Cucurbit[7]uril-Catalyzed Beckmann Rearrangement of Arylketoximes.

With the existence of cucurbit[7]uril (Q[7]), a supramolecular catalysis strategy for the Beckmann rearrangement of aryl ketoximes to N-substituted amides was successfully established. The cavity of Q[7] was found to be essential for substrate encapsulation and the rearrangement reaction through comparative experiments and studies on host-guest interactions. This supramolecular strategy provides an efficient route for the rearrangement reaction incorporating a carbonation intermediate.

Multiparametric MRI subregion radiomics for preoperative assessment of high-risk subregions in microsatellite instability of rectal cancer patients: A multicenter study.

BACKGROUND: Microsatellite instability (MSI) is associated with treatment response and prognosis in patients with rectal cancer (RC). However, intratumoral heterogeneity limits MSI testing in patients with RC. We developed a subregion radiomics model based on multiparametric magnetic resonance imaging (MRI) to preoperatively assess high-risk subregions with MSI and predict the MSI status of patients with RC. METHODS: This retrospective study included 475 patients (training cohort, 382; external test cohort, 93) with RC from two participating hospitals between April 2017 and June 2023. In the training cohort, subregion radiomic features were extracted from multiparametric MRI, which included T2-weighted, T1-weighted, diffusion-weighted, and contrast-enhanced T1-weighted imaging. MSI-related subregion radiomic features, classical radiomic features, and clinicoradiological variables were gathered to build five predictive models using logistic regression. Kaplan-Meier survival analysis was conducted to explore the prognostic information. RESULTS: Among the 475 patients (median age, 64 years [interquartile range, IQR: 55-70 years];304 men and 171 women), the prevalence of MSI was 11.16% (53/475). The subregion radiomics model outperformed the classical radiomics and clinicoradiological models in both training (area under the curve [AUC]=0.86, 0.72, and 0.59, respectively) and external test cohorts (AUC=0.83, 0.73, and 0.62, respectively). The subregion-clinicoradiological model combining clinicoradiological variables and subregion radiomic features performed the optimal, with AUCs of 0.87 and 0.85 in the training and external test cohorts, respectively. The 3-year disease-free survival rate of MSI groups predicted based on the model was higher than that of the predicted microsatellite stability (MSS) groups in both patient cohorts (training, P=0.032; external test, P=0.046). CONCLUSIONS: We developed and validated a model based on subregion radiomic features of multiparametric MRI to evaluate high-risk subregions with MSI and predict the MSI status of RC preoperatively, which may assist in individualized treatment decisions and positioning for biopsy.

[Classification of anal fistulas based on magnetic resonance imaging].

OBJECTIVE: To explore the diagnostic value of magnetic resonance imaging(MRI) in anal fistula. METHODS: A total of 2160 patients were clinically diagnosed with anal fistula at the Sixth Affiliated Hospital of Sun Yat-sen University from March 2010 to September 2015. Among them, 232 cases with operative history at other hospital, 218 with Crohn's disease, 6 with rectum cancer and 8 with other disease were excluded, and 1696 patients were finally enrolled and retrospectively analyzed. The saggital FSE T2WI imaging was confirmed based on the midline of body, and then the coronal and axial scanning line were confirmed. The key point was that the coronal scanning line must parallel and the axial scanning line must be perpendicular to the major axis of anal canal. The characteristics of anal fistula were recorded, and anal fistula were classified as five types, including intersphincteric, transphincteric, suprasphincteric, extrasphincteric and superficial fistula according to the Parks classification and our experience. The distribution of internal opening was described by using lithotomy position clock method. RESULTS: Of 1696 patients, 1456 were males and 240 females with median age of 26.5 (0.2 to 87.0) years. Age of 8.4% (143/1696) cases was under 20 years old, of 57.4%(973/1696) cases was between 20 to 40, of 28.4%(482/1696) cases was between 40 to 60, of 5.8%(98/1696) cases was over 60. The 1696 MR examinations included 1128 on 1.5T MR and 568 on 0.5T MR. Of all the anal fistulas was 29.0%(492) high position and 71.0%(1204) was low position. Among the 1696 patients, 1057 were intersphincteric fistulas(62.3%), 407 were transphincteric fistulas(24.0%), 68 were suprasphincteric fistulas(4.0%), 54 were extrasphincteric fistulas (3.2%), 67 were superficial fistulas(4.0%), and 43(2.5%) were difficult to classify. A total of 1996 internal openings were found and most of them were located around the dentate line of 5-7 o'clock in lithotomy position(47.7%, 952/1996). CONCLUSIONS: Anal fistula mainly occur in young men, and the most common type is intersphincteric fistula. MRI can accurately classify anal fistulas and clearly demonstrate internal openings, and provide reliable evidence for clinical treatment and surgery.

Association of rs662799 in APOA5 with CAD in Chinese Han population.

BACKGROUND: CAD (Coronary Artery Disease) is a complex disease that influenced by various environmental and genetic factors. Previous studies have found many single nucleotide polymorphisms (SNPs) associated with the risk of CAD occurrence. However, the results are inconsistent. In this study, we aim to investigate genetic etiology in Chinese Han population by analysis of 7 SNPs in lipid metabolism pathway that previously has been reported to be associated with CAD. METHODS: A total of 631 samples were used in this study, including 435 CAD cases and 196 normal healthy controls. SNP genotyping were conducted via multiplex PCR amplifying followed by NGS (next-generation sequencing). RESULTS: Rs662799 in APOA5 (Apolipoprotein A5) gene was associated with CAD in Chinese Han population (Odds-ratio = 1.374, P-value = 0.03). No significant association was observed between the rest of SNPs and CAD. Stratified association analysis revealed rs5882 was associated with CAD in non-hypertension group (Odds-ratio = 1.593, P-value = 0.023). Rs1800588 was associated with CAD in smoking group (Odds-ratio = 1.603, P-value = 0.035). CONCLUSION: The minor allele of rs662799 was the risk factor of CAD occurrences in Chinese Han population.

[The value of MRI with CUBE sequence in early evaluation of the efficacy of neoadjuvant therapy for locally advanced rectal cancer].

OBJECTIVE: To investigate the value of MRI with CUBE sequence in early evaluation of the efficacy of neoadjuvant therapy (NAT) for locally advanced rectal cancer. METHODS: Inclusion criteria: (1) rectal cancer proven by biopsy; (2) locally advanced rectal cancer (T3-4 or positive lymph nodes) with distance from lower edge of tumor to anal verge within 12 cm diagnosed by MRI before NAT; (3) acceptance of NAT treatment regulations and completion of NAT; (4) completion of routine MRI scan and CUBE scan before and after 2-course NAT chemotherapy (including new neoadjuvant chemotherapy and chemoradiotherapy); (5) completion of surgery 6-8 weeks after NAT; (6) exclusion of any previous NAT due to rectal malignant tumor or other tumors; (7) exclusion of poor image quality of preoperative routine MRI insufficient for rectal cancer staging or of CUBE image insufficient for tumor volume measurement. Fifty patients with advanced local rectal cancer were recruited in our hospital from February 2014 to January 2016. All the patients underwent MRI before and after 2-course neoadjuvent therapy. Tumor volume on CUBE were measured and the volume changes were calculated: volume difference= pre-treatment volume-post-treatment volume, volume change rate= (pre-treatment volume-post-treatment volume)/ pre-treatment volume. All the patients were categorized into sensitive and non-sensitive group according to postsurgical pathology. Comparisons were made between both groups before and after therapy. ROC curve was used to evaluate the value of CUBE-associated parameters in predicting the efficacy of rectal cancer. RESULTS: Among enrolled 50 patients with rectal cancer, 31 were male and 19 were female, with mean age of 49.1 years (range 21 to 70 years). T-staging by MRI before NAT was T2N1-2 in 1 case, T3 in 43 cases, T4 in 6 cases. The number of patients after NAT from tumor regression grading (TRG) 0 to TRG3 was 14, 13, 18, 5, respectively. The sensitive group and insensitive group were 45 cases and 5 cases. Mean tumor volume before and after preoperative 2-course NAT was 18.70 (4.14 to 91.77) cm3 and 9.26 (1.02 to 52.58) cm3, respectively, whose difference was significant (U=-5.826, P<0.001). Both measure values of overall tumor volume before and after preoperative NAT between sensitive group and insensitive group did not show significant differences(all P>0.05). While sensitivity group had significantly higher volume difference and change rate compared to insensitive group [ (11.90±10.01) cm3 vs. (0.65±3.93) cm3, P=0.005; 0.45±0.28 vs. 0.09±0.36, P=0.010]. ROC curve revealed that the optimal cutoff value of accurate identification of patients with NAT sensitive was 1.96 cm3 for volume difference with sensitivity 86.7% and specificity 80%, and 0.06 for volume change rate with sensitivity 93.3% and specificity 60%. CONCLUSION: MRI CUBE can predict the efficacy of NAT for early rectal cancer patients accurately and sensitively through the detection of tumor volume change before and after NAT.

Rectal cancer restaging using 3D CUBE vs. 2D T2-weighted technique after neoadjuvant therapy: a diagnostic study.

OBJECTIVE: This study aimed to compare the accuracy of rectal cancer restaging after neoadjuvant therapy with 3D CUBE sequence with 2D T2-weighted fast spin-echo (FSE) sequence. METHODS: This retrospective study comprised 72 patients with rectal cancer confirmed by colonoscopy and biopsy. After neoadjuvant therapy, all patients underwent pelvic magnetic resonance imaging (MRI) examination at 1.5T MRI sequences including a single coronal 3D CUBE T2-weighted FSE sequence with 1.4 mm thickness and a 2D T2-weighted FSE sequence in the sagittal, coronal and axial planes with 5 mm thickness. The total acquisition time of the two sequences was recorded. Results were compared with postsurgical pathology (gold standard). The diagnostic accuracy was evaluated; and receiver operating characteristic (ROC) curves and the area under the curves (AUC) were calculated. RESULTS: The T category staging accuracy of 3D T2WI and 2D T2WI was 81.9% and 72.2%, respectively, for reviewer 1 and 86.1% and 75.0% for reviewer 2. The AUC of 3D was higher than that of 2D (0.878 vs. 0.783 for reader 1 and 0.905 vs. 0.796 for reader 2; both P < 0.05) when judging whether the tumor broke through the muscle layer. There was no significant difference between 3D and 2D in judging whether lymph nodes were malignant (AUC 0.719 vs. 0.698 for reader 1 and 0.740 vs. 0.698 for reader 2; both P > 0.05). There were no significant differences in the visibility of the rectal wall layer, tumor lesion and the overall image quality (all P > 0.05). Compared with 2D sequences, the 3D sequence had shorter acquisition time and higher signal intensity ratio (both P < 0.05). CONCLUSION: 3D CUBE T2-weighted sequences offer better diagnostic accuracy in rectal cancer restaging after neoadjuvant therapy when compared with 2D T2-weighted FSE sequences; it has a shorter scanning time and more versatility of orientation reconstruction.

Liver acquisition with acceleration volume acquisition gadolinium-enhanced magnetic resonance combined with T2 sequences in the diagnosis of local recurrence of rectal cancer.

To investigate the efficacy of liver acquisition with acceleration volume acquisition (LAVA) gadolinium-enhanced magnetic resonance (MR) sequences and to assess its added accuracy in diagnosing local recurrence (LR) of rectal cancer with conventional T2-weighted fast spin echo (FSE) sequences. Pelvic MRI, including T2-weighted FSE sequences, gadolinium-enhanced sequences of LAVA and T1-weighted FSE with fat suppression, was performed on 225 patients with postoperative rectal cancer. Two readers evaluated the presence of LR according to "T2" (T2 sequences only), "T2 + LAVA-Gad" (LAVA and T2 imaging), and "T2 + T1-fs-Gad" (T1 fat suppression-enhanced sequence with T2 images). To evaluate diagnostic efficiency, imaging quality with LAVA and T1-fs-Gad by subjective scores and the signal intensity (SI) ratio. In the result, the SI ratio of LAVA was significantly higher than that of T1-fs-Gad (p = 0.0001). The diagnostic efficiency of "T2 + LAVA-Gad" was better than that of "T2 + T1-fs-Gad" (p = 0.0016 for Reader 1, p = 0.0001 for Reader 2) and T2 imaging only (p = 0.0001 for Reader 1; p = 0.0001 for Reader 2). Therefore, LAVA gadolinium-enhanced MR increases the accuracy of diagnosis of LR from rectal cancer and could replace conventional T1 gadolinium-enhanced sequences in the postoperative pelvic follow-up of rectal cancer.

Clinical Significance of 2 Deep Posterior Perianal Spaces to Complex Cryptoglandular Fistulas.

BACKGROUND: Confusion exists regarding the clinical significance of the deep posterior intersphincteric space and deep postanal space to complex perianal fistulas. OBJECTIVE: The purpose of this study was to assess the clinical significance of the 2 deep posterior perianal spaces and to describe in detail the courses of posterior complex cryptoglandular fistula extensions. DESIGN: This was a retrospective study. MRI-based characteristics of selected perianal fistulas were independently evaluated by examiners who focused on lesions in these 2 spaces and were blinded to each other's findings. SETTINGS: This study was conducted in the colorectal surgery and radiology departments of a large university teaching hospital in China. PATIENTS: Included in the study were patients who underwent pelvic MRI for posterior perianal fistula between October 2012 and December 2014. MAIN OUTCOME MEASURES: The occurrence rates of these 2 deep perianal space lesions in posterior cryptoglandular fistulas were determined. RESULTS: A total of 513 primary posterior cryptoglandular fistulas were identified in 508 patients, including 167 deep posterior intersphincteric space lesions (32.6%) and 23 deep postanal space lesions (4.5%). Of those, 173 fistulas (33.7%) were evaluated as complex. The former and latter spaces were involved in 79.2% (137/173) and 13.3% (23/173) of posterior complex fistulas. Compared with deep postanal space lesions, deep posterior intersphincteric space lesions were more common in cases with high transsphincteric or suprasphincteric fistulas (80.1% vs 15.8%), synchronous multiple transsphincteric fistulas (82.4% vs 20.6%), horseshoe-like fistulas (85.5% vs 14.5%), and supralevator fistulas (93.5% vs 16.1%). Similar incidences were also seen in cases with ischioanal-involved horseshoe-like fistulas (75.0% vs 25.0%). LIMITATIONS: This study was limited by its retrospective nature. CONCLUSIONS: The deep posterior intersphincteric space is more likely than the deep postanal space to be involved in complex cryptoglandular fistulas and is likely to play a more important role in the management of complex cryptoglandular fistulas.

[Application of adaptive iterative dose reduction technique in CT enterography in diagnosing Crohn disease].

OBJECTIVE: To evaluate the application of low-dose CT enterography with adaptive iterative dose reduction(AIDR) technique in diagnosing Crohn's disease. METHODS: Retrospective analysis was performed on 26 patients diagnosed as Crohn's disease by the multidisciplinary team in our hospital. Low-dose CT enterography with 640-slice MDCT was performed on these 26 patients using adaptive iterative dose reduction(AIDR) technique. Characteristics of Crohn's disease in CT enterography images were independently analyzed by two radiologists who were experienced in Crohn's disease with calculating the total radiation dosage. RESULTS: The radiation dosage of 26 patients ranged from 5.58 to 12.90 [mean (9.00±2.00)] mSv, which was lower than conventional scan (around 15 mSv) known from the literatures. According to the images of CT enterography of 26 cases, bowel wall thickening with abnormal enhancement and lymphadenectasis were found in 25 cases with total 109 segmental bowel wall thickening. Among 25 thickening cases, enterostenosis was found in 16 cases, stratification enhancement in 12 cases and comb sign in 14 cases. Besides, it was found that 8 cases with hyperdense fat on the mesenteric side, 7 cases with intestinal fistula, 6 cases with abdominal cavity abscess, and 3 cases with anal fistula. CONCLUSION: CT enterography of Crohn's disease with adaptive iterative dose reduction technique is an effective method to evaluate Crohn's disease without compromising image quality with reduced radiation dosage.