[Current status of influencing factors for postoperative anastomotic leakage in low rectal cancer].

The incidence of anastomotic leakage, a common and serious postoperative complication of low rectal cancer, remains high. Clarifying the risk factors for anastomotic leakage in patients with low rectal cancer after surgery can help guide clinical treatment and help patients improve their prognosis. The current literature suggests that the risk factors affecting the occurrence of anastomotic leakage after low rectal cancer include three aspects: (1) individual factors: male gender, high body mass index, malnutrition, smoking, alcoholism, and metabolic diseases; (2) tumor factors: the lower margin of tumor <5 cm from the anal verge, tumor diameter >2.5 cm, late tumor stage, high level of tumor markers and preoperative intestinal obstruction; (3) surgical factors: long operative time (>180 min), intraoperative bleeding (≥70 ml), more than 2 cartridges of stapling for anastomosis, contamination of the operative field, epidural analgesia and intraoperative hypothermia. Notably, the surgical approach (laparoscopic, open and hand-assisted laparoscopic surgery) was not a factor influencing the occurrence of postoperative anastomotic leakage in low rectal cancer. The findings on the effects of receiving neoadjuvant therapy, gut microbiota,intestinal bowel preparation, insufficient time for preoperative antibiotic prophylaxis, left colonic artery dissection, intraoperative blood transfusion, pelvic drainage, transanal drainage and combined organ resection, and postoperative diarrhea on postoperative anastomotic leakage in low rectal cancer are controversial. However, clinical workers can still take measures to reduce the risk of anastomotic leakage according to the above risk factors by making a good assessment before surgery, actively avoiding them during and after surgery, and taking measures for each step, so as to bring maximum benefits to patients.

[Treatment strategy of gastrointestinal stromal tumors in the background of COVID-19].

COVID-19, caused by SARS-COV-2, has the characteristics of world epidemic, highly infectious and large base of death. In China, transmission route of SARS-COV-2 has been contained so effectively that COVID-19 has been well controlled due to the proactive national prevention and control strategy. However, not only does it bring a huge impact on the existing medical structure model, but also an objective impact on the treatment of patients with chronic diseases such as malignant tumors. Based on the progress reported in the domestic and international literatures and the actual management experience of our team, this paper reflects on the treatment strategies for patients with gastrointestinal stromal tumor (GIST) during the epidemic period of COVID-19. We focus on risk stratification for primary GIST and forming treatment strategies accordingly. Major considerations include the impact of delayed operation, the burden of medical resources, the waiting time for elective operation, and the principle of emergency operation. In addition, we focus on the level of evidence for non-surgical approaches with a view to developing a holistic strategy of "priority management principles" to guide clinical treatment in the context of limited resources and different GIST priorities.

[Anatomical controversies involved in radical resection of rectal cancer].

The concept of total mesorectal resection provides a quality control standard that can be followed for radical resection of rectal cancer, but some anatomical problems are still controversial. Compared with traditional open surgery, laparoscopic radical rectal surgery has better surgical vision, better neurological protection, better operating space. However, if the surgeon has insufficient understanding of the anatomy, collateral damage may occur, such as uncontrollable bleeding during the operation, postoperative urination and defecation dysfunction and so on. Based on the interpretation of the researches at home and abroad, combined with the clinical experience, we elucidate some associated issues, including anatomic variation of inferior mesenteric vessels, the controversy of inferior mesenteric artery ligation plane, the controversy of lymph node dissection in No. 253, the anatomical variation of middle rectal artery, and the anatomical controversy of lateral lymph node dissection in rectal cancer, in order to provide better cognitive process for the clinical front-line surgeons.

[Treatment strategies for colorectal cancer patients in tumor hospitals under the background of corona virus disease 2019].

In December 2019, a new outbreak of corona virus disease 2019 began to occur. Its pathogen is 2019-nCoV, which has the characteristics of strong infectivity and general susceptibility. The current situation of prevention and control of new coronavirus pneumonia is severe. In this context, as front-line medical workers bearing important responsibilities and pressure, while through strict management strategy, we can minimize the risk of infection exposure. By summarizing the research progress and guidelines in recent years in the fields of colorectal cancer disease screening, treatment strategies (including early colorectal cancer, locally advanced colorectal cancer, obstructive colorectal cancer, metastatic colorectal cancer and the treatment of patients after neoadjuvant therapy), the choice of medication and time limit for adjuvant therapy, the protective measures for patients undergoing emergency surgery, the re-examination of postoperative patients and the protection of medical staff, etc., authors improve treatment strategies in order to provide more choices for patients to obtain the best treatment under the severe epidemic situation of new coronavirus pneumonia. Meanwhile we hope that it can also provide more timely treatment modeling schemes for colleagues.

[Thinking of treatment strategies for colorectal cancer patients in tumor hospitals under the background of coronavirus pneumonia].

In December 2019, a new outbreak of coronavirus pneumonia began to occur. Its pathogen is 2019-nCoV, which has the characteristics of strong infectivity and general susceptibility. The current situation of prevention and control of new coronavirus pneumonia is severe. In this context, as front-line medical workers bearing important responsibilities and pressure, while through strict management strategy, we can minimize the risk of infection exposure. By summarizing the research progress and guidelines in recent years in the fields of colorectal cancer disease screening, treatment strategies(including early colorectal cancer, locally advanced colorectal cancer, obstructive colorectal cancer, metastatic colorectal cancer and the treatment of patients after neoadjuvant therapy), the choice of medication and time limit for adjuvant therapy, the protective measures for patients undergoing emergency surgery, the re-examination of postoperative patients and the protection of medical staff, etc., authors improve treatment strategies in order to provide more choices for patients to obtain the best treatment under the severe epidemic situation of new coronavirus pneumonia. Meanwhile we hope that it can also provide more timely treatment modeling schemes for colleagues.

Investigation of an InP-based image converter with optical excitation.

An image converter based on an indium phosphide has been developed to measure the two-dimensional spatial profile of the incident photon flux by probing the rapid change of the refractive index in the semiconductor. The spatial resolution, dynamic range, and temporal response of this image converter have been investigated with optical methods. The results show that the spatial resolution is ∼15 cycles/mm at the percent modulation transfer function of 0.5, the dynamic range is about 100, and the time response is in the order of 600 ps. This scheme can provide an alternative choice as an imaging diagnostic for experiments in the area of high-energy density physics.

Influence of suppression of CapG gene expression by siRNA on the growth and metastasis of human prostate cancer cells.

This study investigated CapG gene expression in prostate cancer cell lines; in addition, we explored the effects of CapG suppression on DU145 cell growth, and the underlying mechanism with which CapG affects DU145 cell growth and invasiveness. The expression of CapG and 18 related genes in DU145 cells was analyzed by flow cytometry, quantitative polymerase chain reaction (qPCR), CCK8 assay, western blot, and the trans-well assay. DU145 cells were transfected with designed small interfering RNA (siRNA). CapG expression was quantified by qPCR and western blot. DU145 cell proliferation and invasiveness was analyzed using the CCK8, flow cytometric, and trans-well assays. CapG, TMPRSS1, EGFR, ETS-1, ERBB2, AKT, Cyclin D1, P21, Bcl-2, and Bak1 gene and Bcl-2, Cyclin D1, and CapG protein expressions were significantly lower in the siRNA group compared to the negative control group (P < 0.05). The proliferation of CapG siRNA DU145 cells was lower than that of the two control groups, 48 h after transfection. The cell inhibition rate was 24.5, 35.4, and 16,5% at 24, 48, and 72 h, respectively. The growth curve indicated that CapG siRNA DU145 cells showed a significantly slower proliferation rate (P < 0.05). The trans-well assay showed a significant decrease in the migratory and invasive capacities of DU145 cells in the siRNA group (P < 0.05). The suppression of CapG expression caused a significant decrease in the proliferation, invasiveness, and metastasis of DU145 cells. The mechanism with which CapG, with other oncogenes, influences cancer cell cycle remains to be elucidated.

Hepatic resection for synchronous hepatic metastasis from gastric cancer.

BACKGROUND: The role of surgical resection for synchronous hepatic metastases arising from gastric adenocarcinoma has not been established. This study was designed to explore the clinicopathologic features and surgical results of these patients. METHODS: Twenty-five (4.8%) of 526 patients diagnosed with synchronous hepatic metastatic gastric cancer received hepatectomy and gastrectomy at the same time; 2 cases underwent repeat hepatectomy after intrahepatic recurrence. Clinicopathologic parameters of the hepatic metastases and the surgical results for all 25 patients were analysed. RESULTS: The 1-, 3-, and 5-year overall survival (OS) and recurrence-free survival (RFS) rates after resection were 96.0%, 70.4%, and 29.4%, respectively, and 56.0%, 22.3%, and 11.1%, respectively. Five patients survived for more than 5 years after surgery, and no mortality has occurred within 30 days after resection. Univariate analysis revealed that patients with multiple hepatic metastases suffered poorer OS (P = 0.026) and RFS (P = 0.035) than those with solitary hepatic metastasis. Postoperative adjuvant chemotherapy was a significant indicator of a favourable OS (P = 0.022). Number of metastatic lesions remained significant in the multivariate analysis of OS and RFS (P = 0.039, P = 0.049, respectively). None of variables of the primary lesion was a significant prognostic factor for those patients. CONCLUSIONS: Gastric cancer patients with a solitary synchronous liver metastasis may be good candidates for hepatic resection. Postoperative adjuvant chemotherapy may provide a benefit by aiding in OS.

Formation dynamics of excitons and temporal behaviors of Fano resonance due to the exciton-impurity-phonon configuration interaction in ZnO.

Formation dynamics of free and neutral donor bound excitons (FX and D(0)X) in a high quality ZnO single crystal are studied by means of time-resolved photoluminescence (TRPL) at various temperatures. At low-temperatures, FX and D(0)X formation times are determined to be ~5 and ~10 ps, respectively, by fitting the rise process with the Boltzmann sigmoidal function. Temporal information of FX- and D(0)X-longitudinal optical (LO) phonon coupling is also acquired by measuring TRPL spectra of the first-order LO phonon-assisted FX and D(0)X transitions. In particular, interesting time evolution of luminescence intensity in the Fano resonance region due to the configuration interaction of exciton-impurity-phonon is explored.

Clinical and genetic characterization of complete androgen insensitivity syndrome in a Chinese family.

We studied a family with two cousins who were diagnosed with complete androgen insensitivity syndrome, an X-linked disorder caused by mutations in the androgen receptor gene. A pedigree analysis and a molecular study using PCR and DNA sequencing clarified each female family member's androgen receptor status and revealed a mutation consisting of the deletion of exon 2 and surrounding introns of the androgen receptor gene. Based on the relative nucleotide positions, we concluded that the deletion mutation in exon 2 and its surrounding introns was approximately 6000 to 7000 bp. This mutation, never previously fully characterized using DNA sequencing, was responsible for complete androgen insensitivity syndrome in this family. Pedigree analysis with a molecular study of the androgen receptor gene in affected families facilitates genetic counseling provided to family members.

Overexpression of AIB1 negatively affects survival of surgically resected non-small-cell lung cancer patients.

BACKGROUND: The amplified in breast cancer 1 (AIB1) gene has been considered to play an oncogenic role in human cancers, but its clinical/prognostic significance in non-small-cell lung cancer (NSCLC) is still unclear. PATIENTS AND METHODS: The methods of immunohistochemistry and FISH were utilized to examine protein expression and amplification of AIB1 in 230 informative surgically resected NSCLCs and in 30 samples of normal lung tissues. RESULTS: Overexpression and amplification of AIB1 were found in 48.3% and 8.2% of NSCLCs, respectively. AIB1 overexpression was associated with AIB1 gene amplification and cell proliferation but not related to estrogen receptor (ER)-alpha, ER-beta, progesterone receptor or androgen receptor status. A positive correlation between AIB1 overexpression and an ascending pathologic node stage in lung adenocarcinoma (ADC) was observed (P = 0.043). Univariate survival analysis demonstrated a significant association of AIB1 overexpression with shortened patient survival, especially for those with stage III disease (P < 0.001). Importantly, AIB1 expression was evaluated as the most significant predictor for survival in multivariate analysis (hazards ratio = 2.069, P < 0.001). CONCLUSION: Overexpression of AIB1 might provide a selective advantage for lymph node metastasis of lung ADC and serve as a useful biomarker for poor prognosis for NSCLC patients.

Chemotherapy induces NEDP1-mediated destabilization of MDM2.

MDM2 is an E3 ligase that promotes ubiquitin-mediated destruction of p53. Cellular stresses such as DNA damage can lead to p53 activation due in part to MDM2 destabilization. Here, we show that the stability of MDM2 is regulated by an ubiquitin-like NEDD8 pathway and identify NEDP1 as a chemotherapy-induced isopeptidase that deneddylates MDM2, resulting in MDM2 destabilization concomitant with p53 activation. Concordantly, RNAi-mediated knockdown of endogenous NEDP1 blocked diminution of MDM2 levels and increased chemoresistance of tumor cells. These findings unveil the regulation of MDM2 stability through NEDP1 as a common molecular determinant governing chemotherapy-induced p53-dependent cell death.

Image reconstructions with the rotating RF coil.

Recent studies have shown that rotating a single RF transceive coil (RRFC) provides a uniform coverage of the object and brings a number of hardware advantages (i.e. requires only one RF channel, averts coil-coil coupling interactions and facilitates large-scale multi-nuclear imaging). Motion of the RF coil sensitivity profile however violates the standard Fourier Transform definition of a time-invariant signal, and the images reconstructed in this conventional manner can be degraded by ghosting artifacts. To overcome this problem, this paper presents Time Division Multiplexed-Sensitivity Encoding (TDM-SENSE), as a new image reconstruction scheme that exploits the rotation of the RF coil sensitivity profile to facilitate ghost-free image reconstructions and reductions in image acquisition time. A transceive RRFC system for head imaging at 2 Tesla was constructed and applied in a number of in vivo experiments. In this initial study, alias-free head images were obtained in half the usual scan time. It is hoped that new sequences and methods will be developed by taking advantage of coil motion.

An efficient BiCGstab solved impedance method for induced field evaluation with a hyperthermia applicator.

This paper presents a stabilized Bi-conjugate gradient algorithm that can significantly improve the performance of the impedance method, which has been widely applied to model low-frequency field induction phenomena in voxel phantoms. The improved quasi-static impedance method offers remarkable computational advantages in terms of convergence performance and memory consumption over the conventional, stationary iterative method-based algorithm. The scheme has been validated against other numerical/analytical solutions on a lossy, multilayered sphere phantom with an ideal coil loop excitation. To further demonstrate the computational performance and application capability of the developed algorithm, the induced fields inside a whole body human phantom responding to hyperthermia device was evaluated. The simulation results show the numerical accuracy and superior performance of the method.

A new decoupling method for quadrature coils in magnetic resonance imaging.

A powerful decoupling method is introduced to obtain decoupled signal voltages from quadrature coils in magnetic resonance imaging (MRI). The new method uses the knowledge of the position of the signal source in MRI, the active slice, to define a new mutual impedance which accurately quantifies the coupling voltages and enables them to be removed almost completely. Results show that by using the new decoupling method, the percentage errors in the decoupled voltages are of the order of 10(-7) % and isolations between two coils are more than 170 dB.

An inverse methodology for high frequency RF head coil design with preemphasized B/sub 1/ field in MRI.

An inverse methodology to assist in the design of radio-frequency (RF) head coils for high field MRI application is described in this work. Free space time-harmonic electromagnetic Green's functions and preemphasized B/sub 1/ field are used to calculate the current density on the coil cylinder. With B/sub 1/ field preemphasized and lowered in the middle of the RF transverse plane, the calculated current distribution can generate an internal magnetic field that can reduce the EM field/tissue interactions at high frequencies. The current distribution of a head coil operating at 4 T is calculated using inverse methodology with preemphasized B/sub 1/ fields. FDTD is employed to calculate B/sub 1/ field and signal intensity inside a homogenous cylindrical phantom and human head. A comparison with conventional RF birdcage coil is reported here and demonstrated that inverse-method designed coil with preemphasized B/sub 1/ field can help in decreasing the notorious bright region caused by EM field/tissue interactions in the human head images at 4 T.