201
|
Bonds DE, Lasser N, Qi L, Brzyski R, Caan B, Heiss G, Limacher MC, Liu JH, Mason E, Oberman A, O'Sullivan MJ, Phillips LS, Prineas RJ, Tinker L. The effect of conjugated equine oestrogen on diabetes incidence: the Women's Health Initiative randomised trial. Diabetologia 2006; 49:459-68. [PMID: 16440209 DOI: 10.1007/s00125-005-0096-0] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2005] [Accepted: 10/25/2005] [Indexed: 10/25/2022]
Abstract
AIMS/HYPOTHESIS Recent clinical trials have found that the combination of conjugated equine oestrogen (CEO) and medroxyprogesterone has a protective effect on the incidence of type 2 diabetes. To determine the effect of CEO alone on the incidence of diabetes mellitus in postmenopausal women, we analysed the results of the Women's Health Initiative oestrogen-alone trial. METHODS The Women's Health Initiative is a randomised, double-masked trial comparing the effect of daily 0.625 mg CEO with placebo during 7.1 years of follow-up of 10,739 postmenopausal women who were aged 50-79 years and had previously had a hysterectomy. Diabetes incidence was ascertained by self-report of treatment with insulin or oral hypoglycaemic medication. Fasting glucose, insulin and lipoproteins were measured in an 8.6% random sample of study participants, at baseline and at 1, 3 and 6 years. RESULTS The cumulative incidence of treated diabetes was 8.3% in the oestrogen-alone group and 9.3% in the placebo group (hazard ratio 0.88, 95% CI 0.77-1.01, p=0.072). During the first year of follow-up, a significant fall in insulin resistance (homeostasis model assessment of insulin resistance) in actively treated women compared with the control subjects (Year 1 baseline between-group difference -0.53) was seen. However, there was no difference in insulin resistance at the 3- or 6-year follow-up. CONCLUSIONS/INTERPRETATION Postmenopausal therapy with oestrogen alone may reduce the incidence of treated diabetes. The effect is smaller than that seen with oestrogen plus progestin. CEO should not, however, be used with the intention of preventing diabetes, as its well-described adverse effects preclude long-term use for primary prevention.
Collapse
|
202
|
Shi H, Wang X, Zhao N, Qi L, Ma J. Growth Mechanism of Penniform BaWO4 Nanostructures in Catanionic Reverse Micelles Involving Polymers. J Phys Chem B 2005; 110:748-53. [PMID: 16471598 DOI: 10.1021/jp0545694] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The formation of penniform BaWO4 nanostructures made of nanowires or nanobelts under the direction of a block copolymer in catanionic reverse micelles has been studied in detail. On the basis of the experimental results obtained from the BaWO4 crystallization in aqueous polymer solutions and careful transmission electron microscopy (TEM) observations of BaWO4 nanostructures formed in reverse micelles containing polymers, a detailed two-stage growth mechanism has been proposed for the formation of the penniform nanostructures in reverse micelles, which involves the polymer-controlled shaft formation (Stage 1) and the mixed surfactants-controlled barb growth (Stage 2). During Stage 1, poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) induced the formation of c-axis-oriented shuttle-like nanocrystals and the subsequent oriented attachment of these shuttle-like nanocrystals resulted in the formation of [100]-oriented shafts with many parallel [001]-oriented pricks. During Stage 2, [001]-oriented nanowires or nanobelts grew gradually from the pricks into barbs, leading to the formation of well-defined penniform BaWO4 nanostructures with the barb morphology essentially determined by the mixing ratio r of the anionic to cationic surfactants (i.e., nanowires were formed at r=1 while nanobelts were formed at r deviating from 1). The current understanding of the growth mechanism of penniform BaWO4 nanostructures in catanionic reverse micelles involving polymers may be potentially applied for designing a new synthesis system for the controlled synthesis of other hierarchical 1D nanostructures with desired architectures.
Collapse
|
203
|
Ma Y, Qi L, Shen W, Ma J. Selective synthesis of single-crystalline selenium nanobelts and nanowires in micellar solutions of nonionic surfactants. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2005; 21:6161-4. [PMID: 15982016 DOI: 10.1021/la050801l] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Single-crystalline nanobelts and nanowires of trigonal selenium (t-Se) have been selectively synthesized in micellar solutions of nonionic surfactants. In particular, t-Se nanobelts about 30 nm in thickness were obtained in micellar solutions of poly(oxyethylene(20)) octadecyl ether (C18EO20), whereas t-Se nanowires were obtained in micellar solutions of poly(oxyethylene(10)) dodecyl ether (C12EO10). The obtained t-Se nanobelts exhibit a low-energy absorption peak that is considerably red shifted from that for t-Se nanowires, which has been presumably attributed to the lower degree of crystal perfection for the t-Se nanobelts with rectangular cross sections.
Collapse
|
204
|
Semmes OJ, Cazares LH, Ward MD, Qi L, Moody M, Maloney E, Morris J, Trosset MW, Hisada M, Gygi S, Jacobson S. Discrete serum protein signatures discriminate between human retrovirus-associated hematologic and neurologic disease. Leukemia 2005; 19:1229-38. [PMID: 15889159 DOI: 10.1038/sj.leu.2403781] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The human T-cell leukemia virus type I (HTLV-I) is the causative agent for adult T-cell leukemia (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Approximately 5% of infected individuals will develop either disease and currently there are no diagnostic tools for early detection or accurate assessment of disease state. We have employed high-throughput expression profiling of serum proteins using mass spectrometry to identify protein expression patterns that can discern between disease states of HTLV-I-infected individuals. Our study group consisted of 42 ATL, 50 HAM/TSP, and 38 normal controls. Spectral peaks corresponding to peptide ions were generated from MS-TOF data. We applied Classification and Regression Tree analysis to build a decision algorithm, which achieved 77% correct classification rate across the three groups. A second cohort of 10 ATL, 10 HAM and 10 control samples was used to validate this result. Linear discriminate analysis was performed to verify and visualize class separation. Affinity and sizing chromatography coupled with tandem mass spectrometry was used to identify three peaks specifically overexpressed in ATL: an 11.7 kDa fragment of alpha trypsin inhibitor, and two contiguous fragments (19.9 and 11.9 kDa) of haproglobin-2. To the best of our knowledge, this is the first application of protein profiling to distinguish between two disease states resulting from a single infectious agent.
Collapse
|
205
|
Qi L, Corella D, Sorlí JV, Portolés O, Shen H, Coltell O, Godoy D, Greenberg AS, Ordovas JM. Genetic variation at the perilipin (PLIN) locus is associated with obesity-related phenotypes in White women. Clin Genet 2005; 66:299-310. [PMID: 15355432 DOI: 10.1111/j.1399-0004.2004.00309.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Perilipin coats intracellular lipid droplets and modulates adipocyte lipolysis. We have evaluated the association between several polymorphisms at the perilipin (PLIN) locus (PLIN1 : 6209T > C, PLIN4 : 11482G > A, PLIN5 : 13041A > G, and PLIN6 : 14995A > T) with obesity-related phenotypes in 1589 White subjects randomly selected from a general Spanish population. In women (n = 801), the less common alleles of PLIN1 and PLIN4, in strong linkage disequilibrium (D' : 0.96), were significantly associated with lower body mass index. Carriers of the allele 2 (6209C) at the PLIN1 locus weighed significantly less (-2.2 kg; p = 0.007) than women homozygotes for the wild-type genotype. The same was true for 11482A carriers at PLIN4 (p = 0.01). Moreover, the PLIN4 variant was associated with significantly lower waist-to-hip ratio, plasma glucose, and triacylglycerol concentrations. No significant associations with these obesity-related phenotypes were found in men. In agreement with these results, statistically significant gene-gender interactions were obtained when the risk of obesity was estimated (281 subjects were obese and 1308 non-obese). Only in women, PLIN1 and PLIN4 variant alleles (6209C and 11482A) were associated with a lower obesity risk [Odds ratio (OR) = 0.58, 95% confidence interval (CI): 0.38-0.93 and OR = 0.56, 95% CI: 0.36-0.89, respectively]. In summary, our data suggest that common alleles at the PLIN locus modulate body weight and metabolic variables in humans.
Collapse
|
206
|
Yang J, Qi L, Lu C, Ma J, Cheng H. Morphosynthesis of Rhombododecahedral Silver Cages by Self-Assembly Coupled with Precursor Crystal Templating. Angew Chem Int Ed Engl 2005; 44:598-603. [PMID: 15602755 DOI: 10.1002/anie.200461859] [Citation(s) in RCA: 164] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|
207
|
Yang J, Qi L, Lu C, Ma J, Cheng H. Morphosynthesis of Rhombododecahedral Silver Cages by Self-Assembly Coupled with Precursor Crystal Templating. Angew Chem Int Ed Engl 2005. [DOI: 10.1002/ange.200461859] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
208
|
Sun HL, Shi H, Zhao F, Qi L, Gao S. Shape-dependent magnetic properties of low-dimensional nanoscale Prussian blue (PB) analogue SmFe(CN)6·4H2O. Chem Commun (Camb) 2005:4339-41. [PMID: 16113741 DOI: 10.1039/b507240a] [Citation(s) in RCA: 79] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Unique nanorods and nanobelts of Prussian blue (PB) analogue SmFe(CN)6.4H2O have been successfully synthesized by using reverse micelles as colloidal soft templates; magnetic studies show that the shape of the low-dimensional nanoscale material is a dominating factor for its coercivity due to the effect of shape anisotropy.
Collapse
|
209
|
Zhang D, Qi L. Synthesis of mesoporous titania networks consisting of anatase nanowires by templating of bacterial cellulose membranes. Chem Commun (Camb) 2005:2735-7. [PMID: 15917937 DOI: 10.1039/b501933h] [Citation(s) in RCA: 131] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Mesoporous titania networks consisting of interconnected anatase nanowires have been synthesized by using unique bacterial cellulose membranes as natural biotemplates; the titania networks exhibit enhanced photocatalytic activity compared with titania microfiber networks.
Collapse
|
210
|
Lu C, Qi L, Yang J, Zhang D, Wu N, Ma J. Simple Template-Free Solution Route for the Controlled Synthesis of Cu(OH)2and CuO Nanostructures. J Phys Chem B 2004. [DOI: 10.1021/jp046772p] [Citation(s) in RCA: 290] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
211
|
Qi L, Shen H, Larson I, Barnard JR, Schaefer EJ, Ordovas JM. Genetic variation at the hormone sensitive lipase: gender-specific association with plasma lipid and glucose concentrations. Clin Genet 2004; 65:93-100. [PMID: 14984467 DOI: 10.1111/j.0009-9163.2004.00196.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Hormone-sensitive lipase (HSL) catalyzes the intracellular hydrolysis of triacylglycerols and cholesteryl esters, and it is involved in regulating body fat, steroidogenesis, and insulin secretion. Thus, genetic variability at the HSL locus (LIPE) may play a significant role on lipid metabolism and the risk of obesity and type 2 diabetes. Therefore, we have examined two LIPE single nucleotide polymorphism (SNP) [14672C>G in the promoter region and 17948C>T (rs1206034) on intron 2] in relation to plasma lipids, anthropometrical and glucose-related phenotypes in a population of mostly overweight and obese men (373) and women (361). In women, the 17948T allele was associated with decreased total cholesterol (TC, p = 0.001), LDL-cholesterol (LDLc, p < 0.001) and apoE concentrations (p = 0.041). Conversely, female carriers of the LIPE 14672G allele had significantly higher TC (p = 0.047), LDLc (p = 0.041), and apoE (p = 0.041) levels. Although we did not find significant associations in men, we observed that male carriers of the LIPE 14672G who did not drink alcohol showed higher glucose levels than non-carriers (p = 0.008), whereas there were no allele-related differences among drinkers (p = 0.019 for the interaction). These SNPs were not significantly associated with anthropometrical variables. In summary, variation at this locus showed gender-specific associations with lipids and glucose measures, and the latter was influenced by alcohol drinking.
Collapse
|
212
|
Lu C, Qi L, Ma J, Cheng H, Zhang M, Cao W. Controlled growth of micropatterned, oriented calcite films on a self-assembled multilayer film. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2004; 20:7378-7380. [PMID: 15323478 DOI: 10.1021/la048655r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
A micropatterned multilayer film, which was fabricated from layer-by-layer electrostatic self-assembly of nitrodiazoresin (NDR)/poly(acrylic acid) (PAA) followed by photolithography, was utilized as a structured template for the biomimetic mineralization of calcium carbonate. Micropatterned CaCO3 films consisting of regularly aligned calcite crystals oriented in the <104> direction were selectively deposited on the patterned NDR/PAA multilayer film.
Collapse
|
213
|
Ma Y, Qi L, Ma J, Wu Y, Liu O, Cheng H. Large-pore mesoporous silica spheres: synthesis and application in HPLC. Colloids Surf A Physicochem Eng Asp 2003. [DOI: 10.1016/j.colsurfa.2003.08.010] [Citation(s) in RCA: 138] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
214
|
Jiang J, Zhong C, Qi L, Yu Y. [Immunocytochemical localization of two facilitated glucose transporters of Schistosoma mansoni in the tegument of Schistosoma japonicum]. ZHONGGUO JI SHENG CHONG XUE YU JI SHENG CHONG BING ZA ZHI = CHINESE JOURNAL OF PARASITOLOGY & PARASITIC DISEASES 2003; 17:222-4. [PMID: 12563769] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
AIM To observe the distribution of Schistosoma mansoni glucose transport proteins, SGTP1 and SGTP4, in the tegument of Schistosoma japonicum. METHODS The rapidly frozen fixation technique and ultracryomicrotomy were adopted for preparing ultrathin cryosections of S. japonicum. Anti-SGTP1 and anti-SGTP4 antibodies were used to localize the corresponding antigens in the tegument of adult S. japonicum by immunocytochemical technique. RESULTS SGTP1 was localized on the basal membrane of the tegument and its infoldings, SGTP4 was localized on the apical membrane of the tegument and its invaginations of S. japonicum. CONCLUSION The same localization for SGTP 1 and SGTP4 in the tegument of S. japonicum and S. mansoni exhibited apparent homology between SGTPs of the two schistosomes.
Collapse
|
215
|
Abstract
Cardiovascular disease (CVD) and osteoporosis (OP) are two common degenerative processes that contribute in great measure to the decline in performance and quality of life of the elderly population. Traditionally, these disorders have been considered as distinct and unrelated entities. However, over the last few years, there has been increasing evidence supporting an important link between CVD and OP. Several genetic association and linkage studies have shown the existence of common genetic determinants for cardiovascular and skeletal diseases. These genes code for several key players on the metabolism of nutrients, such as lipids, calcium and folate, as well as other factors (e.g. sex hormone receptors) that are known to be subject to dietary modulation, suggesting the links at the level of dietary response. Some dietary factors have shown similarities in influencing the risks of both conditions. However, some others act differently in relation with their effects on the development of cardiovascular disease and osteoporosis. We therefore suggest that, any dietary and behavioral recommendations targeting to the 'global health' of the ageing population would take a comprehensive consideration of their potentially diverse effects (beneficial or deleterious) on the risks of various ageing related disorders, and would be tailored to the individual genetic background.
Collapse
|
216
|
Abstract
Single crystals of calcite exhibiting a morphology of well-defined 8-armed stars, which evolved from original rhombohedral calcite crystals with their 8 points extending radially into eight arms, were produced by crystallization of CaCO3 in agarose gels.
Collapse
|
217
|
Yang D, Qi L, Ma J. Hierarchically ordered networks comprising crystalline ZrO2 tubes through sol–gel mineralization of eggshell membranes. ACTA ACUST UNITED AC 2003. [DOI: 10.1039/b301077e] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
218
|
Shi H, Qi L, Ma J, Cheng H. Polymer-directed synthesis of penniform BaWO4 nanostructures in reverse micelles. J Am Chem Soc 2003; 125:3450-1. [PMID: 12643705 DOI: 10.1021/ja029958f] [Citation(s) in RCA: 214] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Novel penniform superstructures of BaWO4 nanowires have been successfully synthesized in catanionic reverse micelles by using a double-hydrophilic block copolymer as the directing agent. This synthetic method is very simple, mild, and controllable, and it provides a novel method for direct solution-growth of hierarchical nanostructures based on inorganic nanowires.
Collapse
|
219
|
Wang JP, Qi L, Zheng B, Liu F, Moore MR, Ng JC. Porphyrins as early biomarkers for arsenic exposure in animals and humans. Cell Mol Biol (Noisy-le-grand) 2002; 48:835-43. [PMID: 12699241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Abstract
We studied the effect of arsenic exposure on the haem biosynthetic pathway in the rat and humans. Significant increases in protoporphyrin IX, coproporphyrin III, coproporphyrin I were observed in the blood, liver and kidney, and in the urine of rats after a single dose of arsenic. The level of increase was dependent on the arsenic species present. Most of porphyrin concentrations in the tissues increased within 24 hr and urinary excretion elevated within 48 hr. In the human study, we collected urine samples from 113 people who live in Xing Ren of Guizhou Province, a coal-borne arsenicosis endemic area in southwest of PR China and from 30 people who live in Xing Yi (about 80 km southwest of Xing Ren) where arsenicosis is not prevalent. We analyzed the urinary porphyrins using HPLC. Results indicate that all urinary porphyrins were higher in the arsenic exposed group than those in the control group. Women, children and older age people spend much of their time indoors, they had greater increases of urinary arsenic and porphyrins. They were the higher risk groups among the study subjects. A positive correlation between the urinary arsenic levels and porphyrin concentrations demonstrated the effect of arsenic on haem biosynthesis. Significant alteration in the porphyrin excretion profiles of the younger age (<20 y) arsenic exposed group suggested that porphyrins could be used as early warning biomarkers for chronic exposure to arsenic.
Collapse
|
220
|
Zhang D, Qi L, Ma J, Cheng H. Formation of crystalline nanosized titania in reverse micelles at room temperature. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b206996b] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
221
|
Shi H, Qi L, Ma J, Cheng H. Synthesis of single crystal BaWO4 nanowires in catanionic reverse micelles. Chem Commun (Camb) 2002:1704-5. [PMID: 12196958 DOI: 10.1039/b204995c] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
High aspect-ratio, single crystal BaWO4 nanowires with diameters as small as 3.5 nm and lengths up to more than 50 microns were synthesized in catanionic reverse micelles formed by an equimolar mixture of two surfactants: undecylic acid and decylamine.
Collapse
|
222
|
Zhang D, Qi L, Cheng H, Ma J. Preparation of ZnS Nanorods by a Liquid Crystal Template. J Colloid Interface Sci 2002; 246:413-6. [PMID: 16290431 DOI: 10.1006/jcis.2001.8081] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2001] [Accepted: 10/30/2001] [Indexed: 11/22/2022]
Abstract
ZnS nanorods were synthesized in lamellar liquid crystals of C(12)E(4) by mixing zinc ions and thioacetamide (TAA) solution. The effects of the reactant concentration and the surfactant/water molar ratio in the liquid crystal system on the morphology and size of the ZnS particles were investigated. The prepared ZnS particles are regular nanorods having a width of about 60 nm and a length of about 80-380 nm, with a largest aspect ratio of about 6.3. A lamellar liquid crystal templating mechanism has been proposed to interpret the experimental results.
Collapse
|
223
|
Zhang D, Qi L, Ma J, Cheng H. Biomimetic growth of strontium oxalate aggregates with unusual morphologies in the presence of poly(methacrylic acid). CrystEngComm 2002. [DOI: 10.1039/b207956a] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
224
|
Friebe B, Kynast RG, Zhang P, Qi L, Dhar M, Gill BS. Chromosome healing by addition of telomeric repeats in wheat occurs during the first mitotic divisions of the sporophyte and is a gradual process. Chromosome Res 2001; 9:137-46. [PMID: 11321369 DOI: 10.1023/a:1009283003903] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Alien gametocidal chromosomes cause extensive chromosome breakage prior to S-phase in the first mitotic division of gametophytes lacking the alien chromosome. The broken chromosomes may be healed either by addition of telomeric repeats in the gametophyte or undergo fusions to form dicentric or translocation chromosomes. We show that dicentric chromosomes undergo breakage fusion-bridge (BFB) cycles in the first few mitotic divisions of the sporophyte, are partially healed before the germ line differentiation regimen, and are healed completely in the ensuing gametophytic stage. The gametocidal factor on chromosome 4Mg of Aegilops geniculata was used to induce dicentrics involving the satellite chromosomes1B and 6B of wheat, Triticum aestivum. The dicentrics 1BS x 1BL-2AL x 2AS and 6BS x 6BL-4BL x 4BS initiated BFB cycles that ceased 2 to 4 weeks after seed germination. At the end of the BFB cycles, we observed deficient 1B and 6B chromosomes with breakpoints in proximal regions of the 1BL and 6BL arms. The process of chromosome healing was analyzed in root tip meristems, at meiotic metaphase I, and in the derived progenies by fluorescence in-situ hybridization analysis using a telomeric probe pAtT4. The results show that chromosome healing in wheat occurs during very early mitotic divisions in the sporophyte by de-novo addition of telomeric repeats and is a gradual process. Broken chromosome ends have to pass through several cell divisions in the sporophyte to acquire the full telomeric repeat length.
Collapse
|
225
|
Qi L, Cölfen H, Antonietti M, Li M, Hopwood JD, Ashley AJ, Mann S. Formation of BaSO4 Fibres with Morphological Complexity in Aqueous Polymer Solutions. Chemistry 2001. [DOI: 10.1002/1521-3765(20010817)7:16%3c3526::aid-chem3526%3e3.0.co%3b2-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
226
|
Qi L, Cölfen H, Antonietti M, Li M, Hopwood JD, Ashley AJ, Mann S. Formation of BaSO4 fibres with morphological complexity in aqueous polymer solutions. Chemistry 2001; 7:3526-32. [PMID: 11560323 DOI: 10.1002/1521-3765(20010817)7:16<3526::aid-chem3526>3.0.co;2-z] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BaSO4 fibres with morphological complexity were formed in aqueous solution with polyacrylate and partially monophosphonated poly(ethyleneoxide)-block-poly(methacrylic acid) additives by a simple precipitation reaction. For polyacrylate, formation of the fibrous deposits was strongly dependent on the level of supersaturation (S) and Ba2+:polymer molar ratio (R). At S = 60 to 80, and R = 3 to 14, highly anisotropic crystalline fibres consisting of bundles of BaSO4 nanofilaments were formed after several weeks, although the yield was low. The nanofilaments were also organized into cone-shaped aggregates at S = 80, and at lower R values these formed higher-order structures that consisted of multiple cone-on-cone assemblies with remarkable self-similarity. Increasing the supersaturation produced ovoid or cross-shaped dendritic particles for the range of molar ratios studied. In contrast, BaSO4 crystallisation in the presence of a partially phosphonated block copolymer gave a high yield of BaSO4 fibres up to 100 microm in length, and consisting of co-aligned bundles of 30 nm-diameter defect-free single-crystal nanofilaments with a uniform growth tip. A model for the defect-free growth of BaSO4 nanofilaments in aqueous polymer solutions based on amorphous precursor particles, vectorially directing forces and van der Waals attraction is proposed.
Collapse
|
227
|
Qi L, Ostrand-Rosenberg S. H2-O inhibits presentation of bacterial superantigens, but not endogenous self antigens. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:1371-8. [PMID: 11466355 DOI: 10.4049/jimmunol.167.3.1371] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
H2-O/HLA-DO are MHC class II accessory molecules that modulate exogenous Ag presentation. Most class II accessory molecules are expressed in all professional APC; however, H2-O is only expressed in B cells and medullary thymic epithelial cells. Because B cells present exogenous Ags and superantigens (SAgs), and medullary thymic epithelial cells are specialized APC for self Ags during negative selection in the thymus, we have hypothesized that H2-O might play a role in MHC class II-restricted SAg and self Ag presentation. In this study, we demonstrate that H2-O expression inhibits presentation of the bacterial SAgs staphylococcal enterotoxins A and B to four SAg-reactive T hybridoma cells. In contrast, H2-O has no effect on presentation of endogenous self Ags, as measured by tumorigenicity in vivo and Ag presentation to three self Ag-specific T hybridoma cells. Additional experiments suggest that H2-O inhibits presentation of exogenous Ags by both newly synthesized and recycling MHC class II molecules. These data suggest H2-O may have a physiological role in tolerance induction and SAg-mediated toxic shock.
Collapse
|
228
|
Zhang F, Qi L, Chen H. [Value of P-glycoprotein and glutathione S-transferase-pi as chemo-resistant indicators in ovarian cancers]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 2001; 23:313-6. [PMID: 11783115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE This study was conducted to assess the predictive value of P-glycoprotein (P-gp) and glutathione S-transferase-pi(GST-pi) as indicators of resistance to chemotherapy in ovarian cancers. METHODS Expressions of P-gp and GST-pi were immunohistochemically studied in paraffin sections from 30 normal ovaries and 74 resected specimens of primary epithelial ovarian cancer from patients who had not received any chemotherapy before surgery. RESULTS There were no detectable P-gp or GST-pi expression in the 30 patients with normal ovaries. In 74 cases of ovarian cancer tissue, P-gp was positive in 14 (18.9%) and GST-pi positive in 55 (74.3%) showing a highly significant correlation (P < 0.01). However, expression of P-gp and GST-pi was not associated with any of the clinicopathological parameters, such as clinical stage, histologic or tumor grade (P > 0.05). The evaluation of chemotherapy for postoperative residual ovarian cancer patients showed that all the six lesions showing P-gp positive were drug-resistant whereas only nine of the twenty-one tumors showing negative results were drug-resistant. Of 27 clinically measurable resected lesions, this difference in the response rates of the two groups was significant (P < 0.05). The predictive value of positive P-gp stain for drug resistance was 100% (6/6), and that of negative stain for objective responders was 57.1%(12/21). The response rate to chemotherapy of the GST-pi positive group (13.3%-2/15) was significantly lower than that of the SGT-pi negative group (83.3%-10/12, P < 0.01). The predictive value of positive GST-pi stain for drug resistance was 86.7%(13/15) and that of negative stain for objective responders was 83.3%(10/12). The survival rates of P-gp negative and GST-pi negative tumor patients were significantly higher than those of P-gp positive and GST-pi positive tumor patients (P < 0.01, P < 0.05, respectively). CONCLUSION These data suggest that P-gp and GST-pi expression in tumor cells are related to drug resistance in epithelial ovarian cancer. They are useful indicators of resistance to chemotherapy.
Collapse
|
229
|
Qi L, Friebe B, Gill BS. Meiotic metaphase I pairing behavior of a 5BL recombinant isochromosome in wheat. Chromosome Res 2001; 8:671-6. [PMID: 11196130 DOI: 10.1023/a:1026785119376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
A recombinant isochromosome i5BLrec of wheat was developed with one arm and the proximal 36% of the other arm of Chinese Spring (CS) origin and the distal 64% of the recombined arm of Triticum turgiduM subsp. dicoccoides origin. The i5BLrec provides an unusual opportunity to analyze the role of the centromere or arm heterozygosity in chromosome prealignment and synapsis during meiosis. In monosomic condition, the i5BLrec formed a ring univalent in 86.8% of the pollen mother cells (PMCs) at meiotic metaphase I. In the disomic condition, the two i5BLrec preferentially paired as a normal bivalent in 74.8% of the PMCs, which differed significantly (p <0.01) from the normal bivalent pairing of 51% observed in diisosomic 5BL chromosomes of the CS (Di5BL(CS)) control plants. In plants with one i5BLrec and a normal 5B(CS), the long arm of 5B(CS) paired with the homologous arm of i5BLrec in 54.4% of the PMCs, and 40.4% of the PMCs had a 5B(CS) univalent and a i5BLrec ring univalent. The implications of the i5BLrec pairing data on the mechanism of Ph1 gene action are discussed.
Collapse
|
230
|
Cölfen H, Qi L. A systematic examination of the morphogenesis of calcium carbonate in the presence of a double-hydrophilic block copolymer. Chemistry 2001; 7:106-16. [PMID: 11205002 DOI: 10.1002/1521-3765(20010105)7:1<106::aid-chem106>3.0.co;2-d] [Citation(s) in RCA: 414] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
In this paper, a systematic study of the influence of various experimental parameters on the morphology and size of CaCO3 crystals after room-temperature crystallization from water in the presence of poly(ethylene glycol)-block-poly(methacrylic acid) (PEG-b-PMAA) is presented. The pH of the solution, the block copolymer concentration, and the ratio [polymer]/[CaCO3] turned out to be important parameters for the morphogenesis of CaCO3, whereas a moderate increase of the ionic strength (0.016 M) had no influence. Depending on the experimental conditions, the crystal morphologies can be tuned from calcite rhombohedra via rods, ellipsoids or dumbbells to spheres. A morphology map is presented which allows the prediction of the crystal morphology from a combination of pH, and CaCO3 and polymer concentration. Morphologies reported in literature for the same system but under different crystallization conditions agree well with the predictions from the morphology map. A closer examination of the growth of polycrystalline macroscopic CaCO3 spheres by TEM and time-resolved dynamic light scattering showed that CaCO3 macrocrystals are formed from strings of aggregated amorphous nanoparticles and then recrystallize as dumbbell-shaped or spherical calcite macrocrystal.
Collapse
|
231
|
Li Y, Wang Y, Qi L. [Determination of serum soluble interleukin-6 receptor and soluble gp130 levels in patient with pregnancy induced hypertension and its significance]. ZHONGHUA FU CHAN KE ZA ZHI 2001; 36:18-9. [PMID: 11778537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To observe the changes of serum soluble interleukin-6 receptor (sIL-6R) and soluble gp130 (sgp130) in patients with pregnancy induced hypertension. METHODS Enzyme linked immunosorbent assay (ELISA) was used to determine serum sIL-6R and sgp130 levels in 40 patients with pregnancy induced hypertension (study group), 20 normal non-pregnant women (control group I) and 20 normal pregnant women (control group II). RESULTS In study group, sIL-6R was (196.7 +/- 12.9) micrograms/L and sgp130 was (379.4 +/- 79.3) micrograms/L. In control group I, sIL-6R was (174.8 +/- 46.2) micrograms/L and sgp130 was (273.6 +/- 28.3) micrograms/L. In control group II, sIL-6R was (174.4 +/- 48.3) micrograms/L and sgp130 was (254.4 +/- 34.7) micrograms/L. SIL-6R and sgp 130 were higher in study group than those in control groups with significant difference (P < 0.01). In study group, the more severe the patients, the higher the sIL-6R and sgp130 levels. There was significant difference (P < 0.01). There was no difference in sIL-6R and sgp130 levels between control groups (P > 0.05). CONCLUSIONS Serum sIL-6R and sgp130 levels are related to the development of pregnancy induced hypertension.
Collapse
|
232
|
Qi L, Qi L, Qiou QJ, Yu QL. [The development of endoscope workstation]. ZHONGGUO YI LIAO QI XIE ZA ZHI = CHINESE JOURNAL OF MEDICAL INSTRUMENTATION 2001; 25:26-29. [PMID: 12583298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This paper introduces an endoscope workstation, which solved the weak points of multimedia endoscope database used by most hospitals. The endoscope workstation was built on pedal-switch and NTFS file system. This paper also Introduces how to make program optimal and quick inputting. The workstation has promoted the efficiency of the doctor's operation.
Collapse
|
233
|
VanLoock MS, Agrawal RK, Gabashvili IS, Qi L, Frank J, Harvey SC. Movement of the decoding region of the 16 S ribosomal RNA accompanies tRNA translocation. J Mol Biol 2000; 304:507-15. [PMID: 11099376 DOI: 10.1006/jmbi.2000.4213] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The ribosome undergoes pronounced periodic conformational changes during protein synthesis. Of particular importance are those occurring around the decoding site, the region of the 16 S rRNA interacting with the mRNA-(tRNA)(2) complex. We have incorporated structural information from X-ray crystallography and nuclear magnetic resonance into cryo-electron microscopic maps of ribosomal complexes designed to capture structural changes at the translocation step of the polypeptide elongation cycle. The A-site region of the decoding site actively participates in the translocation of the tRNA from the A to the P-site upon GTP hydrolysis by elongation factor G, shifting approximately 8 A toward the P-site. This implies that elongation factor G actively pushes both the decoding site and the mRNA/tRNA complex during translocation.
Collapse
MESH Headings
- Base Sequence
- Binding Sites
- Cryoelectron Microscopy
- Crystallography, X-Ray
- Escherichia coli/chemistry
- Escherichia coli/genetics
- Guanosine Diphosphate/metabolism
- Guanosine Triphosphate/analogs & derivatives
- Guanosine Triphosphate/metabolism
- Hydrolysis
- Models, Molecular
- Nuclear Magnetic Resonance, Biomolecular
- Nucleic Acid Conformation
- Peptide Chain Elongation, Translational
- Peptide Elongation Factor G/metabolism
- Protein Conformation
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 16S/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Ribosomes/chemistry
- Ribosomes/genetics
- Ribosomes/metabolism
Collapse
|
234
|
Qi L, Rojas JM, Ostrand-Rosenberg S. Tumor cells present MHC class II-restricted nuclear and mitochondrial antigens and are the predominant antigen presenting cells in vivo. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2000; 165:5451-61. [PMID: 11067897 DOI: 10.4049/jimmunol.165.10.5451] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
MHC class II-restricted tumor Ags presented by class II(+) tumor cells identified to date are derived from proteins expressed in the cytoplasm or plasma membrane of tumor cells. It is unclear whether MHC class II(+) tumor cells present class II-restricted epitopes derived from other intracellular compartments, such as nuclei and/or mitochondria, and whether class II(+) tumor cells directly present Ag in vivo. To address these questions, a model Ag, hen egg lysozyme, was targeted to various subcellular compartments of mouse sarcoma cells, and the resulting cells were tested for presentation of three lysozyme epitopes in vitro and for presentation of nuclear Ag in vivo. In in vitro studies, Ags localized to all tested compartments (nuclei, cytoplasm, mitochondria, and endoplasmic reticulum) are presented in the absence invariant chain and H-2M. Coexpression of invariant chain and H-2M inhibit presentation of some, but not all, of the epitopes. In vivo studies demonstrate that class II(+) tumor cells, and not host-derived cells, are the predominant APC for class II-restricted nuclear Ags. Because class II(+) tumor cells are effective APC in vivo and probably present novel tumor Ag epitopes not presented by host-derived APC, their inclusion in cancer vaccines may enhance activation of tumor-reactive CD4(+) T cells.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Antigen-Presenting Cells/immunology
- Antigen-Presenting Cells/metabolism
- Antigen-Presenting Cells/transplantation
- Antigens, Differentiation, B-Lymphocyte/biosynthesis
- Antigens, Differentiation, B-Lymphocyte/genetics
- Cell Compartmentation/genetics
- Cell Compartmentation/immunology
- Cell Nucleus/genetics
- Cell Nucleus/immunology
- Cell Nucleus/metabolism
- Cytosol/immunology
- Cytosol/metabolism
- HLA-D Antigens/biosynthesis
- HLA-D Antigens/genetics
- Histocompatibility Antigens Class II/biosynthesis
- Histocompatibility Antigens Class II/genetics
- Histocompatibility Antigens Class II/metabolism
- Humans
- Hybridomas
- Immunodominant Epitopes/administration & dosage
- Immunodominant Epitopes/metabolism
- Mice
- Mice, Inbred A
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Nude
- Mitochondria/genetics
- Mitochondria/immunology
- Mitochondria/metabolism
- Molecular Sequence Data
- Muramidase/biosynthesis
- Muramidase/genetics
- Muramidase/immunology
- Neoplasm Transplantation
- Peptide Fragments/biosynthesis
- Peptide Fragments/genetics
- Peptide Fragments/immunology
- Sarcoma, Experimental/genetics
- Sarcoma, Experimental/immunology
- Sarcoma, Experimental/metabolism
- Spleen/cytology
- Spleen/immunology
- Spleen/transplantation
- Transfection
- Tumor Cells, Cultured
Collapse
|
235
|
Abstract
Previous suggestions of CpG-specific apoptotic commitment implied critical epigenetic modulation of housekeeping genes which have canonical CpG islands at 5' promoter regions. Differential housekeeping gene activity however has not been shown. Using a focussed microarray (genechip) of 22 housekeeping genes we show this in apoptosis induced in human Chang liver cells by DCNP (2,6-dichloro-4-nitrophenol), a non-genotoxic inhibitor of sulfate detoxification. 3-7 folds downregulation of 9 genes in glycolysis, tricarboxylic acid cycle and the respiratory electron transport chain suggested gene-directed energy depletion which was correlated with observed ATP depletion. 4 folds downregulation of the pyruvate dehydrogenease gene suggested gene-directed metabolic acidosis which was correlated with observed cell acidification. Other differential housekeeping gene activity, including 4 folds upregulation of microtubular alpha-tubulin gene, and 2 folds upregulation of ubiquitin, also had a bearing on apoptosis. Broadspectrum zVAD-fmk caspase inhibition abolished 200 bp DNA ladder fragmentations but not the CpG-specific megabase fragmentations and other hallmarks of cell destruction, suggesting a caspase-independent cell death. Death appeared committed at gene-level.
Collapse
|
236
|
Qi L, Sit KH. Housekeeping genes commanded to commit suicide in CpG-cleavage commitment upstream of Bcl-2 inhibition in caspase-dependent and -independent pathways. MOLECULAR CELL BIOLOGY RESEARCH COMMUNICATIONS : MCBRC 2000; 3:319-27. [PMID: 10964757 DOI: 10.1006/mcbr.2000.0232] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A CpG-specific commitment common to both caspase-dependent and -independent cell deaths implies critical gene activity from epigenetic modulation. Using a focused microarray (genechip) of 22 housekeeping genes, which have canonical CpG islands at 5'-promoter regions, here we show critical regulation of vital intermediary metabolism and cell structure that are common to both caspase-dependent fasL-mediated and caspase-independent etoposide-mediated cell deaths. Gene activity of at least twofold under or over control levels and common to both cell death pathways was considered to be significantly regulated in common. Seven genes controlling energy production in glycolysis, tricarboxylic acid cycle, and the respiratory electron transport chain were significantly downregulated in common. Energy depletion is lethal. Downregulated pyruvate dehydrogenase E1 gene, in addition, suggested primary metabolic acidification. Cell acidification is also lethal. Critical derangement of the cell structure was suggested by common downregulation of the basal histone gene H2A.X which is required for nucleosome assembly. Common upregulation of the alpha-tubulin gene suggested perturbation of vital microtubular dynamics. Gene-commanded cell suicide was suggested. We further show that a Bcl-2 overexpression of three- to fourfold above normal levels could not prevent the CpG-specific megabase DNA cleavages in the two cell death pathways, but abolished their low-molecular-weight 200-bp ladder cleavages. Together with incomplete suppression of the other apoptotic expressions, the Bcl-2 inhibition point appeared downstream from the CpG-cleavage commitment point.
Collapse
|
237
|
Tesauro M, Thompson WC, Rogliani P, Qi L, Chaudhary PP, Moss J. Intracellular processing of endothelial nitric oxide synthase isoforms associated with differences in severity of cardiopulmonary diseases: cleavage of proteins with aspartate vs. glutamate at position 298. Proc Natl Acad Sci U S A 2000; 97:2832-5. [PMID: 10717002 PMCID: PMC16015 DOI: 10.1073/pnas.97.6.2832] [Citation(s) in RCA: 386] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An endothelial nitric oxide synthase (eNOS) polymorphism in exon 7 (894 G/T) resulting in glutamate or aspartate, respectively, at position 298 on the protein is correlated with severity of cardiopulmonary diseases. Because glutamate and aspartate are considered to be conservative replacements, the polymorphism was thought to be a marker for a functional locus elsewhere in the gene. We now show in transfected cells, primary human endothelial cells, and human hearts, that eNOS with aspartate, but not glutamate, at position 298 is cleaved, resulting in the generation of 100-kDa and 35-kDa products. Recombinant or native eNOS was examined by immunoblotting either in lysates (COS7) or after partial purification over 2',5'-ADP-Sepharose and calmodulin-Sepharose. Immunoblotting after SDS/PAGE with a carboxyl-terminal antibody showed a single major protein band in the predicted position for eNOS at 135 kDa. An additional band at approximately 100 kDa was present only in the recombinant 298Asp eNOS and in the eNOS synthesized by primary cells and heart tissue with a G/T genotype. Using an eNOS amino-terminal-specific antibody, an immunoreactive band at approximately 35 kDa, corresponding to the residual N-terminal cleavage fragment, was observed in those cells with a T genotype. Thus, eNOS with aspartate but not glutamate at position 298 is cleaved, resulting in the generation of N-terminal 35-kDa and C-terminal 100-kDa fragments. Thus, the eNOS gene with polymorphisms at nucleotide 894 generates protein products with differing susceptibility to cleavage, suggesting that, in contrast to prior predictions, this polymorphism has a functional effect on the eNOS protein.
Collapse
|
238
|
|
239
|
Abstract
Peach, peanut, fiber, and flower (see picture) crystal morphologies are achieved from the precipitation of simple minerals in the presence of specifically adsorbing polymers. These crystal design effects are illustrated using BaSO(4) and double-hydrophilic block copolymers, the latter featuring carboxylate, sulfonate, phosphonate, and aspartic acid groups.
Collapse
|
240
|
Qi L, Ostrand-Rosenberg S. MHC class II presentation of endogenous tumor antigen by cellular vaccines depends on the endocytic pathway but not H2-M. Traffic 2000; 1:152-60. [PMID: 11208095 DOI: 10.1034/j.1600-0854.2000.010207.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
We have developed cell-based cancer vaccines that activate anti-tumor immunity by directly presenting endogenously synthesized tumor antigens to CD4+ T helper lymphocytes via MHC class II molecules. The vaccines are non-conventional antigen-presenting cells because they express MHC class II, do not express invariant chain or H-2M, and preferentially present endogenous antigen. To further improve therapeutic efficacy we have studied the intracellular trafficking pathway of MHC class II molecules in the vaccines using endoplasmic reticulumlocalized lysozyme as a model antigen. Experiments using endocytic and cytosolic pathway inhibitors (chloroquine, primaquine, and brefeldin A) and protease inhibitors (lactacystin, LLnL, E64, and leupeptin) indicate antigen presentation depends on the endocytic pathway, although antigen degradation is not mediated by endosomal or proteasomal proteases. Because H2-M facilitates presentation of exogenous antigen via the endocytic pathway, we investigated whether transfection of vaccine cells with H-2M could potentiate endogenous antigen presentation. In contrast to its role in conventional antigen presentation, H-2M had no effect on endogenous antigen presentation by vaccine cells or on vaccine efficacy. These results suggest that antigen/MHC class II complexes in the vaccines may follow a novel route for processing and presentation and may produce a repertoire of class II-restricted peptides different from those presented by professional APC. The therapeutic efficacy of the vaccines, therefore, may reside in their ability to present novel tumor peptides, consequently activating tumor-specific CD4+ T cells that would not otherwise be activated.
Collapse
|
241
|
Qi L, Sit KH. CpG-specific common commitment in caspase-dependent and -independent cell deaths. MOLECULAR CELL BIOLOGY RESEARCH COMMUNICATIONS : MCBRC 2000; 3:33-41. [PMID: 10683315 DOI: 10.1006/mcbr.2000.0186] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cell death in mammals seems to have caspase-dependent and -independent pathways unlike that in Caenorhabditis elegans where CED-3 protease activation is the central command. A recent suggestion to define apoptosis as the caspase-dependent or caspase-committed cell death form and leave cell death committed by other pathways as just cell death was meant to categorize the apparent divergence in mammalian cell death pathways. However, we show CpG oligonucleotides (ODN) blocking caspase-dependent fas(CD95) ligand-mediated apoptosis as well as caspase-independent etoposide-mediated apoptosis and etoposide-zVAD-mediated necrosis. CpG specificity was demonstrated by reversing the CpG motif or replacing it with a methylated motif (mCpG) which failed to inhibit. CpG ODN blocked CpG-specific DNA cleavage by rare-cutting NotI restriction, which produced a megabase cleavage pattern similar to that in the fasL and etoposide cell death inductions. CpG ODN inhibition was similar to that by CpG-specific SssI methylase. A common CpG-specific commitment point preceding caspase-dependent and -independent cell death pathways was suggested. CpG-specific modulation is a key epigenetic mechanism in genomic imprinting, resisting nuclease restriction, and patterning of chromatin conformations. It is now shown to have a powerful effect modulating cell death.
Collapse
|
242
|
Wang Z, Shi Z, She B, Qin J, Guo H, Qi L, Zhu Y. [A follow-up study of anterior deciduous cross-bite]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 1999; 17:348-51. [PMID: 12539384] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To determine the relationship between anterior deciduous crossbite and anterior permanent crossbite, Angle classification of malocclusion and class III jaw relationship through a follow-up study in community children. METHODS A follow-up study was done six years later in 102 children who were out of 120 children having anterior deciduous crossbite detected in a survey of six years before. Other 102 children with normal occlusion of deciduous and permanent teeth were treated as the control group. RESULTS There were 51 out of 102 cases developed anterior permanent crossbite. In comparison with the group with 1-2 anterior deciduous crossbite, the group with more than two neighboring anterior deciduous crossbite had more significant probability to turn into anterior permanent crossbite, OR = 6.8 (95% CI: 2.7-17.6). The patients with more than 2 neighboring anterior deciduous teeth crossbite had significantly more chance of developing Angle III malocclusion and class III jaw relationship than those in the control group and those with 1-2 anterior deciduous teeth crossbite. CONCLUSION Clinical orthodontists should pay more attention to the patients with more than 2 neighboring anterior deciduous crossbite.
Collapse
|
243
|
Qi L, Gao Y, Ma J. Synthesis of ribbons of silver nanoparticles in lamellar liquid crystals. Colloids Surf A Physicochem Eng Asp 1999. [DOI: 10.1016/s0927-7757(99)00053-9] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
244
|
Ostrand-Rosenberg S, Pulaski BA, Clements VK, Qi L, Pipeling MR, Hanyok LA. Cell-based vaccines for the stimulation of immunity to metastatic cancers. Immunol Rev 1999; 170:101-14. [PMID: 10566145 DOI: 10.1111/j.1600-065x.1999.tb01332.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We are developing vaccines for inducing immunity to metastatic cancers. Although primary tumors are frequently cured by surgery, chemotherapy, or radiation therapy, metastatic lesions often do not respond to these treatments or proliferate after conventional therapy is terminated. Vaccine therapy for established metastases as well as prophylactic vaccine treatment to prevent outgrowth of latent metastatic tumor cells would therefore be beneficial. Our goal is to activate CD4+ and CD8+ T lymphocytes; however, we have focused on activating tumor-specific CD4+ T-helper lymphocytes because of their pivotal role as regulatory cells and in the generation of long-term immunological memory. The vaccines are based on the premise that tumor cells express potentially immunogenic antigens that could be targeted for T-cell activation, and that if appropriately genetically modified, tumor cells could be antigen presenting cells for these antigens. To facilitate direct antigen presentation to CD4+ T cells, tumor cells have been transfected with syngeneic major histocompatibility complex class II, co-stimulatory molecule, and/or superantigen genes. In vivo studies in three mouse tumor models demonstrate that vaccination protects against future challenge with wild-type tumor, cures some solid primary tumors, reduces established metastatic disease, and extends mean survival time. Antigen presentation studies demonstrate that in vivo vaccine efficacy is directly related to in vitro antigen presentation activity. The relevance of antigen presentation activity of the vaccines is further confirmed by in vivo studies demonstrating that during the immunization process, the vaccines directly present tumor-encoded antigens to CD4+ T lymphocytes. Adaptation of these vaccines for the treatment of human metastatic cancers is discussed.
Collapse
|
245
|
Novoradovsky A, Brantly ML, Waclawiw MA, Chaudhary PP, Ihara H, Qi L, Eissa NT, Barnes PM, Gabriele KM, Ehrmantraut ME, Rogliani P, Moss J. Endothelial nitric oxide synthase as a potential susceptibility gene in the pathogenesis of emphysema in alpha1-antitrypsin deficiency. Am J Respir Cell Mol Biol 1999; 20:441-7. [PMID: 10030842 DOI: 10.1165/ajrcmb.20.3.3144] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
A role for endothelial nitric oxide synthase (NOS3) in the susceptibility of individuals with alpha1-antitrypsin (alpha1AT) deficiency to destructive lung disease was evaluated. Six polymorphic sites were identified within the NOS3 gene (i.e., -924A/G, -788C/T, -691C/T, 774C/T, 894G/T, and 1998C/G). The genotype distribution was determined in 339 patients and 94 control individuals. Frequency of the 774T allele in severely affected individuals was 0.417 versus 0.269 in control subjects (P = 0.018), whereas the 894T allele frequency was 0.427 versus 0.280 in control subjects (P = 0.024). Patients with less severe lung disease had the 774T and 894T allele frequencies of 0.289 and 0.344, respectively, similar to frequencies in a control group (P > 0.3). No direct correlation between pulmonary function and five other NOS3 polymorphisms was observed. Thus, functional allelic variants that are in linkage disequilibrium with the 774C/T and 894G/T may be present in the specified genomic area. These data are consistent with a modulatory role for NOS3 in destructive lung disease associated with alpha1AT deficiency.
Collapse
|
246
|
Yao L, Su C, Qi L, Liu C, Hu Y, Zhao H. [The substituent structures and characteristic infrared spectra of alpha-furan esters]. GUANG PU XUE YU GUANG PU FEN XI = GUANG PU 1999; 19:32-34. [PMID: 15818909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The characteristic infrared bands of the alpha-furoic esters, alpha-furancarbinol esters and alpha-furanacrylic esters were assigned, and the changing rules of the IR absorption frequency of the alpha-furan esters with alpha-substituent structure were discussed. The results indicated there are three characteristic bands in alpha-furan ring. The strong absorption at 1641 cm(-1) is assigned to the C=C double bond stretching mode in the alpha-furanacrylic esters, while the absorption at 973 cm(-1) is the out-of-plane =C-H bending mode for a trans di-substituted alkene, the strong absorption at about 1713 cm(-1) is assigned to a C=O stretch, and the three strong absorptions near 1305, 1260 and 1165 cm(-1) are due to the symmetric and assymmetric stretching vibrations of C-O-C bond in the ester groups.
Collapse
|
247
|
|
248
|
Qi L, Sun D. A Survey of Some Nonsmooth Equations and Smoothing Newton Methods. APPLIED OPTIMIZATION 1999. [DOI: 10.1007/978-1-4613-3285-5_7] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
249
|
Qi L, Liu D, Han Z, Wang F. [Design and study of carbon fiber tracheal prosthesis]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 1998; 15:328-34. [PMID: 12552773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
32 healty adult dogs were selected for this experiment. 10 of them were subjected to the tracheal biomechanics test using indices including the relation between stretcher ratio (lambda) and stress (T), the squeeze stress (delta jy) of medical silk thread on trachea, the side stress (Ts) inducing the tracheal collapse, the functional maximum angle (psi max) of tracheal, and the sever area torsion angle (theta max) of tracheal functional maximum curved. According to the indices measured, two types of tracheal prosthesis were designed, and were made of carbon fiber and silicon. They were the straight tube type tracheal prosthesis and the bifurcate type tracheal prosthesis. The straight tube type tracheal prosthesis was studied with a design of two groups comprising a total of 11 dogs. In the experiment group (n = 6), the outer surface of the tube was not coated with silicon, the average survival period was 379.8 days. In the control group (n = 5), the outer surface of the tube was coated with silicon, the average survival period was 90.4 days. The bifurcate type tracheal prosthesis was studied in 11 dogs, the average survival period was 4.32 days. The main causes of death in the experiment were infection and anastomotic dehiscent.
Collapse
|
250
|
Qi L, Sit KH. Euchromatin megabase cleavages and conjoint apoptotic-autophagic death expression with nucleolar ball-and-socket joint dislocations in human Chang liver cells arrested in S-phase by etoposide. Eur J Cell Biol 1998; 77:239-46. [PMID: 9860140 DOI: 10.1016/s0171-9335(98)80112-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
Etoposide induced a megabase (Mb) fragmentation pattern identical with that from genomic digestion by NotI restriction endonuclease which specifically cleaves CpG islands in euchromatin domains. Redigestion by NotI produced no change, suggesting cleavage in the same or closely related sites in euchromatin domains. Preferential euchromatin cleavage was further suggested by harvested metaphase chromosomes showing self-inflicted resolution of light G-bandings (R-bandings), the euchromatin domains. Autodegeneration following Mb euchromatin fragmentations was shown by their degradation into 200 bp ladders, and expressions of apoptotic and "non-apoptotic" active death morphologies that were also seen conjointly in the same cell. The endstage further showed heterochromatin masses anchored to the nucleolus by novel ball-and-socket joints where dislocations occurred with nuclear leakage.
Collapse
|