota in colorectal carcinogenesis.METHODS An azoxymethane(AOM)/dextran sodium sulfate(DSS)-induced colitis mouse model was established. Fortytwo female FVB/N mice were randomly divided into the following three groups: group 1(10 mice, negative control) was treated with vehicle, group 2(16 mice, positive control) was treated with AOM plus vehicle, and group 3(16 mice, EG) was treated with AOM plus EGCG. For aberrant crypt foci(ACF) evaluation, the colons were rapidly took out after sacrifice, rinsed with saline, opened longitudinally, laid flat on a polystyrene board, and fixed with 10% buffered formaldehyde solution before being stained with 0.2% methylene blue in saline. For tumor evaluation, the colon was macroscopically inspected and photographed, then the total number of tumors was enumerated and tumor size measured. For histological examination, the fixed tissues were paraffin-embedded and sectioned at 5 mm thickness. Microbial genomic DNA was extracted from fecal and intestinal content samples using a commercial kit. The V4 hypervariable regions of 16 S r RNA were PCR-amplified with the barcoded fusion primers. Using the best hit classification option, the sequences from each sample were aligned to the RDP 16 S r RNA training set to classify the taxonomic abundance in QIIME. Statistical analyses were then performed.RESULTS Treatment of mice with 1% EGCG caused a significant decrease in the mean number of ACF per mouse, when compared with the model mice treated with AOM/DSS(5.38 ± 4.24 vs 13.13 ± 3.02, P < 0.01). Compared with the positive control group, 1% EGCG treatment dependently decreased tumor load per mouse by 85%(33.96 ± 6.10 vs 2.96 ± 2.86, respectively, P < 0.01). All revealed that EGCG could inhibit colon carcinogenesis by decreasing the number of precancerous lesions as well as solid tumors, with reduced tumor load and delayed histological progression of CRC. During the cancerization, the diversity of gut microbiota increased, potential carcinogenic bacteria such as Bacteroides were enriched, and the abundance of butyrate-producing bacteria(Clostridiaceae, Ruminococcus, etc.) decreased continuously. In contrast, the structure of gut microbiota was relatively stable during the intervention of EGCG on colon carcinogenesis. Enrichment of probiotics(Bifidobacterium, Lactobacillu, etc.) might be a potential mechanism for EGCG's effects on tumor suppression. Via bioinformatics analysis, principal coordinate analysis and cluster analysis of the tumor formation process, we found that the diversity of gut microbiota increased in the tumor model group while that in the EGCG interfered group(EG) remained relatively stable.CONCLUSION Gut microbiota imbalance might be a potential mechanism for the prevention of malignant transformation by EGCG, which is significant for diagnosis, treatment, prognosis evaluation, and prevention of colorectal cancer.

Suppression of colorectal tumorigenesis by recombinant Bacteroides fragilis enterotoxin-2 in vivo

AIM To evaluate the impact of recombinant Bacteroides fragilis enterotoxin-2 (BFT-2, or Fragilysin) on colorectal tumorigenesis in mice induced by azoxymethane/dextran sulfate sodium (AOM/DSS). METHODS Recombinant proBFT-2 was expressed in Escherichia coli strain Rosetta (DE3) and BFT-2 was obtained and tested for its biological activity via colorectal adenocarcinoma cell strains SW-480. Seventy C57BL/6J mice were randomly divided into a blank (BC; n = 10), model (AD; n = 20), model + low-dose toxin (ADLT; n = 20, 10 mu g), and a model + high-dose toxin (ADHT; n = 20, 20 mu g) group. Mice weight, tumor formation and pathology were analyzed. Immunohistochemistry determined Ki-67 and Caspase-3 expression in normal and tumor tissues of colorectal mucosa. RESULTS Recombinant BFT-2 was successfully obtained, along with its biological activity. The most obvious weight loss occurred in the AD group compared with the ADLT group (21.82 +/- 0.68 vs 23.23 +/- 0.91, P < 0.05) and the ADHT group (21.82 +/- 0.68 vs 23.57 +/- 1.06, P < 0.05). More tumors were found in the AD group than in the ADLT and ADHT groups (19.75 +/- 3.30 vs 6.50 +/- 1.73, P < 0.05; 19.75 +/- 3.30 vs 6.00 +/- 2.16, P < 0.05). Pathology showed that 12 mice had adenocarcinoma and 6 cases had adenoma in the AD group. Five mice had adenocarcinoma and 15 had adenoma in the ADLT group. Four mice had adenocarcinoma and 16 had adenoma in the ADHT group. The incidence of colorectal adenocarcinoma in both the ADHT group and the ADHT group was reduced compared to that in the AD group (P < 0.05, P < 0.05). The positive rate of Ki-67 in the ADLT group and the ADHT group was 50% and 40%, respectively, both of which were lower than that found in the AD group (94.44%, P < 0.05, P < 0.05). Caspase-3 expression in the ADLT group and the ADHT group was 45% and 55%, both of which were higher than that found in the BC group (16.67%, P < 0.05, P < 0.05). CONCLUSION Oral administration with lower-dose biologically active recombinant BFT-2 inhibited colorectal tumorigenesis in mice.

膀胱阴道瘘的围手术期处理及手术技巧(附62例报告)

目的总结膀胱阴道瘘(VVF)的围手术期处理及手术技巧。方法回顾性分析2010年1月-2017年11月该院泌尿外科收治的62例VVF患者的临床资料。术前均通过膀胱镜检查和膀胱亚甲蓝实验以及相关的影像学检查确诊。手术方式采用耻骨上经膀胱修补术、经阴道修补术、腹腔镜下修补术及最近开展的机器人辅助腹腔镜下修补术。结果 62例患者术后随访1个月～2年60例治愈,在2例失败的患者中,1例经留置导尿管保守治疗后自愈。结论术前明确诊断、进行充分的术前准备、选择合适的手术修补时期、注意术中精细分离和缝合技巧是提高修补手术成功率的关键。

Transanal minimally invasive surgery vs endoscopic mucosal resection for rectal benign tumors and rectal carcinoids: A retrospective analysis

BACKGROUND Transanal minimally invasive surgery(TAMIS)is a good choice for resection of rectal neoplasms.Endoscopic mucosal resection(EMR)is also widely used in the treatment of benign rectal tumors such as rectal polyps and rectal adenomas.However,no studies have compared the outcome of TAMIS and EMR.AIM To compare the short-term outcomes after TAMIS and EMR for rectal carcinoid and benign tumors(including rectal polyps and adenomas).METHODS From January 2014 to January 2019,44 patients who received TAMIS and 53 patients who received EMR at The Fifth People's Hospital of Shanghai were selected.Primary outcomes(surgical-related)were operating time,blood loss,length of postoperative hospital stay,rate of resection margin involvement and lesion fragmentation rate.The secondary outcomes were complications such as hemorrhage,urinary retention,postoperative infection and reoperation.RESULTS No significant differences were observed in terms of blood loss(12.48±8.00 mL for TAMIS vs 11.45±7.82 mL for EMR,P=0.527)and length of postoperative hospital stay(3.50±1.87 d for TAMIS vs 2.72±1.98 d for EMR,P=0.065)between the two groups.Operating time was significantly shorter for EMR compared with TAMIS(21.19±9.49 min vs 49.95±15.28 min,P=0.001).The lesion fragmentation rate in the EMR group was 22.6%(12/53)and was significantly higher than that(0%,0/44)in the TAMIS group(P=0.001).TAMIS was associated with a higher urinary retention rate(13.6%,6/44 vs 1.9%,1/53 P=0.026)and lower hemorrhage rate(0%,0/44 vs 18.9%,10/53 P=0.002).A significantly higher reoperation rate was observed in the EMR group(9.4%,5/53 vs 0%,0/44 P=0.036).

Cutting balloon treatment of anastomotic biliary stenosis after liver transplantation: Report of two cases

Biliary stenosis is a common complication after liver transplantation,and has an incidence rate ranging from4.7%to 12.5%based on our previous study.Three types of biliary stenosis(anastomotic stenosis,nonanastomotic peripheral stenosis and non-anastomotic central hilar stenosis)have been identified.We report the outcome of two patients with anastomotic stricture after liver transplantation who underwent successfulcutting balloon treatment.Case 1 was a 40-year-old male transplanted due to subacute fulminant hepatitis C.Case 2 was a 57-year-old male transplanted due to hepatitis B virus-related end-stage cirrhosis associated with hepatocellular carcinoma.Both patients had similar clinical scenarios:refractory anastomotic stenosis after orthotopic liver transplantation and failure of balloon dilation of the common bile duct to alleviate biliary stricture.

Observation of gapless corner modes of photonic crystal slabs in synthetic translation dimensions

Second-order topological photonic crystals support localized corner modes that deviate from the conventional bulk-edge correspondence.However,the frequency shift of corner modes spanning the photonic band gap has not been experimentally reported.Here,we observe the gapless corner modes of photonic crystal slabs within a parameter space by considering translation as an additional synthetic dimension.These corner modes,protected by topological pumping in synthetic translation dimensions,are found to exist independently of the specific corner configuration.The gapless corner modes are experimentally imaged via the near-field scanning measurement and validated numerically by full-wave simulations.We propose a topological rainbow with gradient translation,demonstrating the ability to extract and separate specific frequency components of light into different spatial locations.Our work contributes to the advancement of topological photonics and provides valuable insights into the exploration of gapless corner modes in synthetic dimensions.

In-plane excitation of a topological nanophotonic corner state at telecom wavelengths in a cross-coupled cavity

In silicon photonics,the cavity mode is a fundamental mechanism to design integrated passive devices for on-chip optical information processing.Recently,the corner state in a second-order topological photonic crystal(PC)rendered a global method to achieve an intrinsic cavity mode.It is crucial to explore such a topological corner state in silicon photonic integrated circuits(PICs)under in-plane excitation.Here,we study both theoretically and experimentally the topological nanophotonic corner state in a silicon-on-insulator PC cavity at a telecommunications wavelength.In theory,the expectation values of a mirror-flip operation for the Bloch modes of a PC slab are used to characterize the topological phase.Derived from topologically distinct bulk polarizations of two types of dielectric-vein PCs,the corner state is induced in a 90-deg-bend interface,localizing at the corner point of real space and the Brillouin zone boundary of reciprocal space.To implement in-plane excitation in an experiment,we fabricate a cross-coupled PC cavity based on the bend interface and directly image the corner state near 1383 nm using a far-field microscope.Finally,by means of the temporal coupled-mode theory,the intrinsic Q factor of a cross-coupled cavity(about 8000)is retrieved from the measured transmission spectra.This work gives deterministic guidance and potential applications for cavity-mode-based passive devices in silicon PICs,such as optical filters,routers,and multiplexers.

Ideal nodal rings of one-dimensional photonic crystals in the visible region

Three-dimensional(3D)artificial metacrystals host rich topological phases,such as Weyl points,nodal rings,and 3D photonic topological insulators.These topological states enable a wide range of applications,including 3D robust waveguides,one-way fiber,and negative refraction of the surface wave.However,these carefully designed metacrystals are usually very complex,hindering their extension to nanoscale photonic systems.Here,we theoretically proposed and experimentally realized an ideal nodal ring in the visible region using a simple 1D photonic crystal.The TT-Berrry phase around the ring is manifested by a 2π reflection phase's winding and the resultant drumhead surface states.By breaking the inversion symmetry,the nodal ring can be gapped and the n-Berry phase would diffuse into a toroidal-shaped Berry flux,resulting in photonic ridge states(the 3D extension of quantum valley Hall states).Our results provide a simple and feasible platform for exploring 3D topological physics and its potential applications in nanophotonics.

Dual-polarization two-dimensional valley photonic crystals

The recent realization of valley physics in photonic systems has enriched the topological phases of light with protected edge modes and shown applications in designing high-performance photonic devices. However, the widely reported valley Hall effect of light in two-dimensional systems is limited to one single polarization. Here, we present dual-polarization two-dimensional valley photonic crystals by simultaneously opening two frequency accidental degenerate Dirac cones. Two band gaps with different polarizations are characterized by opposite-valley Chern numbers, which are confirmed by the opposite-phase vortex distributions of bulk modes and opposite Berry curvatures. This situation results in the polarization-dependent refraction of bulk and edge modes, which locate in opposite valleys. The polarization-independent topological valley transport is also demonstrated. Our work shows the flexible control of light in topological photonic systems with a polarization degree of freedom and has applications in polarization multiplexing photonic devices.

Intrinsic in-plane nodal chain and generalized quaternion charge protected nodal link in photonics

Nodal lines are degeneracies formed by crossing bands in three-dimensional momentum space.Interestingly,these degenerate lines can chain together via touching points and manifest as nodal chains.These nodal chains are usually embedded in two orthogonal planes and protected by the corresponding mirror symmetries.Here,we propose and demonstrate an in-plane nodal chain in photonics,where all chained nodal lines coexist in a single mirror plane instead of two orthogonal ones.Nodal lines are degeneracies formed by crossing bands in three-dimensional momentum space.Interestingly,these degenerate lines can chain together via touching points and manifest as nodal chains.These nodal chains are usually embedded in two orthogonal planes and protected by the corresponding mirror symmetries.Here,we propose and demonstrate an in-plane nodal chain in photonics,where all chained nodal lines coexist in a single mirror plane instead of two orthogonal ones.The chain point is stabilized by the intrinsic symmetry that is specific to electromagnetic waves at theГpoint of zero frequency.By adding another mirror plane,we find a nodal ring that is constructed by two higher bands and links with the in-plane nodal chain.The nodal link in momentum space exhibits non-Abelian characteristics on a C_(2)T-invariant plane,where admissible transitions of the nodal link structure are determined by generalized quaternion charges.Through near-field scanning measurements of bi-anisotropic metamaterials,we experimentally mapped out the in-plane nodal chain and nodal link in such systems.The chain point is stabilized by the intrinsic symmetry that is specific to electromagnetic waves at the r point of zero frequency.By adding another mirror plane,we find a nodal ring that is constructed by two higher bands and links with the in-plane nodal chain.The nodal link in momentum space exhibits non-Abelian characteristics on a C2T-invariant plane,where admissible transitions of the nodal link structure are determined by generalized quaternion charges.Through near-field scanning measurements of bi-anisotropic metamaterials,we experimentally mapped out the in-plane nodal chain and nodal link in such systems.

Coalition formation based on a task-oriented collaborative ability vector

Coalition formation is an important coordination problem in multi-agent systems, and a proper description of collaborative abilities for agents is the basic and key precondition in handling this problem. In this paper, a model of task-oriented collaborative abilities is established, where five task-oriented abilities are extracted to form a collaborative ability vector. A task demand vector is also described. In addition, a method of coalition formation with stochastic mechanism is proposed to reduce excessive competitions. An artificial intelligent algorithm is proposed to compensate for the difference between the expected and actual task requirements, which could improve the cognitive capabilities of agents for human commands. Simulations show the effectiveness of the proposed model and the distributed artificial intelligent algorithm.