Objective:To summarize the successful diagnosis and treatment experience of two patients with peritoneal dialysis complicated with cholangiolithiasis and cholangitis who received endoscopic retrograde cholangiopancreatography (ERCP).Methods:A retrospective analysis was conducted on the clinical data of two patients with peritoneal dialysis combined with bile duct stones at Peking University Third Hospital who underwent ERCP combined with endoscopic sphincterotomy and were successfully transferred out of the hospital. Observe successful removal of bile duct stones and adverse events related to surgery, such as pancreatitis, summarize experience, and conduct literature review.Result:The overall success rate of stone removal in 2 patients was 100%, and they recovered well after treatment without severe postoperative bleeding. One patient developed postoperative pancreatitis and secondary peritonitis after ECRP, and active anti infection treatment did not affect peritoneal function. Regular peritoneal dialysis was maintained during the perioperative period, and postoperative close follow-up and flexible adjustment of peritoneal dialysis dose and concentration were carried out to ensure a smooth transition of patients to regular and stable peritoneal dialysis.Conclusion:ERCP is a feasible treatment for PD patients combined with choledocholithiasis, and can be well tolerated by them. The treatment of peritoneal dialysis patients requires long-term follow-up and management, and multidisciplinary cooperation is required when acute complications occur.

Polymyxin B and polymyxin E (colistin) are presently considered the last line of defense against human infections caused by multidrug-resistant Gram-negative organisms such as carbapenemase-producer Enterobacterales, Acinetobacter baumannii, and Klebsiella pneumoniae. Yet resistance to this last-line drugs is a major public health threat and is rapidly increasing. Polymyxin S₂ (S₂) is a polymyxin B analogue previously synthesized in our institute with obviously high antibacterial activity and lower toxicity than polymyxin B and colistin. To predict the possible resistant mechanism of S₂ for wide clinical application, we experimentally induced bacterial resistant mutants and studied the preliminary resistance mechanisms. Mut-S, a resistant mutant of K. pneumoniae ATCC BAA-2146 (Kpn2146) induced by S₂, was analyzed by whole genome sequencing, transcriptomics, mass spectrometry and complementation experiment. Surprisingly, large-scale genomic inversion (LSGI) of approximately 1.1 Mbp in the chromosome caused by IS26 mediated intramolecular transposition was found in Mut-S, which led to mgrB truncation, lipid A modification and hence S₂ resistance. The resistance can be complemented by plasmid carrying intact mgrB. The same mechanism was also found in polymyxin B and colistin induced drug-resistant mutants of Kpn2146 (Mut-B and Mut-E, respectively). This is the first report of polymyxin resistance caused by IS26 intramolecular transposition mediated mgrB truncation in chromosome in K. pneumoniae. The findings broaden our scope of knowledge for polymyxin resistance and enriched our understanding of how bacteria can manage to survive in the presence of antibiotics.

Objective:To investigate the effect of coix seed oil on chemosensitivity of colon cancer cells.Methods:HT29 cell line was cultured in vitro. Different concentrations of coix seed oil (1, 2, 4, 8 mg/ml) and 30 μg/ml 5-fluorouracil (5-FU) were incubated with HT29 cells for 24 hours to simulate chemotherapy. The cell proliferation inhibition rate, apoptosis rate and cell cycle ratio were measured by methyl thiazolyl tetrazolium (MTT) method and flow cytometry, and the protein expression of cleaved caspase-3 was measured by Western blot. Results:The inhibition rate of cell proliferation in 1, 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 5-FU group and coix oil group, and the inhibition rate in 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 1 mg/ml coix oil + 5-FU group ( P<0.05). The apoptosis rate in 5-FU group, coix oil group and 1, 2, 4, 8 mg/ml coix oil + 5-FU group was higher than that in the blank control group ( P<0.05). The apoptosis rate in 1, 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 5-FU group and coix oil group ( P<0.05). The apoptosis rate of 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that of 1 mg/ml coix oil + 5-FU group ( P<0.05). The expression of cleaved caspase-3 in each group was basically in line with the apoptosis rate of flow cytometry. The percentage of G1/M phase cells in 5-FU group, coix oil group and 1, 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in the blank control, and the percentage of S phase cells was lower comparing with blank control ( P<0.05). Besides, the percentage of G1/M phase cells in 1, 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 5-FU group and coix oil group, and the percentage of S phase cells was significantly lower than that in 5-FU group and coix oil group ( P<0.05). The percentage of G1/M phase cells in 2, 4, 8 mg/ml coix oil + 5-FU group was significantly higher than that in 1 mg/ml coix oil + 5-FU group, and the percentage of S phase cells was significantly lower than that in 1 mg/ml coix oil + 5-FU group ( P<0.05). Conclusions:Coix seed oil may enhance the chemosensitivity of colon cancer cells by inducing cell cycle arrest and apoptosis.

Objective:To explore the effect and mechanism of 5-Aminolevulinic Acid-Photodynamic Therapy (5-ALA-PDT) on the apoptosis of the human colonic carcinoma HT-29 cells.Methods:HT-29 cells were cultured in vivio and divided into four groups: blank control group, 5-ALA group, PDT group and 5-ALA-PDT group.The control group was not given photosensitizer and light treatment; 5-ALA group was given photosensitizer ; PDT group was given light treatment; 5-ALA-PDT group was given photosensitizer and light treatment at the same time. Flow cytometry was used to observe the apoptosis of HT-29 cells. Reverse transcription polymerase chain reaction (RT-PCR) was used to observe the expression of B-type lymphoma-2 (Bcl-2) and Bcl-2 associated X protein (Bax) in HT-29 cells. Ultraviolet spectrophotometry was used to detect the expression of Caspase-3. Results:The apoptotic rate of 5-ALA-PDT group was significantly higher than that of blank control group, 5-ALA group and PDT group ( P<0.05). Compared with the blank control group, 5-ALA-PDT group and PDT group, the expression of Bcl-2 in the 5-ALA-PDT group was statistically significant ( P<0.05), but there was no significant difference in Bax expression among the four groups ( P>0.05). The expression of Bax/Bcl-2 in 5-ALA-PDT group was significantly higher than that in blank control group, 5-ALA group and PDT group ( P<0.05). The expression of Caspase-3 in 5-ALA-PDT group was significantly higher than that in blank control group, 5-ALA group and PDT group ( P<0.05). Conclusions:5-ALA-PDT can induce apoptosis of HT-29 cells, and its mechanism may be related to the induction of apoptosis through Bax/Bcl-2 pathway.

Objective:To investigate the accumulation of porphyrin metabolites [uroporphyrinogen (UP) Ⅰ and coproporphyrinogen (CP) Ⅲ] induced by 5-aminolevulinic acid (5-ALA) in the urine of rats with colorectal cancer.Methods:The rat model of colorectal cancer was established by dimethylhydrazine (DMH). Urine samples were collected from 30 colorectal cancer rats (colorectal cancer group) and 30 normal rats (normal group). Each animal was given 5-ALA (50 mg/kg) by gavage, and urine was collected after 2, 4, 6 and 8 h. The contents of urinary porphyromogen Ⅰ and porphyromogen faecalis Ⅲ in urine were detected by high performance liquid chromatography (HPLC).Results:There was no significant difference in the contents of UP Ⅰ and CP Ⅲ in urine between colorectal cancer group and normal group before oral administration of 5-ALA ( P>0.05). After oral administration of 5-ALA, the contents of UP Ⅰ and CP Ⅲ in urine of colorectal cancer group were significantly higher than those of normal group ( P<0.05). The contents of UP Ⅰ and CP Ⅲ in urine of colorectal cancer group reached the highest value at 4 hours. According to the receiver operating characteristic (ROC) curve drawn from 4-hour test results, the threshold value of UP Ⅰ for colorectal cancer diagnosis was 50.43 μmol/g, with corresponding sensitivity 96.7%, and the specificity 63.3%, respectively. The threshold value of CP Ⅲ for colorectal cancer diagnosis was 108.85 μmol/g, with corresponding sensitivity 66.7%, and the specificity 86.7%, respectively. Conclusions:The accumulation of porphyrin metabolites induced by 5-ALA in the urine of rats with colorectal cancer is significant. The porphyrin metabolites in urine may be a new tumor marker of colorectal cancer, which provides an experimental basis for the diagnosis of colorectal cancer.

Objective:To investigate the changes of porphyrin metabolites in urine of patients with colorectal cancer before and after operation and their correlation with prognosis.Methods:One hundred patients with colorectal cancer were collected in First Affiliated Hospital of Hebei North University from June 2016 to December 2016, urine was collected before operation, 1 week after operation, 1 year after operation and before recurrence. The contents of urinary porphyrin metabolites of uroporphyrinogenI (UP Ⅰ) and coproporphyrinogen Ⅲ(CP Ⅲ) were detected by high performance liquid chromatography. Toanalyse the changes of UPⅠ and CPⅢ levels before and after operaction of colorectal cancer and their correlation with clinicopathologicalcharacteristics,and the recurrence and metastasis after operation.Results:The levels of UPⅠ and CPⅢ in urine of patients with colorectal cancer after operation were significantly lower than those before operation [(66.80 ± 17.62) μmol/g vs. (35.58 ± 9.32) μmol/g, (20.14 ± 3.14) μmol/g vs. (10.38 ± 0.85) μmol/g] ( P<0.05). The levels of UP Ⅰ and CP Ⅲ in urine of patients with Dukes C/D stage were significantly higher than those with Dukes A/B stage [(45.26 ± 5.26) μmol/g vs. (28.56 ± 3.45) μmol/g, (86.57 ± 6.58) μmol/g vs. (52.48 ± 3.36) μmol/g], the levels of UP Ⅰand CPⅢ in urine of patients with lymph node metastasis were significantly higher than those without lymph node metastasis [(45.44 ± 5.46) μmol/g vs. (30.27 ± 6.07) μmol/g, (86.67 ± 6.87) μmol/g vs. (56.10 ± 11.08) μmol/g], there were significant differences ( P<0.05). Urinary levels of UPⅠ and CPⅢ were independent risk factors for recurrence and metastasis of colorectal cancer after operation ( OR=1.149 and 1.065, P<0.05). Conclusions:Porphyrin metabolites (UPⅠ and CPⅢ) in urine may serve as a new marker for assessing colorectal cancer.

As d-amino acids play important roles in the physiological metabolism of bacteria, combination of d-amino acids with antibiotics may provide synergistic antibacterial activity. The aim of the study was to evaluate and activity of d-serine alone and in combination with -lactams against methicillin-resistant (MRSA) strains, and to explore the possible sensitization mechanisms. The activity of d-serine, -lactams alone and in combinations was evaluated both by standard MICs, time-kill curves and checkerboard assays, and by murine systemic infection model as well as neutropenic thigh infection model. An synergistic effect was demonstrated with the combination of d-serine and -lactams against MRSA standard and clinical strains. Importantly, the combinations enhanced the therapeutic efficacy in the animal models as compared to -lactam alone groups. Initial mechanism study suggested possible revision of d-alanine-d-alanine residue to d-alanine-d-serine in peptidoglycan by adding of d-alanine in the medium, which may cause decreased affinity to PBPs during transpeptidation. In conclusion, d-serine had synergistic activity in combination with -lactams against MRSA strains both and . Considering the relatively good safety of d-serine alone or in combination with -lactams, d-serine is worth following up as new anti-MRSA infection strategies.

Objective: To study the application of urinary 5-aminolevulinic acid (5-ALA)detection in screening and identification of colorectal cancer and adenomatous polyps. Methods: The clinical data of 500 high-risk patients(including 22 cases with colorectal cancer, 134 cases with adenomatous polyps, and 344 cases with other patients) at the First Affiliated Hospital of Hebei North University from January 2018 to October 2018 were collected. High performance liquid chromatography(HPLC) was used to detect urinary 5-ALA and fecal occult blood test was used to detect faeces. Sensitivity and specificity of two methods was compared. At the same time, urine samples of 431 cases(including 22 cases with colorectal cancer, 134 cases with adenomatous polyps and 275 cases with colorectal normal mucosa)were collected, and the difference of the content of urinary 5-ALA among three groups was compared. Results: The sensitivity of urinary 5-ALA for the colorectal cancer screening was74.9%, and the specificity was 72.5%. The sensitivity of urinary 5-ALA for the adenomatous polyps screening was 70.1%, and the specificity was75.0%. The sensitivity of fecal occult blood test for the colorectal cancer screening was 63.6%, and the specificity was 62.1%. The sensitivity of fecal occult blood test for the adenomatous polyps screening was 42.3%, and the specificity was 62.5%. The content of urinary 5-ALA of the colorectal cancer group [(9.35 ± 0.46) μmol/g] was significantly higher than that of the adenomatous polyps group [(7.24 ± 0.64) μmol/g] (P < 0.05) and normal colorectal mucosa group [(3.12 ± 0.24) μmol/g] (P < 0.05), and the content of urinary 5-ALA of the adenomatous polyps group was significantly higher than that of colorectal normal mucosa group (P < 0.05). Conclusions For screening of colorectal cancer and adenomatous polyps, the content of urinary 5-ALA by HPLC is better than fecal occult blood test, and this approach can do great help to identify colorectal cancer, adenomatous polyps and normal colorectal mucosa.

Objective To investigate the relationship between the right-to-left shunt(RLS)detected with contrast-enhanced transcranial Doppler (c-TCD) and recurrent stroke in patients with cryptogenic stroke.Methods The consecutive patients w ith ischemic stroke w ere enrol ed. The patients w ith cryptogenic stroke w ere screened according to the TOAST criteria. They w ere divided into either a RLS positive group or a RLS negative group according to the c-TCD findings, and then they w ere fol ow ed up for a period of one year. They w ere also divided into a recurrent group and a non-recurrent group according to w hether they had recurrence or not. Results A total of 118 patients w ith cryptogenic ischemic stroke w ere enrol ed, including 46 in the RLS positive group, 72 in the RLS negative group, 10 in the recurrent group, and 108 in the non-recurrent group. There w ere no significant differences in demographic and baseline data betw een the RLS negative group and the RLS positive group. There w ere significant differences in RLS positive rate (7/10 vs.39/108; P=0.046) and proportion of patients with server RLS (2/10 vs.1/108; P=0.019) betw een the recurrent group and the non-recurrent group. Multivariate logistic regression analysis show ed that the positive RLS w as an independent predictor of recurrent stroke (odds ratio 4.896, 95% confidence interval 1.135-21.120;P=0.033). Conclusions The positive RLS may be an independent risk factor for the recurrence in patients w ith cryptogenic ischemic stroke.

Objective To investigate the phenotypic and genetic characteristics of the lysostaphin‐resistant Staphylococcus aureus variants induced by recombinant lysostaphin in vitro .Methods Three clinical isolates of S . aureus ,including two resistant to methicillin (MRSA ) and one susceptible to methicillin (MSSA ) were induced by treatment with sub‐MIC of recombinant lysostaphin via one‐step selection in vitro .Susceptibility of the variants to antibiotics were determined and compared with their parental strains .The full length of femABX genes was amplified by polymerase chain reaction and sequenced to identify the potential mutation sites in these genes .The growth‐curve in liquid medium and virulence in a mouse systemic infection model of both parental and variant strains were observed . Results The frequency of lysostaphin resistance in S . aureus was between 10-4 to 10-8 following induction by lysostaphin . Resistance to lysostaphin was associated with a significant decrease in growth rate in vitro and virulence in vivo ,as well as increased susceptibility toβ‐lactams evidenced by the M IC of β‐lactams against the variants as low as 1/4 000 to 1/2 of the M IC against their parental strains . Sequencing of f emA BX genes showed mutation in femA gene in both variants ,which resulted in a premature termination codon .Conclusions Resistance of S . aureus to lysostaphin may develop following induction by recombinant lysostaphin in vitro . The lysostaphin‐resistant S . aureus variants are characteristic of lower growth rate , decreased virulence ,and higher susceptibility to β‐lactams .