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Song Y, Mai Z, Zhang Y, Zhao R. Transapical transcatheter aortic-valve replacement for a patient with horizocardia aortic insufficiency. Asian J Surg 2024; 47:2361-2362. [PMID: 38245424 DOI: 10.1016/j.asjsur.2024.01.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2023] [Accepted: 01/11/2024] [Indexed: 01/22/2024] Open
Affiliation(s)
- Yanyan Song
- Department of Cardiovascular Surgery, General Hospital of Ningxia Medical University, Yinchuan, 750004, China
| | - ZhiYan Mai
- Ningxia Medical University, Yinchuan, 750000, China
| | - YuJing Zhang
- Department of Cardiovascular Surgery, General Hospital of Ningxia Medical University, Yinchuan, 750004, China.
| | - Rong Zhao
- Department of Cardiovascular Surgery, General Hospital of Ningxia Medical University, Yinchuan, 750004, China; Ningxia Medical University, Yinchuan, 750000, China.
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Mai Z, Li J, Feng Y, Zhang X. [Diffusion tensor field estimation based on 3D U-Net and diffusion tensor imaging model constraint]. Nan Fang Yi Ke Da Xue Xue Bao 2023; 43:1224-1232. [PMID: 37488805 PMCID: PMC10366516 DOI: 10.12122/j.issn.1673-4254.2023.07.19] [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] [Subscribe] [Scholar Register] [Indexed: 07/26/2023]
Abstract
OBJECTIVE To propose a diffusion tensor field estimation network based on 3D U-Net and diffusion tensor imaging (DTI) model constraint (3D DTI-Unet) to accurately estimate DTI quantification parameters from a small number of diffusion-weighted (DW) images with a low signal-to-noise ratio. METHODS The input of 3D DTI-Unet was noisy diffusion magnetic resonance imaging (dMRI) data containing one non-DW image and 6 DW images with different diffusion coding directions. The noise-reduced non-DW image and accurate diffusion tensor field were predicted through 3D U-Net. The dMRI data were reconstructed using the DTI model and compared with the true value of dMRI data to optimize the network and ensure the consistency of the dMRI data with the physical model of the diffusion tensor field. We compared 3D DTI-Unet with two DW image denoising algorithms (MP-PCA and GL-HOSVD) to verify the effect of the proposed method. RESULTS The proposed method was better than MP-PCA and GL-HOSVD in terms of quantitative results and visual evaluation of DW images, diffusion tensor field and DTI quantification parameters. CONCLUSION The proposed method can obtain accurate DTI quantification parameters from one non-DW image and 6 DW images to reduce image acquisition time and improve the reliability of quantitative diagnosis.
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Affiliation(s)
- Z Mai
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Guangzhou 510515, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Guangzhou 510515, China
| | - J Li
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Guangzhou 510515, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Guangzhou 510515, China
| | - Y Feng
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Guangzhou 510515, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Guangzhou 510515, China
| | - X Zhang
- School of Biomedical Engineering, Southern Medical University, Guangzhou 510515, China
- Guangdong Provincial Key Laboratory of Medical Image Processing, Guangzhou 510515, China
- Guangdong Province Engineering Laboratory for Medical Imaging and Diagnostic Technology, Guangzhou 510515, China
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De Silva P, Saad M, Mai Z, Bano S, Camargo A, Kidd M, Choe J, Hasan T. 180P Photodynamic priming of pancreatic cancer: Enabling immunotherapy. Ann Oncol 2021. [DOI: 10.1016/j.annonc.2021.10.200] [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: 11/26/2022] Open
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Deng T, Duan X, Liu B, Lan Y, Cai C, Zhang T, Zhu W, Mai Z, Wu W, Zeng G. Association between phosphodiesterase type 5 inhibitors use and risk of melanoma: a meta-analysis. Neoplasma 2019. [PMID: 29534582 DOI: 10.4149/neo_2018_170111n23] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
This meta-analysis aimed to clarify the actual association between the phosphodiesterase type 5 inhibitors (PDE5-Is) use and the risk of melanoma in erectile dysfunction (ED) patients. A systematic literature search was conducted in online databases in October, 2016 to identify studies focusing on the association between PDE5-Is use and the risk of melanoma. Summarized multivariate adjusted risk ratios (RRs) and 95% confidence intervals (CIs) were calculated to assess the strength of associations. A total of six clinical trials containing more than one million participants were included. ED patients using PDE5-Is shared a significant high risk of melanoma (RR=1.12, 95% CI=1.03-1.21, p=0.006). Positive associations were observed in all kinds of prescriptions: single prescription (RR=1.20, 95% CI=1.06-1.35, p=0.003), medium number of prescription (RR=1.15, 95% CI=1.01-1.30, p=0.03), and high number of prescription (RR=1.18, 95% CI=1.05-1.34, P=0.006). Additionally, PDE5-Is were also found to be significantly associated with increased risk of basal cell carcinoma (RR=1.14, 95% CI=1.09-1.19, p<0.00001). Our study indicates that PDE5-Is use could significantly increase the risk of melanoma and basal cell carcinoma. However, the risk of melanoma did not rise significantly with the increased number of prescriptions. Consequently, owing to the lack of information about other potential synergistic factors, it is difficult for us to make a solid conclusion that application of PDE5-Is is the direct cause of increased risk of melanoma. Their relationship needs to be validated by further evidences.
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Yang J, Yang Q, Mai Z, Zhou X, Ma N. 0195 Influences of Screen Media Use Near Bedtime on Daytime Sleepniess and Self-satisfaction among College Students: The Mediating Effect of Valid Sleep Time. Sleep 2018. [DOI: 10.1093/sleep/zsy061.194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J Yang
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
| | - Q Yang
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
| | - Z Mai
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
| | - X Zhou
- School of Psychological and Cognitive Sciences, Peking University, Beijing, CHINA
| | - N Ma
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
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Mai Z, Zhou J, Lin Y, Fu Y, Hu P, Zhou X, Ma N. 0226 Sense Of Fairness Alters After Sleep Loss: A Preliminary Research. Sleep 2018. [DOI: 10.1093/sleep/zsy061.225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Z Mai
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
| | - J Zhou
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
| | - Y Lin
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
| | - Y Fu
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
| | - P Hu
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
| | - X Zhou
- School of Psychological and Cognitive Sciences, Peking University, Beijing, CHINA
| | - N Ma
- Center for Sleep Research, School of Psychology, South China Normal University, Guangzhou, CHINA
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Guglielmetti C, Veraart J, Roelant E, Mai Z, Daans J, Van Audekerke J, Naeyaert M, Vanhoutte G, Delgado Y Palacios R, Praet J, Fieremans E, Ponsaerts P, Sijbers J, Van der Linden A, Verhoye M. Diffusion kurtosis imaging probes cortical alterations and white matter pathology following cuprizone induced demyelination and spontaneous remyelination. Neuroimage 2015; 125:363-377. [PMID: 26525654 DOI: 10.1016/j.neuroimage.2015.10.052] [Citation(s) in RCA: 102] [Impact Index Per Article: 11.3] [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: 07/07/2015] [Revised: 10/15/2015] [Accepted: 10/19/2015] [Indexed: 12/21/2022] Open
Abstract
Although MRI is the gold standard for the diagnosis and monitoring of multiple sclerosis (MS), current conventional MRI techniques often fail to detect cortical alterations and provide little information about gliosis, axonal damage and myelin status of lesioned areas. Diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI) provide sensitive and complementary measures of the neural tissue microstructure. Additionally, specific white matter tract integrity (WMTI) metrics modelling the diffusion in white matter were recently derived. In the current study we used the well-characterized cuprizone mouse model of central nervous system demyelination to assess the temporal evolution of diffusion tensor (DT), diffusion kurtosis tensor (DK) and WMTI-derived metrics following acute inflammatory demyelination and spontaneous remyelination. While DT-derived metrics were unable to detect cuprizone induced cortical alterations, the mean kurtosis (MK) and radial kurtosis (RK) were found decreased under cuprizone administration, as compared to age-matched controls, in both the motor and somatosensory cortices. The MK remained decreased in the motor cortices at the end of the recovery period, reflecting long lasting impairment of myelination. In white matter, DT, DK and WMTI-derived metrics enabled the detection of cuprizone induced changes differentially according to the stage and the severity of the lesion. More specifically, the MK, the RK and the axonal water fraction (AWF) were the most sensitive for the detection of cuprizone induced changes in the genu of the corpus callosum, a region less affected by cuprizone administration. Additionally, microgliosis was associated with an increase of MK and RK during the acute inflammatory demyelination phase. In regions undergoing severe demyelination, namely the body and splenium of the corpus callosum, DT-derived metrics, notably the mean diffusion (MD) and radial diffusion (RD), were among the best discriminators between cuprizone and control groups, hence highlighting their ability to detect both acute and long lasting changes. Interestingly, WMTI-derived metrics showed the aptitude to distinguish between the different stages of the disease. Both the intra-axonal diffusivity (Da) and the AWF were found to be decreased in the cuprizone treated group, Da specifically decreased during the acute inflammatory demyelinating phase whereas the AWF decrease was associated to the spontaneous remyelination and the recovery period. Altogether our results demonstrate that DKI is sensitive to alterations of cortical areas and provides, along with WMTI metrics, information that is complementary to DT-derived metrics for the characterization of demyelination in both white and grey matter and subsequent inflammatory processes associated with a demyelinating event.
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Affiliation(s)
- C Guglielmetti
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - J Veraart
- iMinds - Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium; Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - E Roelant
- StatUa Center for Statistics, University of Antwerp, Antwerp, Belgium
| | - Z Mai
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - J Daans
- Experimental Cell Transplantation Group, Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | | | - M Naeyaert
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - G Vanhoutte
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | | | - J Praet
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
| | - E Fieremans
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY, USA
| | - P Ponsaerts
- Experimental Cell Transplantation Group, Laboratory of Experimental Hematology, Vaccine and Infectious Disease Institute (Vaxinfectio), University of Antwerp, Antwerp, Belgium
| | - J Sijbers
- iMinds - Vision Lab, Department of Physics, University of Antwerp, Antwerp, Belgium
| | | | - M Verhoye
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
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Mai Z, Malik Z, Spring B, Hasan T. A novel mutual prodrug-induced, and quantitatively and selectively enhanced PpIX accumulation in brain tumors. Photodiagnosis Photodyn Ther 2011. [DOI: 10.1016/j.pdpdt.2011.03.293] [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: 11/25/2022]
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9
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Spring B, Elrington S, Mai Z, Zheng L, Abu-Yousif A, Hasan T. Quantitative, multi-scale fluorescence imaging reveals rapid tumor permeation and intracellular delivery of liposome-associated bevacizumab. Photodiagnosis Photodyn Ther 2011. [DOI: 10.1016/j.pdpdt.2011.03.243] [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: 11/30/2022]
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10
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Zhong W, Celli JP, Rizvi I, Mai Z, Spring BQ, Yun SH, Hasan T. In vivo high-resolution fluorescence microendoscopy for ovarian cancer detection and treatment monitoring. Br J Cancer 2009; 101:2015-22. [PMID: 19920823 PMCID: PMC2795438 DOI: 10.1038/sj.bjc.6605436] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Background: In patients with advanced ovarian cancer (OvCa), microscopic residual tumour nodules that remain after surgical debulking frequently escape detection by current treatment assessment methods and lead to disease recurrence. The aim of this study was to evaluate the use of high-resolution fibre-optic fluorescence imaging of the clinically approved photodynamic therapy (PDT) agent benzoporphyin-derivative monoacid ring A (BPD-MA) for detection of microscopic OvCa and for monitoring treatment response. Methods: Our fluorescence microendoscope consists of a flexible imaging fibre coupled to a custom epi-fluorescence system optimised for imaging BPD-MA, which, after a single administration, serves as both an imaging agent and a light-activated therapeutic agent. After characterisation in an in vitro OvCa 3D model, we used the flexible imaging fibre to minimally invasively image the peritoneal cavity of a disseminated OvCa murine model using BPD-MA administered intraperitoneally (i.p.). To evaluate longitudinal changes in response to treatment, we compared sets of images obtained before and after PDT with those from untreated mice imaged at the same time points. Results: By comparison with histopathology, we report an 86% sensitivity for tumour detection in vivo using the microendoscope. Using a custom routine to batch process-image data in the monitoring study, treated mice exhibited an average decrease of 58.8% in tumour volumes compared with an increase of 59.3% in untreated controls (P<0.05). Conclusions: Our findings indicate the potential of this approach as a reporter of treatment outcome that could aid in the rational design of strategies to mitigate recurrent OvCa.
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Affiliation(s)
- W Zhong
- Wellman Center for Photomedicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
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Sinha AK, Anand S, Ortel BJ, Chang Y, Mai Z, Hasan T, Maytin EV. Methotrexate used in combination with aminolaevulinic acid for photodynamic killing of prostate cancer cells. Br J Cancer 2006; 95:485-95. [PMID: 16868543 PMCID: PMC2360674 DOI: 10.1038/sj.bjc.6603273] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.7] [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] [Indexed: 11/25/2022] Open
Abstract
Photodynamic therapy (PDT) using 5-aminolaevulinic acid (ALA) to drive production of an intracellular photosensitiser, protoporphyrin IX (PpIX), is a promising cancer treatment. However, ALA-PDT is still suboptimal for thick or refractory tumours. Searching for new approaches, we tested a known inducer of cellular differentiation, methotrexate (MTX), in combination with ALA-PDT in LNCaP cells. Methotrexate alone promoted growth arrest, differentiation, and apoptosis. Methotrexate pretreatment (1 mg l−1, 72 h) followed by ALA (0.3 mM, 4 h) resulted in a three-fold increase in intracellular PpIX, by biochemical and confocal analyses. After exposure to 512 nm light, killing was significantly enhanced in MTX-preconditioned cells. The reverse order of treatments, ALA-PDT followed by MTX, yielded no enhancement. Methotrexate caused a similar relative increase in PpIX, whether cells were incubated with ALA, methyl-ALA, or hexyl-ALA, arguing against a major effect upon ALA transport. Searching for an effect among porphyrin synthetic enzymes, we found that coproporphyrinogen oxidase (CPO) was increased three-fold by MTX at the mRNA and protein levels. Transfection of LNCaP cells with a CPO-expressing vector stimulated the accumulation of PpIX. Our data suggest that MTX, when used to modulate intracellular production of endogenous PpIX, may provide a new combination PDT approach for certain cancers.
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Affiliation(s)
- A K Sinha
- Department of Dermatology, Wellman Center for Photomedicine, Harvard Medical School, Boston, MA 02114, USA
| | - S Anand
- Department of Dermatology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
- Department of Biomedical Engineering, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
| | - B J Ortel
- Department of Dermatology, Wellman Center for Photomedicine, Harvard Medical School, Boston, MA 02114, USA
| | - Y Chang
- Department of Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Z Mai
- Department of Dermatology, Wellman Center for Photomedicine, Harvard Medical School, Boston, MA 02114, USA
| | - T Hasan
- Department of Dermatology, Wellman Center for Photomedicine, Harvard Medical School, Boston, MA 02114, USA
| | - E V Maytin
- Department of Dermatology, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
- Department of Biomedical Engineering, Cleveland Clinic Foundation, Cleveland, OH 44195, USA
- Department of Biomedical Engineering, Cleveland Clinic Foundation, ND-20, 9500 Euclid Avenue, Cleveland, OH 44195, USA; E-mail:
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Chirgwin SR, Rao UR, Mai Z, Coleman SU, Nowling JM, Klei TR. Kinetics of T cell cytokine gene expression in gerbils after a primary subcutaneous Brugia pahangi infection. J Parasitol 2005; 91:264-8. [PMID: 15986598 DOI: 10.1645/ge-348r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [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: 11/10/2022] Open
Abstract
The majority of patients infected with lymphatic filariae are microfilaremic but tend to manifest little obvious pathology because of the infections. Data collected from the Mongolian gerbil-Brugia spp. model for human lymphatic filariasis suggest this experimental animal model system most closely represents this patient group and will be useful in studying immunological parameters associated with chronic infections. This article reports the quantitation of interleukin (IL)-4, IL-5, IL-10, IL-13, and interferon (IFN)-gamma messenger RNA (mRNA) in gerbils after a primary subcutaneous infection with Brugia pahangi. Chronically infected gerbils showed elevated IL-4 in all tissues, compared with earlier time points, linking this Th2 cytokine to the downregulation of responsiveness, which develops in gerbils and humans. Both IL-5 and IL-13 mRNA expression were transient in all tissues. The peak in IL-5 at 14-28 days postinfection reflects the peak of peripheral eosinophilia observed in B. pahangi-infected gerbils. Little IFN-gamma mRNA was reported from chronically infected gerbils. The data collected thus far suggest that the expression profile of many of the measured cytokines in B. pahangi-infected gerbils reflects what is seen in an important subset of humans infected with lymphatic filariae, the microfilaremic, asymptomatic patient.
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Affiliation(s)
- S R Chirgwin
- Department of Pathobiological Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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Field J, Wilson MP, Mai Z, Majerus PW, Samuelson J. An Entamoeba histolytica inositol 1,3,4-trisphosphate 5/6-kinase has a novel 3-kinase activity. Mol Biochem Parasitol 2000; 108:119-23. [PMID: 10802324 DOI: 10.1016/s0166-6851(00)00197-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- J Field
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, 665 Huntington Avenue, Boston, MA, USA
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Ghosh SK, Field J, Frisardi M, Rosenthal B, Mai Z, Rogers R, Samuelson J. Chitinase secretion by encysting Entamoeba invadens and transfected Entamoeba histolytica trophozoites: localization of secretory vesicles, endoplasmic reticulum, and Golgi apparatus. Infect Immun 1999; 67:3073-81. [PMID: 10338523 PMCID: PMC96624 DOI: 10.1128/iai.67.6.3073-3081.1999] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [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: 11/20/2022] Open
Abstract
Entamoeba histolytica, the protozoan parasite that phagocytoses bacteria and host cells, has a vesicle/vacuole-filled cytosol like that of macrophages. In contrast, the infectious cyst form has four nuclei and a chitin wall. Here, anti-chitinase antibodies identified hundreds of small secretory vesicles in encysting E. invadens parasites and in E. histolytica trophozoites overexpressing chitinase under an actin gene promoter. Abundant small secretory vesicles were also identified with antibodies to the surface antigen Ariel and with a fluorescent substrate of cysteine proteinases. Removal of an N-terminal signal sequence directed chitinase to the cytosol. Addition of a C-terminal KDEL peptide, identified on amebic BiP, retained chitinase in a putative endoplasmic reticulum, which was composed of a few vesicles of mixed sizes. A putative Golgi apparatus, which was Brefeldin A sensitive and composed of a few large, perinuclear vesicles, was identified with antibodies to ADP-ribosylating factor and to epsilon-COP. We conclude that the amebic secretory pathway is similar to those of other eukaryotic cells, even if its appearance is somewhat different.
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Affiliation(s)
- S K Ghosh
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts 02115, USA
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Mai Z, Ghosh S, Frisardi M, Rosenthal B, Rogers R, Samuelson J. Hsp60 is targeted to a cryptic mitochondrion-derived organelle ("crypton") in the microaerophilic protozoan parasite Entamoeba histolytica. Mol Cell Biol 1999; 19:2198-205. [PMID: 10022906 PMCID: PMC84012 DOI: 10.1128/mcb.19.3.2198] [Citation(s) in RCA: 158] [Impact Index Per Article: 6.3] [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: 11/20/2022] Open
Abstract
Entamoeba histolytica is a microaerophilic protozoan parasite in which neither mitochondria nor mitochondrion-derived organelles have been previously observed. Recently, a segment of an E. histolytica gene was identified that encoded a protein similar to the mitochondrial 60-kDa heat shock protein (Hsp60 or chaperonin 60), which refolds nuclear-encoded proteins after passage through organellar membranes. The possible function and localization of the amebic Hsp60 were explored here. Like Hsp60 of mitochondria, amebic Hsp60 RNA and protein were both strongly induced by incubating parasites at 42 degreesC. 5' and 3' rapid amplifications of cDNA ends were used to obtain the entire E. histolytica hsp60 coding region, which predicted a 536-amino-acid Hsp60. The E. histolytica hsp60 gene protected from heat shock Escherichia coli groEL mutants, demonstrating the chaperonin function of the amebic Hsp60. The E. histolytica Hsp60, which lacked characteristic carboxy-terminal Gly-Met repeats, had a 21-amino-acid amino-terminal, organelle-targeting presequence that was cleaved in vivo. This presequence was necessary to target Hsp60 to one (and occasionally two or three) short, cylindrical organelle(s). In contrast, amebic alcohol dehydrogenase 1 and ferredoxin, which are bacteria-like enzymes, were diffusely distributed throughout the cytosol. We suggest that the Hsp60-associated, mitochondrion-derived organelle identified here be named "crypton," as its structure was previously hidden and its function is still cryptic.
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Affiliation(s)
- Z Mai
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts 02115, USA
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Mai Z, Horohov DW, Klei TR. Hypoxanthine phosphoribosyltransferase cDNA in gerbils (Meriones unguiculatus). Lab Anim Sci 1998; 48:179-83. [PMID: 10090010] [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: 02/11/2023]
Abstract
Hypoxanthine phosphoribosyltransferase (HPRT) is a purine salvage enzyme that catalyzes conversion of hypoxanthine and guanine to their respective mononucleotides. Because of its ubiquitous nature, HPRT is known as a "housekeeping" gene and has been frequently used as an internal control in reverse transcriptase-polymerase chain reaction (RT-PCR) quantification of cytokine mRNA. Cloning and sequencing of the gerbil HPRT cDNA sequence is an important step in the development of RT-PCR procedures in this model. Two forms of gerbil HPRT cDNA were isolated and molecularly characterized.
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Affiliation(s)
- Z Mai
- Department of Veterinary Microbiology and Parasitology School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803, USA
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Mai Z, Samuelson J. A new gene family (ariel) encodes asparagine-rich Entamoeba histolytica antigens, which resemble the amebic vaccine candidate serine-rich E. histolytica protein. Infect Immun 1998; 66:353-5. [PMID: 9423879 PMCID: PMC107898 DOI: 10.1128/iai.66.1.353-355.1998] [Citation(s) in RCA: 16] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
A family of genes, called ariel, are named for and encode asparagine-rich Entamoeba histolytica antigens containing 2 to 16 octapeptide repeats. Ariel proteins, which are constitutively expressed by trophozoites, belong to a large antigen family that includes the serine-rich E. histolytica protein (SREHP), an amebic vaccine candidate.
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Affiliation(s)
- Z Mai
- Department of Immunology and Infectious Diseases, Harvard School of Public Health, Boston, Massachusetts 02125, USA
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Rosenthal B, Mai Z, Caplivski D, Ghosh S, de la Vega H, Graf T, Samuelson J. Evidence for the bacterial origin of genes encoding fermentation enzymes of the amitochondriate protozoan parasite Entamoeba histolytica. J Bacteriol 1997; 179:3736-45. [PMID: 9171424 PMCID: PMC179172 DOI: 10.1128/jb.179.11.3736-3745.1997] [Citation(s) in RCA: 92] [Impact Index Per Article: 3.4] [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: 02/04/2023] Open
Abstract
Entamoeba histolytica is an amitochondriate protozoan parasite with numerous bacterium-like fermentation enzymes including the pyruvate:ferredoxin oxidoreductase (POR), ferredoxin (FD), and alcohol dehydrogenase E (ADHE). The goal of this study was to determine whether the genes encoding these cytosolic E. histolytica fermentation enzymes might derive from a bacterium by horizontal transfer, as has previously been suggested for E. histolytica genes encoding heat shock protein 60, nicotinamide nucleotide transhydrogenase, and superoxide dismutase. In this study, the E. histolytica por gene and the adhE gene of a second amitochondriate protozoan parasite, Giardia lamblia, were sequenced, and their phylogenetic positions were estimated in relation to POR, ADHE, and FD cloned from eukaryotic and eubacterial organisms. The E. histolytica por gene encodes a 1,620-amino-acid peptide that contained conserved iron-sulfur- and thiamine pyrophosphate-binding sites. The predicted E. histolytica POR showed fewer positional identities to the POR of G. lamblia (34%) than to the POR of the enterobacterium Klebsiella pneumoniae (49%), the cyanobacterium Anabaena sp. (44%), and the protozoan Trichomonas vaginalis (46%), which targets its POR to anaerobic organelles called hydrogenosomes. Maximum-likelihood, neighbor-joining, and parsimony analyses also suggested as less likely E. histolytica POR sharing more recent common ancestry with G. lamblia POR than with POR of bacteria and the T. vaginalis hydrogenosome. The G. lamblia adhE encodes an 888-amino-acid fusion peptide with an aldehyde dehydrogenase at its amino half and an iron-dependent (class 3) ADH at its carboxy half. The predicted G. lamblia ADHE showed extensive positional identities to ADHE of Escherichia coli (49%), Clostridium acetobutylicum (44%), and E. histolytica (43%) and lesser identities to the class 3 ADH of eubacteria and yeast (19 to 36%). Phylogenetic analyses inferred a closer relationship of the E. histolytica ADHE to bacterial ADHE than to the G. lamblia ADHE. The 6-kDa FD of E. histolytica and G. lamblia were most similar to those of the archaebacterium Methanosarcina barkeri and the delta-purple bacterium Desulfovibrio desulfuricans, respectively, while the 12-kDa FD of the T. vaginalis hydrogenosome was most similar to the 12-kDa FD of gamma-purple bacterium Pseudomonas putida. E. histolytica genes (and probably G. lamblia genes) encoding fermentation enzymes therefore likely derive from bacteria by horizontal transfer, although it is not clear from which bacteria these amebic genes derive. These are the first nonorganellar fermentation enzymes of eukaryotes implicated to have derived from bacteria.
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Affiliation(s)
- B Rosenthal
- Department of Tropical Public Health, Harvard School of Public Health, Boston, Massachusetts 02115, USA
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Rosenthal B, Mai Z, Caplivski D, Ghosh S, Meckler J, Samuelson J. A revised endosymbiont hypothesis to explain the bacterial origin of amebic glycolytic and fermentation enzymes. Arch Med Res 1997; 28 Spec No:71-2. [PMID: 9033017] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Affiliation(s)
- B Rosenthal
- Department of Tropical Public Health, Harvard School of Public Health, Boston, MA, USA
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Li M, Mai Z, Li J, Li C, Cui S. Investigation of mosaicity of epitaxic multilayers by the statistical theory of X-ray dynamical diffraction. Acta Crystallogr A 1995. [DOI: 10.1107/s0108767394013000] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Mai Z, Kousoulas KG, Horohov DW, Klei TR. Cross-species PCR cloning of gerbil (Meriones unguiculatus) interleukin-2 cDNA and its expression in COS-7 cells. Vet Immunol Immunopathol 1994; 40:63-71. [PMID: 8128610 DOI: 10.1016/0165-2427(94)90015-9] [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] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
A cDNA clone of the gerbil interleukin-2 (IL-2) gene was isolated by cross-species PCR cloning, and demonstrated to produce a functional gerbil IL-2 protein when inserted in the eucaryotic expression vector pSV-SPORT1 and transfected into COS-7 monkey cells. The open reading frame codes for a polypeptide of 155 amino acid residues with a molecular weight (MW) of 17,601 which includes a putative signal peptide. The mature gerbil IL-2 is deduced to contain 135 amino acid residues and has a calculated MW of 15,496. Culture supernatant of COS-7 cells transfected with pSV-SPORT1-GIL-2, but not pSV-SPORT1 stimulates the proliferation of the IL-2 dependent murine CTLL-2 cells. Molecular characteristics of gerbil IL-2 have been compared with IL-2 of mouse, rat, human, bovine, ovine and porcine origin. The mature form of gerbil IL-2 is similar in molecular weight to all species except the mouse. A N-glycosylation site present in bovine, ovine and porcine IL-2 respectively, is absent in gerbil. Three Cys residues are conserved in all compared mature IL-2 molecules. In these comparisons, gerbil IL-2 has highest identity with rat IL-2 for both nucleotide and amino acid sequence.
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Affiliation(s)
- Z Mai
- Department of Veterinary Microbiology and Parasitology, School of Veterinary Medicine, Louisiana State University, Baton Rouge 70803
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Nan-xian C, Chen-fu Z, Mai Z, Guang-bao R, Wen-bin Z. Closed-form solution for inverse problems of Fermi systems. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1993; 48:1558-1561. [PMID: 9960748 DOI: 10.1103/physreve.48.1558] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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Mai Z, Tao S, Zeng L, Zhang B. Computer simulations of a distorted reciprocal lattice of an Al-Li-Cu single quasicrystal. Phys Rev B Condens Matter 1988; 38:12913-12916. [PMID: 9946261 DOI: 10.1103/physrevb.38.12913] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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Ding Z, Mai Z, Zhang J, Xiang Y, Yu A. Transplantation of cryopreserved murine fetal liver cells for the treatment of lethally irradiated injuries. Cryobiology 1988. [DOI: 10.1016/0011-2240(88)90484-1] [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: 11/30/2022]
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Sun Z, Mai Z, Ge P. Temperature effect of X-ray diffraction intensities from a perfect crystal for the Laue case. Acta Crystallogr A 1987. [DOI: 10.1107/s0108767387079649] [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: 11/10/2022] Open
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Mai Z, Cui S, Ge P. Si—H bonds and H-induced defects in FZ silicon crystal. Acta Crystallogr A 1984. [DOI: 10.1107/s0108767384090188] [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: 11/10/2022] Open
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Mai Z, Cui S, Ge P. The defects in synthetic quartz. Acta Crystallogr A 1981. [DOI: 10.1107/s0108767381092076] [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: 11/10/2022] Open
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