海星共附生真菌Penicillium sp．GGF16－1－2中次级代谢产物研究

目的 全球天然产物社会分子网络（GNPS）和单菌株多次级代谢产物（OSMAC）策略从海洋微生物中寻找结构新颖、活性好的次生代谢产物。方法 在GNPS指导下，通过硅胶柱层析及半制备高效液相色谱（HPLC）等方法对海星共附生真菌penicillium sp. GGF16-1-2在不同培养基的次级代谢产物进行分离纯化。通过核磁共振（NMR）、高分辨质谱（HRMS）、旋光（ORD）和圆二色光谱（CD）等现代波谱解析方法以及对比文献确定化合物的结构。结果 在GNPS追踪指导下从penicillium sp. GGF16-1-2中D培养基分离得到9个聚酮类化合物，依次为phenol A（1）、decarboxydihydrocitrinone（2）、stoloniferol B（3）、sclerotinin A（4）、(1S,3R,4S)-1-(4"-hydroxyl-phenyl)-3,4-dihydro-3,4,5-trimethyl-1H-2- benzopyran-6,8-diol（5）、β-diversonolic ester（6）、sydowinin A（7）、ω-hydroxy-emodin（8）和dibutyl phthalate（9）。而在真1培养基中GNPS预测到二聚体类成分存在，并在GNPS指导下初步分离得到桔霉素二聚类化合物：citrinin H1（10）和dicitrinone B（11）。结论 OSMAC策略和GNPS可以预测并获得骨架丰富、结构新颖的化合物。对海星共附生真菌penicillium sp. GGF16-1-2次生代谢产物研究发现真1培养基比D培养基更适合桔霉素二（多）聚体类化合物的产生。     

Impact of HEC72702 chirality on the selective inhibition of hepatitis B virus capsid dimer: A dynamics–structure–energetics perspective

Chirality in drug design has been attracting wide interests and attention over the years based on its innate potentials of enhancing the selectivity and prowess of therapeutic molecules. This approach was fundamental to the recent design of two inhibitors, where (R,R)‐HEC72702 exhibited higher potency inhibition against hepatitis B virus capsid (HBVC) than (R,S)‐HEC72702. Nevertheless, the detailed molecular mechanism has remained unresolved. Here, we apply multiple computational approaches to explore, validate, and differentiate the binding modes of (R,R) and (R,S) ‐ HEC72702 and to explain the systematic roles mediated by chirality on the distinctive inhibition of HBVC dimer (HBVCd). Our findings revealed that chirality change from R,S to R,R engenders variations in the position of the propanoic acid group of HEC72702 toward the α5′ and C‐TER′ region of HBVCd chain B which could explain the higher inhibitory affinity of (R,R) ‐ HEC72702. Estimated binding free energies revealed a good correlation with bioactivity data. Moreover, analysis of energy decomposition revealed the prominent effects of van der Waals interactions in the binding process of both compounds to HBVCd. Furthermore, hierarchical clustering of residue‐based energetic contributions suggested two hot‐spot residues W125´ and F156´ play crucial roles in the systematic motions of the propanoic acid group toward chain B.     

Fc-Mediated E2-Dimer Subunit Vaccines of Atypical Porcine Pestivirus Induce Efficient Humoral and Cellular Immune Responses in Piglets

Congenital tremor (CT) type A-II in piglets is caused by an emerging atypical porcine pestivirus (APPV), which is prevalent in swine herds and a serious threat to the pig production industry. This study aimed to construct APPV E2 subunit vaccines fused with Fc fragments and evaluate their immunogenicity in piglets. Here, APPV E2Fc and E2ΔFc fusion proteins expressed in Drosophila Schneider 2 (S2) cells were demonstrated to form stable dimers in SDS-PAGE and western blotting assays. Functional analysis revealed that aE2Fc and aE2ΔFc fusion proteins could bind to FcγRI on antigen-presenting cells (APCs), with the affinity of aE2Fc to FcγRI being higher than that of aE2ΔFc. Moreover, subunit vaccines based on aE2, aE2Fc, and aE2ΔFc fusion proteins were prepared, and their immunogenicity was evaluated in piglets. The results showed that the Fc fusion proteins emulsified with the ISA 201VG adjuvant elicited stronger humoral and cellular immune responses than the IMS 1313VG adjuvant. These findings suggest that APPV E2 subunit vaccines fused with Fc fragments may be a promising vaccine candidate against APPV.     

The DiPEP (Diagnosis of PE in Pregnancy) biomarker study: An observational cohort study augmented with additional cases to determine the diagnostic utility of biomarkers for suspected venous thromboembolism during pregnancy and puerperium

This study aimed to estimate the diagnostic utility of biomarkers for suspected venous thromboembolism (VTE) in pregnancy and the puerperium. Research nurses/midwives collected blood samples from 310 pregnant/postpartum women with suspected pulmonary emboli (PE) and 18 with diagnosed deep vein thrombosis (DVT). VTE was diagnosed using imaging, treatment and adverse outcome data. Primary analysis was limited to women with conclusive imaging (36 with VTE, 247 without). The area under the curve (AUC) for each biomarker was: activated partial thromboplastin time 0·669 (95% confidence interval 0·570–0·768), B‐type natriuretic peptide 0·549 (0·453–0·645), C‐reactive protein 0·542 (0·445–0·639), Clauss fibrinogen 0·589 (0·476–0·701), D‐Dimer (by enzyme‐linked immunosorbent assay) 0·668 (0·561–0·776), near‐patient D‐Dimer 0·651 (0·545–0·758), mid‐regional pro‐atrial natriuretic peptide 0·524 (0·418–0·630), prothrombin fragment 1 + 2 0·562 (0·462–0·661), plasmin‐antiplasmin complexes 0·639 (0·536–0·742), prothombin time 0·613 (0·508–0·718), thrombin generation lag time 0·702 (0·598–0·806), thrombin generation endogenous potential 0·559 (0·437–0·681), thrombin generation peak 0·596 (0·478–0·715), thrombin generation time to peak 0·655 (0·541–0·769), soluble tissue factor 0·531 (0·424–0·638) and serum troponin 0·597 (0·499–0·695). No diagnostically useful threshold for diagnosing or ruling out VTE was identified. In pregnancy and the puerperium, conventional and candidate biomarkers have no utility either for their negative or positive predictive value in the diagnosis of VTE.     

Diagnostic utility of an age‐specific cut‐off for d‐dimer for pulmonary embolism assessment when used with various pulmonary embolism risk scores

This retrospective cohort study compared the diagnostic utility (sensitivity, specificity and negative predictive value (NPV)) of the age‐times‐10 adjusted d‐dimer cut‐off used in combination with the original and simplified Well's pulmonary embolism (PE) scores and the original and simplified revised Geneva scores to identify patients in whom PE is classified as unlikely according to each score. The PE risk scores performed similarly with high sensitivity (97.6, 97.1, 96.9 and 97.1% respectively) and NPV (99.3, 99.3, 99.2 and 99.2% respectively). Each missed only one PE. The age‐times‐10 age‐adjusted d‐dimer assay cut‐off performed similarly with each of the clinical risk scores tested with high sensitivity and NPV.