QSAR for prediction of joint toxicity of substituted phenols to tadpoles (Rana japonica).
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Animals↗
Biomedical subjects
L Wang
Publications and source records attributed to L Wang.
Effects of increased muscle mass on bone in male mice overexpressing IGF-I in skeletal muscles.
It has been hypothesized that increase in muscle mass increases the strain on bone resulting in increase in bone mass. The aim of the present study was to determine the effects of increased muscle mass on bone. A colony of transgenic mice that overexpress hIGF-I in muscle, resulting in larger muscles, was established. Six-month-old heterozygous and wild type males were used in this study. The tibial diaphysis, femoral diaphysis and distal femoral metaphysis were analyzed using pQCT densitometry. Heterozygous animals had significantly higher body weight, muscle weight and muscle area when compared with wild type animals. Tibia and femur of the heterozygous mice had significantly higher weights and lengths. The tibial and femoral diaphyses of heterozygous animals had significantly higher cortical bone area, cortical bone mineral content, cortical bone mineral density, cortical thickness and periosteal perimeter when compared with wild type animals. In the distal femoral metaphysis, the total bone area and the cancellous bone area of heterozygous mice were significantly higher than those of wild type animals. In conclusion, increased muscle mass was associated with bigger bones in animals overexpressing IGF-I. Only pure cortical bone increased in both area and mineral content in these animals; cancellous bone, however, increased only in area and not in mineral content and density.
Absorptiometry, Photon↗
Successful treatment of mesenteric vasculitis caused by Henoch-Schönlein purpura with methylprednisolone pulse therapy.
Although mesenteric vasculitis due to Henoch-Schönlein purpura (HSP) is relatively uncommon, it is the most life-threatening manifestation associated with high mortality. We describe a 15-year-old boy with HSP who had massive gastrointestinal bleeding and ileus but delayed onset of the purpuric rash. Abdominal ultrasonography revealed thickening of both small and large intestinal walls, and CT found prominent mesenteric vessels with comb sign and double wall of the bowel. These findings were consistent with mesenteric vasculitis and bowel ischaemia. The ischaemic intestine recovered after methylprednisolone pulse therapy and surgical intervention was avoided. Our report suggests that corticosteroid pulse therapy may help controlling HSP with massive gastrointestinal haemorrhage and ischaemic bowel due to widespread mesenteric vasculitis.
Adolescent↗
Baseline characteristics of the transient pattern electroretinogram in non-human primates: inter-ocular and inter-session variability.
This study assessed the inter-ocular and inter-session variability of the transient pattern electroretinogram (PERG) in a group of non-human primates. The transient PERG was measured both eyes of 29 non-human primates, and again after three months in 23 eyes of 23 of these animals. Signals were elicited using a contrast (90%, 75 cdm(-2)) reversing (5 reversals sec(-1)) checkerboard pattern (0.56 cpd). PERGs were also measured for stimuli of varied spatial frequency (n=8, 0.07-2.22 cpd), contrast (n=4, 20-100%), mean luminance (n=4, 4.7-75 cdm(-2)) and defocus (n=5, +1, +2, +3 diopters). The inter-eye and inter-session limits-of-agreement (LOA; 95%) were determined for each PERG parameter. Variability was also compared with previous studies using the coefficient-of-variability (COV). Pharmacological blockade of the inner retinal contributions to the PERG measured under these conditions was conducted in one animal using intravitreal injection of tetrodotoxin (approximately 6 microM) and N-methyl-D-aspartic acid (approximately 6 microM). The N95 component of the primate transient PERG showed spatial tuning, with a peak between 0.14 and 0.28cpd. This spatial tuning was not as apparent for the P50 component. A linear relationship between P50 and N95 amplitude was found with contrast and mean luminance. Both components were attenuated with the introduction of +2 diopters or more of defocus. The inter-session COV for the P50 and N95 components were 23.8 and 19.2%, respectively, while the LOA were 58 and 46%, respectively. The N95:P50 ratio had smaller inter-session variability, was robust to changes in contrast, mean luminance and defocus, and was effective for characterization of inner-retinal dysfunction after pharmacologic block.
Animals↗
Tremorgenic mycotoxins increase gastric smooth muscle activity of sheep reticulum and rumen in vitro.
Reticulum and rumen strips (consisting of both muscle layers and the myenteric plexus) were superfused with Tyrode Ringer and their contractions recorded isometrically. The strips were subjected to exogenous acetylcholine and electrical field stimulation (EFS) resulting in contractions that could be blocked by atropine. Responses to the tremorgenic mycotoxin penitrem A and others thought to be involved in ryegrass staggers, paxilline and lolitrem B (10(-10)-10(-6)M), were compared with those of control vehicle (0.1% DMSO). The tremorgens were without effect on quiescent preparations. Penitrem A and paxilline enhanced spontaneously active preparations and the amplitude of contractions in response to EFS. Responses to paxilline had a shorter latency than to penitrem A. Responses of spontaneously active preparations were resistant to atropine. Penitrem A, but not paxilline, increased responses to exogenous acetylcholine. Lolitrem B (10(-6)M) increased responses to EFS, but many responses were equivocal, possibly due to the lower solubility of lolitrem B in aqueous solutions compared to the other tremorgens. The results show that these mycotoxins have peripheral excitatory effects on the reticulorumen and it is suggested that such activity in vivo may reflexly affect centrally derived cyclical contractions.
Animals↗
Experience with a porcine hepatocyte-based bioartificial liver support system.
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Ammonia↗
Induction of the specific tolerance and enhancing the allograft survival by transfection of recipient cells with donor MHC class I cDNA.
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Animals↗
Role of cell surface components on Cu2+ adsorption by Pseudomonas putida 5-x isolated from electroplating effluent.
A gram-negative bacterium Pseudomonas putida 5-x with high Cu2+ accumulating capability was isolated from electroplating effluent in Kwun Tong, Hong Kong. The pretreated cells without superficial layer-capsule, isolated cell envelopes and the separated peptidoglycan layer materials were obtained from fresh P. putida 5-x cells, their Cu2+ adsorption capacities and properties were compared with that of the fresh cells. Pretreatment by 0.1 mol L(-1) HCl enhanced Cu2+ adsorption capacity due to the degradation of cell superficial layer-capsule of P. putida 5-x cells. Isolated cell envelopes possessed five times more Cu2+ adsorption capacity than that of fresh intact cell. The Cu2+ adsorption of separated peptidoglycan layer materials indicated that the peptidoglycan layer only played 10-15% part of the Cu2+ adsorption capacity, and implied other cell surface components such as outer membrane or inner membrane might play an important role in such high Cu2+ binding of the cell envelopes. The adsorption process of fresh cells, pretreated cells and cell envelopes of P. putida 5-x could be described with Freundlich isotherm, while the adsorption of Cu2+ by separated peptidoglycan layer materials was better described with Langmuir isotherm.
Adsorption↗
Evaluation of sodium alginate for bone marrow cell tissue engineering.
Sodium alginate has applications as a material for the encapsulation and immobilisation of a variety of cell types for immunoisolatory and biochemical processing applications. It forms a biodegradable gel when crosslinked with calcium ions and it has been exploited in cartilage tissue engineering since chondrocytes do not dedifferentiate when immobilised in it. Despite its attractive properties of degradability, ease of processing and cell immobilisation, there is little work demonstrating the efficacy of alginate gel as a substrate for cell proliferation, except when RGD is modified. In this study we investigated the ability of rat bone marrow cells to proliferate and differentiate on alginates of differing composition and purity. The mechanical properties of the gels were investigated. It was found that high purity and high G-type alginate retained 27% of its initial strength after 12 days in culture and that comparable levels of proliferation were observed on this material and tissue culture plastic. Depending on composition, calcium crosslinked alginate can act as a substrate for rat marrow cell proliferation and has potential for use as 3D degradable scaffold.
Alginates↗
Migration and differentiation of adult rat subventricular zone progenitor cells transplanted into the adult rat striatum.
Adult brain subventricular zone progenitor cells undergo neurogenesis in the olfactory bulb. We tested the hypothesis that cultured adult subventricular zone progenitor cells migrate and differentiate into neurons when transplanted into the adult striatum. Cells in the adult rat subventricular zone were isolated and cultured for 8 days in medium containing basic fibroblast growth factor. These cells proliferated as assayed by bromodeoxyuridine immunostaining, and the majority of them were neuron-specific class III beta-tubulin (TuJ1) immunoreactive at 8 days of culture. These cultured cells were labeled in vitro with bromodeoxyuridine or with lipophilic dye-coated particles and were transplanted into the adult rat striatum. Twenty-eight days after transplantation, the cells migrated 0.5-1.5 mm from the midline of the graft to the surrounding host striatum. Migration of grafted cells in the host striatum was also detected on magnetic resonance imaging in living rats. Morphological analysis revealed that many of these migrated cells exhibited multibranched processes from the cell soma resembling host medium-size striatal projection neurons. Only a few astrocyte-like cells were detected. Double immunostaining showed that many bromodeoxyuridine immunoreactive cells were microtubule-associated protein 2 or immunoreactive with a mouse monoclonal antibody against neuronal nuclear protein, whereas only a few bromodeoxyuridine immunoreactive cells had glial fibrillary acidic protein immunoreactivity. Morphology of bromodeoxyuridine and microtubule-associated protein 2 immunoreactive cells was similar to those of host microtubule-associated protein 2 immunoreactive cells. These results suggest that transplanted cultured adult subventricular zone progenitor cells can migrate and differentiate in response to guidance cues within the adult striatum.
Age Factors↗
Plasma fatty acid composition and incidence of coronary heart disease in middle aged adults: the Atherosclerosis Risk in Communities (ARIC) Study.
BACKGROUND AND AIM: To prospectively investigate the relation of plasma cholesterol ester (CE) and phospholipid (PL) fatty acid (FA) composition with incidence of coronary heart disease (CHD). METHODS AND RESULTS: 3,591 white participants in the Minneapolis field center of the Atherosclerosis Risk in Communities Study, aged 45-64 years, were studied. Plasma FA composition of CEs and PLs was quantified using gas-liquid chromatography and expressed as percentage of total FAs. Incident CHD was identified during 10.7 years of follow-up. In both CE and PL fractions, the proportions of stearic (18:0) acid, dihomo-gamma-linolenic (20:3n6) acid and total saturated fatty acids (SFAs) were significantly higher while arachidonic (20:4n6) acid and total polyunsaturated fatty acids (PUFAs) were significantly lower among participants who developed incident CHD (n = 282). After adjusting for age, gender, smoking, alcohol drinking, sports activity, and non-FA dietary factors, the incidence of CHD was significantly and positively associated with the proportion of dihomo-gamma-linolenic acid but inversely associated with arachiadonic acid. The multiply-adjusted rate ratios (RRs) of CHD incidence for the highest versus the lowest quintile were 1.31 in CE and 1.44 in PL for dihomo-gamma-linolenic acid (p for trend: 0.05 and 0.017, respectively), 0.59 in CE and 0.65 in PL for arachidonic acid (p: 0.016 and 0.024, respectively). Also significantly and positively associated with incident CHD were PL stearic acid and CE linolenic (18:3n3) acid. Only a borderline significant positive association was observed for total SFAs in CE (multivariate RRs across quintiles: 1.00, 1.15, 1.40, 1.62, 1.32; p = 0.07). Total PUFAs or monounsaturated FA were not independently associated with CHD. CONCLUSIONS: Our study found a weak positive association of SFAs with incident CHD. Our findings also confirm that FA metabolism in the body, such as the activity of delta-5 desaturase, which converts dihomo-gamma-linolenic acid to arachidonic acid, may affect the development of CHD.
8,11,14-Eicosatrienoic Acid↗
Mechanisms of rupture of knitted polyester vascular prostheses: an in vitro analysis of virgin prostheses.
OBJECTIVES: Previous explant retrieval studies have shown ruptures occurring on the remeshing line and the guide line of two types of warp-knitted grafts. The aim of our study was to characterize the mechanisms these ruptures. MATERIALS AND METHODS: We performed an in vitro study of the mechanical and chemical characteristics of virgin prostheses. We studied 2 virgin polyester warp-knitted grafts models: the Cooley Double Velour and the Microvel Double Velour constructed by Meadox (USA), using the following techniques: characterization and de-knitting of the textile structure, circumferential tensile strength, filament dynamometry, critical dissolution time of the filaments and scanning electron microscopy. RESULTS: Both prostheses were constructed in the same way but the texturized yarns of the Cooley graft included twice as many filaments (54) than the Microvel (27). There was more adsorbed tension in the Cooley structure than in the Microvel. The circumferential tensile strength test demonstrated that the Cooley graft always ruptured on the remeshing line and the Microvel graft always ruptured at the interface between the remeshing line and the standard line. Filament dynamometry demonstrated a heterogeneous behavior of the filaments inside the yarns, mainly at the remeshing line of the Cooley graft (27.1 cN/tex +/- 11.5% versus 26.1 cN/tex +/- 2.2% for the guide line and 28 cN/tex +/- 6.7% for the standard knit). Critical dissolution time of the filaments was significantly lower for the Microvel grafts (2.5 sec versus 17.2 sec for the Cooley). CONCLUSIONS: Rupture of knitted polyester prostheses are probably an underestimated phenomenon. They may occur at specific areas of the graft. Further studies are required to determine whether all grafts of this type are at risk.
Blood Vessel Prosthesis↗
Prevalence of open-angle glaucoma in Iceland: Reykjavik Eye Study.
PURPOSE: To establish the age- and sex-specific prevalence of open-angle glaucoma (OAG) subsuming pseudoexfoliation (PEX) in the city of Reykjavik. METHODS: Participants 50 years of age and older who were part of the Reykjavik Eye Study and classified as having glaucoma were divided into three categories:Category 1: two or more of the following based on optic nerve stereophotograph reading: vertical cup to disc ratio (VCDR) 97.5th percentile (>0.7), focal glaucomatous disc change, C/D asymmetry of 97.5th percentile difference between eyes (>0.2) as well as glaucomatous visual field defect (GVFD). Category 2: 99.5th percentile of VCDR (>0.8) and 99.5% percentile difference between eyes (>/=0.3), without a GVFD. Category 3: VA<3/60 and IOP>99.5th percentile or VA <3/60 and evidence of filtering surgery. For a glaucoma suspect, one of the following was present: VCDR>99.5th percentile (>0.8), focal glaucomatous disc change, C/D asymmetry of 99.5th percentile (> or =0.3), GVFD only, IOP> or =23 mmHg (97.5 percentile). PEX was diagnosed by the presence of a central shield and/or a peripheral band on the anterior lens capsule. RESULTS: Of 42 persons (22 males and 20 females) with OAG, 13 (31.0%) had PEX. The minimum prevalence of OAG was 4.0% (42/1045) (95% CI 2.8-5.2) for those 50 years and older and 10.3% (95% CI 8.5-12.2) for PEX. The prevalence of OAG increases with age (OR=1.10/year, 95% CI 1.07-1.13, P=0.000) and the same applies for the prevalence of PEX, OR=1.10 (95% CI 1.07-1.12, P=0.000). CONCLUSION: There is a 10% annual increase for both OAG and PEX in persons 50 years and older.
Age Distribution↗
Identification of a novel fusion gene, TTL, fused to ETV6 in acute lymphoblastic leukemia with t(12;13)(p13;q14), and its implication in leukemogenesis.
ETS variant gene 6 (ETV6)/translocation, ETS, leukemia (TEL)-involving chromosomal translocations are frequently observed in various hematologic neoplasms. We describe here a novel ETV6-involving translocation, t(12;13)(p13;q14), found in the case of acute lymphoblastic leukemia, in which ETV6 fused with a previously unknown gene, named Twelve-thirteen Translocation Leukemia gene (TTL), at 13q14. TTL was weakly but ubiquitously expressed in normal human tissues as detected by reverse transcribed-PCR. Three TTL splicing forms were identified, TTL-T from a human testis cDNA library, with an open-reading frame of 402 bp encoding 133 amino acids (aa), and TTL-B1 and -B2 from a human brain cDNA library. These proteins have no homology to known proteins. In leukemic cells from the patient, both reciprocal fusion transcripts, ETV6/TTL and TTL/ETV6, were expressed. The predominant fusion transcript, TTL/ETV6-1, encodes a predicted 530 aa fusion protein containing 89 aa of the N-terminal TTL fusing to the helix-loop-helix domain and ETS-binding domain of ETV6. Although the function of TTL is yet to be elucidated, our findings will provide another insight into the molecular pathogenesis of leukemia having ETV6-involving translocations.
Alternative Splicing↗
BCR-ABL with an e6a2 fusion in a CML patient diagnosed in blast crisis.
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Aged↗
Atmospheric aerosol concentration level and chemical characteristics of water-soluble ionic species in wintertime in Beijing, China.
Total suspended particulate (TSP) samples were collected during wintertime from November 24, 1998 to February 12, 1999 in Beijing. Ionic species including Cl-, NO3(-), SO4(2-), Na+, NH4(+), K+, Mg2+ and Ca2+ were determined by Ion Chromatography (IC). The sum average concentration of all the determined ions accounted for 18.9% of the TSP concentration, and SO4(2-) appeared the dominant ion with an average concentration of 30.84 microg m(-3); the sum mass concentration of SO4(2-), NO3(-), Ca2+ and NH4(+) accounted for about 83.2% of all the eight ions measured. The study indicated that the chemical form of sulfate and ammonium varies with TSP concentration levels. During heavy pollution periods, the average TSP concentration was 0.66 mg m(-3), and the NH4(+)/SO4(2-) molar ratio was low (0.58). It indicated that sulfate may present as CaSO4 and (NH4)2SO4 x CaSO4 x 2H2O. When TSP concentration (average 0.186 mg m(-3)) was relatively low, the NH4(+)/SO4(2-) molar ratio was 1.94, close to the theoretical ratio of 2 of (NH4)2SO4. Under this condition (NH4)2SO4 is expected to exist as the major form of sulfate. When the TSP concentration level was medium (average 0.35 mg m(-3)), the NH4+/SO4(2-) molar ratio appeared an average value (1.27), (NH4)2SO4, (NH4)2SO4 x CaSO4 x 2H2O and CaSO4 are expected to be present in those aerosol particles. Meteorological conditions including wind speed and wind direction were related to the TSP concentration level.
Aerosols↗
A rare leucine codon in adpA is implicated in the morphological defect of bldA mutants of Streptomyces coelicolor.
Streptomycetes are mycelial bacteria that produce sporulating aerial hyphae on solid media. Bald (bld) mutants fail to form aerial mycelium under at least some conditions. bldA encodes the only tRNA species able to read the leucine codon UUA efficiently, implying the involvement of a TTA-containing gene in initiating aerial growth. One candidate for such a gene was bldH, because the bldH109 mutant of Streptomyces coelicolor resembles bldA mutants in some aspects. In the work reported here, adpAc, an S. coelicolor gene similar to the Streptomyces griseus A factor-regulated adpAg, was found to complement the bldH109 mutant partially at both single and multiple copies. The sequence of adpAc from the bldH109 mutant revealed a frameshift. A constructed in frame deletion of adpAc conferred a bald colony phenotype, and the mutant behaved like bldA mutants and bldH109 in its pattern of extracellular signal exchange. Both adpAc and adpAg contain a TTA codon. A TTA-free version of adpAc was engineered by replacing the TTA leucine codon with a cognate TTG leucine codon. The adpA(TTATTG) gene could partially restore aerial mycelium formation to a bldA mutant when it was followed in cis by the gene ornA, as in the natural chromosomal arrangement. This indicated that the UUA codon in adpAc mRNA is the principal target through which bldA influences morphological differentiation. It also implied that translational arrest at the UUA codon in adpAc mRNA caused a polar effect on the downstream ornA, and that the poor translation of both genes contributes extensively to the deficiency of aerial mycelium formation in bldA mutants. Unlike the situation in S. griseus, adpAc transcription does not depend on the host's -butyrolactone signalling system, at least in liquid cultures. In addition, sigma factor BldN, which is the homologue of an S. griseus sigma factor AdsA that is absent from adpAg mutants of S. griseus, was present in the constructed adpAc null mutant of S. coelicolor.
Bacterial Proteins↗
Quantification of ADP and ATP receptor expression in human platelets.
The mechanism of ADP-mediated platelet activation has been difficult to unravel due to the large number of receptors for extracellular nucleotides (P2 receptors). mRNA levels in circulating platelets are very low, but have been shown to be translationally active. By optimizing mRNA extraction and using real time (RT)-PCR we were able to establish a protocol for highly sensitive platelet mRNA quantification in human regular blood samples. In platelets from healthy volunteers, only P2X1, P2Y1 and P2Y12 were found in significant levels, with the following order of expression: P2Y12 >> P2X1 > P2Y1. Other P2 receptors (P2Y2, P2Y4, P2Y6, P2Y11, P2Y13, P2X4, P2X7) had very low expression. As a control measurement to exclude contamination, P2 receptors in buffy coat were quantified but had a completely different profile. Incubation in vitro revealed a more rapid degradation rate for P2X1 receptor mRNA than for P2Y1 and P2Y12, indicating that the level of P2X1 may be relatively higher in newly released platelets and in megacaryocytes. In conclusion, we have developed the first protocol for quantifying mRNA expression in human platelets limiting the P2 receptor drug development targets to P2Y12, P2Y1 and P2X1. Furthermore, the method could be used to study platelet expression for any gene in human materials.
Base Sequence↗