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Biomedical subjects

L Ye

Publications and source records attributed to L Ye.

At least 127 records · Page 7Linked to original sources
PubMed1993

Close linkage of the gene for Werner's syndrome to ANK1 and D8S87 on the short arm of chromosome 8.

Werner's syndrome (WRN) is a rare autosomal recessive disorder characterized by the appearance of features of premature aging in a young adult. Skin fibroblasts from WRN patient demonstrate slow growth, reduced life span in vitro and mutator phenotype. The genetic defect in WRN is unknown. We have studied 23 WRN patients mainly from first or second cousin marriage and have applied homozygosity mapping to search for the WRN locus. A peak lod score of 5.58 at a recombination fraction of 0.03 was obtained with D8S87. We confirmed that the WRN locus was located on the short arm of chromosome 8, 8p11.2-p12.

Adult↗
PubMed1993

[Studies on urinary metabolites of calusterone in man].

The metabolites of calusterone (17 beta-OH-7 beta, 17 alpha-dimethyl-androst-4-ene-3-one) in man has been investigated by GC/MS. After oral administration, the parent compound and seven metabolites were detected in the conjugated fraction. The extraction and fractionation of these metabolites were achieved by using XAD-2 column. The sample was derivatized with MSTFA/TMSI before GC/MS analysis. The mass spectra of the metabolites are presented and the metabolic pathway was discussed.

Doping in Sports↗
PubMed1993

[Cytogenetic and molecular genetic study on a female with complex translocation of t(Y;15) and t(14;21)].

A 27-year-old female having a baby with Down's syndrome was found to have a translocation t(14;21) and an acrocentric marker chromosome 15. The short arm of the marker was darkly stained in both G- and C-banded preparations, and had the normal Ag-NOR, but showed a homogeneously stained region in the distal part of the marker. By means of QM staining, the variant was found fluorescent, and Y-body like was found in about 9% interphase nuclei, which suggested that there might exist Y chromosome material in genomic DNA of proband. Dot blot hybridization using DNA probe pY3.4 derived from the heterochromatic region on the long arm of Y chromosome demonstrated that the proband carried Y chromosome material in her genome. Further, by in situ hybridization with the same probe, it showed that the variant of the marker had specific autoradiographic silver grains. So, the karyotype of the proband indicated that the combination of conventional banding analysis with chromosome-specific probe was of great significance in studying the micro-aberration of human chromosome.

Adult↗
PubMed1992

Domains required for nucleic acid binding activities in chloroplast ribonucleoproteins.

Five ribonucleoproteins (or RNA-binding proteins) from tobacco chloroplasts have been identified to date; each of these contains an acidic N-terminal domain (24-64 amino acids) and two conserved RNA-binding domains (82-83 amino acids). All five ribonucleoproteins can bind to ssDNA and dsDNA but show high specificity for poly(G) and poly(U). Here we present the nucleic acid binding activity of each domain using a series of deletion mutant proteins made in vitro from the chloroplast 29 kDa ribonucleoproteins. The acidic domain does not have a positive effect on binding activities and proteins lacking this domain show higher affinities for nucleic acids than the wild-type proteins. Mutant proteins containing single RNA-binding domains can bind to poly(G) and poly(U), though with lower affinities than proteins containing two RNA-binding domains. The spacer region (11-37 amino acids) between the two RNA-binding domains does not interact with poly(G) or poly(U) by itself, but is required for the additive activity of the two RNA-binding domains. Proteins consisting of two RNA-binding domains but lacking the spacer have the same activity as those containing only one RNA-binding domain. Possible roles for each domain in chloroplast ribonucleoproteins are discussed.

Amino Acid Sequence↗
PubMed1992

Electron microscopical demonstration of horseradish peroxidase by use of tetramethylbenzidine as chromogen and sodium tungstate as stabilizer (TMB-ST method): a tracing method with high sensitivity and well preserved ultrastructural tissue.

Until now methods using tetramethylbenzidine (TMB) for electron microscopy (TMB-EM methods) are all unable to provide a maximum demonstration of transported horseradish peroxidase (HRP) while maintaining good ultrastructural tissue preservation. In order to solve this problem, we have attempted to adapt a newly developed, highly sensitive TMB method using sodium tungstate (ST) as the stabilizer (TMB-ST method) for HRP electron microscopic retrograde and anterograde fiber tracing. The present study shows that the TMB-ST method combined with diaminobenzidine-cobalt (DAB-Co) is more sensitive than existing TMB-EM methods and that ultrastructural details are well preserved with this combined method. The resultant reaction product complex after osmication is stable and is observed as characteristic crystal-like structures which are extremely electron dense and often aggregated into clumps. In contrast, the TMB-ST method without the DAB-Co step frequently produces a moderate electron-dense reaction product. Therefore, we recommend the TMB-ST method combined with DAB-Co for HRP electron microscopy.

3,3'-Diaminobenzidine↗
PubMed1992

[A mid-infrared spectra study of a series of benzocrown ether and macrocyclic polyether diester].

With a Nicolet 20 SX B Fourier Transform infrared spectrometer, the mid-infrared spectra in region of 4000-400 cm-1 were observed for a series of benzocrown ether and macrocyclic polyether diester. A difference in the wavelength of absorption of the ether bond was found between benzocrown ether and macrocyclic polyether diester. The wavelength of absorption of the ether bond of the compounds I-IV moved down about 25 cm-1, as compared with that of the compounds V-IX.

Ethers, Cyclic↗
PubMed1992

Molecular cytogenetic study of short arm aberrations in human D, G group chromosomes.

Six cases of Dp+/Gp+, 10 cases of D/G translocation, 1 case of supernumerary marker chromosome, and 1 case of Yqs were studied using molecular and cytogenetic techniques. The Ag-NOR frequencies of the Dp+ and Gp+ groups were found to be higher than those of normal controls, while their satellite association frequencies were lower. Autoradiographic silver grains were not significantly distributed along the p+ part of the marker chromosome as revealed by chromosomal in situ hybridization using an rRNA probe. This result differs from our previous report. It is suggested that there might be different mechanisms for the formation of p+ on acrocentric chromosomes. D/G translocation cases were found to have lost their NOR. A study of supernumerary marker chromosomes and Yqs cases suggested that the marker chromosome and Yqs exerted no phenotypic effect. The mechanism of their formation is discussed.

Adolescent↗
PubMed1992

[Interphase cytogenetic studies of human X chromosome].

The chromosome in situ hybridization with human X chromosome alpha satellite DNA probe (pBamX7) on human lymphocyte metaphases and interphase nuclei was performed for interphase cytogenetic studies. The individuals with numerical or structural abnormalities of X chromosome were studied. The results showed that the probe hybridized specifically to the centromeric region (p11----q11) of X chromosome. The number of silver grain clusters in interphase nuclei was correlated with that of X chromosome. Most of the clusters located near the nuclear membrane where inactive X chromatins (Barr-bodies) were usually found. The method of ascertaining the number of X chromosomes by in situ hybridization was much more reliable than that by counting the number of Barr-bodies. The modified R-banding technique was introduced and the significance of this work was also discussed.

Chromosome Aberrations↗
PubMed1991

[The chromatographic-mass spectrometric analysis and detection of anabolic steroids in human urines and metabolic study].

Nineteen anabolic steroids were separately administered to healthy men. Anabolic steroid metabolites were isolated and extracted from the collected urine samples following an integrated procedure. The main metabolic pathways of these drugs were made clear after the investigation by GC-MS. Based on the obtained chromatographic-mass spectrometric data of anabolic steroids, a method for large scale and routine analysis of anabolic steroids was set up.

Adult↗
PubMed1990

[Permeability of 5 methemoglobin formers through red cell membrane].

By measuring the methemoglobin formation, the permeabilities of some cyanide antidotes passing through mouse erythrocyte membrane were studied. K3Fe(CN)6(0.1 mol/L) did not permeate the red cell and no methemoglobin formed. To the red cell suspension, adding PAPP 0.07 mmol/L, an useful cyanide antidote, no methemoglobin was found. On the contrary, PHAPP, the metabolite of PAPP, transported into the cell readily and reacted with hemoglobin to form methemoglobin quickly. DMAP and NaNO2 passed through the red cell membrane easily. With comparable amount of methemoglobin formation, the concentration of NaNO2 was about 200 times as much as that of DMAP. A comparison of the anticyanide potency of DMAP and NaNO2, the permeability rate constant, the half time and activation energy were measured as: 0.217 and 0.0506/min; 3.2 and 13.7 min; 17.1 and 50.2 kJ/mol, respectively. Owing to its ready permeability and formation of methemoglobin, DMAP is a better antidote than NaNO2 against cyanide poisoning.

Aminophenols↗