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Tang M, Dong X, Qin M, Wang Z, Fu F, Shi X. [Implementing a relatively rigorous algorithm of dynamic EIT problem on the modified FEM model]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 1998; 15:158-62. [PMID: 12548905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
We deduced a relatively rigorous algorithm of dynamic EIT problem-general inverse algorithm, and implemented it on the computer FEM model. Images which can show the changing of the resistivity(i.e. dynamic resistivity images) were gained. Also we modified the ordinary FEM model according to the characteristic of the EIT problem and implemented the general inverse algorithm on the modified model. The ill-posed condition of the forward matrix based on the modified model was fairly improved. It can be seen from the results that the general inverse algorithm with modified FEM model is an algorithm better than the back-projection algorithm in terms of object locating, image definition, and the ability of dealing with complex object and noise.
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Qin M. [Anatomy of Aconitum finetianum Hand.-Mazz]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1998; 23:69-71, 127. [PMID: 11596262] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The primary xylem of plump taproot of Aconitum finetianum is the diarch with xylem in the center. In the action of the secondary structure of the herb, the meristem is first produced in the secondary phloem, then the anomalous cambium is produced in the secondary xylem forms a new and splits into anomalous structure. In the action of anomalous structure of the herb, the meristem in the secondary phloem sinks inwardly from many sites, and forms many rings with the anomalous cambium. One of these rings forms a special endodermis and the protostele turns into the schizogenous stele.
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Qin M, Kuhn R, Moran S, Quail PH. Overexpressed phytochrome C has similar photosensory specificity to phytochrome B but a distinctive capacity to enhance primary leaf expansion. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 1997; 12:1163-72. [PMID: 9418054 DOI: 10.1046/j.1365-313x.1997.12051163.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Phytochrome C (phyC) is a low-abundance member of the five-membered phytochrome family of photoreceptors in Arabidopsis. Towards developing an understanding of the photosensory and physiological functions of phyC, transgenic Arabidopsis plants were generated that over-express cDNA-encoded phyC and seedling responses to continuous white, red, or far-red light (Wc, Rc or FRc, respectively) were examined. Transgenic seedlings over-expressing phyC displayed enhanced inhibition of hypocotyl elongation in Rc, but were unchanged in responsiveness to FRc relative to wild-type. These data indicate that phyC has photosensory specificity that is similar to that of phyB and thus distinct from that of phyA. phyC overexpressors with levels only 3 to 4 times the level of endogenous phyC exhibited enhanced primary leaf expansion in Wc. This is in contrast to phyA or phyB overexpressors which respectively have levels that are 500- and 100-fold that of overexpressed phyC but showed no enhancement of primary leaf expansion. Therefore, phyC may have some physiological roles that are different to those of phyA and phyB in the control of seedling responses to light signals.
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79
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Qin M, Han M, Li S. [Surgical treatment in pulmonary tuberculosis with sputum long-term Mycobacterium tuberculosis positive]. ZHONGHUA JIE HE HE HU XI ZA ZHI = ZHONGHUA JIEHE HE HUXI ZAZHI = CHINESE JOURNAL OF TUBERCULOSIS AND RESPIRATORY DISEASES 1997; 20:311-2. [PMID: 10374461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
OBJECTIVE To evaluate the importance of surgical treatment in pulmonary tuberculosis with sputum long-term Mycobacterium tuberculosis positive. METHOD Sixty-five patients with pulmonary tuberculosis who failed antituberculosis chemotherapy received lung resection or thoracoplasty. RESULT Sputum negative conversion was found in sixty-three patients without recurrence during 1-3 year follow-up, while sputum positive conversion was found only in one case during the period of follow-up. Among all the patients, one died of respiratory failure after the operation, three complicated with empyema and recovered from operating again. CONCLUSION Surgical operation is still important for treating pulmonary tuberculosis patients with sputum long-term Mycobacterium tuberculosis positive.
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80
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Qin M. [Cytogenetic study for a child patient with mental retardation and eye multiple malformation]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1997; 19:309-11. [PMID: 10453574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
An cytogenetical study was carried out for a 7 years old patient with mental retardation, eye and other multiple malformation. An extra G-positive band was found in the region of 9q12. The possible relationship between this aberration and the abnormal figures was discussed.
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81
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Zhou B, Yang W, Qin M. [Intervention approach and its effect on lowering mortality of ectopic pregnancy in Shanghai]. ZHONGHUA YI XUE ZA ZHI 1997; 77:409-11. [PMID: 9772501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/09/2023]
Abstract
OBJECTIVE To explore an effective intervention approach to lower the mortality of ectopic pregnancy. METHODS We monitored the mortality of ectopic pregnancy during 1987-1995 in Shanghai and experts' audit, focusing on the causes of death from ectopic pregnancy and combining official administration with intervention approach in medical institutions. RESULTS Misdiagnosis and patient's delay to hospital were the causes of death from ectopic pregnancy. There were 523,299 live births in Shanghai from 1987 to 1989, in which 23 cases died from ectopic pregnancy, with a mortality of 4.40/100,000. After implementing the intervention approach, during 1990-1995, 14 cases of the total 625,206 nancies live birth died from ectopic pregnancy, with a mortality of 2.24/100,000, as compared the two, P < 0.05. Accordingly, ectopic pregnancy as the cause of maternal death dropped from the first leading cause to the fourth. CONCLUSION Intensive health care education in masses, medical staffs' awareness to ectopic pregnancy, and intervention, early hospitalization, early diagnosis and early therapy can lower the mortality of ectopic pregnancy.
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82
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Qin M, Yu W, Meng X, Xing X, Xu L. [Normal spinal changes of bone mineral density in 445 individuals: assessment by quantitative computed tomography]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1996; 18:439-43. [PMID: 9388950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Spinal BMD was measured by QCT in 445 normal individuals aged 10-80 including 190 males and 255 females, which were divided into age-groups by every ten years. Statistic results showed that peak bone mass reached at 10-19 age-group for both male and female and that BMD assessed by QCT in females was not lower than that in males and BMD declined with increasing age. In females, BMD results in this study were different from those in USA. An acceleration bone loss was predominantly shown in the period after 40-49 age group. Among many factors related to bone loss, we consider that estrogen change may play a most important role for the remarkable bone loss in our country.
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83
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Angus CW, Tu A, Vogel P, Qin M, Kovacs JA. Expression of variants of the major surface glycoprotein of Pneumocystis carinii. J Exp Med 1996; 183:1229-34. [PMID: 8642264 PMCID: PMC2192330 DOI: 10.1084/jem.183.3.1229] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Previously, we have shown that a multicopy family of related but unique genes encodes the major surface glycoprotein (MSG) of Pneumocystis carinii. To examine whether different members of this gene family are expressed by P. carinii, antisera were prepared against peptides whose sequences were determined from the deduced amino acid sequences of variants of rat-derived MSG. Immunohistochemical staining of serial sections of rat lungs of infected animals showed that at least three variants of MSG were expressed in an individual lobe, that there was a focal expression of these variants within the lung, and that the relative numbers of these foci were different. Indirect immunofluorescent staining of purified P. carinii organisms using these antisera revealed that at least three variants of MSG were present in organisms isolated from an individual rat and that both cysts and trophozoites reacted with each antiserum. A substantial difference in the fraction of organisms reacting with a specific antipeptide antiserum was seen when comparing organisms isolated from rats raised in a single colony over a period of two years as well as organisms isolated at one time point from rats raised in different colonies. This demonstration of antigenic variation in P. carinii supports the hypothesis that P. carinii utilizes such variation for evading host defense mechanisms.
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84
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Qin M, Lee E, Zankel T, Ow DW. Site-specific cleavage of chromosomes in vitro through Cre-lox recombination. Nucleic Acids Res 1995; 23:1923-7. [PMID: 7596819 PMCID: PMC306964 DOI: 10.1093/nar/23.11.1923] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Site-specific recombination systems are useful tools for chromosome engineering in vivo and site-specific DNA cleavage methods have applications in genome analysis and gene isolation. Here, we report a new method to fragment chromosomes in vitro using the Cre-lox site-specific recombination system. Two lox sites were targeted into the 5.7 Mb chromosomes I of Schizosaccharomyces pombe. In vitro recombination between chromosomal lox sites and exogenously provided lox oligonucleotides 'cleaved' the chromosome at the defined lox sequences. Site-specific cleavage of lox sites in the tobacco genome was also demonstrated. This recombination-based cleavage method provides a novel approach for structural and functional analyses of eukaryotic chromosomes as it allows direct isolation of chromosome regions that correspond to phenotypes revealed through Cre-lox mediated chromosome rearrangements in vivo. Moreover, recombination with end-labeled lox oligonucleotides would permit the specific end-labeling of chromosome segments to facilitate the long range mapping of chromosomes.
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85
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Medberry SL, Dale E, Qin M, Ow DW. Intra-chromosomal rearrangements generated by Cre-lox site-specific recombination. Nucleic Acids Res 1995; 23:485-90. [PMID: 7885845 PMCID: PMC306701 DOI: 10.1093/nar/23.3.485] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Chromosomal rearrangements are useful genetic and breeding tools but are often difficult to detect and characterize. To more easily identify and define chromosome deletions and inversions, we have used the bacteriophage P1 Cre-lox site-specific recombination system to generate these events in plants. This involves three steps: (i) the introduction of two lox sites into one locus in a plant genome, including one site within a modified Ds transposon; (ii) Ac transposase-mediated transposition of the Ds-lox element to a new locus on the same chromosome; (iii) Cre-mediated site-specific recombination between the two lox sites that bracket a chromosome segment. We report the production of a deletion and three inversion events in tobacco. The utility of chromosomal segments bracketed by lox sites for targeted manipulation and cloning is discussed.
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Qin M, Liu X, Zhou Q, Tao L, Li W. [The frozen bovine RPE cells release a resolvable material which can promote the proliferation of RPE cells]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1994; 16:462-5. [PMID: 7720146] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
3H-thymidine incorporation (as a proliferation maker) confirms that the frozen bovine RPE cells release a resolvable material which can promote the proliferation of RPE cells, and the molecular weight of the material is more than 10,000 Daltons. This result provided some new explanations about the effect and complications of ophthalmic cryotherapy related to RPE.
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88
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Qin M, Oie S. Does alpha 1-acid glycoprotein act as a non-functional receptor for alpha 1-adrenergic antagonists? J Pharm Pharmacol 1994; 46:896-901. [PMID: 7897595 DOI: 10.1111/j.2042-7158.1994.tb05710.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The ability of a variety of alpha 1-acid glycoproteins (AAG) to affect the intrinsic activity of the alpha 1-adrenergic antagonist prazosin was studied in rabbit aortic strip preparations. From these studies, the activity of AAG appears to be linked to their ability to bind the antagonist. However, a capability to bind prazosin was not the only requirement for this effect. The removal of sialic acid and partial removal of the galactose and mannose residues by periodate oxidation of human AAG all but eliminated the ability of AAG to affect the intrinsic pharmacologic activity of prazosin, although the binding of prazosin was not significantly affected. The presence of bovine AAG, a protein that has a low ability to bind prazosin, reduced the effect of human AAG on prazosin activity. Based upon these results, we propose that AAG is able to bind in the vicinity of the alpha 1-adrenoceptors, therefore extending the binding region for antagonists in such a way as to decrease the ability of the antagonist to interact with the receptor. The carbohydrate side-chains are important for the binding of AAG in the region of the adrenoceptor.
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89
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Fei P, Qin M, Hu T. [Ocular manifestations of patients with gangliosidosis]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1994; 16:285-9. [PMID: 7867097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
This paper describes the ophthalmological findings in 4 patients with gangliosidosis (GLS). The diagnosis was verified by assaying hexosaminidase A and beta-galactosidase activities with marked deficiency. The presence of a cherry-red spot at the macular region, macular degeneration and atrophy of the optic disc were the main ocular manifestations. The ocular pathological changes seen under light and electron microscopy and the inherited error of metabolism of ganglioside are discussed.
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Qin M, Nilsson M, Oie S. Decreased elimination of drug in the presence of alpha-1-acid glycoprotein is related to a reduced hepatocyte uptake. J Pharmacol Exp Ther 1994; 269:1176-81. [PMID: 8014861] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The mechanism by which human alpha-1-acid glycoprotein (hAAG) decreases the intrinsic clearance of prazosin was investigated in primary rat hepatocyte cultures. The intrinsic clearance, equal to the ratio of rate of drug elimination to unbound concentration, is the composite result of uptake and metabolism. From separate elimination and uptake studies we found that the ability of hAAG to decrease the intrinsic clearance of prazosin was related to decreased uptake and not to changes in metabolism. In order to identify the underlying mechanism for the observed decrease in uptake the effect of bovine alpha-1-acid glycoprotein (AAG) on prazosin intrinsic clearance and uptake was also determined. Bovine AAG, in contrast to hAAG, had neither a statistical significant effect on prazosin uptake nor on prazosin intrinsic clearance. Based upon the fact that bovine AAG has little or no ability to bind prazosin in contrast to hAAG, we hypothesize that when a AAG, capable of binding prazosin, associated with cell membranes it will retard the diffusion of drug through the cellular stagnant diffusion layer. Human serum albumin (HSA), in contrast to hAAG, did not decrease the uptake of prazosin although HSA binds prazosin and associates with hepatocytes to the same degree as hAAG. However, HSA associated with rat hepatocytes, in contrast to hAAG, appears to have an operationally reduced ability to bind prazosin suggesting that HSA may not be able to retard diffusion of prazosin to the same degree as hAAG. HSA also may release prazosin which subsequently serves to increase the active concentration of prazosin at the cell surface.
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91
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Qin M, Bayley C, Stockton T, Ow DW. Cre recombinase-mediated site-specific recombination between plant chromosomes. Proc Natl Acad Sci U S A 1994; 91:1706-10. [PMID: 8127869 PMCID: PMC43232 DOI: 10.1073/pnas.91.5.1706] [Citation(s) in RCA: 87] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
We report the use of the bacteriophage P1 Cre-lox system for generating conservative site-specific recombination between tobacco chromosomes. Two constructs, one containing a promoterless hygromycin-resistance gene preceded by a lox site (lox-hpt) and the other containing a cauliflower mosaic virus 35S promoter linked to a lox sequence and the cre coding region (35S-lox-cre), were introduced separately into tobacco plants. Crosses between plants harboring either construct produced plants with the two constructs situated on different chromosomes. Plants with recombination events were identified by selecting for hygromycin resistance, a phenotype expressed upon recombination. Molecular analysis showed that these recombination events occurred specifically at the lox sites and resulted in the reciprocal exchange of flanking host DNA. Progenies of these plants showed 67-100% cotransmission of the new transgenes, 35S-lox-hpt and lox-cre, consistent with the preferential cosegregation of translocated chromosomes. These results illustrate that site-specific recombination systems can be useful tools for the large-scale manipulation of eukaryotic chromosomes in vivo.
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92
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Zeng GF, Qin M, Lin YH, Xi SQ. Tribenzylammonium dibenzylammonium tetrachlorocuprate. Acta Crystallogr C 1994. [DOI: 10.1107/s0108270193007735] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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93
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Qin M, Taniguchi H, Mizuguchi Y. Analysis of the replication region of a mycobacterial plasmid, pMSC262. J Bacteriol 1994; 176:419-25. [PMID: 8288537 PMCID: PMC205065 DOI: 10.1128/jb.176.2.419-425.1994] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
We determined the nucleotide sequence of a DNA fragment which contains the replication region of pMSC262, a Mycobacterium scrofulaceum plasmid used to construct the Mycobacterium-Escherichia coli shuttle vector. The complete sequence of the fragment contained 2,504 bp with an overall G+C content of 69.8%. By deletion analysis, we found that the minimum length required for plasmid replication in M. bovis BCG was about 1.6 kb. Within this region, several open reading frames (ORFs) and a putative replication origin (ori) were identified by computer analysis. One of the ORFs, ORF2, which encodes a putative 28.9-kDa basic protein with characteristics of DNA-binding proteins, appeared to be involved in replication of the plasmid in BCG. By separation of ORF2 and the putative ori region, it was revealed that the relative locations of ORF2 and the putative ori region are likely important for replication in BCG. No DNA or amino acid homologies were found between this replication region and that of pAL5000, another mycobacterial plasmid used for vector plasmid construction. In addition, we found that this replicon did not lead to replication in E. coli and was compatible in BCG with pAL5000-derived vector plasmid pYUB75 (R. G. Barletta, D. D. Kim, S. B. Snapper, B. R. Bloom, and W. R. Jacobs, J., J. Gen. Microbiol. 138:23-30, 1992).
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James MG, Scanlon MJ, Qin M, Robertson DS, Myers AM. DNA sequence and transcript analysis of transposon MuA2, a regulator of Mutator transposable element activity in maize. PLANT MOLECULAR BIOLOGY 1993; 21:1181-1185. [PMID: 8387832 DOI: 10.1007/bf00023614] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The 4942 bp DNA sequence of Zea mays transposon MuA2 was determined. Previous evidence indicated MuA2 controls activity of the Mu1 transposon located in the mutable allele a1-mum2. MuA2 contains two large, ATG-initiated open reading frames (ORFs) of 612 and 232 codons, respectively, located on opposite strands. MuA2 produces two transcripts, each containing one of these ORFs. Four different tandem direct repeat sequences are located downstream of the 612 codon ORF. The restriction map of MuA2 is identical to that of transposon MuR1, which also is known to regulate mutability of a1-mum2. Furthermore, except for a single nucleotide, MuA2 is identical to the Mutator element Mu9.
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Chen LM, Cui YH, Qin M, Wang YL, Bai XL, Ma QS. Identification of a nodD-like gene in Frankia by direct complementation of a Rhizobium nodD-mutant. MOLECULAR & GENERAL GENETICS : MGG 1992; 233:311-4. [PMID: 1603071 DOI: 10.1007/bf00587593] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Clones from a Frankia At4 gene bank were pooled into groups and mass conjugated into a nodD mutant of Rhizobium leguminosarum bv. viciae by triparental matings. When peas were inoculated with the pooled transconjugants, nodulation was observed. A plasmid, pAt2GX containing Frankia DNA, was isolated from bacteria recovered from these nodules. This plasmid was shown to complement a nodD mutant of R. leguminosarum bv. viciae. Thus pAt2GX contains a Frankia gene that is functionally equivalent to nodD of R. leguminosarum bv. viciae.
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Ingels SC, Bennetzen JL, Hulbert SH, Qin M, Ellingboe AH. Mutator Transposable Elements That Occur in Clusters in the Maize Genome. J Hered 1992. [DOI: 10.1093/oxfordjournals.jhered.a111169] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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97
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Qin M. [Studies on the formation of prepared daughter root of common monkshood]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1991; 16:526-7, 574. [PMID: 1804196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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98
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Li WY, Zhou Q, Qin M, Tao L, Lou M, Hu TS. Reduced absolute rate of myo-inositol biosynthesis of cultured bovine retinal capillary pericytes in high glucose. Exp Eye Res 1991; 52:569-73. [PMID: 2065725 DOI: 10.1016/0014-4835(91)90058-m] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
De novo biosynthesis of myo-inositol (MI) by permeabilized cultured bovine retinal capillary pericytes (BRCP) and feline retinal pigment epithelial cells (FRPE), grown in different concentrations of glucose, were studied. After incubation with a physiological concentration of [14C]glucose 6-phosphate (G6P), the radioactive G6P derivatives were quantitated by a single HPLC column. Based on the determined specific activity of [14C]G6P, activities of inositol 1-phosphate synthase (MI synthase) were calculated. The activity of MI synthase was reduced 48% by growing BRCP in a high-glucose medium (20 mM) in comparison with that in the normal medium (glucose 5 mM). In contrast, the de novo MI biosynthesis by FRPE was not changed with increasing concentrations of glucose in the medium. As compared with MI uptake previously studied, the synthesized MI contributes a substantial proportion of cellular MI pool in BRCP. Therefore, in BRCP growing in high glucose the reduced MI biosynthesis aggravates the low MI content resulting from the inhibited MI uptake, and thus leads to altered inositol phospholipid metabolism.
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Li WY, Zhou Q, Tang L, Qin M, Hu TS. Intramural pericyte degeneration in early diabetic retinopathy study in vitro. Chin Med J (Engl) 1990; 103:7-13. [PMID: 2112447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
An experimental model of diseased pericytes was established by using cultured bovine retinal capillary pericytes in high--glucose medium. The high glucose stimulated polyol pathway, reduced cellular myo-inositol content and disturbed inositol phospholipid metabolism which resulted in a decrease in inositol trisphosphate (IP3) level. The correlation of suppressed IP3 levels with reduced DNA synthesis was evident. These findings suggested the biochemical mechanism by which retinal pericytes degenerate in high glucose. To supplement myo--inositol and/or an aldose reductase inhibitor to the high--glucose medium largely reversed the suppressed IP3 level and the decreased DNA synthesis. Therefore, these two manipulations may be considered as in vitro therapy to treat sick pericytes induced by high glucose.
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Li WY, Tang L, Zhou Q, Qin M, Hu TS. DNA-synthesis regulation and correlation with inositol trisphosphate levels in cultured bovine retinal capillary pericytes. Exp Eye Res 1989; 49:677-83. [PMID: 2806431 DOI: 10.1016/s0014-4835(89)80062-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Inositol phosphate (IP), inositol bisphosphate (IP2) and inositol trisphosphate (IP3) in cultured bovine retinal capillary pericytes (BRCP) were quantitated by an ion-pair reverse-phase HPLC. BRCP were grown in media with standard (5 mM) or high (30 mM) glucose, and were either labeled with myo-[2-3H]inositol (20 microCi ml-1) for 60 hr or with dual isotopes (20 microCi ml-1 myo-[2-3H]inositol and 2 microCi ml-1 [14C]glycerol) for 8 hr. In parallel, BRCP in different glucose-media were incubated with 1 microCi ml-1 [3H]thymidine for 4 hr. High glucose significantly suppressed the accumulation of [3H]label in IP, IP2 and IP3, and specifically reduced the incorporation of [14C]glycerol into inositol phospholipids, but not that of neutral lipids and other types of phospholipids. The reduced IP3 level correlated with the decrease in the incorporation of [3H]thymidine into DNA. Both the reduced IP3 formation and DNA synthesis which were induced by high glucose were significantly reversed by adding either myo-inositol or AL1576, an aldose reductase inhibitor (ARI). However, the addition of neither myo-inositol nor ARI stimulated IP3 formation and/or DNA synthesis when BRCP were grown in the standard medium (5 mM glucose). These findings indicate that myo-inositol metabolism and the polyol pathway affect inositol phospholipid-mediated pericyte division in vitro only under the high-glucose condition. These data are compatible with the hypothesis that altered inositol phospholipid metabolism accounts for the loss of pericytes in diabetic retinopathy.
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