[Application of dynamic contrast enhanced status in multiparametric magnetic resonance imaging for prostatic cancer with PI-RADS 4 lesion].

OBJECTIVE: To evaluate the diagnostic value of dynamic contrast enhanced (DCE) of multiparametric magnetic resonance imaging (mpMRI) for prostate imaging reporting and data system (PI-RADS) 4 lesion in prostate peripheral zone. METHODS: The clinical data of patients with PI-RADS 4 lesion in prostate peripheral zone who underwent prostate biopsy from January 2018 to September 2021 in Peking University First Hospital were retrospectively included. According to DCE status, the patients were divided into the conventional group (4 points for diffusion-weighted imaging) and the comprehensive group (3 points for diffusion-weighted imaging + 1 point for DCE positive). Pearson's chi-square test or Fisher's exact test for comparison was conducted between prostate cancer and non-cancer patients. Univariate and multivariate Logistic regression were performed to analyze the correlation of positive biopsy with age, total prostate specific antigen (PSA), free PSA/total PSA (f/tPSA), prostate volume (PV), PSA density (PSAD) and DCE status. RESULTS: Among the 267 prostate biopsy patients, 217 cases were diagnosed as prostatic cancer (81.27%) and 50 cases were non-cancer (18.73%). Statistical analysis between the prostatic cancer group and the non-cancer group showed that there were significant differences in age, tPSA, PV and PSAD (all P < 0.05), but no significant differences in f/tPSA between the two groups. About different PI-RADS 4 lesion groups, the conventional group and the comprehensive group showed significant difference in biopsy results (P=0.001), and the conventional group had a higher positive rate. The PV of comprehensive group was larger than that of the conventional group. Among the prostate cancer patients diagnosed by biopsy, statistical analysis between the conventional group and comprehensive group showed that there were not significant differences in International Society of Urological Pathology (ISUP) grade and distinguishing clinically significant prostate cancer (all P > 0.05). Logistic univariate analysis showed that the diagnosis of prostate cancer was related to age, tPSA, f/tPSA, PV and DCE group status (all P < 0.05). Multivariate analysis showed that age, tPSA, PV and DCE group status (all P < 0.05) were independent risk factors for the diagnosis of prostatic cancer. CONCLUSION: tPSA, f/tPSA, PV and PSAD are the indicators to improve the diagnosis of prostatic cancer with PI-RADS 4 lesion in peripheral zone lesions. DCE status is worth considering, so that we can select patients for biopsy more accurately, reduce the rate of missed diagnosis of prostate cancer as well as avoid unnecessary prostate puncture.

[A head-to-head comparison of contemporary indolent prostate cancer screen protocols in Chinese].

OBJECTIVE: To compare the diagnostic accuracy of five internationally used indolent prostate cancer screen protocols in Chinese prostate cancer patients. METHODS: Retrospective analysis was made of the consecutive cohort of 314 patients, from Jan. 2006 to Apr. 2014, who had both prostate biopsy and radical prostatectomy in Peking University First Hospital. The Gleason score≤6, pT2, tumor volume≤0.5 mL, margin negative and lymph nodes negative were defined as indolent prostate cancer. The predictive value of five indolent screen criteria including Epstein, Memorial Sloan-Kettering Cancer Center (MSKCC), Prostate Cancer Research International: Active Surveillance (PRIAS), University of California, San Francisco (UCSF), and University of Miami (UM) were evaluated in Chinese prostate cancer patients. Measures of diagnostic accuracy and areas under the receiver-operating curve (AUC) were calculated for each protocol and compared. RESULTS: A total of 16% (49 cases) of the patients met the inclusion criteria of at least one protocol, including 24 cases in Epstein, 33 cases in MSKCC, 28 cases in PRIAS, 34 cases in UCSF, and 22 cases in UM. Three percent were eligible for all the studied criteria. UCSF and MSKCC protocols had the highest sensitivity and specificity than the others. The Epstein and PRIAS protocols demonstrated acceptable positive predictive value, but the specificity and sensitivity were inefficient. The UM protocol was performed unsatisfiedly on sensitivity, positive predictive value and AUC. A strict limited protocol which contained all the five protocols could not improve the predictive accuracy. CONCLUSION: The UCSF protocol had better diagnostic accuracy than the others, but the results were not satisfied. A further investigation on indolent prostate cancer screening in Chinese patients is needed.

Enantioselective, organocatalytic reduction of ketones using bifunctional thiourea-amine catalysts.

Prochiral ketones are reduced to enantioenriched, secondary alcohols using catecholborane and a family of air-stable, bifunctional thiourea-amine organocatalysts. Asymmetric induction is proposed to arise from the in situ complexation between the borane and chiral thiourea-amine organocatalyst resulting in a stereochemically biased boronate-amine complex. The hydride in the complex is endowed with enhanced nucleophilicity while the thiourea concomitantly embraces and activates the carbonyl.

Targeting QseC signaling and virulence for antibiotic development.

Many bacterial pathogens rely on a conserved membrane histidine sensor kinase, QseC, to respond to host adrenergic signaling molecules and bacterial signals in order to promote the expression of virulence factors. Using a high-throughput screen, we identified a small molecule, LED209, that inhibits the binding of signals to QseC, preventing its autophosphorylation and consequently inhibiting QseC-mediated activation of virulence gene expression. LED209 is not toxic and does not inhibit pathogen growth; however, this compound markedly inhibits the virulence of several pathogens in vitro and in vivo in animals. Inhibition of signaling offers a strategy for the development of broad-spectrum antimicrobial drugs.

Enantioselective, organocatalytic oxy-michael addition to gamma/delta-hydroxy-alpha,beta-enones: boronate-amine complexes as chiral hydroxide synthons.

An organocatalytic, enantioselective oxy-Michael addition to achiral gamma- and delta-hydroxy-alpha,beta-enones was developed. The key transformation is an unprecedented, asymmetric conjugate addition triggered by complexation between an in situ generated boronic acid hemiester and a chiral amine catalyst. Functionally, the intermediate amine-boronate complex acts as a chiral hydroxide surrogate or synthon. The resultant chiral beta-hydroxy-ketones are obtained in good to excellent yields and high ee following mild oxidative removal of the cyclic boronate. Natural products (R,12Z,15Z)-2-hydroxy-4-oxohenicosa-12,15-dienyl acetate and (+)-(S)-streptenol A were synthesized to demonstrate the utility of this reaction.

Total synthesis of phorboxazole B.

An efficient and highly convergent total synthesis of the potent antitumor agent phorboxazole B has been achieved. The synthetic strategy of this synthesis features: 1) a highly efficient substrate-controlled hydrogenation to construct the functionalized cis-tetrahydropyrane unit; 2) iterative crotyl addition to synthesize the segment that contains alternating hydroxyl and methyl substituents; 3) Hg(OAc)2/I2-induced cyclization to establish the cis-tetrahydropyrane moiety; 4) 1,3-asymmetric induction in the Mukaiyama aldol reaction to afford the stereogenic centers at C9 and C3; and 5) the exploration of the Still-Gennari olefination reaction to complete the macrolide ring of phorboxazoloe B.

An Economic and Practical Synthesis of the 2-Tetrahydrofuranyl Ether Protective Group.

Primary, secondary, and tertiary alcohols as well as phenols and carbohydrates are efficiently transformed into the corresponding 2-tetrahydrofuranyl ethers by a combination of Mn(0) powder and CCl(4) in tetrahydrofuran.

Toward the total synthesis of phorboxazole B: an efficient synthesis of the C20-C46 segment.

An efficient synthesis of the C20-C46 segment of phorboxazole B is described. The key steps involved Hg(OAc)(2)/I(2)-induced cyclization to construct the cis-tetrahydropyran moiety, the coupling of the metalated 2-methyloxazole 7 with lactone 6, and Julia olefination to furnish the conjugated diene moiety.

A novel AlEt3-promoted tandem reductive rearrangement of 1-benzyloxy-2,3-epoxides: new route to 2-quaternary 1,3-diol units.

A novel and highly stereoselective tandem rearrangement-reduction reaction of 1-benzyloxy-2,3-epoxide, under the promotion of triethylaluminum (AlEt3), has been developed to construct a quaternary stereocenter and the hydroxymethyl attached to the carbon center in one-step.