Objective This study aimed to evaluate the role of double‐balloon enteroscopy (DBE) in treating intestinal polyps in patients with Peutz‐Jeghers syndrome (PJS). Methods All patients diagnosed with PJS who underwent a polypectomy under DBE from October 2006 to December 2018 were enrolled. Their clinical records, including surgical history, the method of DBE insertion, the number of DBE procedures, and the maximum size and number of the resected polyps, were retrospectively reviewed. Results Altogether 97 patients were enrolled. For both antegrade and retrograde DBE the maximum size of the resected polyps during the second hospitalization was significantly smaller than that during the first hospitalization (antegrade DBE: [2.13 ± 1.51] cm vs [3.63 ± 0.92] cm, P = 0.012; retrograde DBE: [1.20 ± 1.10] cm vs [2.95 ± 1.95] cm, P = 0.03), but was significantly larger than that during the third hospitalization (antegrade DBE: [2.13 ± 1.51] cm vs [0.88 ± 0.70] cm, P = 0.012; retrograde DBE: [1.20 ± 1.10] cm vs [0.46 ± 0.40] cm, P = 0.048). The interval between the second and third hospitalizations was significantly longer than that between the first and second hospitalizations ([899.00 ± 382.12] days vs [537.27 ± 326.28] days, P = 0.027). The success rate of total enteroscopy was 58.3% (28/48), which was not affected by a history of laparotomy (61.5% vs 52.4%, P = 0.528). The complication rate was 4.4%. Conclusion DBE is clinically safe and effective for the diagnosis and treatment of intestinal polyps in patients with PJS.

Background: Tuberculosis (TB) is one of the most widespread and lethal infectious diseases worldwide. The emergence of drugresistant TB has hampered effective TB treatment and control. Prokaryotic ubiquitin-like Protein-Proteasome System (PPS) contributes to the survival of Mycobacterium tuberculosis in the host. However, whether PPS effects drug resistance of isoniazid monoresistant Mycobacterium tuberculosis (INH-MTB) is still unknown. Objectives: This study aimed at exploring the effect of PPS on drug resistance of INH-MTB strain. Methods: In this study, over-expression of strains and deletion of mutant strains were constructed using electroporation. The researchers identified these constructed strains by Quantitative Reverse Transcription Polymerase Chain Reaction (RT-qPCR) or PCR. The Minimum Inhibitory Concentration (MIC) of isoniazid in INH-MTB strain and its derivative PPS mutant strains were determined using the Resazurin micro-titre assay. Results: The MIC of isoniazid was 8 µg/mL higher in INH-MTB with Pup over-expression strain than that in INH-MTB. The MIC of isoniazid was 4.82 µg/mL, 4.98 µg/mL, 4.99 µg/mL, and 4.9 µg/mL lower in INH-MTB with deletion of Pup, Dop, PafA or Mpa strains than that in INH-MTB, respectively. The differences had statistical significance (P < 0.05). The MIC of isoniazid was 1.03 µg/mL higher in INH-MTB with PafA over-expression strain than that in INH-MTB. The MIC of isoniazid was 1.03 µg/mL and 0.68 µg/mL lower in INH-MTB with Dop, Mpa over-expression strains than that in INH-MTB, respectively. The differences had no statistical significance (P > 0.05). Conclusions: These results show that PPS effects the drug resistance of the INH-MTB strain.