2.P450-mediated dehydrotyrosine formation during WS9326 biosynthesis proceeds via dehydrogenation of a specific acylated dipeptide substrate.
Songya ZHANG ; Lin ZHANG ; Anja GREULE ; Julien TAILHADES ; Edward MARSCHALL ; Panward PRASONGPHOLCHAI ; Daniel J LENG ; Jingfan ZHANG ; Jing ZHU ; Joe A KACZMARSKI ; Ralf B SCHITTENHELM ; Oliver EINSLE ; Colin J JACKSON ; Fabrizio ALBERTI ; Andreas BECHTHOLD ; Youming ZHANG ; Manuela TOSIN ; Tong SI ; Max J CRYLE
Acta Pharmaceutica Sinica B 2023;13(8):3561-3574
WS9326A is a peptide antibiotic containing a highly unusual N-methyl-E-2-3-dehydrotyrosine (NMet-Dht) residue that is incorporated during peptide assembly on a non-ribosomal peptide synthetase (NRPS). The cytochrome P450 encoded by sas16 (P450Sas) has been shown to be essential for the formation of the alkene moiety in NMet-Dht, but the timing and mechanism of the P450Sas-mediated α,β-dehydrogenation of Dht remained unclear. Here, we show that the substrate of P450Sas is the NRPS-associated peptidyl carrier protein (PCP)-bound dipeptide intermediate (Z)-2-pent-1'-enyl-cinnamoyl-Thr-N-Me-Tyr. We demonstrate that P450Sas-mediated incorporation of the double bond follows N-methylation of the Tyr by the N-methyl transferase domain found within the NRPS, and further that P450Sas appears to be specific for substrates containing the (Z)-2-pent-1'-enyl-cinnamoyl group. A crystal structure of P450Sas reveals differences between P450Sas and other P450s involved in the modification of NRPS-associated substrates, including the substitution of the canonical active site alcohol residue with a phenylalanine (F250), which in turn is critical to P450Sas activity and WS9326A biosynthesis. Together, our results suggest that P450Sas catalyses the direct dehydrogenation of the NRPS-bound dipeptide substrate, thus expanding the repertoire of P450 enzymes that can be used to produce biologically active peptides.
3.Risk of Diabetic Retinopathy between Sodium-Glucose Cotransporter-2 Inhibitors and Glucagon-Like Peptide-1 Receptor Agonists (Diabetes Metab J 2023;47:394-404)
Tzu-Yi LIN ; Eugene Yu-Chuan KANG ; Shih-Chieh SHAO ; Edward Chia-Cheng LAI ; Yih-Shiou HWANG
Diabetes & Metabolism Journal 2023;47(4):573-574
4.Risk of Diabetic Retinopathy between Sodium-Glucose Cotransporter-2 Inhibitors and Glucagon-Like Peptide-1 Receptor Agonists
Tzu-Yi LIN ; Eugene Yu-Chuan KANG ; Shih-Chieh SHAO ; Edward Chia-Cheng LAI ; Sunir J. GARG ; Kuan-Jen CHEN ; Je-Ho KANG ; Wei-Chi WU ; Chi-Chun LAI ; Yih-Shiou HWANG
Diabetes & Metabolism Journal 2023;47(3):394-404
Background:
To compare risk of diabetic retinopathy (DR) between patients taking sodium-glucose cotransporter-2 inhibitors (SGLT2is) and those taking glucagon-like peptide-1 receptor agonists (GLP1-RAs) in routine care.
Methods:
This retrospective cohort study emulating a target trial included patient data from the multi-institutional Chang Gung Research Database in Taiwan. Totally, 33,021 patients with type 2 diabetes mellitus using SGLT2is and GLP1-RAs between 2016 and 2019 were identified. 3,249 patients were excluded due to missing demographics, age <40 years, prior use of any study drug, a diagnosis of retinal disorders, a history of receiving vitreoretinal procedure, no baseline glycosylated hemoglobin, or no follow-up data. Baseline characteristics were balanced using inverse probability of treatment weighting with propensity scores. DR diagnoses and vitreoretinal interventions served as the primary outcomes. Occurrence of proliferative DR and DR receiving vitreoretinal interventions were regarded as vision-threatening DR.
Results:
There were 21,491 SGLT2i and 1,887 GLP1-RA users included for the analysis. Patients receiving SGLT2is and GLP-1 RAs exhibited comparable rate of any DR (subdistribution hazard ratio [SHR], 0.90; 95% confidence interval [CI], 0.79 to 1.03), whereas the rate of proliferative DR (SHR, 0.53; 95% CI, 0.42 to 0.68) was significantly lower in the SGLT2i group. Also, SGLT2i users showed significantly reduced risk of composite surgical outcome (SHR, 0.58; 95% CI, 0.48 to 0.70).
Conclusion
Compared to those taking GLP1-RAs, patients receiving SGLT2is had a lower risk of proliferative DR and vitreoretinal interventions, although the rate of any DR was comparable between the SGLT2i and GLP1-RA groups. Thus, SGLT2is may be associated with a lower risk of vision-threatening DR but not DR development.
5.Platelet RNA enables accurate detection of ovarian cancer: an intercontinental, biomarker identification study.
Yue GAO ; Chun-Jie LIU ; Hua-Yi LI ; Xiao-Ming XIONG ; Gui-Ling LI ; Sjors G J G IN 'T VELD ; Guang-Yao CAI ; Gui-Yan XIE ; Shao-Qing ZENG ; Yuan WU ; Jian-Hua CHI ; Jia-Hao LIU ; Qiong ZHANG ; Xiao-Fei JIAO ; Lin-Li SHI ; Wan-Rong LU ; Wei-Guo LV ; Xing-Sheng YANG ; Jurgen M J PIEK ; Cornelis D DE KROON ; C A R LOK ; Anna SUPERNAT ; Sylwia ŁAPIŃSKA-SZUMCZYK ; Anna ŁOJKOWSKA ; Anna J ŻACZEK ; Jacek JASSEM ; Bakhos A TANNOUS ; Nik SOL ; Edward POST ; Myron G BEST ; Bei-Hua KONG ; Xing XIE ; Ding MA ; Thomas WURDINGER ; An-Yuan GUO ; Qing-Lei GAO
Protein & Cell 2023;14(6):579-590
Platelets are reprogrammed by cancer via a process called education, which favors cancer development. The transcriptional profile of tumor-educated platelets (TEPs) is skewed and therefore practicable for cancer detection. This intercontinental, hospital-based, diagnostic study included 761 treatment-naïve inpatients with histologically confirmed adnexal masses and 167 healthy controls from nine medical centers (China, n = 3; Netherlands, n = 5; Poland, n = 1) between September 2016 and May 2019. The main outcomes were the performance of TEPs and their combination with CA125 in two Chinese (VC1 and VC2) and the European (VC3) validation cohorts collectively and independently. Exploratory outcome was the value of TEPs in public pan-cancer platelet transcriptome datasets. The AUCs for TEPs in the combined validation cohort, VC1, VC2, and VC3 were 0.918 (95% CI 0.889-0.948), 0.923 (0.855-0.990), 0.918 (0.872-0.963), and 0.887 (0.813-0.960), respectively. Combination of TEPs and CA125 demonstrated an AUC of 0.922 (0.889-0.955) in the combined validation cohort; 0.955 (0.912-0.997) in VC1; 0.939 (0.901-0.977) in VC2; 0.917 (0.824-1.000) in VC3. For subgroup analysis, TEPs exhibited an AUC of 0.858, 0.859, and 0.920 to detect early-stage, borderline, non-epithelial diseases and 0.899 to discriminate ovarian cancer from endometriosis. TEPs had robustness, compatibility, and universality for preoperative diagnosis of ovarian cancer since it withstood validations in populations of different ethnicities, heterogeneous histological subtypes, and early-stage ovarian cancer. However, these observations warrant prospective validations in a larger population before clinical utilities.
Humans
;
Female
;
Blood Platelets/pathology*
;
Biomarkers, Tumor/genetics*
;
Ovarian Neoplasms/pathology*
;
China
6.The Progression of SARS Coronavirus 2 (SARS-CoV2): Mutation in the Receptor Binding Domain of Spike Gene
Sinae KIM ; Jong Ho LEE ; Siyoung LEE ; Saerok SHIM ; Tam T. NGUYEN ; Jihyeong HWANG ; Heijun KIM ; Yeo-Ok CHOI ; Jaewoo HONG ; Suyoung BAE ; Hyunjhung JHUN ; Hokee YUM ; Youngmin LEE ; Edward D. CHAN ; Liping YU ; Tania AZAM ; Yong-Dae KIM ; Su Cheong YEOM ; Kwang Ha YOO ; Lin-Woo KANG ; Kyeong-Cheol SHIN ; Soohyun KIM
Immune Network 2020;20(5):e41-
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) is a positive-sense singlestranded RNA (+ssRNA) that causes coronavirus disease 2019 (COVID-19). The viral genome encodes twelve genes for viral replication and infection. The third open reading frame is the spike (S) gene that encodes for the spike glycoprotein interacting with specific cell surface receptor – angiotensin converting enzyme 2 (ACE2) – on the host cell membrane. Most recent studies identified a single point mutation in S gene. A single point mutation in S gene leading to an amino acid substitution at codon 614 from an aspartic acid 614 into glycine (D614G) resulted in greater infectivity compared to the wild type SARS-CoV2. We were interested in investigating the mutation region of S gene of SARS-CoV2 from Korean COVID-19 patients. New mutation sites were found in the critical receptor binding domain (RBD) of S gene, which is adjacent to the aforementioned D614G mutation residue. This specific sequence data demonstrated the active progression of SARS-CoV2 by mutations in the RBD of S gene.The sequence information of new mutations is critical to the development of recombinant SARS-CoV2 spike antigens, which may be required to improve and advance the strategy against a wide range of possible SARS-CoV2 mutations.
7.Predictors of difficulty in intubation in patients with obstructive sleep apnoea
Cybil Mei Zhi Wang ; Kenny Peter Pang ; Tan Soo Guan ; Kathleen Ann Pang ; Edward Benjamin Pang ; Tan Yuk Ngi Cherilynn ; Yiong Huak Chan ; Brian W. Rotenberg
The Medical Journal of Malaysia 2019;74(2):133-137
Objective: To evaluate predictors of difficult intubation in
patients with obstructive sleep apnoea (OSA).
Methodology: Prospective series of 405 OSA patients (350
males/55 females) who had upper airway surgery.
Procedures included functional endoscopic sinus surgery,
septoplasty, turbinate reduction, palate/tonsil surgery,
and/or tongue base surgery. Intubation difficulty (ID) was
assessed using Mallampati grade, Laryngoscopic grade
(Cormack and Lehane), and clinical parameters including
BMI, neck circumference, thyromental distance, jaw
adequacy, neck movements and glidescope grading.
Results: Mean age was 41.6 years old; mean BMI 26.6; mean
neck circumference 44.5cm; mean Apnea Hypopnea Index
(AHI) was 25.0; and mean LSAT 82%. The various laryngeal
grades (based on Cormack and Lehane), grade 1 - 53
patients (12.9%), grade 2A - 127 patients (31.0%), grade 2B -
125 patients (30.5%), grade 3 - 93 patients (22.7%) and grade
4 - seven patients (1.7%); hence, 24.4% had difficulties in
intubation. Parameters that adversely affected intubation
were, age of the patient, opening of mouth, retrognathia,
overbite, overjet, limited neck extension, thyromental
distance, Mallampati grade, and macroglossia (p<0.001).
Body mass index (BMI) (p=0.087), neck circumference
(p=0.645), neck aches (p=0.728), jaw aches (p=0.417), tonsil
size (p=0.048), and AHI (p=0.047) had poor correlation with
intubation. BMI-adjusted for Asians and Caucasians,
showed that Asians were more likely to have difficulties in
intubation (adjusted OR = 4.6 (95%Confidence Interval: 1.05
to 20.06) (p=0.043), compared to the Caucasian group.
8.Studies on volatile oils compounds of Acorus macrospadiceus based on GC-MS, an ethnomedicinal and food plant used by local people in southwest China.
Hang SHU ; Taylan MORCOL ; Jie ZHENG ; Li-Dan ZHAO ; Kennelly-J EDWARD ; Chun-Lin LONG
China Journal of Chinese Materia Medica 2018;43(9):1774-1779
Acorus macrospadiceus is a common medicinal and food plant used different ethnic groups in Guizhou and surrounding areas. In this paper, the leaf and rhizome tissues of A. macrospadiceus were hydro-distilled to extract the volatile oils. The chemical constituents of these oils were analyzed by GC-MS and identified using the NIST 14.0 & NIST 14.0s mass spectral libraries. The relative contents of chemical constituents from the different plant parts were determined by area normalization. The analysis of A. macrospadiceus volatile oils resulted in the identification of 25 compounds from the leaf and 36 compounds from the rhizome. The identified compounds accounted for 97.85% of the leaf essential oil content and 97.18% of the rhizome essential oil content. The main volatile constituent of A. macrospadiceus was identified as estragole (93.56% of total oil content in leaf and 71.62% of total oil content in rhizome). Fourteen compounds were found to be common to essential oils of both leaf and rhizome. However, the relative amounts of these compounds were significantly different between the plant parts; the remaining identified compounds were unique to each part. This comparison of volatile oils from the different parts of A. macrospadiceus can serve as a reference for future development. Because of the higher estragole content and better harvesting sustainability of the leaves compared to rhizomes, the leaves of A. macrospadiceus deserve consideration for sustainable development. However, when we use it as a medical plant, we should draw a distinction between it with A. tatarinowii.
9.Intramuscular schwannoma: clinical and magnetic resonance imaging features.
Abhijeet Ashok SALUNKE ; Yongsheng CHEN ; Jun Hao TAN ; Xi CHEN ; Tun-Lin FOO ; Louise Elizabeth GARTNER ; Mark Edward PUHAINDRAN
Singapore medical journal 2015;56(10):555-557
INTRODUCTIONSchwannomas that arise within the muscle plane are called intramuscular schwannomas. The low incidence of these tumours and the lack of specific clinical features make preoperative diagnosis difficult. Herein, we report our experience with intramuscular schwannomas. We present details of the clinical presentation, radiological diagnosis and management of these tumours.
METHODSBetween January 2011 and December 2013, 29 patients were diagnosed and treated for histologically proven schwannoma at the National University Hospital, Singapore. Among these 29 patients, eight (five male, three female) had intramuscular schwannomas.
RESULTSThe mean age of the eight patients was 40 (range 27-57) years. The most common presenting feature was a palpable mass. The mean interval between surgical treatment and the onset of clinical symptoms was 17.1 (range 4-72) months. Six of the eight tumours (75.0%) were located in the lower limb, while 2 (25.0%) were located in the upper limb. None of the patients had any preoperative neurological deficits. Tinel's sign was present in one patient. Magnetic resonance (MR) imaging showed that the findings of split-fat sign, low signal margin and fascicular sign were present in all patients. The entry and exit sign was observed in 4 (50.0%) patients, a hyperintense rim was observed in 7 (87.5%) patients and the target sign was observed in 5 (62.5%) patients. All patients underwent microsurgical excision of the tumour and none developed any postoperative neurological deficits.
CONCLUSIONIntramuscular schwannomas demonstrate the findings of split-fat sign, low signal margin and fascicular sign on MR imaging. These findings are useful for the radiological diagnosis of intramuscular schwannoma.
Adult ; Female ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Muscle Neoplasms ; diagnostic imaging ; Neurilemmoma ; diagnostic imaging ; Postoperative Period ; Retrospective Studies ; Singapore
10.Efficacy and safety of gefitinib or docetaxel in Chinese patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) who had failed previous platinum-based first-line chemotherapy.
Yan SUN ; Yi-long WU ; Long-yun LI ; Mei-lin LIAO ; Guo-liang JIANG ; Edward S KIM ; Jean-yves DOUILLARD ; Tsveta MILENKOVA
Chinese Journal of Oncology 2011;33(5):377-380
OBJECTIVETo compare the efficacy and safety of gefitinib or docetaxel in Chinese patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) who had failed previous platinum-based first-line chemotherapy.
METHODSWe retrospectively reviewed 222 Chinese NSCLC patients in the subgroup of INTEREST (gefitinib versus docetaxel in previously treated non-small cell lung cancer) study. Survival analysis was evaluated by Kaplan-Meier method, and Functional Assessment of Cancer Therapy-Lung (FACT-L) was used to compare the quality of life between gefitinib group and docetaxel group.
RESULTSA total of 222 patients were analyzed in this subgroup study. 107 patients were treated with gefitinib, and 115 patients treated with docetaxel. There were all balanced between the two groups in terms of sex, age, staging and pathology in patient characteristics. The median overall survival in the two groups was similar (11 months in the gefitinib group vs. 14.0 months in the docetaxel group, P = 0.783). The progression-free survival (PFS) was also similar between the two groups (median PFS: 3.4 months in gefitinib group vs. 3.8 months in docetaxel group, P = 0.214). The response rate in gefitinib group was significantly higher than that in the docetaxel group (21.9% vs. 9.1%, P = 0.016).
CONCLUSIONThe efficacy of gefitinib is similar with that of docetaxel in pretreated patients with locally advanced or metastatic NSCLC, however, gefitinib is more favorable in the tolerance and quality of life improvement.
Adult ; Antineoplastic Agents ; adverse effects ; therapeutic use ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; pathology ; Diarrhea ; chemically induced ; Disease-Free Survival ; Exanthema ; chemically induced ; Female ; Humans ; Lung Neoplasms ; drug therapy ; pathology ; Male ; Neoplasm Staging ; Neutropenia ; chemically induced ; Platinum ; therapeutic use ; Quality of Life ; Quinazolines ; adverse effects ; therapeutic use ; Randomized Controlled Trials as Topic ; Remission Induction ; Retrospective Studies ; Survival Rate ; Taxoids ; adverse effects ; therapeutic use


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