This paper presents a new method for extract three-dimensional （3D） discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition. In order to reduce the high amount of pol...This paper presents a new method for extract three-dimensional （3D） discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition. In order to reduce the high amount of pollen information and noise disturbance, the geometric normalized curvature voxels with the principal curvedness are first extracted to represent the intrinsic pollen volumetric data. Then the curvature voxels are decomposed into radial and angular components with spherical harmonic transform in spherical coordinates. Finally the 3D discrete Fourier transform is applied to the decomposed curvature voxels to obtain the 3D spherical Fourier descriptors for pollen recognition. Experimental results show that the presented descriptors are invariant to different pollen particle geometric transformations, such as pose change and spatial rotation, and can obtain high recognition accuracy and speed simultaneously.展开更多
BACKGROUND Immune-mediated necrotizing myopathy is a rare autoimmune myopathy characterized by muscle weakness and elevated serum creatine kinase,with unique skeletal muscle pathology and magnetic resonance imaging fe...BACKGROUND Immune-mediated necrotizing myopathy is a rare autoimmune myopathy characterized by muscle weakness and elevated serum creatine kinase,with unique skeletal muscle pathology and magnetic resonance imaging features.CASE SUMMARY In this paper,two patients are reported:One was positive for anti-signal recognition particle antibody,and the other was positive for anti-3-hydroxy-3-methylglutaryl coenzyme A reductase antibody.CONCLUSION The clinical characteristics and treatment of the two patients were analysed,and the literature was reviewed to improve the recognition,diagnosis,and treatment of this disease.展开更多
To the Editor,Immune-mediated necrotizing myopathy(IMNM)is a type of inflammatory myopathy subdivided into three major subtypes:anti-signal recognition particle(anti-SRP)IMNM,anti-3-hydroxy-3-methylglutaryl coenzyme A...To the Editor,Immune-mediated necrotizing myopathy(IMNM)is a type of inflammatory myopathy subdivided into three major subtypes:anti-signal recognition particle(anti-SRP)IMNM,anti-3-hydroxy-3-methylglutaryl coenzyme A reductase(anti-HMGCR)IMNM,and seronegative IMNM,which accounts for 10%–20%of cases.Patients usually present with subacute symmetrical muscle weakness,usually involving the proximal and pharyngeal muscles with sig-nificantly elevated creatinine kinase levels.Associated symptoms include myalgia,fatigue,and weight loss.^(1,2)Anti-SRP IMNM usually presents with a more fulminant course,with early dysphagia and possible respiratory failure,while this is rarer in anti-HMGCR and seronegative IMNM.Notably,seronegative IMNM is linked to malignancy,resulting in decreased survival.^(3)展开更多
The co-translational targeting or insertion of secretory and membrane proteins into the endoplasmic reticulum （ER） is a key biological process mediated by the signal recognition particle （SRP）. In eukaryotes, the ...The co-translational targeting or insertion of secretory and membrane proteins into the endoplasmic reticulum （ER） is a key biological process mediated by the signal recognition particle （SRP）. In eukaryotes, the SRP68-SRP72 （SRP68/72） heterodimer plays an essen- tial role in protein translocation. However, structural information on the two largest SRP proteins, SRP68 and SRP72, is limited, espe- cially regarding their interaction. Herein, we report the first crystal structures of human apo-SRP72 and the SRP68/72 complex at 2.91A. and 1.7A resolution, respectively. The SRP68-binding domain of SRP72 contains four atypical tetratricopeptide repeats （TPR） and a flexible C-terminal cap. Apo-SRP72 exists mainly as dimers in solution. To bind to SRP68, the SRP72 homodimer disassociates, and the indispensable C-terminal cap undergoes a pronounced conformational change to assist formation of the SRP68/72 heterodi- mer. A 23-residue polypeptide of SRP68 is sufficient for tight binding to SRP72 through its unusually hydrophobic and extended sur- face. Structural, biophysical, and mutagenesis analyses revealed that cancer-associated mutations disrupt the SRP68-SRP72 interaction and their co-localization with ER in mammalian cells. The results highlight the essential role of the SRP68-SRP72 inter- action in SRP-mediated protein translocation and provide a structural basis for disease diagnosis, pathophysiology, and drug design.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No. 60472061)the Natural Science Foundation of Jiangsu Province,China (Grant No. BK20090149)the Natural Science Foundation of Higher Education Institutions of Jiangsu Province,China (Grant No. 08KJD520019).
文摘This paper presents a new method for extract three-dimensional （3D） discrete spherical Fourier descriptors based on surface curvature voxels for pollen particle recognition. In order to reduce the high amount of pollen information and noise disturbance, the geometric normalized curvature voxels with the principal curvedness are first extracted to represent the intrinsic pollen volumetric data. Then the curvature voxels are decomposed into radial and angular components with spherical harmonic transform in spherical coordinates. Finally the 3D discrete Fourier transform is applied to the decomposed curvature voxels to obtain the 3D spherical Fourier descriptors for pollen recognition. Experimental results show that the presented descriptors are invariant to different pollen particle geometric transformations, such as pose change and spatial rotation, and can obtain high recognition accuracy and speed simultaneously.
文摘BACKGROUND Immune-mediated necrotizing myopathy is a rare autoimmune myopathy characterized by muscle weakness and elevated serum creatine kinase,with unique skeletal muscle pathology and magnetic resonance imaging features.CASE SUMMARY In this paper,two patients are reported:One was positive for anti-signal recognition particle antibody,and the other was positive for anti-3-hydroxy-3-methylglutaryl coenzyme A reductase antibody.CONCLUSION The clinical characteristics and treatment of the two patients were analysed,and the literature was reviewed to improve the recognition,diagnosis,and treatment of this disease.
文摘To the Editor,Immune-mediated necrotizing myopathy(IMNM)is a type of inflammatory myopathy subdivided into three major subtypes:anti-signal recognition particle(anti-SRP)IMNM,anti-3-hydroxy-3-methylglutaryl coenzyme A reductase(anti-HMGCR)IMNM,and seronegative IMNM,which accounts for 10%–20%of cases.Patients usually present with subacute symmetrical muscle weakness,usually involving the proximal and pharyngeal muscles with sig-nificantly elevated creatinine kinase levels.Associated symptoms include myalgia,fatigue,and weight loss.^(1,2)Anti-SRP IMNM usually presents with a more fulminant course,with early dysphagia and possible respiratory failure,while this is rarer in anti-HMGCR and seronegative IMNM.Notably,seronegative IMNM is linked to malignancy,resulting in decreased survival.^(3)
文摘The co-translational targeting or insertion of secretory and membrane proteins into the endoplasmic reticulum （ER） is a key biological process mediated by the signal recognition particle （SRP）. In eukaryotes, the SRP68-SRP72 （SRP68/72） heterodimer plays an essen- tial role in protein translocation. However, structural information on the two largest SRP proteins, SRP68 and SRP72, is limited, espe- cially regarding their interaction. Herein, we report the first crystal structures of human apo-SRP72 and the SRP68/72 complex at 2.91A. and 1.7A resolution, respectively. The SRP68-binding domain of SRP72 contains four atypical tetratricopeptide repeats （TPR） and a flexible C-terminal cap. Apo-SRP72 exists mainly as dimers in solution. To bind to SRP68, the SRP72 homodimer disassociates, and the indispensable C-terminal cap undergoes a pronounced conformational change to assist formation of the SRP68/72 heterodi- mer. A 23-residue polypeptide of SRP68 is sufficient for tight binding to SRP72 through its unusually hydrophobic and extended sur- face. Structural, biophysical, and mutagenesis analyses revealed that cancer-associated mutations disrupt the SRP68-SRP72 interaction and their co-localization with ER in mammalian cells. The results highlight the essential role of the SRP68-SRP72 inter- action in SRP-mediated protein translocation and provide a structural basis for disease diagnosis, pathophysiology, and drug design.
