551
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Du Y, Dodel R, Hampel H, Buerger K, Lin S, Eastwood B, Bales K, Gao F, Moeller HJ, Oertel W, Farlow M, Paul S. Reduced levels of amyloid beta-peptide antibody in Alzheimer disease. Neurology 2001; 57:801-5. [PMID: 11552007 DOI: 10.1212/wnl.57.5.801] [Citation(s) in RCA: 178] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate whether it was possible to detect the presence and different levels of naturally occurring anti-beta-amyloid (Abeta) antibodies in the CSF of patients with AD and age-matched controls by employing a sensitive ELISA. BACKGROUND Immunization with preaggregated amyloid beta-peptide (Abeta(1-42)) and administration of antibodies against Abeta into amyloid precursor protein APP(V717F)- transgenic mice (an animal model of AD) have recently been reported to dramatically reduce amyloid plaque deposition, neuritic dystrophy, and astrogliosis, most likely by enhancing Abeta clearance from brain. METHODS A sensitive ELISA was performed to detect levels of naturally occurring anti-Abeta antibodies in the CSF of patients with AD and age-matched controls. Additionally, an immunoprecipitation assay was performed to confirm that naturally occurring anti-Abeta antibodies also exist in the human blood. RESULT - Naturally occurring antibodies directed against Abeta were found in the CSF and plasma of patients with AD and healthy control subjects. Moreover, CSF anti-Abeta antibody titers are significantly lower in patients with AD compared with healthy control subjects. CONCLUSION Naturally occurring antibodies directed against Abeta exist in human CSF and plasma. The CSF anti-Abeta antibody titers may be helpful in better understanding the effects of future immunologic therapies for AD.
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552
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Freiberg A, Lin S, Timpmann K, Blankenship RE. Exciton dynamics in FMO bacteriochlorophyll protein at low temperatures. J Phys Chem B 2001; 101:7211-20. [PMID: 11542264 DOI: 10.1021/jp9633761] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A time response over almost 5 decades (from 10(-13) to about 10(-8) s) to a (sub)picosecond laser pulse excitation has been observed in the Fenna, Matthews, and Olson (FMO) antenna protein trimer. The FMO protein is unique in having a fine-structured bacteriochiorophyll a Qy exciton absorption spectrum over the whole investigated temperature range between 6 and 160 K. As measured by a two-color pump-probe differential absorption, the population decay of the exciton states of seven strongly coupled bacteriochlorophyll a molecules in a protein monomer is the dominant dynamical process in the subpicosecond time domain. The through-band scattering takes a few picoseconds and depends only weakly on temperature, probably because of a low density of exciton states. At low temperatures, evidence for a slow pico-nanosecond relaxation process has also been obtained via time-dependent red-shift and broadening of the exciton emission spectrum. Two nonexclusive tentative interpretations to this effect have been provided. The phenomenon may be due to exciton solvation in the surrounding protein and water-glycerol matrix or/and due to slow scattering of closely spaced bacteriochlorophyll a exciton states in a protein trimer. The shape of the excited-state absorption spectrum (arising from transitions between singly and doubly excited exciton states) and its oscillator strength has been roughly estimated from the analysis of the pump-probe spectrum. The spectrum peaks at around 805 nm and is less featured compared to the ground-state absorption spectrum. Both spectra have comparable strength.
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553
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Lin S, Tornatore P, King D, Orlando R, Weinberger SR. Limited acid hydrolysis as a means of fragmenting proteins isolated upon ProteinChip array surfaces. Proteomics 2001; 1:1172-84. [PMID: 11990511 DOI: 10.1002/1615-9861(200109)1:9<1172::aid-prot1172>3.0.co;2-q] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
ProteinChip array technology enables protein purification, protein profiling, and biomarker discovery on a convenient biochip platform. Traditional proteomic approaches towards protein identification rely upon the generation of peptides through the use of specific proteases. However, for a variety of reasons, the digestion of proteins bound to planar arrays by specific proteases, such as trypsin, has proven to be difficult, at times providing little or no protein digestion at all. Additionally, should more than one protein be present on the array surface, the digestion product consists of peptides from different proteins, adding another dimension of complexity to database mining approaches. These factors have driven our group to explore alternative means of on-chip protein digestion. In this article, we describe an approach to generate peptide maps by limited acid hydrolysis. Depending upon the adsorbed protein, this method requires between 500 femtomole to 5 picomole of protein for on-chip hydrolysis. Besides generating several internal peptide fragments, limited acid hydrolysis also has the advantage of generating peptide ladders from the N- or C-terminus of the protein. From these ladders, partial primary sequence of the protein can be directly derived when analyzed by a simple laser desorption/ionization mass spectrometer. Furthermore, tandem mass spectrometry can be performed on several internal peptide fragments, thus facilitating the identification of several proteins within a mixture. Based upon the preliminary results of this work, we continue to explore the possibility of using limited acid hydrolysis to identify unknown proteins captured on ProteinChip array surfaces.
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554
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Holmes JF, Miller PQ, Panacek EA, Lin S, Horne NS, Mower WR. Epidemiology of thoracolumbar spine injury in blunt trauma. Acad Emerg Med 2001; 8:866-72. [PMID: 11535478 DOI: 10.1111/j.1553-2712.2001.tb01146.x] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE To evaluate the prevalence, distribution, and demographics of thoracolumbar (TL) spine injuries following blunt trauma. METHODS Prospective, cross-sectional study of a consecutive sample of all blunt trauma patients presenting initially to the emergency department (ED) of a Level 1 trauma center and undergoing thoracic and/or lumbar spine radiography from August 1997 to November 1998. The age, sex, and mechanism of injury of each patient as well as location and type of spine injury were recorded for those patients with vertebral fractures, dislocations, or subluxations. RESULTS Two thousand four hundred four blunt trauma patients were enrolled. Vertebral injuries were identified in 152 individuals (6.3%, 95% CI = 5.4% to 7.4%). Two hundred sixty distinct anatomic levels of injury were identified in these 152 individuals. Of these 260 injuries, 42 (16.2%) occurred at L1, 38 (14.6%) at L2, 29 (11.1%) at L3, and 27 (10.4%) at T12, making these the most commonly injured vertebrae. Injuries were most common (34 patients) in those aged 30-39 years and were least common (12 patients) in those under 18 years. Compression fractures (52%) were the most common injury in the thoracic spine, while transverse process fractures (48%) were the most common injuries in the lumbar spine. CONCLUSIONS The prevalence of TL injuries in ED blunt trauma patients undergoing TL radiographs is 6.3%. The most commonly injured area of the TL spine is the thoracolumbar junction.
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555
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Tagat JR, McCombie SW, Steensma RW, Lin S, Nazareno DV, Baroudy B, Vantuno N, Xu S, Liu J. Piperazine-based CCR5 antagonists as HIV-1 inhibitors. I: 2(S)-methyl piperazine as a key pharmacophore element. Bioorg Med Chem Lett 2001; 11:2143-6. [PMID: 11514156 DOI: 10.1016/s0960-894x(01)00381-x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Optimization of the piperidino-piperazines 1 and 2 provided early leads 3 and 4, which showed good activity in the CCR5-RANTES binding assay and in antiviral assays. A systematic study around these structures showed that the 2(S)-methyl piperazine is essential for CCR5 affinity, which is further enhanced by forming the 2,6-dimethyl benzamide of the piperidine.
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556
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Melkozernov AN, Lin S, Blankenship RE, Valkunas L. Spectral inhomogeneity of photosystem I and its influence on excitation equilibration and trapping in the cyanobacterium Synechocystis sp. PCC6803 at 77 K. Biophys J 2001; 81:1144-54. [PMID: 11463655 PMCID: PMC1301583 DOI: 10.1016/s0006-3495(01)75771-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Ultrafast transient absorption spectroscopy was used to probe excitation energy transfer and trapping at 77 K in the photosystem I (PSI) core antenna from the cyanobacterium Synechocystis sp. PCC 6803. Excitation of the bulk antenna at 670 and 680 nm induces a subpicosecond energy transfer process that populates the Chl a spectral form at 685--687 nm within few transfer steps (300--400 fs). On a picosecond time scale equilibration with the longest-wavelength absorbing pigments occurs within 4-6 ps, slightly slower than at room temperature. At low temperatures in the absence of uphill energy transfer the energy equilibration processes involve low-energy shifted chlorophyll spectral forms of the bulk antenna participating in a 30--50-ps process of photochemical trapping of the excitation by P(700). These spectral forms might originate from clustered pigments in the core antenna and coupled chlorophylls of the reaction center. Part of the excitation is trapped on a pool of the longest-wavelength absorbing pigments serving as deep traps at 77 K. Transient hole burning of the ground-state absorption of the PSI with excitation at 710 and 720 nm indicates heterogeneity of the red pigment absorption band with two broad homogeneous transitions at 708 nm and 714 nm (full-width at half-maximum (fwhm) approximately 200--300 cm(-1)). The origin of these two bands is attributed to the presence of two chlorophyll dimers, while the appearance of the early time bleaching bands at 683 nm and 678 nm under excitation into the red side of the absorption spectrum (>690 nm) can be explained by borrowing of the dipole strength by the ground-state absorption of the chlorophyll a monomers from the excited-state absorption of the dimeric red pigments.
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Järbe TU, Lamb RJ, Lin S, Makriyannis A. (R)-methanandamide and Delta 9-THC as discriminative stimuli in rats: tests with the cannabinoid antagonist SR-141716 and the endogenous ligand anandamide. Psychopharmacology (Berl) 2001; 156:369-80. [PMID: 11498713 DOI: 10.1007/s002130100730] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2000] [Accepted: 02/09/2001] [Indexed: 10/27/2022]
Abstract
RATIONALE AND OBJECTIVES (R)-methanandamide (AM-356), a metabolically more stable chiral analog of the endocannabinoid ligand anandamide, was used as a representative of fatty acid ethanolamide CB1 receptor ligands to characterize the discriminative stimulus functions of anandamides. METHODS Rats discriminated between 10 mg/kg (R)-methanandamide and vehicle administered IP 15 min prior to session onset. Another group of rats was initially trained to discriminate between 3 mg/kg Delta9-THC and vehicle given IP 30 min prior to session onset; for anandamide testing, the animals were retrained with 1.8 and 5.6 mg/kg Delta9-THC. A two lever operant methodology (FR10) was used. RESULTS Delta9-THC was more potent than (R)-methanandamide at both 15 and 30 min post-injection, irrespective of the training drug used. Additional tests with 10 and 18 mg/kg (R)-methanandamide suggested that the effects were declining by 1 h. The cannabinoid antagonist SR 141716 (0.3 and 1 mg/kg) produced rightward shifts in the Delta9-THC dose-response curve for Delta9-THC-appropriate responding and for (R)-methanandamide-appropriate responding (surmountable antagonism). SR-141716 (0.3 and 1 mg/kg) antagonized the ability of (R)-methanandamide to occasion either Delta9-THC-appropriate responding or (R)-methanandamide-appropriate responding. This antagonism was surmountable only at a dose of 0.3 mg/kg SR-1421716 in the (R)-methanandamide-trained rats. SR-141716 did not antagonize the rate-decreasing effects of (R)-methanandamide in either the Delta9-THC or the (R)-methanandamide trained rats. Response suppression precluded testing doses higher than 30 mg/kg (R)-methanandamide. Tests with SR-141716 (1 and 10 mg/kg) alone resulted in <3% Delta9-THC-appropriate responding. With 10 mg/kg SR-141716, response rate was significantly lower as compared to the rate observed during a vehicle test. Tests with anandamide (10 and 18 mg/kg) resulted in 41% and 85% (R)-methanandamide-appropriate responding at a 3-min pre-treatment time, but in a maximum of 15% (R)-methanandamide-appropriate responding at a longer (15 min) pre-treatment time. In the Delta9-THC (1.8 and 5.6 mg/kg) trained rats, anandamide never produced more than about 20% Delta9-THC-appropriate responding. CONCLUSION The results add to a growing body of evidence indicating that there are both similarities and dissimilarities between classical cannabinoids such as THC and endogenous fatty acid ethanolamides.
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558
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Lin S, Song G, Zhou F. [Mortality study of major non-communicable diseases in Shanghai, from 1951 to 1998]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2001; 22:265-8. [PMID: 11718063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
OBJECTIVE To study the transition of major non-communicable diseases (NCDs) in Shanghai. METHODS Demographic and mortality data since early 1950s in Shanghai was used. Linear regression model was employed to evaluate the mortality trends of diseases. RESULTS During the past five decades, age-adjusted mortality had been gradually decreasing, with leading cause of deaths shifting from infectious diseases to NCDs. In 1998, the average life expectancy reached 77.03, and the three leading causes of deaths, i.e. tumor, cardio-vascular diseases and respiratory diseases, accounted for 75% of all deaths. The crude mortality of major NCDs increased consistently. However, the age-adjusted mortality trends of major NCDs decreased during the past two decades after a 30-year's increase. Turnover took place in the late 1970s for tumors, for coronary heart in late 1980s diseases and in the early 1990s for strokes. For malignant tumors, the age-adjusted mortality of breast cancer, cancer of colon and rectum did not significantly decrease in the past two decades. CONCLUSION The increase of crude mortality of major NCDs was mainly due to the trend of aging in Shanghai. It is suggested that the risk factors of major NCDs had decreased to some extent but the behavior and dietary related risk factors remained serious.
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559
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Bahr JL, Kodis G, de la Garza L, Lin S, Moore AL, Moore TA, Gust D. Photoswitched singlet energy transfer in a porphyrin-spiropyran dyad. J Am Chem Soc 2001; 123:7124-33. [PMID: 11459493 DOI: 10.1021/ja010058t] [Citation(s) in RCA: 113] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A photochromic nitrospiropyran moiety (Sp) has been covalently linked to a zinc (PZn) and to a free-base (P(H2)) porphyrin. In the resulting dyads (P(Zn)-Sp(c) and P(H2)-Sp(c)), the porphyrin first excited singlet states are unperturbed by the closed form of the attached spiropyran. Excitation of the spiropyran moiety of either dyad in the near-UV region results in ring opening to a merocyanine form (P-Sp(o)) that absorbs at 600 nm. The open form re-closes thermally in 2-methyltetrahydrofuran with a time constant of 20 s, or following irradiation into the 600 nm band. Excitation of the zinc porphyrin moiety in the merocyanine form of the dyad yields 1PZn-Sp(o). The lifetime of the zinc porphyrin excited state is reduced from its usual value of 1.8 ns to 130 ps by singlet-singlet energy transfer to the merocyanine moiety to give PZn-1Sp(o). The quantum yield of energy transfer is 0.93. Quenching is also observed in the free base dyad, where 1P(H2)-Sp(o) and P(H2)-1Sp(o) exchange singlet excitation energy. This photoswitchable quenching phenomenon provides light-activated control of the porphyrin excited states, and consequently control of any subsequent energy or electron-transfer processes that might be initiated by these excited states in more complex molecular photonic or optoelectronic devices.
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560
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Wang G, Huang H, Dai R, Lee KY, Lin S, Mivechi NF. Suppression of heat shock transcription factor HSF1 in zebrafish causes heat-induced apoptosis. Genesis 2001; 30:195-7. [PMID: 11477707 DOI: 10.1002/gene.1064] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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561
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Goutopoulos A, Fan P, Khanolkar AD, Xie XQ, Lin S, Makriyannis A. Stereochemical selectivity of methanandamides for the CB1 and CB2 cannabinoid receptors and their metabolic stability. Bioorg Med Chem 2001; 9:1673-84. [PMID: 11425567 DOI: 10.1016/s0968-0896(01)00088-8] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Several chiral, analogues of the endogenous cannabinoid receptor ligand, arachidonylethanolamide (anandamide), methylated at the 2,1' and 2' positions using asymmetric synthesis were evaluated in order to study (a) stereoselectivity of binding to CB1 and CB2 cannabinoid receptors; and (b) metabolic stability with regard to anandamide amidase. Enantiomerically pure 2-methyl arachidonic acids were synthesized through diastereoselective methylation of the respective chiral 2-oxazolidinone enolate derivatives and CB1 and CB2 receptor affinities of the resulting chiral anandamides were evaluated using a standard receptor binding assay. Introduction of a single 2-methyl group increased affinity for CB1, led to limited enantioselectivity and only modestly improved metabolic stability. However, a high degree of enantio- and diastereoselectivity was observed for the 2,1'-dimethyl analogues. (R)-N-(1-methyl-2-hydroxyethyl)-2-(R)-methyl-arachidonamide (4) exhibited the highest CB1 receptor affinity in this series with a K(i) of 7.42 nM, an at least 10-fold improvement on anandamide (K(i)=78.2 nM). The introduction of two methyl groups at the 2-position of anandamide led to no change in affinity for CB1 but somewhat enhanced metabolic stability. Conversely, chiral headgroup methylation in the 2-gem-dimethyl series led to chiral analogues possessing a wide range of CB1 affinities. Of these the (S)-2,2,2'-trimethyl analogue (12) had the highest affinity for CB1 almost equal to that of anandamide. In agreement with our previous anandamide structure-activity relationship work, the analogues in this study showed high selectivity for the CB1 receptor over CB2. The results are evaluated in terms of stereochemical factors affecting the ligand's affinity for CB1 using receptor-essential volume mapping as an aid. Based on the results, a partial CB1 receptor site model is proposed, that bears two hydrophobic pockets capable of accommodating 1'- and 2-methyl groups
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562
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564
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Lin S, Shi S, LeGeros RZ, LeGeros JP. Three-dimensional finite element analyses of four designs of a high-strength silicon nitride implant. IMPLANT DENT 2001; 9:53-60. [PMID: 11307234 DOI: 10.1097/00008505-200009010-00010] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The effects of implant shape and size on the stress distribution around high-strength silicon nitride implants under vertical and oblique forces were determined using a three-dimensional finite element analysis. Finite element models were designed using as a basis the serial sections of the mandible. Using Auto-CAD software, the model simulated the placement of implants in the molar region of the left mandible. Results of the analyses demonstrated that mainly the implant root shape and the directions of bite forces influence the stress distributions in the supporting bone around each implant. Implant size is a lesser factor. The serrated implants presented a larger surface area to the bone than either the cylindrical or tapered implants, which resulted in lower compressive stress around the serrated implants. With increasing implant diameter and length, compressive stress decreased. The mean compressive stress distribution on the serrated implants was more flat (platykurtic) than on either the cylindrical or tapered implants. Results of studies on two load directions (vertical and oblique) showed that, in either case, the compressive stress in the cortical bone around the neck of the implant was higher than in the cancellous bone along the length of the implant. The most extreme principal compressive stress was found with oblique force. This study provides the first information on the relationship between shape of the silicon nitride implant and stress on the supporting bone.
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Abstract
Acyl-coenzyme A:cholesterol acyltransferase (ACAT) is an intracellular enzyme that produces cholesteryl esters in various tissues. In mammals, two ACAT genes (ACAT1 and ACAT2) have been identified. Together, these two enzymes are involved in storing cholesteryl esters as lipid droplets, in macrophage foam-cell formation, in absorbing dietary cholesterol, and in supplying cholesteryl esters as part of the core lipid for lipoprotein synthesis and assembly. The key difference in tissue distribution of ACAT1 and ACAT2 between humans, mice and monkeys is that, in adult human liver (including hepatocytes and bile duct cells), the major enzyme is ACAT1, rather than ACAT2. There is compelling evidence implicating a role for ACAT1 in macrophage foam-cell formation, and for ACAT2 in intestinal cholesterol absorption. However, further studies at the biochemical and cell biological levels are needed in order to clarify the functional roles of ACAT1 and ACAT2 in the VLDL or chylomicron synthesis/assembly process.
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Sweet CR, Lin S, Cotter RJ, Raetz CR. A Chlamydia trachomatis UDP-N-acetylglucosamine acyltransferase selective for myristoyl-acyl carrier protein. Expression in Escherichia coli and formation of hybrid lipid A species. J Biol Chem 2001; 276:19565-74. [PMID: 11279221 DOI: 10.1074/jbc.m101868200] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chlamydia trachomatis lipid A is unusual in that it is acylated with myristoyl chains at the glucosamine 3 and 3' positions. We have cloned and expressed the gene encoding UDP-N-acetylglucosamine 3-O-acyltransferase of C. trachomatis (CtlpxA), the first enzyme of lipid A biosynthesis. C. trachomatis LpxA displays approximately 20-fold selectivity for myristoyl-ACP over R/S-3-hydroxymyristoyl-ACP under standard assay conditions, consistent with the proposed structure of C. trachomatis lipid A. CtLpxA is the first reported UDP-N-acetylglucosamine acyltransferase that prefers a non-hydroxylated acyl-ACP to a hydroxyacyl-ACP. When CtlpxA was expressed in RO138, a temperature-sensitive lpxA mutant of Escherichia coli, five new hybrid lipid A species were made in vivo after 2 h at 42 degrees C, in place of Escherichia coli lipid A. These compounds were purified and analyzed by matrix-assisted laser desorption ionization/time of flight mass spectrometry. In each case, a myristoyl chain replaced one or both of the ester linked 3-hydroxymyristoyl residues of E. coli lipid A. With prolonged growth at 42 degrees C, all the ester-linked 3-hydroxymyristoyl residues were replaced with myristate chains. Re-engineering the structure of E. coli lipid A should facilitate the microbiological production of novel agonists or antagonists of the innate immunity receptor TLR-4, with possible uses as adjuvants or anti-inflammatory agents.
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Zhuang X, Lin S, Zheng J, Wang L, Sun G, Li Y. [The prognostic research of expression and relationship between Helicobacter pylori of c-met oncogene correlation with gastric mucosal proliferation]. ZHONGHUA NEI KE ZA ZHI 2001; 40:381-4. [PMID: 11798602] [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 determine whether there is a relationship between Helicobacter pylori (Hp) and expression of c-met oncogene and proliferating cell nuclear antigen (PCNA) in gastric mucosal lesions, and prognostic significance of gastric carcinomas(GC). METHODS Expression of c-met and PCNA were investigated in 145 gastric mucosal lesions by using immunohistochemistry. Hp was examined by Warthin-Starry method. RESULTS For chronic superficial gastritis (CSG), chronic atrophic gastritis and intestinal metaplasia (CAS + IM), dysplasia(DYS), early GC and advanced GC, the positive rates of c-met and PCNA were higher in IM, DYS and GC than in CSG (P < 0.05). Expressions of c-met and PCNA increased with the increasing proliferation of gastric mucosa, in rank correlation test, they had a close relationship (P < 0.01). Expressions of c-met and PCNA were correlated significantly with histologic type, serosal invasion and lymph node metastasis. In particular, the expression of c-met and PCNA were significantly higher in Borrmann type 4 GC, type 3 GC and type 1, 2 than in early GC(P < 0.05). By rank correlation test, c-met and PCNA have a close relationship (P < 0.001). Expressions of c-met of Hp positive were higher than Hp negative in intestinal GC (P < 0.05). Expressions of c-met were correlated significantly with Hp positive in CAG + IM, DYS and GC. The survival rate of patients with Hp infection was significantly poorer than that of patients with Hp non-infection. CONCLUSIONS The expression of c-met may be is associated with proliferation and malignant transformation of gastric mucosa. These results suggest that expression of c-met may be a new prognostic factor in gastric carcinoma. Hp infection and expression of c-met may be associated with in proliferation and malignant transformation of gastric mucosa. Hp infection is associated with prognosis of gastric carcinoma.
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Jiang S, Xin R, Qian Y, Lin S, Li F, Wu X, Wang D, Tang G, Jiang K. [Study of susceptibility loci located within Xp11 in attention deficit hyperactivity disorder]. ZHONGHUA YI XUE YI CHUAN XUE ZA ZHI = ZHONGHUA YIXUE YICHUANXUE ZAZHI = CHINESE JOURNAL OF MEDICAL GENETICS 2001; 18:169-72. [PMID: 11402442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/20/2023]
Abstract
OBJECTIVE To detect the genetic relationship between monoamine oxidase(MAO) A type gene and attention deficit hyperactivity disorder(ADHD) in Chinese. METHODS The haplotype-based haplotype relative risk(HHRR) and the transmission disequilibrium test(TDT) methods were used to analyze the genetic association and linkage in 60 ADHD children and their parents. RESULTS In this sample were found significant association (chi(2)=4.90, P<0.05) and linkage (chi(2)=4.84, P<0.05) between the MAOCA 114bp allele and DSM-III-R-diagnosed ADHD in trios composed of father, mother and affected offspring. CONCLUSION The above results suggested that ADHD was associated and in linkage with MAO A gene, and the susceptibility loci might reside in chromosome Xp11 for ADHD.
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Lin S, Liehr S, Cooperman BS, Cotter RJ. Sequencing cyclic peptide inhibitors of mammalian ribonucleotide reductase by electrospray ionization mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2001; 36:658-663. [PMID: 11433539 DOI: 10.1002/jms.167] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Mammalian ribonucleotide reductase (mRR) is a potential target for cancer intervention. A series of lactam-bridged cyclic peptide inhibitors (1-9) of mRR have been synthesized and tested in previous work. These inhibitors consist of cyclic and linear regions, causing their mass spectral characterization to be a challenge. We determined the fragmentation mechanism of cyclic peptides 1-9 using an ion-trap mass spectrometer equipped with an ESI source. Low-energy collision-induced dissociation of sodiated cyclic peptides containing linear branches follows a general pathway. Fragmentation of the linear peptide region produced mainly a and b ions. The ring peptide region was more stable and ring opening required higher collision energy, mainly occurring at the amide bond adjacent to the lactam bridge. The sodium ion, which bound to the carbonyl oxygen of the lactam bridge, acted as a fixed charge site and directed a charge-remote, sequence-specific fragmentation of the ring-opened peptide. Amino acid residues were cleaved sequentially from the C-terminus to the N-terminus. Our findings have established a new way to sequence cyclic peptides containing a lactam bridge based on charge-remote fragmentation. This methodology will permit unambiguous identification of high-affinity ligands within cyclic peptide libraries.
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Lin S, McLennan AG, Ying K, Wang Z, Gu S, Jin H, Wu C, Liu W, Yuan Y, Tang R, Xie Y, Mao Y. Cloning, expression, and characterization of a human inosine triphosphate pyrophosphatase encoded by the itpa gene. J Biol Chem 2001; 276:18695-701. [PMID: 11278832 DOI: 10.1074/jbc.m011084200] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
ITP and dITP exist in all cells. dITP is potentially mutagenic, and the levels of these nucleotides are controlled by inosine triphosphate pyrophosphatase (EC ). Here we report the cloning, expression, and characterization of a 21.5-kDa human inosine triphosphate pyrophosphatase (hITPase), an enzyme whose activity has been reported in many animal tissues and studied in populations but whose protein sequence has not been determined before. At the optimal pH of 10.0, recombinant hITPase hydrolyzed ITP, dITP, and xanthosine 5'-triphosphate to their respective monophosphates whereas activity with other nucleoside triphosphates was low. K(m) values for ITP, dITP, and xanthosine 5'-triphosphate were 0.51, 0.31, and 0.57 mm, respectively, and k(cat) values were 580, 360, and 640 s(-1), respectively. A divalent cation was absolutely required for activity. The gene encoding the hITPase cDNA sequence was localized by radiation hybrid mapping to chromosome 20p in the interval D20S113-D20S97, the same interval in which the ITPA inosine triphosphatase gene was previously localized. A BLAST search revealed the existence of many similar sequences in organisms ranging from bacteria to mammals. The function of this ubiquitous protein family is proposed to be the elimination of minor potentially mutagenic or clastogenic purine nucleoside triphosphates from the cell.
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MESH Headings
- Amino Acid Sequence
- Blotting, Northern
- Chromatography, Gel
- Chromosomes, Human, Pair 20
- Cloning, Molecular
- DNA, Complementary/metabolism
- Databases, Factual
- Escherichia coli/metabolism
- Humans
- Hydrogen-Ion Concentration
- Hydrolysis
- Inosine Triphosphate/analogs & derivatives
- Inosine Triphosphate/metabolism
- Kinetics
- Models, Biological
- Molecular Sequence Data
- Pyrophosphatases/biosynthesis
- Pyrophosphatases/chemistry
- Pyrophosphatases/genetics
- RNA/metabolism
- Radiation Hybrid Mapping
- Recombinant Proteins/metabolism
- Ribonucleotides/metabolism
- Sequence Homology, Amino Acid
- Substrate Specificity
- Tissue Distribution
- Transcription, Genetic
- Inosine Triphosphatase
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571
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Sun A, Lin S, Wei Y. [Observation of preventing of bone loss during early postmenopause by percutaneous estradiol in Chinese postmenopausal women]. ZHONGHUA FU CHAN KE ZA ZHI 2001; 36:348-51. [PMID: 11783133] [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 investigate the optimal regimen for application of percutaneous estradiol gel in preventing bone loss in Chinese postmenopausal women. METHODS A 3-year open randomized clinical study was designed. The percutaneous estradiol gel was used in a cyclic regimen combined with micronized progesterone (MP) or medroxyprogesterone acetate (MPA). Sixty healthy women (naturally menopause for 1 to 5 years) were recruited and divided into four groups according to estrogen dosage and two kinds of progestin. All were given for 25 d/month. The cortical bone mineral density (BMD) of right radius was measured by single photon absorptiometry. The trabecular BMD in lumbar vertebrae was measured by quantitative CT. The spine and hip BMD were also measured by dual energy X-ray absorptiometry at baseline, 6, 12, 18, 24 and 36 months, respectively. The bone metabolic markers, scores of menopausal symptoms were also evaluated. RESULTS Fifty-nine patients (98%) completed 1 year and 56 patients (93%) 2 years, 51 (85%) 3 years of study. The symptoms were alleviated by 80% after 6 months treatment on average. By the end of 24 month, the mean increases of BMD ranged from 4.3% to 7.5% in trabecular bone, and by the end of 36 month 4.2% to 6.2% in the lumbar (L) 2-4, 1.6% to 3.8% in the femur neck, with significant differences (P < 0.05). Comparing the 4 groups with each other, no significant differences (P > 0.05) were found in improvement of symptoms, bone markers and BMD. CONCLUSIONS Both daily estrogen containing 0.75 mg and 1.5 mg E2 are effective to prevent the early postmenopausal bone loss and improve the menopausal symptoms. During 3 years treatment, the BMD of lumbar increased continuously and the BMD of hip increased in the first 2 years and then plateau.
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572
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Zhao S, Ye Q, Sun A, Wang H, Lang J, Lin S, Wu J, Fan J, Liao J, Peng Y, Lu S, Xiao B. [A clinical evaluation on reconstruction in extended partial laryngectomy for transglottic cancer]. ZHONGHUA ER BI YAN HOU KE ZA ZHI 2001; 36:216-9. [PMID: 12761929] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE Transglottic cancer has been a definite indication for total laryngectomy in decades, compromising function of the larynx. The purpose of this study is to present a new radical surgery of extended partial laryngectomy and reconstruction to restore the essential function of larynx. METHODS Forty-one cases of transglottic cancer were treated by extended vertical laryngectomy (26/41), extended frontolateral laryngectomy (5/41) and subtotal laryngectomy (10/41); the defects of larynx were reconstructed by rotary door myocutaneous flap in twenty-seven cases, by sternohyoideus flap in seven cases, by osteomuscular flap in five cases and by sternocleidomastoid flap in two cases. RESULTS The 3 and 5 year survival rates were 85.7% (30/35) and 74.1% (20/27) respectively, those for stage III were 84.6% (22/26) and 76.2% (16/21), for stage IV were 3/4 and 1/2 respectively. All cases resumed acceptable voice, 92.7% (38/41) and enjoyed satisfactory phonation. The over-all decannulation rate was 87.8% (36/41), those with rotary door myocutaneous flap was 96.3% (26/27), with sternohyoideus flap was 5/7, with osteomuscular flap was 4/5 and with sternocleidomastoid flap was 1/2. All patients had normal swallow function. CONCLUSION Extended partial laryngectomy is a kind of radical operation in selected cases of transglottic cancer. The method of reconstruction with rotary door myocutaneous flap can improve curative effect and the essential functions of the larynx.
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573
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Nishimura Y, Yu Y, Kotani Y, Nishiuma T, Lin S, Maeda H, Yokoyama M. Bronchial hyperresponsiveness and exhaled nitric oxide in patients with cardiac disease. Respiration 2001; 68:41-5. [PMID: 11223729 DOI: 10.1159/000050461] [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: 11/19/2022] Open
Abstract
BACKGROUND Increased concentrations of exhaled nitric oxide (NO) correlate with increased airway inflammation and measurement of exhaled NO is a noninvasive method for the management of bronchial asthma. In various cardiac diseases, bronchial hyperresponsiveness is observed, as is bronchial asthma. However, there have been few studies on the relationship between exhaled NO and bronchial responsiveness in cardiac diseases. OBJECTIVE The aim of this study was to clarify the association between exhaled NO and bronchial hyperresponsiveness in patients with cardiac disease. METHODS We measured expired NO and bronchial responsiveness to inhaled methacholine in 19 patients with cardiac diseases and 17 with bronchial asthma. We divided the cardiac disease patients into two groups according to their bronchial responsiveness to inhaled methacholine: BHR(+) group consisted of 12 patients with bronchial hyperresponsiveness and BHR(-) group consisted of 7 patients without bronchial hyperresponsiveness. RESULTS The concentration of exhaled NO in the asthmatic patients was significantly higher than that in the BHR(+) and BHR(-) groups (142.0 +/- 17.0, 33.6 +/- 6.4 and 42.3 +/- 10.3 ppb, respectively, p < 0.01). There was no significant difference in exhaled NO between BHR(+) and BHR(-) groups. There were also no significant differences in the parameters of bronchial hyperresponsiveness between the cardiac BHR(+) and bronchial asthma groups. These results indicate that bronchial hyperresponsiveness in patients with cardiac diseases is not a consequence of eosinophilic inflammation or of exhaled NO. CONCLUSION We conclude that bronchial hyperresponsiveness in patients with cardiac diseases can occur independently of NO production.
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574
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Huang H, Vogel SS, Liu N, Melton DA, Lin S. Analysis of pancreatic development in living transgenic zebrafish embryos. Mol Cell Endocrinol 2001; 177:117-24. [PMID: 11377827 DOI: 10.1016/s0303-7207(01)00408-7] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Using DNA constructs containing regulatory sequences of the zebrafish Pdx-1 and insulin genes, germline transgenic zebrafish expressing the green fluorescent protein (GFP) reporter gene in the pancreas were generated. For both constructs, the GFP expression patterns in transgenic embryos were consistent with the mRNA expression patterns detected by RNA in situ hybridization. A deletion promoter analysis revealed that positive and negative cis-acting elements were involved in regulation of insulin gene expression. Three-dimensional reconstructions imaged from living embryos using two-photon laser-scanning microscopy (TPLSM) demonstrated that the zebrafish pancreas is formed from a single dorsal pancreatic cell mass. This is in contrast to mammals where the pancreas derives from both dorsal and ventral anlage. These transgenic fish should be useful for in vivo studies of factors involved in specifying and regulating pancreatic development and function.
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575
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Zhang H, Wada J, Hida K, Tsuchiyama Y, Hiragushi K, Shikata K, Wang H, Lin S, Kanwar YS, Makino H. Collectrin, a collecting duct-specific transmembrane glycoprotein, is a novel homolog of ACE2 and is developmentally regulated in embryonic kidneys. J Biol Chem 2001; 276:17132-9. [PMID: 11278314 DOI: 10.1074/jbc.m006723200] [Citation(s) in RCA: 182] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Collectrin, a novel homolog of angiotensin-converting enzyme-related carboxypeptidase (ACE2), was identified during polymerase chain reaction-based cDNA subtraction and up-regulated in 5/6 ablated kidneys at hypertrophic phase. Collectrin, with 222 amino acids, has an apparent signal peptide and a transmembrane domain; the sequence is conserved in mouse, rat, and human and shares 81.9% identity. Human collectrin has 47.8% identity with non-catalytic extracellular, transmembrane, and cytosolic domains of ACE2; however, unlike ACE and ACE2, collectrin lacks active dipeptidyl carboxypeptidase catalytic domains. The collectrin mRNA transcripts are expressed exclusively in the kidney. In situ hybridization reveals its mRNA expression in renal collecting ducts, and immunohistochemistry shows that it is localized to the luminal surface and cytoplasm of collecting ducts. Immunoprecipitation studies, using [35S]methionine-labeled renal cortical and inner medullar collecting duct cells, i.e. M-1 and mIMCD-3, indicate that the protein size is approximately 32 kDa. During the development of mouse kidney, mRNA signal is detectable at day 13 of gestation, and the protein product is observed in the ureteric bud branches. Its expression is progressively increased during later stages of the gestation extending into the neonatal periods and then is decreased in adult life. Up-regulated expression of collectrin in the hypertrophic kidneys after renal ablation and restricted spatio-temporal expression during development indicates a possible role(s)in the process of progressive renal failure and renal organogenesis.
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