Objective To evaluate MRI in judging the therapeutic effect of argon-helium cryoablation therapy for prostate cancer. Methods The clinical data and imaging materials of 16 patients with prostate cancer , who had received ultrasound-guided argon-helium knife cryogenic treatment at authors ’ hospital during the period from March 2012 to Oct. 2014, were retrospectively and comprehensively analyzed. The preoperative and postoperative laboratory test results were compared with MRI findings, and the ablation effect was assessed, focusing on the surgical residue, metastasis, etc. Results One months after the surgery, MRI demonstrated that satisfactory ablation extent was obtained in all patients, the ablated tumor tissue was characterized by long-T2 signal and no obvious recurrence could be found on DWI and DCE-MRI. A slight decrease of PSA level was observed. Six months after the surgery, MRI revealed that the prostate size was significantly reduced, PSA level was markedly decreased and no obvious evidence of recurrence was observed. No severe postoperative complications, such as urethral necrosis, urethral stricture or urethro-rectal fistula, occurred. During the 6-month following-up time, one patient died from other causes. Conclusion MRI has excellent clinical application value in estimating the ablation extent and in judging postoperative recurrence or metastasis of prostate cancer after argon-helium cryoablation treatment.

Objective To evaluate the diagnostic capabilities of T2 WI features in peripheral zone prostate cancer.Methods The characteristics of T2 WI in 56 cases of peripheral zone prostate cancer,75 cases of benign prostatic hyperplasia and 7 cases of prostatitis confirmed by pathology were analyzed retrospectively.Eight indexes were initially screened byχ2 test,then indexes with significant difference were entered into multivariate Logistic regression analysis.Results The indexes showing statistical differences between prostate cancer and benign prostatic disorders were as following:lesion shape,signal intensity,signal uniformity,boundary of peripheral zone and transition zone,the volume of peripheral zone and prostatic capsule on T2 WI (P<0.05).Margin of lesion and capsule between two groups were not statistical differences (P>0.05).By multivariate Logistic analysis,the statistically significant difference were found in lesion shape, the volume of peripheral zone,prostatic capsule and boundary of peripheral zone and transition zone.Conclusion The lesion shape, volume of peripheral zone and prostatic capsule on T2 WI are independent risk factors for peripheral zone prostate cancer.

Cyclodipeptide (CDP) composed of two amino acids is the simplest cyclic peptide. These two amino acids form a typical diketopiperazine (DKP) ring by linking each other with peptide bonds. This characteristic stable ring skeleton is the foundation of CDP to display extensive and excellent bioactivities, which is beneficial for CDPs' pharmaceutical research and development. The natural CDP products are well isolated from actinomycetes. These bacteria can synthesize DKP backbones with nonribosomal peptide synthetase (NRPS) or cyclodipeptide synthase (CDPS). Moreover, actinomycetes could produce a variety of CDPs through different enzymatic modification. The presence of these abundant and diversified catalysis indicates that actinomycetes are promising microbial resource for exploring CDPs. This review summarized the pathways for DKP backbones biosynthesis and their post-modification mechanism in actinomycetes. The aim of this review was to accelerate the genome mining of CDPs and their isolation, purification and structure identification, and to facilitate revealing the biosynthesis mechanism of novel CDPs as well as their synthetic biology design.
Actinobacteria/metabolism* ; Actinomyces/metabolism* ; Biological Products/metabolism* ; Bacteria/metabolism* ; Diketopiperazines/metabolism* ; Amino Acids