Objective To explore the changes of gut microbiota in response to abdominal and pelvic radiotherapy and its potential relationship with intestinal infection.Methods Irradiation was delivered to the abdominal region of BALB/c mice,following the regular human pelvic-radiotherapy protocol,2.0 Gy/d,continuous 5 d/week.Samples of ileum tissue and the intestinal content were collected at different time points of irradiation procedure,including after 3 and 5 weeks,and at 1 week after 6 weeks of irradiation.Quantitative RT-PCR was used to measure the mRNA level of antimicrobial peptides and pro-inflammtory factors.Bacterial translocation was determined by PCR.The gut microbiota was characterized by the denaturing gradient electrophoresis assay.Results The expressions of cryptdin-1 and cryptdin-4 were decreased after 3 weeks of irradiation and at 1 week after 6 weeks of irradiation(t =-7.43,-3.54,-4.72,-4.27,P ＜ 0.05),while they were significantly increased at the 5 weeks of radiation (t =6.15,5.75,P ＜ 0.05).The diversity index and richness of gut microbiota after 3 or 5 weeks irradiation were significantly decreased (t =-3.49,-4.19,-3.44,-4.97,P ＜ 0.05).The gut microbiota dysbiosis of the irradiated mice was characterized with the decrease of probiotics of Lactobacillus and the increasing of opportunistic pathogen of Escherichia coli,Shigella flexneri,et al.Bacterial translocation episodes were more frequently in the irradiated mice than that of control animal.The mRNA levels of IL-1β、IL-6 and TNF-α were significantly increased after 3 or 5 weeks of irradiation (t =4.85,6.16,7.71,4.60,4.86,5.97,P ＜ 0.05).Compared with the control,the expression levels of IL-1β and TNF-α at the 1 week after 6 weeks of irradiation ending was also obviously enhanced (t =3.67,5.88,P ＜0.05).Conclusions Pelvic radiotherapy can induce abnormality of enteric antimicrobial peptides and may result in gut microbiota dysbiosis.The disturbed gut microbial flora may further trigger an incurrence of bacterial translocation and enteritis.Therefore,the gut microbiota may be a potential interfering target to alleviate radiotherapy adverse effect.

Objective: To investigate the changes of perioperative immune index in patients with breast cancer and its clinical significance. Methods: Th1 cells, Th2 cells, Th1/Th2 ratio and regulatory T cells (Treg) were detected in peripheral blood of 103 patients with primary breast cancer and 116 patients with breast fibroma before surgery and on the 1st, 3rd and 5th day following operation. The relationship of changes in T lymphocyte subsets and clinicopathological characteristics, as well as tumor-free survival of breast cancer patients, was analyzed. Results: The levels of Th1 cells in breast cancer group on the 1st, 3rd and 5th day following operation were (12.20±0.45)%, (13.89±0.47)%, (14.04±0.49)%, which were significantly lower than those before operation [(15.82 + 0.51)%, all P<0.05 ]. Treg cells, however, with the number of (3.82±0.13)%, (3.25±0.11)%, (2.95 ±0.11)%, were remarkably higher than those before operation [(2.53 ±0.11)%, all P<0.05]. With respect to breast fibroma patients, there was no significant difference compared with those before operation of Th1 cells, Th2 cells and Treg cells (all P>0.05). The changes of Th1 cells were associated with the degree of differentiation, T stage, N stage, TNM stage, HER-2 status and Ki-67 (all P<0.05). Treg cells were related to T stage, N stage and HER-2 status (all P<0.05). Tumor-free survival in the Th1-cell-increasing group was significantly better than that in the Th1-cell-decreasing group (P=0.045), while cell-decreasing group of Treg showed the improved outcomes (P=0.012). Conclusions The levels of Th1 cells and Treg cells are important indicators of cellular immune function in patients with breast cancer. Moreover, the perioperative changes of Th1 cells and Treg cells are associated with the size of tumors, pathological parameters, clinical stages and tumor-free survival outcomes.

Urethra stricture is one of the most common diseases of the urinary system. Accurate imaging diagnosis is key to the selection of surgical approach. At present, X-ray urethral imaging can show the form of urethra cavity, but not the tissues around the urethra. Sonourethrography (SUG) can dynamically identify the urethral cavity and the surrounding tissues without radiation exposure. Multi-layer spiral CT urethrography (CTU) has advantages of no need to adjust the position, quick scanning and reconstruction of the three-dimensional image, which can accurately show the location, length and degree of urethral stricture, and the spatial relationship with the surrounding tissues. Magnetic resonance urethrography (MRU) can provide useful information of the urethral stricture and soft tissues around the urethra, especially in urethral strictures caused by pelvic fractures and complex urethral stenosis. The choice of imaging method should be based on the etiology, anatomy, types of urethral injury and the general situation of patients. Appropriate imaging method can improve the diagnostic accuracy.

OBJECTIVES: To isolate potassium ion channel Kv4.1 inhibitor from centipede venom, and to determine its primary and spatial structure. METHODS: Ion-exchange chromatography and reversed-phase high-performance liquid chromatography were performed to separate and purify peptide components of centipede venom, and their inhibiting effect on Kv4.1 channel was determined by whole-cell patch clamp recording. The molecular weight of isolated peptide Kv4.1 channel inhibitor was identified with MALDI-TOF, its primary sequence was determined by Edman degradation sequencing and two-dimensional mass spectrometry, its patial structure was established based on iterative thread assembly refinement online analysis. RESULTS: A peptide SsTx-P2 was separated from centipede venom with the molecular weight of 6122.8, and its primary sequence consists of 53 amino acid residues, showed as NH₂-ELTWDFVRTCCKLFPDKSECTKACATEFTGGDESRLKDVWPRKLRSGDSRLKD-OH. Peptide SsTx-P2 potently inhibited the current of Kv4.1 channel transiently transfected in HEK293 cell, with 1.0 μmol/L SsTx-P2 suppressing 95% current of Kv4.1 channel. Its spatial structure showed that SsTx-P2 shared a conserved helical structure. CONCLUSIONS The study has isolated a novel peptide SsTx-P2 from centipede venom, which can potently inhibit the potassium ion channel Kv4.1, and its spatial structure displays a certain degree of conservation.

Unlike healthy, non-transformed cells, the proteostasis network of cancer cells is taxed to produce proteins involved in tumor development. Cancer cells have a higher dependency on molecular chaperones to maintain proteostasis. The chaperonin T-complex protein ring complex (TRiC) contains eight paralogous subunits (CCT1-8), and assists the folding of as many as 10% of cytosolic proteome. TRiC is essential for the progression of some cancers, but the roles of TRiC subunits in osteosarcoma remain to be explored. Here, we show that CCT4/TRiC is significantly correlated in human osteosarcoma, and plays a critical role in osteosarcoma cell survival. We identify a compound anticarin-β that can specifically bind to and inhibit CCT4. Anticarin-β shows higher selectivity in cancer cells than in normal cells. Mechanistically, anticarin-β potently impedes CCT4-mediated STAT3 maturation. Anticarin-β displays remarkable antitumor efficacy in orthotopic and patient-derived xenograft models of osteosarcoma. Collectively, our data uncover a key role of CCT4 in osteosarcoma, and propose a promising treatment strategy for osteosarcoma by disrupting CCT4 and proteostasis.