251
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Fan M, Peng B, Luo L. [Effects of gu chi san on cultured human gingival fibroblasts]. Zhonghua Kou Qiang Yi Xue Za Zhi 1995; 30:298-300, 320. [PMID: 8728974] [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: 02/01/2023]
Abstract
The present study demonstrates that Gu Chi San is able to increase the bone density in the clinical and animal tests. This study finds that Gu Chi San has no cytotoxicity on HGFs, and 1g/L Gu Chi San extracts can stimulate the mitosis and enhance the DNA synthesis of HGFs. The results indicate that certain substances are present in Gu Chi San.
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Affiliation(s)
- M Fan
- College of Stomatology, Hubei Medical University, Wuhan
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252
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Fan M, Chen LC, Ragan MA, Gutell RR, Warner JR, Currie BP, Casadevall A. The 5S rRNA and the rRNA intergenic spacer of the two varieties of Cryptococcus neoformans. J Med Vet Mycol 1995; 33:215-21. [PMID: 8531018 DOI: 10.1080/02681219580000451] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The intergenic spacers (IGS) separating the 23S-like and 16S-like rDNAs of the two varieties of the human pathogenic fungus Cryptococcus neoformans were amplified, cloned and sequenced. The C. neoformans var. neoformans IGS was 2421 nt with 5S rRNA at positions 1228-1345 3' of the 23S-like rRNA. The C. neoformans var. gattii IGS was 2480 nt with 5S rRNA at positions 1268-1385 3' of the 23S-like rRNA. For both varieties the 5S rDNA genes were in the same orientation as the 16S-5.8-23S genes and encode a 118 nt molecule of identical sequence. Phylogenetic comparison of C. neoformans 5S rDNA with that of other fungi placed this fungus in close relationship with other basidiomycetes including Tremella mesenterica, Bullera alba, and Cryptococcus laurentii. A secondary structure model for the deduced 5S rRNA was constructed by comparative sequence analysis. Polymerase chain reaction-amplified IGS of 12 C. neoformans var. neoformans strains revealed extensive size variation ranging from 100 to 300 nt. Size variation between strains in the length of the IGS may be useful for distinguishing strains. Structurally, the IGS were characterized by the presence of occasional short direct GC-rich 19-nt repeats. Overall IGS sequence identity between the C. neoformans varieties was only 78.5%, in sharp contrast to the identical or nearly identical sequences for the rDNA genes, and suggests rapid evolution for IGS sequences.
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MESH Headings
- Base Sequence
- Basidiomycota/classification
- Basidiomycota/genetics
- Consensus Sequence
- Cryptococcus/classification
- Cryptococcus/genetics
- Cryptococcus neoformans/classification
- Cryptococcus neoformans/genetics
- Cryptococcus neoformans/isolation & purification
- DNA Primers
- DNA, Fungal/genetics
- DNA, Fungal/isolation & purification
- DNA, Ribosomal/genetics
- DNA, Ribosomal/isolation & purification
- Humans
- Introns
- Molecular Sequence Data
- Nucleic Acid Conformation
- Phylogeny
- Polymerase Chain Reaction
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 5S/chemistry
- RNA, Ribosomal, 5S/genetics
- Repetitive Sequences, Nucleic Acid
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Affiliation(s)
- M Fan
- Department of Medicine (Division of Infectious Diseases), Albert Einstein College of Medicine, Bronx, NY 10461, USA
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253
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He H, Fan M, Ling J. [Clinical studies of a caries-defense varnish containing sialin-like material]. Zhonghua Kou Qiang Yi Xue Za Zhi 1995; 30:175-7. [PMID: 7489656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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254
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Casadevall A, DeShaw M, Fan M, Dromer F, Kozel TR, Pirofski LA. Molecular and idiotypic analysis of antibodies to Cryptococcus neoformans glucuronoxylomannan. Infect Immun 1994; 62:3864-72. [PMID: 8063403 PMCID: PMC303042 DOI: 10.1128/iai.62.9.3864-3872.1994] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.0] [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: 01/28/2023] Open
Abstract
Antibodies to the Cryptococcus neoformans capsular glucuronoxylomannan (GXM) form the basis of two potential therapeutic intervention strategies, i.e., conjugate vaccines and passive antibody therapy. To better understand the molecular basis of the antibody response, the heavy- and light-chain immunoglobulin variable region (VH and VL, respectively) sequences of seven monoclonal antibodies (MAbs) to GXM were determined. Rabbit anti-idiotypic serum was made to the previously characterized murine MAb 2H1 and used to study MAb 2H1 idiotype expression in other GXM-binding MAbs and immune sera. MAb E1 originated from a C3H/HeJ mouse immunized with C. neoformans serotype A polysaccharide. MAbs 471, 1255, 339, 3C2, 386, and 302 originated from BALB/c mice immunized with polysaccharide of serotypes A, A, B, C, D, and D, respectively, conjugated to sheep erythrocytes. In the E1, VH uses V11 from the T15 gene family and JH3 and has a D segment of three amino acids, and the VL uses a VKSer-like gene family element and JK5. In MAbs 471 and 3C2, the VH uses VH7183-like gene family elements and JH2 and has D segments of seven amino acids, and the VL uses VK5.1 and JK1. In MAbs 1255 and 339, the VH uses VH10-like gene elements and JH4 and has six codon D segments, and the VL uses a VK21-like gene element and JK5. In MAbs 302 and 386, respectively, the VH uses VHGAM-like gene elements and JH2 and JH3 and has six and four codon D segments, and VL uses VK4/5-like gene elements and JK1.VH usage, MAb 2H1 idiotype expression, and fine specificity mapping define a minimum of three GXM epitopes which elicit protective antibodies. The results confirm that the antibody response is highly restricted, suggest a close relationship between molecular structure and serological properties, and provide insight into protein structural motifs important for GXM binding.
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Affiliation(s)
- A Casadevall
- Department of Medicine, Albert Einstein College of Medicine, Bronx, New York 10461
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255
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256
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Fan M, Currie BP, Gutell RR, Ragan MA, Casadevall A. The 16S-like, 5.8S and 23S-like rRNAs of the two varieties of Cryptococcus neoformans: sequence, secondary structure, phylogenetic analysis and restriction fragment polymorphisms. J Med Vet Mycol 1994; 32:163-80. [PMID: 7525916 DOI: 10.1080/02681219480000231] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The nucleotide sequences of the 16S-like, 5.8S and 23S-like rDNAs from the two varieties of Cryptococcus neoformans, C. neoformans var. neoformans and C. neoformans var. gattii, were determined. The rRNA locus has the typical eukaryote organization of 16S-5.8S-23S with the 16S-like and 5.8S rRNA genes separated by a 124-nucleotide spacer and the 5.8S and 23S-like rRNA genes separated by a 187-nucleotide spacer in each strain. The C. neoformans var. neoformans and C. neoformans var. gattii 16S-like, 5.8S and 23S-like rRNAs are, respectively 1802, 158, and 3358 nucleotides in length and share > 99% nucleotide sequence identity, a finding which strongly supports the present taxonomic classification of two varieties within a species. Comparative structure analysis was used to construct secondary-structure models for the deduced 16S-like and 5.8S-23S-like rRNA sequences, which are similar to those of other fungal rRNAs. The C. neoformans 16S-like and 23S-like rRNA sequences were aligned with other eukaryote sequences based on secondary and higher-order structures predicted by comparative structure analysis for phylogenetic analysis. There was good correspondence between the 16S-like and 23S-like derived phylogenetic trees. The closest known fungal relative is Trichosporon beigelii. Southern blot analysis revealed one C. neoformans strain with two types of DNA repeats coding for rRNA which differed in size by about 1000 bp. Restriction fragment length polymorphisms in the rDNA locus provide useful markers for the study of epidemiology and pathogenesis of C. neoformans infections.
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MESH Headings
- Base Sequence
- Cryptococcus neoformans/genetics
- Molecular Sequence Data
- Phylogeny
- Polymorphism, Restriction Fragment Length
- RNA, Bacterial/chemistry
- RNA, Bacterial/genetics
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/chemistry
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 5.8S/chemistry
- RNA, Ribosomal, 5.8S/genetics
- Species Specificity
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Affiliation(s)
- M Fan
- Department of Medicine, Albert Einstein College of Medicine, Bronx, NY 10461
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257
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258
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Zhou L, Fan M, Chen J, Cai H, Zhou F, Zhu H. [Analysis of fatty acid composition of spotted fever group rickettsiae isolated in China by gas chromatography]. Wei Sheng Wu Xue Bao 1993; 33:290-6. [PMID: 8256442] [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: 01/29/2023]
Abstract
In present paper, fatty acid composition of seven Chinese isolates of SFG rickettsiae and six prototype strains of SFG rickettsiae were analyzed by GC-MS. Tested prototype strains of SFG rickettsiae were R. sibirica (strains 232 and 246), R. conorii (Simko), R. rickettsi (R), R. akari (Kaplan), R. australis (W58); Chinese isolates were An-84, Se-85, W-88 (human strain), MT-84, FT-84 (D. nuttalli strain), TO-85 (ova of nuttalli) and Chinese reference strain -JH-74 (D. nuttalli). They were propagated in yolk sacs of embryonated hen eggs and purified by centrifugation in a 30%-36%-42% discontinuous renografin density gradient. The fatty acid composition of selected strains of SFG rickettsiae was analyzed by gas chromatography, and then comparison being carried out by single linkage on mini-computer. Identification of the strains was performed based on the results obtained from GC-MS. Results showed that the fatty acid profiles of all the isolates from China were quantitatively similar to that of R. sibirica and quite different from other prototype strains of SFG rickettsiae.
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Affiliation(s)
- L Zhou
- Institute of Epidemiology and Microbiology, Chinese Academy of Preventive Medicine, Beijing
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259
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He B, Fan M, Liu SH, Gan SD. [Change of beta tubulin gene expression in the motoneurons of spinal cord during nerve regeneration]. Sheng Li Xue Bao 1993; 45:354-8. [PMID: 8296210] [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: 01/29/2023]
Abstract
After crushing the right sciatic nerve of rat, the contents of both tubulin and beta tubulin mRNA increased significantly in the ventral horns of spinal cord. Analysis of tubulin in bilateral ventral horns by SDS-PAGE showed that tubulin in the injured side increased by 17%-121% of the control side. The results of in situ hybridization indicated with the signals of hybridization with beta tubulin cDNA probes were 27%-70% higher in motoneurons of the ventral horns in the injury side than the control. Northern blotting analysis of tubulin mRNA in ventral horns also revealed an increase of tubulin gene expression.
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Affiliation(s)
- B He
- Institute of Basic Medical Sciences, Beijing
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260
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Chung PH, Crivello JV, Fan M. The use of platinum and rhodium catalysts for the preparation and cationic ring-opening polymerization of silicon-containing epoxides. ACTA ACUST UNITED AC 1993. [DOI: 10.1002/pola.1993.080310712] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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261
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Yu L, Ming Y, Fan M. Studies on the photochromic mechanism of 1,2-dimethyl-5-phenyl-3-pyrryl succinic anhydride. Res Chem Intermed 1993. [DOI: 10.1163/156856793x00415] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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262
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Yu X, Jin Y, Fan M, Xu G, Liu Q, Raoult D. Genotypic and antigenic identification of two new strains of spotted fever group rickettsiae isolated from China. J Clin Microbiol 1993; 31:83-8. [PMID: 8093253 PMCID: PMC262626 DOI: 10.1128/jcm.31.1.83-88.1993] [Citation(s) in RCA: 91] [Impact Index Per Article: 2.9] [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: 01/28/2023] Open
Abstract
Four isolates of spotted fever group rickettsiae isolated from ticks in China were compared with all known species and strains of spotted fever group rickettsiae by immunofluorescence assay, DNA polymerase chain reaction followed by restriction endonuclease fragment length polymorphism analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and Western immunoblot. The Chinese isolates belonged to three types, including a novel serotype which has not been described before. One isolate obtained from tick ova of Dermacentor nuttallii in Inner Mongolia was antigenically and genotypically identical to Rickettsia sibirica. Two isolates obtained from Dermacentor sinicus collected from Beijing were identical, different from other members of spotted fever group rickettsiae but apparently closely related to R. sibirica. HA-91, a strain isolated from Hyalomma asiaticum bv. kozlovi olenew, was antigenically and genotypically unique among spotted fever group rickettsiae, and we feel that data presented here should prompt consideration of it as a new species on the basis of current rickettsial taxonomy.
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Affiliation(s)
- X Yu
- Unité des Rickettsies, Faculté de Médecine, Marseille, France
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263
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Fan M, Ascher PW, Schröttner O, Ebner F, Germann RH, Kleinert R. Interstitial 1.06 Nd:YAG laser thermotherapy for brain tumors under real-time monitoring of MRI: experimental study and phase I clinical trial. J Clin Laser Med Surg 1992; 10:355-61. [PMID: 10147968 DOI: 10.1089/clm.1992.10.355] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
This paper presents the experimental and clinical results of interstitial 1.06 Nd:YAG laser thermotherapy (ILTT) for brain tumors under real-time monitoring by magnetic resonance imaging. The authors chose a laser heat source for interstitial thermotherapy of brain tumors for several important reasons: (1) Laser heat delivery is less complicated and more controlled; (2) laser effects on tissue can be tested, monitored, and controlled by MRI. A 1.064 nm Nd:YAG laser and a specially designed laser optic fiber (ILTT) were used in C.W. mode this study. The laser was used at 4 W at a C.W. mode pulse and total exposure duration was 10 minutes (total energy was 2400 joules). Temperature distribution was determined with a microprocessor-based thermometer and by the levels of the signal intensity under MRI. The relationship between the temperature and MRI signal intensity allowed exploration of the possibility of using MRI as a noninvasive temperature monitoring method. Two patients with glioblastoma and one patient with a brain metastasis were treated with this modality. The results and indications are presented and discussed.
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Affiliation(s)
- M Fan
- Department of Neurosurgery, University of Graz, Austria
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264
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Abstract
This study was performed to investigate the pulmonary vascular reactivity during hypothermia. It was found that the pulmonary vessels were more sensitive to alveolar hypoxia in hypothermic dogs, and that hypoxic pulmonary vasoconstriction (HPV) was enhanced, which could be inhibited by alpha 1-adrenoceptor blocker prazosin. The concentration of arterial plasma norepinephrine (NE) increased in dogs with hypothermia or in those with hypothermia plus hypoxia, but there was no significant difference between these two groups. The plasma level of 5-hydroxytryptamine (5-HT) was reduced during hypoxia in hypothermic dogs. Increase in plasma 6-keto-PGF1 alpha, which appeared in hypoxic dogs, was not observed during hypoxia in hypothermic dogs. These findings suggest that a potentiation in the sensitivity and reactivity of alpha-adrenoceptor in pulmonary vessels and a decrease in the modulation of PGI2 might be responsible for the enhancement of HPV. 5-HT seemed not to play a contributing role in the alteration of HPV.
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Affiliation(s)
- M Fan
- Department of Pathophysiology, Tongji Medical University, Wuhan
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265
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Fan M, Zhu ZH, Wang DX. Effect of endotoxin on hypoxic pulmonary vasoconstriction--the role of prostaglandins and leukotrienes. J Tongji Med Univ 1992; 12:11-6. [PMID: 1619691 DOI: 10.1007/bf02887752] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this study, we observed the effect of endotoxemia on hypoxic pulmonary vasoconstriction (HPV) in dogs and explored roles played by prostaglandins and leukotrienes in this process. 5 micrograms/kg BW of E. coli endotoxin induced transient rise in pulmonary arterial pressure and pulmonary vascular resistance (PVR). 30 min after injection of endotoxin when PVR tended to decline, pulmonary vasoconstriction response to alveolar hypoxia was lost, and the ratio of TXB2 to 6-keto-PGF1 alpha decreased significantly. HPV was enhanced at 60-100 min and then returned to the control level at 2 h after injection of endotoxin. At these periods the ratio of TXB2 to 6-keto-PGF1 alpha was the same as before use of endotoxin, whereas plasma concentration of leukotrienes was markedly increased. Indomethacin could prevent the early loss of HPV, but no effect on the late increment of HPV was found. Diethylcarbamazine, which blocked the production of leukotrienes after use of endotoxin, could inhibit late increment of HPV. We concluded that the early loss of HPV was related to the vasodilator prostacyclin, and the late increment of HPV was mainly brought about by leukotrienes.
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Affiliation(s)
- M Fan
- Department of Pathophysiology, Tongji Medical University, Wuhan
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266
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268
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Jin XR, Fan M, Wang ZQ, Su YC, Yang GT, Hu HB, Zhang YP, Feng CJ, Ding YX, Wang DX. Strain difference in pulmonary vascular responsiveness to hypoxia in rats. J Tongji Med Univ 1990; 10:134-40. [PMID: 2255001 DOI: 10.1007/bf02986450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The difference in pulmonary vascular response to hypoxia between Hilltop Sprague-Dawley (HT) rats and Wistar (W) rats was studied. Effects of inhibitor of leukotriene (LT) synthesis or prostaglandin (PG) synthesis on hypoxic pulmonary vasoconstriction (HPV) and chronic pulmonary hypertension were observed, and variations in plasma TXB2 and 6-keto-PGF1 alpha during hypoxia were determined. The results showed that in rats of both strains LTs are the major mediator of HPV, which is also mediated by vasoconstrictive PGs in HT rats, while modulated by vasodilative PGs in W rats. This might be the crucial mechanism responsible for the higher pulmonary vascular responsiveness in HT rats. Differences in the modulating effect of histamine and in the structural feature of pulmonary arteriole might be contributing factors as well.
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Affiliation(s)
- X R Jin
- Department of Pathophysiology, Tongji Medical University, Wuhan
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269
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Fan M. [Changes in the axoplasmic transport of cytoskeletal protein and regenerated nerve structure in the process of nerve regeneration]. Sheng Li Ke Xue Jin Zhan 1990; 21:264-6. [PMID: 1700864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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270
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Abstract
A long solenoid is capable of producing, at least theoretically, a B1 field that is relatively more homogeneous than other known structures. This paper describes the design of a UHF probe incorporating a one-turn solenoid associated with a pair of parallel-plate transmission line feeders and presents a practical example used in a 360-MHz spectrometer for micro-imaging experiments. Numerical evaluation of the solenoid inductance using King's method for direct calculation of elliptic integrals is also included.
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271
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Han FY, Chen BX, Fan M. [Histo-pathology of the transected spinal cord in rats]. Zhonghua Wai Ke Za Zhi 1987; 25:1-5, 60. [PMID: 3595334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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272
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Kinney TB, Fan M, Chin AK, Finn JC, Hayden WG, Fogarty TJ. Shear force in angioplasty: its relation to catheter design and function. AJR Am J Roentgenol 1985; 144:115-22. [PMID: 3155481 DOI: 10.2214/ajr.144.1.115] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The inability to successfully position angioplasty catheters and the occurrence of complications during angioplasty procedures can, in part, be related to the shear forces generated during catheter introduction. Shear forces are the axial contact forces that the catheter system exerts on the inner arterial surfaces during advancement. The shear forces exerted by three different catheter designs (coaxial dilator, coaxial balloon, and linear extrusion) were measured in normal and atherosclerotic arteries; in modeled stenoses of variable severity, length, and compliance; and in modeled vessel angulations. The results with modeled vessels show that the linear extrusion catheter reduces the level of shear forces, particularly in narrow, long, noncompliant stenoses and in tortuous vessels. The stenotic artery results also show that the linear extrusion catheter minimizes these forces in tight lesions. The relative differences in forces are explained by the mechanism of action for each catheter. The reported occurrences of technical difficulties, complications, and long-term patency rates are then interpreted on the basis of the relative differences in measured shear forces. The results of this study combined with preliminary clinical data indicate that linear extrusion should facilitate placement and reduce associated complications.
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273
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Kan S, Gonord P, Fan M, Sauzade M, Courtieu J. Automatic NMR field-frequency lock-pulsed phase locked loop approach. Rev Sci Instrum 1978; 49:785. [PMID: 18699193 DOI: 10.1063/1.1135615] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A self-contained deuterium frequency-field lock scheme for a high-resolution NMR spectrometer is described. It is based on phase locked loop techniques in which the free induction decay signal behaves as a voltage-controlled oscillator. By pulsing the spins at an offset frequency of a few hundred hertz and using a digital phase-frequency discriminator this method not only eliminates the usual phase, rf power, offset adjustments needed in conventional lock systems but also possesses the automatic pull-in characteristics that dispense with the use of field sweeps to locate the NMR line prior to closure of the lock loop.
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Affiliation(s)
- S Kan
- Institut d'Electronique Fondamentale, Laboratoire associe au CNRS, Universite Paris-Sud, 91405 Orsay, FranceLaboratoire de Chimie Organique Structurale, Universite Paris Sud, 91405 Orsay, France
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