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Xiao H, Fang W, Lin M, Zhou Z, Fei H, Chen C. [A multiscale carotid plaque detection method based on two-stage analysis]. Nan Fang Yi Ke Da Xue Xue Bao 2024; 44:387-396. [PMID: 38501425 PMCID: PMC10954526 DOI: 10.12122/j.issn.1673-4254.2024.02.22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/20/2024]
Abstract
OBJECTIVE To develop a method for accurate identification of multiscale carotid plaques in ultrasound images. METHODS We proposed a two-stage carotid plaque detection method based on deep convolutional neural network (SM-YOLO).A series of algorithms such as median filtering, histogram equalization, and Gamma transformation were used to preprocess the dataset to improve image quality. In the first stage of the model construction, a candidate plaque set was built based on the YOLOX_l target detection network, using multiscale image training and multiscale image prediction strategies to accommodate carotid artery plaques of different shapes and sizes. In the second stage, the Histogram of Oriented Gradient (HOG) features and Local Binary Pattern (LBP) features were extracted and fused, and a Support Vector Machine (SVM) classifier was used to screen the candidate plaque set to obtain the final detection results. This model was compared quantitatively and visually with several target detection models (YOLOX_l, SSD, EfficientDet, YOLOV5_l, Faster R-CNN). RESULTS SM-YOLO achieved a recall of 89.44%, an accuracy of 90.96%, a F1-Score of 90.19%, and an AP of 92.70% on the test set, outperforming other models in all performance indicators and visual effects. The constructed model had a much shorter detection time than the Faster R-CNN model (only one third of that of the latter), thus meeting the requirements of real-time detection. CONCLUSION The proposed carotid artery plaque detection method has good performance for accurate identification of carotid plaques in ultrasound images.
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Affiliation(s)
- H Xiao
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
| | - W Fang
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
| | - M Lin
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
| | - Z Zhou
- Guangzhou Shangyi Network Information Technology Co., Ltd., Guangzhou 510515, China
| | - H Fei
- Guangdong Provincial People's Hospital Affiliated to Southern Medical University, Guangzhou 510180, China
| | - C Chen
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
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Fei H, Wang Q, Shang F, Xu W, Chen X, Chen Y, Li H. HC-Net: A hybrid convolutional network for non-human primate brain extraction. Front Comput Neurosci 2023; 17:1113381. [PMID: 36846727 PMCID: PMC9947775 DOI: 10.3389/fncom.2023.1113381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
Brain extraction (skull stripping) is an essential step in the magnetic resonance imaging (MRI) analysis of brain sciences. However, most of the current brain extraction methods that achieve satisfactory results for human brains are often challenged by non-human primate brains. Due to the small sample characteristics and the nature of thick-slice scanning of macaque MRI data, traditional deep convolutional neural networks (DCNNs) are unable to obtain excellent results. To overcome this challenge, this study proposed a symmetrical end-to-end trainable hybrid convolutional neural network (HC-Net). It makes full use of the spatial information between adjacent slices of the MRI image sequence and combines three consecutive slices from three axes for 3D convolutions, which reduces the calculation consumption and promotes accuracy. The HC-Net consists of encoding and decoding structures of 3D convolutions and 2D convolutions in series. The effective use of 2D convolutions and 3D convolutions relieves the underfitting of 2D convolutions to spatial features and the overfitting of 3D convolutions to small samples. After evaluating macaque brain data from different sites, the results showed that HC-Net performed better in inference time (approximately 13 s per volume) and accuracy (mean Dice coefficient reached 95.46%). The HC-Net model also had good generalization ability and stability in different modes of brain extraction tasks.
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Affiliation(s)
- Hong Fei
- College of Information and Computer, Taiyuan University of Technology, Taiyuan, China
| | - Qianshan Wang
- College of Information and Computer, Taiyuan University of Technology, Taiyuan, China
| | - Fangxin Shang
- Country Intelligent Healthcare Unit, Baidu, Beijing, China
| | - Wenyi Xu
- College of Information and Computer, Taiyuan University of Technology, Taiyuan, China
| | - Xiaofeng Chen
- College of Information and Computer, Taiyuan University of Technology, Taiyuan, China
| | - Yifei Chen
- College of Information and Computer, Taiyuan University of Technology, Taiyuan, China
| | - Haifang Li
- College of Information and Computer, Taiyuan University of Technology, Taiyuan, China,*Correspondence: Haifang Li,
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Restrepo LJ, DePew AT, Moese ER, Tymanskyj SR, Parisi MJ, Aimino MA, Duhart JC, Fei H, Mosca TJ. γ-secretase promotes Drosophila postsynaptic development through the cleavage of a Wnt receptor. Dev Cell 2022; 57:1643-1660.e7. [PMID: 35654038 DOI: 10.1016/j.devcel.2022.05.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 04/06/2022] [Accepted: 05/10/2022] [Indexed: 12/27/2022]
Abstract
Developing synapses mature through the recruitment of specific proteins that stabilize presynaptic and postsynaptic structure and function. Wnt ligands signaling via Frizzled (Fz) receptors play many crucial roles in neuronal and synaptic development, but whether and how Wnt and Fz influence synaptic maturation is incompletely understood. Here, we show that Fz2 receptor cleavage via the γ-secretase complex is required for postsynaptic development and maturation. In the absence of γ-secretase, Drosophila neuromuscular synapses fail to recruit postsynaptic scaffolding and cytoskeletal proteins, leading to behavioral deficits. Introducing presenilin mutations linked to familial early-onset Alzheimer's disease into flies leads to synaptic maturation phenotypes that are identical to those seen in null alleles. This conserved role for γ-secretase in synaptic maturation and postsynaptic development highlights the importance of Fz2 cleavage and suggests that receptor processing by proteins linked to neurodegeneration may be a shared mechanism with aspects of synaptic development.
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Affiliation(s)
- Lucas J Restrepo
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Alison T DePew
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Elizabeth R Moese
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Stephen R Tymanskyj
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Michael J Parisi
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Michael A Aimino
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Juan Carlos Duhart
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Hong Fei
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA
| | - Timothy J Mosca
- Department of Neuroscience, Vickie and Jack Farber Institute of Neuroscience, Thomas Jefferson University, Bluemle Life Sciences Building, Philadelphia, PA 19107, USA.
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Fei H, Naqvi MAUH, Naqvi SZ, Xu L, Song X, Li X, Yan R. Trichinella spiralis: Knockdown of gamma interferon inducible lysosomal thiol reductase (GILT) results in the reduction of worm burden. PLoS Negl Trop Dis 2021; 15:e0009958. [PMID: 34847145 PMCID: PMC8631631 DOI: 10.1371/journal.pntd.0009958] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2021] [Accepted: 10/29/2021] [Indexed: 11/18/2022] Open
Abstract
Trichinella spiralis is mammalian skeletal muscles parasite which may cause trichinellosis in animals and humans. Gamma interferon inducible lysosomal thiol reductase (GILT) is a widespread superfamily which plays key role in processing and presentation of MHC class II restricted antigen by catalyzing disulfide bond reduction. There are no reports about GILT in T. spiralis. In present study, GILT from T. spiralis (Tsp-GILT) was cloned, analyzed by multiple-sequence alignment, and predicted by 3D structure model. Recombinant Tsp-GILT (about 46 kDa) was efficiently expressed in Escherichia coli and thiol reductase activity suggested that in acidic environment the addition of a reducing agent is needed. Soaking method was used to knockdown expression of Tsp-GILT using small interference RNA (siRNA). Immunofluorescence assay confirmed the transformation of siRNA into muscle larva (ML) and new born larva (NBL). Quantitative real time-PCR (QRT-PCR) analysis revealed that transcription level of Tsp-GILT mRNA can be up-regulated by stimulation of mouse IFN-γ and down-regulated by siRNA2 in vitro. NBLs soaked with siRNA2 showed 32.3% reduction in the generation of MLs. MLs soaked with siRNA2 showed 26.2% reduction in the next generation of MLs, but no significant effect was observed on adult worms or NBLs. These findings concluded that GILT may play important roles in the development of T. spiralis parasite. Trichinella spiralis is the most important pathogen causing trichinellosis of animals and humans. Reports in mammal animals showed that gamma interferon inducible lysosomal thiol reductase (GILT) play key roles in processing and presentation of MHC class II restricted antigens. However, there were no reports about GILT in nematode T. spiralis. In this study, GILT gene from T. spiralis (Tsp-GILT) was cloned and analyzed. The predicted 3D structure of Ts-GILT protein was found similar with that of Homo sapiens and Sus scrofa. To further evaluate the roles of Tsp-GILT in T. spiralis development, a soaking method was used to knockdown the expression of Tsp-GILT gene by siRNA. It was found that NBLs soaked with siRNA showed 32.3% reduction in the generation of MLs, and MLs soaked with siRNA showed 26.2% reduction in the next generation of MLs. Current study concluded that siRNA knockdown of gamma interferon inducible lysosomal thiol reductase from Trichinella spiralis significantly reduce the larval infectivity, development and survival.
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Affiliation(s)
- Hong Fei
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Muhammad Ali-ul-Husnain Naqvi
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Sana Zahra Naqvi
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Lixin Xu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xiaokai Song
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Xiangrui Li
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
| | - Ruofeng Yan
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing, China
- * E-mail:
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Ren G, Juan YH, Fei H, Lin Q, Paul S, Wang J, Chen R, Liu H. Congenital absence of the pericardium and tricuspid regurgitation. QJM 2018; 111:895-897. [PMID: 30239954 DOI: 10.1093/qjmed/hcy213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Indexed: 02/05/2023] Open
Affiliation(s)
- G Ren
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
- Shantou University Medical College, Shantou, Guangdong Province, China
| | - Y-H Juan
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou, Chang Gung University, Taoyuan, Taiwan
| | - H Fei
- Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - Q Lin
- Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
| | - S Paul
- Case Western University Cleveland Clinic Lerner College of Medicine, Cleveland, OH, USA
| | - J Wang
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
- School of Medicine, South China University of Technology, Guangzhou, Guangdong Province, China
| | - R Chen
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
- School of Medicine, South China University of Technology, Guangzhou, Guangdong Province, China
| | - H Liu
- Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong, China
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Babkova T, Fei H, Kazantseva N, Sapurina I, Saha P. Enhancing the supercapacitor performance of flexible MnO x Carbon cloth electrodes by Pd-decoration. Electrochim Acta 2018. [DOI: 10.1016/j.electacta.2018.03.143] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Liu T, Huang J, Ehsan M, Wang S, Fei H, Zhou Z, Song X, Yan R, Xu L, Li X. Protective immunity against Eimeria maxima induced by vaccines of Em14-3-3 antigen. Vet Parasitol 2018; 253:79-86. [PMID: 29605008 DOI: 10.1016/j.vetpar.2018.02.027] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Revised: 02/09/2018] [Accepted: 02/10/2018] [Indexed: 11/26/2022]
Abstract
Eimeria maxima 14-3-3 (Em14-3-3) open reading frame (ORF) which consisted of 861 bp encoding a protein of 286 amino acids was successfully amplified and sequenced. Subsequently, the Em14-3-3 ORF was subcloned into pET-32a (+) and pVAX1, respectively. RT-PCR and immunoblot analyses confirmed that the target gene was successfully transcribed and expressed in vivo. Immunofluorescence analysis showed that Em14-3-3 was expressed in both the sporozoites and merozoites. The animal experiments demonstrated that both rEm14-3-3 and pVAX1-14-3-3 could clearly alleviate jejunum lesions and body weight loss. The Em14-3-3 vaccines could increase oocyst decrease ratio, as well as produce an anticoccidial index of more than 165. The percentages of CD4+ in both the Em14-3-3 immunized groups were much higher, when compared with those of PBS, pET32a (+), and pVAX1 controls (P < 0.05). Similarly, the anti-Em14-3-3 antibody titers of both rEm14-3-3 and pVAX1-14-3-3 immunized groups showed higher levels compared with those of PBS, pET32a (+), and pVAX1 controls (P < 0.05). The IFN-γ and tumor growth factor-β (TGF-β) levels showed significant increments in the rEm14-3-3 and pVAX1-14-3-3 immunized groups, when compared with those in the negative controls (P < 0.05). These results demonstrated that Em14-3-3 could be used as a promising antigen candidate for developing vaccines against E. maxima.
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Affiliation(s)
- Tingqi Liu
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Jingwei Huang
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Muhammad Ehsan
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Shuai Wang
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Hong Fei
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Zhouyang Zhou
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Xiaokai Song
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Ruofeng Yan
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Lixin Xu
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China
| | - Xiangrui Li
- College of Veterinary Medicine, Nanjing Agriculture University, 1 Weigang, Nanjing, Jiangsu 210095, PR China.
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Blackburn D, Sarrigiannis P, Yifan Z, De Marco M, Bell S, Venneri A, Billings S, Farrow T, Fei H, Unwin Z, Blythe M, Lawrence S, Wilkinson I. A novel quantitative EEG approach to distiguish Alzheimer’s disease from fronto tempura dementia and healthy controls. J Neurol Sci 2017. [DOI: 10.1016/j.jns.2017.08.903] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Liu H, Juan YH, Wang Q, Xie J, Hou Q, Fei H, Zhang X, Zhou H, Liang C, Lin YC, Kwong RY, Saboo SS. Aortic root ring sign: multimodality imaging of aortic root abscess. QJM 2016; 109:53-4. [PMID: 25852152 DOI: 10.1093/qjmed/hcv073] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- H Liu
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China,
| | - Y-H Juan
- Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan
| | - Q Wang
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China
| | - J Xie
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China
| | - Q Hou
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China
| | - H Fei
- Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China
| | - X Zhang
- Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China
| | - H Zhou
- Department of Thoracic Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and
| | - C Liang
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China
| | - Y-C Lin
- Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan
| | - R Y Kwong
- Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - S S Saboo
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Yu B, Zhao S, Hu D, Ambegaonakr BM, DYSIS-China Study Investigators, Jia Er BA, Guiwen C, Buxing C, Hong C, Jin C, Jing C, Liefeng C, Min C, Qiong C, Shaoliang C, Tielong C, Xiaofei C, Xiaohong C, You C, Guoli C, Mei C, Hongliang C, Qin C, Shiwei C, Yong C, Shudong D, Henghua D, Xiaomei D, Yirong D, Xiaoyan D, Birong D, Yumei D, Yugang D, Ping D, Lei D, Limei F, Ningyuan F, Lixia F, Lie F, Jun G, GeWeihong, Hongmin G, Minxia G, Qinghua H, Fengchang H, Dayi H, Lingzhi H, Xueqiang H, Yaojun H, Yiming H, Zhiping H, Fei H, Qi H, Dejia H, Gewen H, Hongman H, Liming H, Qiong H, Ruowen H, Taifu H, Bin J, Kai J, Hui J, Huigen J, Jinsong K, Bao L, Chengjiang L, Hongjuan L, Jun(Xinjiang) L, Jun(Jiangsu) L, Nanfang L, Qifu L, Qiang L, Xin L, Xueyou L, Yanbing L, Yanping L, Yansheng L, Yong L, Yuling L, Zhanquan L, Zhengfang L, Li L, Yongxue L, Zerong L, Yuhua L, Fan L, Hong L, Hui L, Minling L, Qiang L, Qingsong L, Shaokui L, Weidong L, Xueping L, Xinjian L, Benyan L, Shaonian L, Suxin L, Hong L, LvYun, Aiqun M, Jianhua M, Qiang M, Yan M, Changsheng M, Yide M, Yiming M, NieXiaoli, NiuXiaoyuan, Hongtao P, Mingkang P, Qiaoqing P, Huifen Q, Qiumin Q, Lijie Q, Liqun R, Jingshan S, Qiang S, Jing H, Xiuyun S, Yongquan S, Liangyi S, Zhi S, Zhiyuan S, Yufeng S, Chunyan T, TengXiaochun, Haoming T, Wenhua T, Qinwei T, TuQiuyun, Keying W, Aihong W, Chaohui W, Chunning W, Dezhao W, Guixia W, Hanqiao W, Jianan W, Jianjun W, Lan W, Xiaoming W, Yaping W, Yangwei W, Yongjun W, Meifang W, Yidong W, Hongyun W, Chun W, Dongmei W, Jiang W, Jun W, Xiaolin W, Zonggui W, XiGuangxia, Yi X, Qian X, Xiaoping X, Yulong X, Anding X, XueYuanming, Chuanzhu Y, Tao Y, Xiaowei Y, Gangyi Y, Jian Y, Wangpingm Y, Xiaosu Y, Xinchun Y, Yifang Y, Yu Y, Mingyu Y, Min Y, Ping Y, Bo Y, Jiangyi Y, Jinming Y, Yan Y, Ling Z, Longyi Z, Xiaoyun Z, Baorong Z, Bei Z, Chaoxin Z, Xuelian Z, Dadong Z, Dongping Z, Fuchun Z, Hong Z, Huifang Z, Liping Z, Liyang Z, Rufu Z, Saidan Z, Weijuan Z, Dong Z, Gang Z, Shuiping Z, Xiuxin Z, Qiangsun Z, Yang Z, Xiaohui Z, Yali Z, Yujie Z, Yi Z, Yulan Z, Xiangping Z. Gender differences in lipid goal attainment among Chinese patients with coronary heart disease: insights from the DYSlipidemia International Study of China. Eur Heart J Suppl 2015. [DOI: 10.1093/eurheartj/suv018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Cahill JF, Fei H, Cohen SM, Prather KA. Characterization of core-shell MOF particles by depth profiling experiments using on-line single particle mass spectrometry. Analyst 2015; 140:1510-5. [PMID: 25587577 DOI: 10.1039/c4an01913j] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Materials with core-shell structures have distinct properties that lend themselves to a variety of potential applications. Characterization of small particle core-shell materials presents a unique analytical challenge. Herein, single particles of solid-state materials with core-shell structures were measured using on-line aerosol time-of-flight mass spectrometry (ATOFMS). Laser 'depth profiling' experiments verified the core-shell nature of two known core-shell particle configurations (<2 μm diameter) that possessed inverted, complimentary core-shell compositions (ZrO2@SiO2 versus SiO2@ZrO2). The average peak area ratios of Si and Zr ions were calculated to definitively show their core-shell composition. These ratio curves acted as a calibrant for an uncharacterized sample – a metal-organic framework (MOF) material surround by silica (UiO-66(Zr)@SiO2; UiO = University of Oslo). ATOFMS depth profiling was used to show that these particles did indeed exhibit a core-shell architecture. The results presented here show that ATOFMS can provide unique insights into core-shell solid-state materials with particle diameters between 0.2-3 μm.
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Affiliation(s)
- J F Cahill
- Organic and Biological Mass Spectrometry Group, Chemical Sciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6131, USA
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Fei H, Ke P, Wang N, Shen H, Huang J, Tan J, Liang L, Song X. An evaluation comparing Californium252 neutron brachytherapy with neoadjuvant intra-arterial embolism chemotherapy assisted surgery effect for treating advanced cervical carcinoma patients. EUR J GYNAECOL ONCOL 2015; 36:442-446. [PMID: 26390700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
PURPOSE OF INVESTIGATION To compare the therapeutic and side effects of using Californium252 (252Cf) neutron brachytherapy with neoadjuvant intra-arterial embolism chemotherapy in combination with surgery for treating Stage Ib2-IIb cervical cancers (CCs). MATERIALS AND METHODS Thirty-two Stage Ib2-IIb CC patients were enrolled and randomly divided into two groups from January 2007 to April 2010 in the present Hospital. Prior to surgery within four weeks, a total of 17 cases were treated with 252Cf neutron brachytherapy (700-800 cGy doses at point A) once a week (Group A), and 15 cases were treated by neoadjuvant intra-arterial embolism chemotherapy using a combination of bleomycin, carboplatin, and cyclophosphamide twice (Group B). The clinical symptoms and signs, side effects, and relapse condition follow up until July 2013 were compared between the two groups for the perioperation. RESULTS Reductions in tumor mass and CR+PR were not significantly different between the groups before the surgery (p > 0.05). Abdominal pain and pelvic adhesions were significantly more severe in Group B (p < 0.05). There were no significant differences in surgical time, blood loss or the other side effects between Groups A and B (p > 0.05). The percentage of pelvic tumor recurrences in Group A was lower than that of the patients in Group B (11.8% vs 20.0%) although with no significant difference at present. No distant metastasis has been found in both two groups. CONCLUSION Except for less abdominal pain and pelvic adhesions, 252Cf neutron brachytherapy has perioperative effects similar to those of neoadjuvant intra-arterial embolism chemotherapy.
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Liu H, Juan YH, Fei H, Mei P, Zhang X, Xu W, Liang C, Wang Q, Saboo SS. Tumor involvement of the left atrium and mitral valve: imaging features of intra-cardiac malignancy. QJM 2014; 107:747-9. [PMID: 24633259 DOI: 10.1093/qjmed/hcu058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- H Liu
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Y-H Juan
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - H Fei
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - P Mei
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - X Zhang
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - W Xu
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - C Liang
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Q Wang
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - S S Saboo
- From the Department of Radiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China, Department of Cardiovascular Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA, Department of Medical Imaging and Intervention, Chang Gung Memorial Hospital, Linkou and Chang Gung University, Taoyuan, Taiwan, Department of Cardiology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Pathology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, Department of Cardiovascular Surgery, Guangdong General Hospital, Guangdong Academy of Medical Sciences, GuangZhou, GuangDong, China and Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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14
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Xiao W, YanQing C, Fei H, LiXia L, Chong Z. Delineation of the Clinical Target Volume in Early-Stage Nasopharyngeal Carcinoma Treated With Intensity Modulated Radiation Therapy: Long-Term Follow-Up of a Phase 2 Study. Int J Radiat Oncol Biol Phys 2014. [DOI: 10.1016/j.ijrobp.2014.05.1616] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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15
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Wenhua L, Dongye L, Yanbin Z, Tongda X, Hong Z, Fei H. Prevention of contrast-induced acute kidney injury with the sodium bicarbonate in ACS patients undergoing PCI. Heart 2011. [DOI: 10.1136/heartjnl-2011-300867.326] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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16
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Zhang L, Wang C, Wu X, Chen H, Fei H. Hydrothermal synthesis, crystal structure, and thermal analysis of a Novel trinuclear manganese complex: Mn3(C12H8N2)2(C10H11O5)6. RUSS J COORD CHEM+ 2011. [DOI: 10.1134/s1070328411040129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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17
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Leng WH, Li X, Fei H, Zhang JQ, Cao CN. Comment on "Photocatalytic oxidation mechanism of As(III) on TiO2: unique role of As(III) as a charge recombinant species". Environ Sci Technol 2011; 45:2028-2031. [PMID: 21306102 DOI: 10.1021/es1040046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
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18
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Wenhua L, Fei H, Dongye L, Tongda X, Yanbin Z. e0476 Observation the change of neutrophil gelatinase-associated lipocalin levels in patients undergoing coronary angiography and percutaneous coronary intervention. Heart 2010. [DOI: 10.1136/hrt.2010.208967.476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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19
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Wang Q, Zhang H, Zhao B, Fei H. IL-1beta caused pancreatic beta-cells apoptosis is mediated in part by endoplasmic reticulum stress via the induction of endoplasmic reticulum Ca2+ release through the c-Jun N-terminal kinase pathway. Mol Cell Biochem 2008; 324:183-90. [PMID: 19109696 DOI: 10.1007/s11010-008-9997-9] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2008] [Accepted: 12/11/2008] [Indexed: 10/21/2022]
Abstract
Endoplasmic reticulum (ER) homeostasis is crucial for beta-cell function and survival. Direct as well as indirect evidence has pointed toward Ca(2+) as an important determinant of interleukin-1beta (IL-1beta)-induced beta-cell dysfunction and apoptosis. In the present study, we show that IL-1beta-induced apoptosis and necrosis in primary rat beta-cells and MIN6 cells largely depends on ER stress, ER Ca(2+) release, and c-Jun N-terminal kinase (JNK) activation. beta-cells also showed marked sensitivity to apoptosis induced by sarcoendoplasmic reticulum Ca(2+) ATPase (SERCA) blockers, thapsigargin and cyclopiazonic acid (CPA). IL-1beta induced ER Ca(2+) release, which was paralleled by an IL-1beta-dependent induction of JNK activation and the ER stress response, including activation of PRK (RNA-dependent protein kinase)-like ER kinase (PERK). Furthermore, reduced activation of JNK, utilizing JNK inhibitor SP600125, resulted in significant protection from IL-1beta- or thapsigargin-induced apoptosis via ER stress. In conclusion, our results suggest that the IL-1beta-induced depletion of ER Ca(2+) and activation of the ER stress via JNK pathway are potential contributory mechanisms to beta-cell death.
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Affiliation(s)
- Q Wang
- Key Laboratory of Microbial Metabolism, School of Life Sciences and Biotechnology, Ministry of Education, Shanghai Jiaotong University, Shanghai, People's Republic of China.
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20
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Gao L, Fei H, Connors NC, Zhang J, Levitan IB. Drosophila ortholog of succinyl-CoA synthetase {beta} subunit: a novel modulator of Drosophila KCNQ channels. J Neurophysiol 2008; 99:2736-40. [PMID: 18385479 DOI: 10.1152/jn.01314.2007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Voltage-gated KCNQ potassium channels are responsible for slowly activating potassium currents in heart, brain, and other tissues. Functional defects of KCNQ channels are linked with many diseases, including epilepsy and cardiac arrhythmias. Therefore KCNQ potassium channels have been widely studied, especially in the CNS. We have identified Drosophila CG11963, which encodes a protein orthologous to the beta subunit of mammalian succinyl-CoA synthetase (SCS, also known as succinate thiokinase), as a novel modulator of Drosophila KCNQ channels. Direct interaction of CG11963 and dKCNQ was demonstrated by yeast two-hybrid screen and coimmunoprecipitation. Cell surface biotinylation experiments further confirmed that CG11963 resides on the plasma membrane of tsA-201 cells. Coexpression of CG11963 with dKCNQ shifts the conductance-voltage (G-V) relationship of dKCNQ channels to more positive membrane potentials in Chinese hamster ovary (CHO) cells. Moreover, directly dialyzing glutathione S-transferase fusion CG11963 protein into CHO cells also shifts the dKCNQ G-V curve rightward. The effect of CG11963 persists in the presence of 1 mM adenosine triphosphate (ATP), a substrate of SCS. Taken together, our data define CG11963 as a new dKCNQ-binding protein capable of modulating the properties of the channel. Our evidence suggests that this modulation is mediated by direct interaction of CG11963 with the channel and is not dependent on ATP.
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Affiliation(s)
- Lei Gao
- Department of Neuroscience, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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21
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Zeng H, Weiger TM, Fei H, Levitan IB. Mechanisms of two modulatory actions of the channel-binding protein Slob on the Drosophila Slowpoke calcium-dependent potassium channel. ACTA ACUST UNITED AC 2006; 128:583-91. [PMID: 17074977 PMCID: PMC2151581 DOI: 10.1085/jgp.200609653] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Slob57 is an ion channel auxiliary protein that binds to and modulates the Drosophila Slowpoke calcium-dependent potassium channel (dSlo). We reported recently that residues 1–39 of Slob57 comprise the key domain that both causes dSlo inactivation and shifts its voltage dependence of activation to more depolarized voltages. In the present study we show that removal of residues 2–6 from Slob57 abolishes the inactivation, but the ability of Slob57 to rightward shift the voltage dependence of activation of dSlo remains. A synthetic peptide corresponding in sequence to residues 1–6 of Slob57 blocks dSlo in a voltage- and dose-dependent manner. Two Phe residues and at least one Lys residue in this peptide are required for the blocking action. These data indicate that the amino terminus of Slob57 directly blocks dSlo, thereby leading to channel inactivation. Further truncation to residue Arg16 eliminates the modulation of voltage dependence of activation. Thus these two modulatory actions of Slob57 are independent. Mutation within the calcium bowl of dSlo greatly reduces its calcium sensitivity (Bian, S., I. Favre, and E. Moczydlowski. 2001. Proc. Natl. Acad. Sci. USA. 98:4776–4781). We found that Slob57 still causes inactivation of this mutant channel, but does not shift its voltage dependence of activation. This result confirms further the independence of the inactivation and the voltage shift produced by Slob57. It also suggests that the voltage shift requires high affinity Ca2+ binding to an intact calcium bowl. Furthermore, Slob57 inhibits the shift in the voltage dependence of activation of dSlo evoked by Ca2+, and this inhibition by Slob57 is greater at higher free Ca2+ concentrations. These results implicate distinct calcium-dependent and -independent mechanisms in the modulation of dSlo by Slob.
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Affiliation(s)
- Haoyu Zeng
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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22
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Abstract
We have cloned and characterized mouse and human variants of MONaKA, a novel protein that interacts with and modulates the plasma membrane Na,K-ATPase. MONaKA was cloned based on its sequence homology to the Drosophila Slowpoke channel-binding protein dSlob, but mouse and human MONaKA do not bind to mammalian Slowpoke channels. At least two splice variants of MONaKA exist; the splicing is conserved perfectly between mouse and human, suggesting that it serves some important function. Both splice variants of MONaKA are expressed widely throughout the CNS and peripheral nervous system, with different splice variant expression ratios in neurons and glia. A yeast two-hybrid screen with MONaKA as bait revealed that it binds tightly to the beta1 and beta3 subunits of the Na,K-ATPase. The association between MONaKA and Na,K-ATPase beta subunits was confirmed further by coimmunoprecipitation from transfected cells, mouse brain, and cultured mouse astrocytes. A glutathione S-transferase-MONaKA fusion protein inhibits Na,K-ATPase activity from whole brain or cultured astrocytes. Furthermore, transfection of MONaKA inhibits 86Rb+ uptake via the Na,K-ATPase in intact cells. These results are consistent with the hypothesis that MONaKA modulates brain Na,K-ATPase and may thereby participate in the regulation of electrical excitability and synaptic transmission.
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Affiliation(s)
- Hua Mao
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
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23
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Jaramillo AM, Zeng H, Fei H, Zhou Y, Levitan IB. Expression and function of variants of slob, slowpoke channel binding protein, in Drosophila. J Neurophysiol 2005; 95:1957-65. [PMID: 16339006 DOI: 10.1152/jn.00427.2005] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Slob binds to and modulates the Drosophila Slowpoke (dSlo) calcium-activated potassium channel and also recruits the ubiquitous signaling protein 14-3-3 to the channel regulatory complex. RT-PCR reveals the presence of multiple slob transcripts in Drosophila heads. The transcripts are predicted to encode proteins that we call Slob51 (kDa), Slob57, Slob65, and Slob71. Slob51 and Slob65 are splice variants that lack a motif important for the binding of 14-3-3. Previous microarray analyses demonstrated the circadian cycling of slob mRNA, and we show by quantitative PCR that more than one transcript cycles in fly heads. Using in situ hybridization, we observe differences in the expression patterns of the different transcripts. Immunohistochemistry on Drosophila heads reveals Slob71/65 protein to be enriched in the lateral neurons, in contrast to Slob57/51 protein, which is expressed most prominently in the pars intercerebralis neurons and dorsal giant interneurons. Using a heterologous expression system, we show that different Slobs bind to different extents to dSlo and 14-3-3. These data reveal an unexpected diversity of the dSlo/Slob/14-3-3 dynamic regulatory complex.
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Affiliation(s)
- Angela M Jaramillo
- Department of Neuroscience, University of Pennsylvania School of Medicine, 3450 Hamilton Walk, Philadelphia, PA 19104, USA
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25
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Zeng H, Weiger TM, Fei H, Jaramillo AM, Levitan IB. The amino terminus of Slob, Slowpoke channel binding protein, critically influences its modulation of the channel. ACTA ACUST UNITED AC 2005; 125:631-40. [PMID: 15897294 PMCID: PMC2234080 DOI: 10.1085/jgp.200509252] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The Drosophila Slowpoke calcium-dependent potassium channel (dSlo) binding protein Slob was discovered by a yeast two-hybrid screen using the carboxy-terminal tail region of dSlo as bait. Slob binds to and modulates the dSlo channel. We have found that there are several Slob proteins, resulting from multiple translational start sites and alternative splicing, and have named them based on their molecular weights (in kD). The larger variants, which are initiated at the first translational start site and are called Slob71 and Slob65, shift the voltage dependence of dSlo activation, measured by the whole cell conductance-voltage relationship, to the left (less depolarized voltages). Slob53 and Slob47, initiated at the third translational start site, also shift the dSlo voltage dependence to the left. In contrast, Slob57 and Slob51, initiated at the second translational start site, shift the conductance-voltage relationship of dSlo substantially to more depolarized voltages, cause an apparent dSlo channel inactivation, and increase the deactivation rate of the channel. These results indicate that the amino-terminal region of Slob plays a critical role in its modulation of dSlo.
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Affiliation(s)
- Haoyu Zeng
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia 19104, USA
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26
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Fei H, Martin TR, Jaskowiak KM, Hatle JD, Whitman DW, Borst DW. Starvation affects vitellogenin production but not vitellogenin mRNA levels in the lubber grasshopper, Romalea microptera. J Insect Physiol 2005; 51:435-43. [PMID: 15890187 DOI: 10.1016/j.jinsphys.2004.11.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2004] [Revised: 11/29/2004] [Accepted: 11/30/2004] [Indexed: 05/02/2023]
Abstract
The interaction of juvenile hormone (JH) and nutrition was studied during the oviposition cycle of the Eastern Lubber grasshopper (Romalea microptera). Starvation of females early or in the middle of the cycle inhibited oocyte growth. Starvation for 4 days also reduced hemolymph levels of JH III and vitellogenesis (Vg) to 25% and 15%, respectively, of the levels in fed animals. Likewise, Vg production by fat body fragments incubated in vitro was reduced to 2% of the levels in fed animals and total protein synthesis was reduced to 25%, suggesting that starvation had a stronger effect on Vg synthesis than on protein synthesis. These effects were reversed when starved animals were fed again. However, fat body levels of Vg-mRNA were similar in fed and starved animals, indicating that starvation did not affect transcript levels. We tested whether the decline in JH levels mediated the other starvation effects by infusing animals with JH III or vehicle for 2 days at the onset of starvation. Infusion of JH elevated JH and Vg-mRNA levels 670% and 103%, respectively, above the levels in vehicle-infused animals. However, Vg production and hemolymph levels of Vg were similar to the levels in vehicle-infused animals. These data suggest that JH alone is insufficient to stimulate Vg production.
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Affiliation(s)
- Hong Fei
- Department of Biological Sciences, Illinois State University, Normal, 61790-4120, USA
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27
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Cibulsky SM, Fei H, Levitan IB. Syntaxin-1A Binds to and Modulates the Slo Calcium-Activated Potassium Channel via an Interaction That Excludes Syntaxin Binding to Calcium Channels. J Neurophysiol 2005; 93:1393-405. [PMID: 15496493 DOI: 10.1152/jn.00789.2004] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
From its position in presynaptic nerve terminals, the large conductance Ca2+-activated K+ channel, Slo, regulates neurotransmitter release. Several other ion channels known to control neurotransmitter release have been implicated in physical interactions with the neurotransmitter release machinery. For example, the Cav2.2 (N-type) Ca2+ channel binds to and is modulated by syntaxin-1A and SNAP-25. Furthermore, a close juxtaposition of Slo and Cav2.2 is presumed to be necessary for functional coupling between the two channels, which has been shown in neurons. We report that Slo exhibits a strong association with syntaxin-1A. Robust co-immunoprecipitation of Slo and syntaxin-1A occurs from transfected HEK293 cells as well as from brain. However, despite this strong interaction and the known association between syntaxin-1A and the II–III loop of Cav2.2, these three proteins do not co-immunoprecipitate in a trimeric complex from transfected HEK293 cells. The Slo-syntaxin-1A co-immunoprecipitation is not significantly influenced by [Ca2+]. Multiple relatively weak interactions may sum up to a tight physical coupling of full-length Slo with syntaxin-1A: the C-terminal tail and the S0–S1 loop of Slo each co-immunoprecipitate with syntaxin-1A. The presence of syntaxin-1A leads to reduced Slo channel activity due to an increased V1/2 for activation in 100 nM, 1 μM, and 10 μM Ca2+, reduced voltage-sensitivity in 1 μM Ca2+, and slower rates of activation in 10 μM Ca2+. Potential physiological consequences of the interaction between Slo and syntaxin-1A include enhanced excitability through modulation of Slo channel activity and reduced neurotransmitter release due to disruption of syntaxin-1A binding to the Cav2.2 II–III loop.
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Affiliation(s)
- Susan M Cibulsky
- Department of Neuroscience, University of Pennsylvania, Philadelphia, Pennsylvania.
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Li S, Friesen J, Fei H, Ding X, Borst D. The lobster mandibular organ produces soluble and membrane-bound forms of 3-hydroxy-3-methylglutaryl-CoA reductase. Biochem J 2004; 381:831-40. [PMID: 15086315 PMCID: PMC1133893 DOI: 10.1042/bj20031930] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2003] [Revised: 04/06/2004] [Accepted: 04/15/2004] [Indexed: 11/17/2022]
Abstract
In a previous study [Li, Wagner, Friesen and Borst (2003) Gen. Comp. Endocrinol. 134, 147-155], we showed that the MO (mandibular organ) of the lobster Homarus americanus has high levels of HMGR (3-hydroxy-3-methylglutaryl-CoA reductase) and that most (approx. 75%) of the enzyme activity is soluble. In the present study, we report the biochemical and molecular characteristics of this enzyme. HMGR had two forms in the MO: a more abundant soluble form (66 kDa) and a less abundant membrane-bound form (72 kDa). Two cDNAs for HMGR were isolated from the MO. A 2.6-kb cDNA encoded HMGR1, a 599-amino-acid protein (63 kDa), and a 3.2-kb cDNA encoded HMGR2, a 655-amino-acid protein (69 kDa). These two cDNAs had identical 3'-ends and appeared to be products of a single gene. The deduced amino acid sequences of these two proteins revealed a high degree of similarity to other class I HMGRs. Hydropathy plots indicated that the N-terminus of HMGR1 lacked a transmembrane region and HMGR2 had a single transmembrane segment. Recombinant HMGR1 expressed in Sf9 insect cells was soluble and had kinetic characteristics similar to native HMGR from the MO. Treatment with phosphatase did not affect HMGR activity, consistent with the observation that neither HMGR1 nor HMGR2 has a serine at position 490 or 546, the position of a conserved phosphorylation site found in class I HMGR from higher eukaryotes. Other lobster tissues (i.e. midgut, brain and muscles) had low HMGR activities and mRNA levels. MO with higher HMGR activities had higher HMGR mRNA levels, implying that HMGR is regulated, in part, at the transcription level.
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Affiliation(s)
- Sheng Li
- *Department of Biological Science, Illinois State University, Normal, IL 61790, U.S.A
| | - Jon A. Friesen
- †Department of Chemistry, Illinois State University, Normal, IL 61790, U.S.A
| | - Hong Fei
- *Department of Biological Science, Illinois State University, Normal, IL 61790, U.S.A
| | - Xiang Ding
- *Department of Biological Science, Illinois State University, Normal, IL 61790, U.S.A
| | - David W. Borst
- *Department of Biological Science, Illinois State University, Normal, IL 61790, U.S.A
- To whom correspondence should be addressed (e-mail )
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Zeng H, Fei H, Levitan IB. The slowpoke channel binding protein Slob from Drosophila melanogaster exhibits regulatable protein kinase activity. Neurosci Lett 2004; 365:33-8. [PMID: 15234468 DOI: 10.1016/j.neulet.2004.04.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2004] [Revised: 04/08/2004] [Accepted: 04/13/2004] [Indexed: 10/26/2022]
Abstract
The slowpoke channel binding protein Slob from Drosophila melanogaster contains a putative protein kinase domain within its amino acid sequence. We find that Slob exhibits weak and barely detectable protein kinase activity in vitro, as evidenced by autophosphorylation and by phosphorylation of exogenously added histone as substrate. The phosphorylation of histone is enhanced markedly when Slob is pretreated with the catalytic subunit of cyclic AMP-dependent protein kinase (PKAc). Mass spectrometric and mutational analysis demonstrates that the major site of phosphorylation by PKAc within Slob is serine 54. The enhancement of Slob kinase activity by PKAc pretreatment is eliminated when serine 54 in Slob is mutated to alanine (S54A). Furthermore, Slob kinase activity is enhanced in an S54E mutant that mimics phosphorylation at serine 54, and there is no further enhancement of S54E Slob kinase activity by pretreatment with PKAc. The results are consistent with the hypothesis that Slob exhibits regulatable protein kinase activity, whose activity is enhanced by phosphorylation at serine 54.
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Affiliation(s)
- Haoyu Zeng
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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Abstract
Slob modulates the activity of the Drosophila Slowpoke calcium-dependent potassium channel (dSlo) via its direct binding to the channel. To characterize the molecular detail of the protein-protein interaction between Slob and dSlo, we constructed a series of Slob mutants that are progressively truncated at either the carboxyl or amino terminal end, and examined the binding of these Slob mutants to dSlo using a co-immunoprecipitation approach. Our data suggest that a small region of 42 amino acids (residues 191-233) in Slob is essential for Slob to interact with the dSlo channel.
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Affiliation(s)
- Yi Zhou
- Department of Neuroscience, School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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31
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Ishii M, Fei H, Friedman JM. Targeted disruption of GPR7, the endogenous receptor for neuropeptides B and W, leads to metabolic defects and adult-onset obesity. Proc Natl Acad Sci U S A 2003; 100:10540-5. [PMID: 12925742 PMCID: PMC193597 DOI: 10.1073/pnas.1334189100] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Gold-thioglucose (GTG) induces lesions in the ventromedial nucleus of the hypothalamus, resulting in hyperphagia and obesity. To identify genes involved in the hypothalamic regulation of energy homeostasis, we used a screen for genes that are dysregulated in GTG-induced obese mice. We found that GPR7, the endogenous G protein-coupled receptor for the recently identified ligands neuropeptide B and neuropeptide W, was down-regulated in hypothalamus after GTG treatment. Here we show that male GPR7-/- mice develop an adult-onset obese phenotype that progressively worsens with age and was greatly exacerbated when animals are fed a high-fat diet. GPR7-/- male mice were hyperphagic and had decreased energy expenditure and locomotor activity. Plasma levels of glucose, leptin, and insulin were also elevated in these mice. GPR7-/- male mice had decreased hypothalamic neuropeptide Y RNA levels and increased proopiomelanocortin RNA levels, a set of effects opposite to those evident in ob/ob mice. Furthermore, ob/ob GPR7-/- and Ay/a GPR7-/- double mutant male mice had an increased body weight compared with normal ob/ob or Ay/a male mice, suggesting that the obesity of GPR7-/- mice is independent of leptin and melanocortin signaling. Female mice did not show any significant weight increase or associated metabolic defects. These data suggest a potential role for GPR7 and its endogenous ligands, neuropeptide B and neuropeptide W, in regulating energy homeostasis independent of leptin and melanocortin signaling in a sexually dimorphic manner.
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Affiliation(s)
- Makoto Ishii
- Laboratory of Molecular Genetics, The Rockefeller University, New York, NY 10021, USA
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32
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Zhou Y, Reddy S, Murrey H, Fei H, Levitan IB. Monomeric 14-3-3 protein is sufficient to modulate the activity of the Drosophila slowpoke calcium-dependent potassium channel. J Biol Chem 2003; 278:10073-80. [PMID: 12529354 DOI: 10.1074/jbc.m211907200] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Drosophila 14-3-3zeta (D14-3-3zeta) modulates the activity of the Slowpoke calcium-dependent potassium channel (dSlo) by interacting with the dSlo binding protein, Slob. We show here that D14-3-3zeta forms dimers in vitro. Site-directed mutations in its putative dimerization interface result in a dimerization-deficient form of D14-3-3zeta. Both the wild-type and dimerization-deficient forms of D14-3-3zeta bind to Slob with similar affinity and form complexes with dSlo. When dSlo and Slob are expressed in mammalian cells, the dSlo channel activity is similarly modulated by co-expression of either the wild-type or the dimerization-deficient form of D14-3-3zeta. In addition, dSlo is still modulated by wild-type D14-3-3zeta in the presence of a 14-3-3 mutant, which does not itself bind to Slob but forms heterodimers with the wild-type 14-3-3. These data, taken together, suggest that monomeric D14-3-3zeta is capable of modulating dSlo channel activity in this regulatory complex.
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Affiliation(s)
- Yi Zhou
- Department of Neuroscience, University of Pennsylvania School of Medicine, Philadelphia 19104, USA.
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Fei H, Luo MJ, Ye YZ, Ding DF, Chi CW. The Inhibitory Activities of Recombinant Eglin C Mutants on Kexin and Furin, Using Site-directed Mutagenesis and Molecular Modeling. Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao (Shanghai) 2002; 33:591-599. [PMID: 12035048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
Mammalian furin and yeast kexin are members of the proprotein convertase family involved in the proteolytic processing of many important precursor proteins. Here the gene coding for the subtilisin inhibitor eglin C was totally synthesized and expressed in E.coli. Substitution of residues at each position P(1), P(2) and P(4) of eglin C with a basic residue using protein engineering could make eglin C a very strong inhibitor for furin (K(i) around 10(-9) mol/L),and even more strong for kexin (K( i ) around 10(-11) mol/ L). Results indicated that (1) A basic residue Lys or Arg at P(1) site is prerequisite for the inhibitor. (2) The second mutation with basic residue at P(4) site drastically increase the inhibitory activity by two orders of magnitude. (3) A basic residue at P(2) site is favorable for the binding to the enzyme, but unfavorable for the stability of the inhibitor, resulting in a temporary inhibition. (4) A hydrophobic residue is preferential at P(3) site. Based on the known crystal structures of subtilisin and eglin C, the interaction between the enzyme and inhibitor was modeled, and their involved residues were predicted which gave a good explanation to the experimental results.
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Affiliation(s)
- H Fei
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry and Cell Biology, the Chinese Academy of Sciences, Shanghai 200031, China.
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Songnian Z, Xiaoyun X, Fei H, Jiang Z. Rotating annulus experiment: large-scale helical soliton in the atmosphere? Phys Rev E Stat Nonlin Soft Matter Phys 2001; 64:056621. [PMID: 11736130 DOI: 10.1103/physreve.64.056621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2000] [Revised: 03/15/2001] [Indexed: 05/23/2023]
Abstract
A typhoon is a cyclone vortex with a warm low pressure center, formed over tropical oceanic waters. A large-scale rotating annulus experiment of fluid dynamics is carried out, under the conditions of dynamic similarity, geometric similarity, and the similarity of boundary conditions. In the first step, with the help of infrared heaters, the basic flow field and helical structure of a single typhoon were successfully simulated; then two model typhoons were generated, and their interactions tested. It demonstrated that they did separate after colliding with each other, and their respective basic shapes were restored, which confirms the basic dynamic features of typhoons in nature as solitons. It was also shown that the formation of their helical structures is related to the adapting process of atmosphere to the rotation of the earth and that their dynamic characteristics as solitons come from a result of an equilibrium between their dispersion and the nonlinear convergence of the anticyclones, with whose combined actions their structure remains stable for a long period, which in turn means that they are indeed three-dimensional helical solitons.
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Affiliation(s)
- Z Songnian
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
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Abstract
Acyclovir controlled-release capsules (CRCs) were prepared by a three-step process: (1) melt granulation of acclovir; (2) coating of granules with ethyl-cellulose, (3) incorporation of coated granules into hard gelatin capsules. In vitro release experiments showed that the main factors affecting the release rate were the mean particle size of the actylovir raw material and the amount of coating material applied. Release of acyclovir from the capsules was in accordance with the Higuchi equation. Pharmacokinetic studies in dogs after oral administration of acyclovir controlled-release capsules showed that the formulation was successful in providing slow release of aciclovir and was superior to a commercially available controlled-release formulation.
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Affiliation(s)
- J Tu
- Department of Pharmaceutics, China Pharmaceutical University, Nanjing, Peoples Republic of China.
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36
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Zhu BC, Henderson G, Chen F, Fei H, Laine RA. Evaluation of vetiver oil and seven insect-active essential oils against the Formosan subterranean termite. J Chem Ecol 2001; 27:1617-25. [PMID: 11521400 DOI: 10.1023/a:1010410325174] [Citation(s) in RCA: 112] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Repellency and toxicity of 8 essential oils (vetiver grass, cassia leaf, clove bud, cedarwood, Eucalyptus globules, Eucalyptus citrodora, lemongrass and geranium) were evaluated against the Formosan subterranean termite, Coptotermes formosanus Shiraki. Vetiver oil proved the most effective repellent because of its long-lasting activity. Clove bud was the most toxic, killing 100% of termites in 2 days at 50 micrograms/cm2. The tunneling response of termites to vetiver oil also was examined. Vetiver oil decreased termite tunneling activity at concentrations as low as 5 micrograms/g sand. Tunneling and paper consumption were not observed when vetiver oil concentrations were higher than 25 micrograms/g sand. Bioactivity of the 8 oils against termites and chemical volatility were inversely associated. Listed in decreasing order of volatility, the major constituents of the 8 oils were: eucalyptol, citronellal, citral, citronellol, cinnamaldehyde, eugenol, thujopsene, and both alpha- and beta-vetivone. Vetivor oil is a promising novel termiticide with reduced environmental impact for use against subterranean termites.
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Affiliation(s)
- B C Zhu
- Louisiana State University Agricultural Center, Louisiana Agricultural Experimental Station, Department of Biological Sciences, USA
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Boackle RJ, Dutton SL, Fei H, Vesely J, Malamud D, Furness AR. Salivary non-immunoglobulin agglutinin inhibits human leukocyte elastase digestion of acidic proline-rich salivary proteins. J Dent Res 2001; 80:1550-4. [PMID: 11499511 DOI: 10.1177/00220345010800061401] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Saliva contains acidic proline-rich salivary proteins that are involved in the formation of the salivary pellicle coating supragingival tooth surfaces. However, human leukocyte elastase, arriving in gingival exudates from inflamed periodontal tissues, degrades the acidic proline-rich salivary proteins, preventing binding to hydroxylapatite surfaces. Here it is reported that high-molecular-weight non-immunoglobulin salivary agglutinin inhibited the proteolytic action of human leukocyte elastase on purified acidic proline-rich salivary proteins. Inhibition was eliminated with monoclonal antibody to a protein determinant on the salivary agglutinin. The addition of antibody against salivary agglutinin blocked the inhibitory effect of parotid saliva on exogenously applied human leukocyte elastase, allowing for the elastase-mediated digestion of the salivary acidic proline-rich salivary proteins. Salivary agglutinin, therefore, is a physiologically important inhibitor of human leukocyte elastase and is able to inhibit elastase-mediated digestion of salivary acidic proline-rich proteins.
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Affiliation(s)
- R J Boackle
- Department of Stomatology, Medical University of South Carolina, Charleston 29425, USA.
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38
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Fei H, Maeda S, Kirii H, Fujigaki S, Maekawa N, Fujii H, Wada H, Saito K, Seishima M. Evaluation of two different homogeneous assays for LDL-cholesterol in lipoprotein-X-positive serum. Clin Chem 2000; 46:1351-6. [PMID: 10973865] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
BACKGROUND The purpose of this study was to evaluate the performance of two homogeneous assays for LDL-cholesterol (LDL-C), a polyethylene/cyclodextrin (PC) assay and a detergent (D) assay, which are based on different principles, in cholestatic serum. METHODS We compared serum LDL-C concentrations determined by the two assays for healthy normolipidemic subjects (n = 42) and cholestatic patients (n = 51). LDL-C concentrations obtained with the homogeneous assays were also compared with those obtained by HPLC for patients' sera. In the interference study, conjugated bile acids were added to normal serum, and their effects on the two assays were examined. The effects of lipoprotein-X (LP-X), intermediate-density lipoprotein (IDL), and apolipoprotein (apo) E-rich HDL on the LDL-C assays were also investigated by adding these lipoproteins to normal serum. RESULTS The LDL-C concentrations obtained with the D assay were higher than those obtained with the PC assay in the serum with high LP-X. The bias for LDL-C vs LP-X in cholestatic serum correlated with LP-X concentration (r = 0.582; P: <0.0001; n = 51). In the interference study, no effect of bile acids on the LDL-C assays was observed. However, the D assay measured 51.0% of the cholesterol in LP-X, whereas no reactivity was observed for LP-X in the PC assay. In addition, the D assay and the PC assay measured IDL-cholesterol at 31.2% and 52.4%, respectively, and measured apo E-rich HDL-C at 7.6% and 17.8%, respectively. CONCLUSIONS Although both homogeneous LDL-C assays are suitable for most cases, the present study showed that each homogeneous assay has a different limitation for cholestatic serum with gross alterations in lipoproteins.
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Affiliation(s)
- H Fei
- Department of Laboratory Medicine, Gifu University School of Medicine, 40 Tsukasa-machi, Gifu 500-8705, Japan
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He Z, Yuan J, Chen Z, Liu S, Shen Z, Fei H. [Chemosensitivity test for 170 human breast carcinoma samples]. Hunan Yi Ke Da Xue Xue Bao 2000; 23:531-4. [PMID: 10806759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
We tested the in vitro sensitivity of 170 primary breast carcinoma samples to the anti-cancer drugs conventionally used in clinical chemotherapy. It was found that: 1. The high sensitivity rate (HSR) of breast carcinoma cells to 5-fluorouracil (5-Fu), mitomycin (MMC), cisplatin (DDP), adriamycin(ADM), methotrexate(MTX), vincristin(VCR), vepesid(VP-16), taxol, and vindesine(VDS) were 57.1%, 49.4%, 48.3%, 35.8%, 21.8%, 21.2%, 10%, 18.2% and 20.9%, respectively. The increase of HSR of cancer cells to 5-Fu, MMC, DDP, taxol was more significant than that of the other drugs tested (P < 0.05). 2. No correlation was shown between drug sensitivity and factors, i.e. pathological type, clinical type, expression of estrogen receptor (ER) and epithelium growth factor receptor(EGFR) for breast carcinoma (P > 0.05). 3. Cyclosporin A can increase part of the sensitivity of ADM-resistant breast carcinoma cells to ADM.
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Affiliation(s)
- Z He
- Cancer Research Institute, Hunan Medical University, Changsha
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Fei H, Li Y, Wang LX, Luo MJ, Ling MH, Chi CW. Nonhistone protein purified from porcine kidney acts as a suicide substrate inhibitor on furin-like enzyme. Acta Pharmacol Sin 2000; 21:265-70. [PMID: 11324429] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
AIM To search and purify a naturally occurring protein inhibitor of the furin-like enzyme from the porcine kidney. METHODS Recombinant kexin, a furin-like enzyme, from the yeast secretion expression was used as a target enzyme. The inhibitor component was extracted and purified from the acetone powder of porcine kidney. The inhibitory activity was monitored using a fluorogenic peptide substrate Boc-Arg-Val-Arg-MCA at spectrofluorimeter. RESULTS The purified inhibitor component is a basic protein with an isoelectric point over 9.5. Its partial N-terminal sequence of 22 residues was determined, showing a high homology with nonhistone chromosomal protein HMG-17 in which there are four sites composed of dibasic residues, susceptible to be cleaved by the furin-like enzyme. This nonhistone protein could strongly compete with the fluorogenic substrate. However, this nonhistone protein would be degraded as a substrate by kexin if it was incubated with the enzyme for long time before adding the fluorogenic substrate, and subsequently lost its temporary inhibitory activity. CONCLUSION The nonhistone protein isolated from the porcine kidney functioned as a suicide substrate inhibitor for the furin-like enzyme.
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Affiliation(s)
- H Fei
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, Chinese Academy of Sciences, Shanghai 200031, China
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Xiong YM, Lan ZD, Wang M, Liu B, Liu XQ, Fei H, Xu LG, Xia QC, Wang CG, Wang DC, Chi CW. Molecular characterization of a new excitatory insect neurotoxin with an analgesic effect on mice from the scorpion Buthus martensi Karsch. Toxicon 1999; 37:1165-80. [PMID: 10400300 DOI: 10.1016/s0041-0101(98)00253-0] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Besides the neurotoxins active on mammals, a new excitatory insect selective toxin with a mice analgesic activity was found and purified from the venom of the scorpion Buthus martensi Karsch (BmK) (Ji, Y.H., Mansuelle, P., Terakawa, S., Kopeyan, C., Yanaihara, N., Hsu, K., Rochat, H., 1996. Toxicon 34, 987; Luo, M.J., Xiong, Y.M., Wang, M., Wang, D.C., Chi, C.W., 1997. Toxicon 35, 723.). This peptide (designated as BmK IT-AP) is composed of 72 amino acid residues. Its primary structure was determined by automated Edman degradation of the N-terminal part of the reduced and S-carboxamidemethylated protein and its lysylendopeptidase degraded fragments. Based on the determined sequence, the gene specific primers were designed and synthesized for 3' and 5' RACE (rapid amplification of cDNA ends). Their partial cDNA fragments obtained by 3' and 5' RACEwere cloned and sequenced and the full length cDNA sequence of BmK IT-AP was then completed by overlapping their two partial cDNA sequences. It encodes a precursor of 90 amino acid residues: a signal peptide of 18 residues and a mature peptide of 72 residues which are consistent with the determined protein sequence of BmK IT-AP. The genomic DNA of the peptide was also amplified by PCR from the scorpion genomic DNA and sequenced, which is a first report on the genomic structure of a scorpion toxin specific for insects. Its sequence revealed an intron of 590 bp inserted in the end part of the signal peptide. The peptide caused a fast excitatory contraction paralysis on house fly larvae. Furthermore, the peptide also showed an obvious analgesic effect on mice, as assayed by using a twisting test model. This effect of BmK IT-AP well characterized at molecular level is first reported among the known scorpion insect neurotoxins.
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Affiliation(s)
- Y M Xiong
- State Key Laboratory of Molecular Biology, Shanghai Institute of Biochemistry, Academia Sinica, People's Republic of China
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Chen J, Yang A, Fei H, Jin R, He M, Wang B. A rapid screening and diagnosis on fragile X syndrome by PCR. Curr Med Sci 1999; 19:145-8. [PMID: 12840860 DOI: 10.1007/bf02886897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/1998] [Indexed: 10/19/2022]
Abstract
Polymerase chain reaction (PCR) technique combined with direct detection by silver staining on denaturing DNA sequencing gel was used to analyze the (CGG)n repeats within the FMR1 gene on 169 suspected patients with mental retardation and 33 kindreds of 6 fragile X families. The results showed that: (1) No PCR products were detected in 3 males in the suspected group. (2) In the fragile X family studies, the 5 male probands failed to show any PCR products. (3) Diplex PCR with the primers flanking the FRAXE locus was used to serve as an internal control for the 8 above-mentioned males and only normal products of the FRAXE locus were detected, indicating that the possibility of false negative results of the FRAXA locus could be eliminated. These findings suggested that analysis of (CGG)n repeat within the FMR1 gene by PCR technique could efficiently detect premutation carriers and that negative PCR products in mentally retarded males might highly imply the diagnosis of fragile X syndrome after the false negative results have been excluded by diplex PCR. This PCR assay is suitable for the screening and diagnosis of fragile X syndrome in a large number of populations due to its rapidity, simplicity, stability and reliability.
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Affiliation(s)
- J Chen
- Department of Pediatrics, Xiehe Hospital, Tongji Medical University, Wuhan 430022
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Liang X, Fei H, Xiao Y, Liu S, Yang A. [Detection of minimal residual disease in acute lymphoblastic leukemia using PCR-molecule hybridization of RNA transcripts]. Zhonghua Yi Xue Yi Chuan Xue Za Zhi 1998; 15:164-6. [PMID: 9621126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To detect acute lymphoblastic leukemia's(ALL's) minimal residual disease(MRD) rapidly and effectively. METHODS In this assay, the gamma T-cell receptor gene rearrangements serve as marker genes. The gene rearrangements are amplified from the diagnostic specimens using a consensus V segment primer and a consensus J segment primer to which the promoter T7 RNA polymerase has been appended. The PCR product from this amplification is transcribed into a radiolabeled RNA probe. The opposite DNA strand is transcribed into test RNA from the PCR product of different staged specimens. The test RNA is hybridized with the probe, and later the digestion with RNase A, Polyacrylamide gel electrophoresis and autoradiography are in progress. RESULTS According to the mechanism, the perfectly matched RNA duplex can prevent the digestion of RNase A, and the presence of the leukemia cells in the test specimen can be determined. Logarithmical dilution experiments with DNA of a cell line from ALL have shown that this assay's sensitivity is at the 10(-5) level. Minimal residual disease was successfully detected in a case of ALL during its complete remission stage. But if the probe and test RNA are not from the same individual, the results of this kind of cross hybridization are negative. CONCLUSION The above results suggest that this assay can become an effective measure in the detection of ALL-MRD clinically.
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Affiliation(s)
- X Liang
- Department of Pediatrics, Union Hospital, Tongji Medical University, Wuhan, Hubei Province, 430022 P.R.China
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Li X, Yang A, Fei H. Detection of minimal leukemic cells in cerebral spinal fluid of children with acute lymphoblastic leukemia using the polymerase chain reaction technique. Curr Med Sci 1998; 18:49-53. [PMID: 10806804 DOI: 10.1007/bf02888281] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/1997] [Indexed: 10/19/2022]
Abstract
V delta 2D delta 3 rearrangements of T cell receptor (TCR) gene from cerebral-spinal fluid (CSF) cells was detected for diagnosis and monitoring of central nervous system leukemia (CNSL) in children with acute lymphoblastic leukemia (ALL) using polymerase chain reaction (PCR) technique. 20 patients were studied and in 12 of them the results of PCR and dot hybridization with clonospecific probes were positive, showing the presence of minimal blast cells in CSF. Our study suggested that the PCR method is an effective tool for clinical diagnosis of CNSL and is much more sensitive than routine CSF examination.
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Affiliation(s)
- X Li
- Institute of Hematology, Xiehe Hospital, Tongji Medical University, Wuhan
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45
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Fei H, Okano HJ, Li C, Lee GH, Zhao C, Darnell R, Friedman JM. Anatomic localization of alternatively spliced leptin receptors (Ob-R) in mouse brain and other tissues. Proc Natl Acad Sci U S A 1997; 94:7001-5. [PMID: 9192681 PMCID: PMC21274 DOI: 10.1073/pnas.94.13.7001] [Citation(s) in RCA: 534] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Leptin's effects are mediated by interactions with a receptor that is alternatively spliced, resulting in at least five different murine forms: Ob-Ra, Ob-Rb, Ob-Rc, Ob-Rd, and Ob-Re. A mutation in one splice form, Ob-Rb, results in obesity in mice. Northern blots, RNase protection assays, and PCR indicate that Ob-Rb is expressed at a relatively high level in hypothalamus and low level in several other tissues. Ob-Ra is expressed ubiquitously, whereas Ob-Rc, -Rd, and -Re RNAs are only detectable using PCR. In hypothalamus, Ob-Rb is present in the arcuate, ventromedial, dorsomedial, and lateral hypothalamic nuclei but is not detectable in other brain regions. These nuclei are known to regulate food intake and body weight. The level of Ob-Rb in hypothalamus is reduced in mice rendered obese by gold thioglucose (GTG), which causes hypothalamic lesions. The obesity in GTG-treated mice is likely to be caused by ablation of Ob-Rb-expressing neurons, which results in leptin resistance.
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Affiliation(s)
- H Fei
- Laboratory of Molecular Genetics, Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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46
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Lin D, Zhang S, Murakami H, Wu Z, Totsuya T, Gu X, Hu G, Chen T, Hu F, Fei H. Impact mass chemotherapy with praziquantel on schistosomiasis control in Fanhu village, People's Republic of China. Southeast Asian J Trop Med Public Health 1997; 28:274-9. [PMID: 9444005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The paper describes the endemic situation of schistosomiasis japonica in Fanhu village, Poyang Lake region, China and the effect of the strategy of combining annual mass chemotherapy with health education on schistosomiasis control in the community. The results showed that the prevalence of infection with schistosome reduced form 26.0% in 1992 to 10.7% in 1994, the intensity of infection in residents decreased from 1.92 in 1992 to 0.55 in 1994 and the condition of hepatomegaly, splenomegaly and liver fibrosis also improved after chemotherapy in the individuals in the case prospective study. Moreover, the future strategies of schistosomiasis control in this area have been suggested according to the transmission of schistosomiasis in the lake region and the effect of anti-schistosomiasis control indifferent populations.
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Affiliation(s)
- D Lin
- Jiangxi Provincial Institute of Parasitic Diseases (JPIPD), Nanchang, PR China
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Fei H, Yazmajian D, Hanna MS, Frame LH. Termination of reentry by lidocaine in the tricuspid ring in vitro. Role of cycle-length oscillation, fast use-dependent kinetics, and fixed block. Circ Res 1997; 80:242-52. [PMID: 9012746 DOI: 10.1161/01.res.80.2.242] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
We hypothesized that drugs with rapid recovery kinetics from use-dependent sodium channel block could promote oscillatory termination of reentry by enhancing interval-dependent conduction. Mechanisms of termination were related to properties of the reentrant circuit. Nine adjustable reentrant preparations were used in which the canine atrial tricuspid ring was cut and then reconnected electronically by sensing activation on one side of the cut and pacing the other after an adjustable delay. The cycle length and diastolic interval during reentry were manipulated by changing this delay. Lidocaine (1.28 x 10(-5) mol/L) significantly increased refractoriness (94 +/- 39 ms) and the slope of the conduction curve (-0.12 +/- 0.07) at the site of block during pacing. Lidocaine terminated sustained reentry by two mechanisms. Early termination resulted from increased cycle length oscillation and refractoriness (reproducible in each experiment) but only at short delays with short initial diastolic intervals. The range of delays showing this mechanism of termination was 100 +/- 48 ms. Increased cycle-length oscillation resulted from an increased slope of the conduction curve. In eight experiments, lidocaine terminated reentry by causing fixed block after 50 minutes of drug superfusion, which prevented reentry at all delays. Fixed block occurred at one of two vulnerable sites and was transiently reversed by acetylcholine. Termination due to refractory block occurred only when the initial diastolic interval was short, and termination due to fixed block developed when there was a susceptible region with a low safety factor for propagation. Fast recovery from sodium channel block promotes oscillatory termination by increasing the slope of the conduction curve.
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Affiliation(s)
- H Fei
- Department of Medicine, University of Pennsylvania, Philadelphia, USA
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Fei H, Hanna MS, Frame LH. Assessing the excitable gap in reentry by resetting. Implications for tachycardia termination by premature stimuli and antiarrhythmic drugs. Circulation 1996; 94:2268-77. [PMID: 8901682 DOI: 10.1161/01.cir.94.9.2268] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
BACKGROUND The shortest excitable gap during reentry may determine responses to pacing and antiarrhythmic drugs. The resetting response has been used clinically to assess the excitable gap, but it cannot directly indicate the shortest excitable gap. METHODS AND RESULTS We studied resetting in the in vitro canine atrial tricuspid ring using an adjustable reentry preparation in which the ring was cut and reconnected electronically with an adjustable delay to vary the cycle length and excitable gap. We reset the tachycardias using 31 delays in 12 experiments. Tachycardias were terminated by premature stimuli in 16 delays. The reset window overestimated the shortest excitable gap by 25 +/- 14 ms, and the maximum degree of advancement of tachycardia underestimated the shortest excitable gap by 22 +/- 11 ms. The slope of the increasing portion of the resetting response curve was steeper in tachycardias terminated by premature stimuli than in those not terminated (-0.69 +/- 0.2 versus -0.37 +/- 0.2, P < .01). The effective refractory period difference between the sites of pacing and of block correlated with the slope of the resetting response curve. Damped cycle length oscillation after a long return cycle during resetting was always present when there was a partially excitable gap. CONCLUSIONS The reset window during pacing within the circuit and the maximum degree of advancement provided equally good estimates bracketing the shortest excitable gap. The slope of the resetting response curve predicted the likelihood of termination by premature stimuli. Damped cycle length oscillation after resetting detected a partially excitable gap.
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Affiliation(s)
- H Fei
- Department of Medicine, University of Pennsylvania, Philadelphia, USA
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Frame LH, Rhee EK, Bernstein RC, Fei H. Reversal of reentry and acceleration due to double-wave reentry: two mechanisms for failure to terminate tachycardias by rapid pacing. J Am Coll Cardiol 1996; 28:137-45. [PMID: 8752806 DOI: 10.1016/0735-1097(96)00096-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
OBJECTIVES We sought to demonstrate mechanisms by which rapid pacing can cause conduction block without terminating reentry. BACKGROUND Rapid pacing can fail to terminate or can accelerate tachycardias in patients. Mechanisms for these responses are poorly understood. METHODS We studied reentry in the canine atrial tricuspid ring and a left ventricular ring in vitro in 12 preparations. Activations were recorded from 10 sites around the ring, and monophasic action potentials were recorded from critical sites of block. Rapid pacing at cycle lengths that intermittently caused conduction block was performed at multiple sites. RESULTS Action potential alternans contributed to block of an orthodromic impulse during rapid pacing. When pacing continued for two stimuli after orthodromic block, a second episode of block could reverse the direction of tachycardia. Continued pacing at this site was likely to produce block of an antidromic impulse, which may initiate double-wave reentry. Double-wave reentry could be sustained or nonsustained. Its cycle length was 56% to 77% of the single-wave cycle length. The ratio of double-wave cycle length to single-wave cycle length was inversely correlated with the relative excitable gap (p < 0.01). Double-wave reentry can be a mechanism for persistent cycle length alternation during tachycardia. CONCLUSIONS Successful termination of reentry by rapid pacing required block of an othrodromic impulse and stopping pacing within one stimulus after orthodromic block. Reversal of reentry makes the circuit resistant to termination from this site of pacing. Antidromic block can cause acceleration due to double-wave reentry when there is a substantial excitable gap.
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Affiliation(s)
- L H Frame
- Department of Medicine, Cardiology Section, Philadelphia Veterans Affairs Medical Center, Pennsylvania 19104, USA
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Fei H, Frame LH. d-Sotalol terminates reentry by two mechanisms with different dependence on the duration of the excitable gap. J Pharmacol Exp Ther 1996; 277:174-85. [PMID: 8613916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
We used eight adjustable preparations in which the canine atrial tricuspid rings were cut and reconnected electronically by sensing activation on one side of the cut and pacing the other after an adjustable delay. A long delay resulted in a long cycle length (CL) and excitable gap (EG) during reentry. Decreasing delay decreased CL and EG. d-Sotalol (4 mg/l) significantly increased effective refractory period (ERP) and action potential duration with no effects on conduction time during constant 400-msec pacing. During reentry, d-sotalol increased action potential durations more than CLs, so it decreased diastolic intervals. It decreased EG by increasing ERP more than CL. Although d-sotalol increased action potential duration more at longer delays with longer CLs, showing reverse use-dependence, it terminated sustained tachycardias by increasing ERP only for the short delays when the initial EG was short. In 5 of 8 experiments, longer equilibration with d-sotalol produced fixed block at a vulnerable site, so reentry could not be induced at any delays. Fixed block could be transiently reversed by ACh and resolved after washout of d-sotalol. We conclude that d-sotalol terminated reentry by two mechanisms: 1) It terminated sustained reentry by increasing ERP when the initial EG was sufficiently short. 2) In some preparations, it caused fixed block at a vulnerable site, which prevented reentry regardless of the initial EG.
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Affiliation(s)
- H Fei
- Cardiovascular Division, Department of Medicine, University of Pennsylvania, Philadelphia, USA
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