Biomedical subjects

M Ye

Publications and source records attributed to M Ye.

At least 37 records · Page 2Linked to original sources

PubMed2000

A tobacco-specific carcinogen in the fetus.

A tobacco-specific carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), and its metabolite, 4-[(methylnitrosamino)-1-(3-pyridyl)but-1-yl]beta-O-D-glucosiduronic+ ++ acid (NNAL-Gluc), have been found in the urine of newborns whose mothers smoked during pregnancy. We set out to determine whether this carcinogen is present in the fetus in early pregnancy. Cell-free amniotic fluid (AF) was obtained through routine amniocentesis for prenatal genetic studies from groups of smokers and non-smokers. NNAL and NNAL-Gluc were quantified by previously published methods. A history of smoking was confirmed by assays for cotinine plus N-beta-D-glucosiduronosyl-(S)-(-) cotinine inner salt (cotinine-Gluc) in AF. NNAL was detected in the AF of 11/21 (52.4%) of smokers and in 2/30 (6.7%) of non-smokers, a statistically significant difference (p=0.0006). There was not convincing evidence of NNAL-Gluc in the AF. This study documents for the first time that the tobacco-specific carcinogen NNAL is present in the fetus in early pregnancy. Further rigorous epidemiological studies are needed to determine whether the offspring of smoking mothers have an increased lifetime risk of cancer.

Amniotic Fluid↗

PubMed2000

Capillary electrochromatography with physically and dynamically absorbed stationary phases.

Adsorption is always considered a troublesome effect in capillary electrophoresis (CE) and capillary electrochromatography (CEC). However, the adsorption effect can also be exploited to prepare or optimize the stationary phase in CEC. Compared with the chemical synthesis of new stationary phase materials for CEC, this method is simpler and more convenient. This review is focused on CEC with physically and dynamically adsorbed stationary phases. Separation of some acidic, basic and neutral solutes as well as enantiomers in CEC with dynamically adsorbed stationary phases are presented. The theory for the migration of charged solutes and the stationary phases currently used in CEC are also briefly reviewed.

Absorption↗

PubMed2000

Gene expression in CD34(+) cells from normal bone marrow and leukemic origins.

INTRODUCTION: To address the molecular regulation of hematopoiesis and the complex mechanism in leukemogenesis, we established the first catalogs of genes expressed in normal bone marrow and leukemia CD34(+) cells. MATERIALS AND METHODS: CD34(+) cell cDNA libraries were constructed using mRNA from adult bone marrow and from a case of acute myeloid leukemia-M5 transformed from myelodysplastic syndrome (MDS-AML). Expressed sequence tags (ESTs) and full-length cDNAs were generated by sequencing and were annotated using bioinformatic tools. RESULTS: From a total of 4142 ESTs obtained from normal bone marrow, 3424 meaningful tags were integrated into 1630 clusters, representing 622 known genes, 522 dbEST entries and 486 novel sequences. Out of 5382 ESTs from MDS-AML, 1985 clusters were produced based on the analysis of 4321 useful ESTs, including 711 known genes, 657 known ESTs and 617 novel sequences. Among 251 transcripts found in both bone marrow and MDS-AML EST datasets and those present in only one dataset, 58 showed statistically significant differences in EST copy numbers between the two tissues (P<0.05). Twenty putative full-length cDNAs for novel genes were also cloned from the MDS-AML library. CONCLUSION: The distinct gene expression patterns in MDS-AML-CD34(+) cells as compared to normal control cells may contribute to the development and/or maintenance of the malignant phenotypes of leukemia cells.

Adult↗

PubMed2000

Study on open tubular capillary affinity liquid chromatography.

A novel mode of affinity chromatography (AC) based on an open tubular capillary column (OTAC) is demonstrated. The OTAC column is prepared by immobilizing Cibacron blue F3GA onto the inner surface of a 50-microm-i.d. capillary column. The AC experiment is performed on a capillary electrophoresis instrument by using its pressure system as the driving force. Bovine serum albumin and lysozyme (Lys) are successfully separated with stepwise gradient elution. The relative standard deviation (RSD) for the elution time of the retained Lys is 0.08%, and good repeatability of its peak area and peak height with an RSD value lower than 2.12% for 10 consecutive runs is observed. The loading capacity and detection limit for the retained Lys are approximately 36 ng and 8.6 ng, respectively. It is also found that the amount of protein adsorbed is unaffected by the flow rate of the loading buffer, and OTAC can be used for the fast determination of biopolymers. Some of the advantages of OTAC over conventional modes of open tubular capillary liquid chromatography are that the detection sensitivity and loading capacity of a sample can be greatly improved, because the relatively large inner diameter of the capillary can be adopted and the whole capillary column can be used to adsorb the solute in OTAC.

Journal Article↗

PubMed2000

Cloning and functional analysis of cDNAs with open reading frames for 300 previously undefined genes expressed in CD34+ hematopoietic stem/progenitor cells.

Three hundred cDNAs containing putatively entire open reading frames (ORFs) for previously undefined genes were obtained from CD34+ hematopoietic stem/progenitor cells (HSPCs), based on EST cataloging, clone sequencing, in silico cloning, and rapid amplification of cDNA ends (RACE). The cDNA sizes ranged from 360 to 3496 bp and their ORFs coded for peptides of 58-752 amino acids. Public database search indicated that 225 cDNAs exhibited sequence similarities to genes identified across a variety of species. Homology analysis led to the recognition of 50 basic structural motifs/domains among these cDNAs. Genomic exon-intron organization could be established in 243 genes by integration of cDNA data with genome sequence information. Interestingly, a new gene named as HSPC070 on 3p was found to share a sequence of 105bp in 3' UTR with RAF gene in reversed transcription orientation. Chromosomal localizations were obtained using electronic mapping for 192 genes and with radiation hybrid (RH) for 38 genes. Macroarray technique was applied to screen the gene expression patterns in five hematopoietic cell lines (NB4, HL60, U937, K562, and Jurkat) and a number of genes with differential expression were found. The resource work has provided a wide range of information useful not only for expression genomics and annotation of genomic DNA sequence, but also for further research on the function of genes involved in hematopoietic development and differentiation.

Alternative Splicing↗

PubMed2000

Pathogenic conversion of live attenuated simian immunodeficiency virus vaccines is associated with expression of truncated Nef.

Rhesus macaques infected with simian immunodeficiency virus (SIV) containing either a large nef deletion (SIVmac239Delta(152)nef) or interleukin-2 in place of nef developed high virus loads and progressed to simian AIDS. Viruses recovered from both juvenile and neonatal macaques with disease produced a novel truncated Nef protein, tNef. Viruses recovered from juvenile macaques infected with serially passaged virus expressing tNef exhibited a pathogenic phenotype. These findings demonstrated strong selective pressure to restore expression of a truncated Nef protein, and this reversion was linked to increased pathogenic potential in live attenuated SIV vaccines.

Amino Acid Sequence↗

PubMed2000

Nonlinear pharmacokinetics of paclitaxel in ovarian cancer patients.

AIM: To characterize the disposition of paclitaxel in patients with ovarian carcinoma after a 3-h infusion. METHODS: Fifteen patients with advanced ovarian cancer were enrolled and were administered paclitaxel in a 3-h infusion at dosing levels of 135 mg/m2, 175 mg/m2, and 235 mg/m2. Thirteen plasma samples were obtained during the infusion and up to 24 h after the infusion. Paclitaxel concentrations in plasma were determined by HPLC assay. Pharmacokinetic parameters were assessed with noncompartment model and model-dependent method. RESULTS: The disposition of paclitaxel in patients with ovarian cancer conformed to a two-compartment model. The main pharmacokinetic parameters of three groups were T1/2 beta (5.18 +/- 3.49), (6.26 +/- 2.21), and (6.99 +/- 1.45) h, AUC (14.71 +/- 0.76), (39.09 +/- 13.10), and (66.52 +/- 12.23) mg.h.L-1, Cl (14.29 +/- 0.74), (7.52 +/- 2.15), and (6.25 +/- 1.93) L.h-1, respectively. CONCLUSION: The disposition of paclitaxel was nonlinear after a 3-h infusion. There was individual variability of metabolism among patients.

Adult↗

PubMed2000

[Clinical experience of long-distance electronic fetal heart rate monitoring system by telephone].

OBJECTIVE: To explore the value of the long-distance electronic fetal heart rate monitoring system by telephone and explore a new way of self-monitoring at home for pregnant woman. METHOD: 204 high risk pregnant women came to our clinic were enrolled in this study. Complications included pregnancy induced hypertension (PIH), intrauterine growth retardation (IUGR), anemia, diabetes, hemolysis, nephropathy. In the study group, 97 women took the terminal part of the fetal heart rate monitoring system home and were requested to auscultate and count fetal heart rate three times a day, while another 107 cases did the self monitoring by fetal movement counting daily and served as control group. For the study group, whenever woman felt any abnormality of her baby, she could contact the long-distance electronic fetal heart rate (FHR) monitoring center in hospital by telephone immediately. The signal of fetal heart beat and fetal movement was converted and analyzed in the electronic FHR monitoring center by computer at the same time. The fetal heart rate curve was printed out, and diagnosis and management could be made. Age, gestational weeks, high risk factors, abnormal non-stress test (NST), Apgar score and birth weight of newborn were analyzed between the experimental and control group retrospectively. RESULTS: There were no obviously differences in age, gestational weeks, weight of newborn, high risk factors between the 2 groups. The incidence of abnormal NST and Apgar score of newborn were significantly higher in the study group than that in the control group, while the incidence of neonatal asphyxia was significantly lower. CONCLUSIONS: This study suggested that the long-distance electronic FHR monitoring by telephone was a reliable, sensitive and applicable method of self-monitoring for pregnant woman at home, use of this system could decrease the incidence of fetal distress, brain damage and perinatal mortality, thus improves the quality of perinatal care.

Adult↗

PubMed2000

[The measurement of normal values of exophthalmos, interpupillary distance and interorbital distance of children and adolescence in Xiamen and the rule of their development].

OBJECTIVE: To investigate the developing rhythm of children and adolescent exophthalmos, interorbital distance (IOD) and interpupillary distance (IPD) and their mutual relationships. The study will provide biometry data for formulating juvenile criteria of correcting spectacles. METHODS: Random sampling was performed among children and adolescence aged 5 - 17 years in Xiamen. Adopting epidemic survey, we measured the biometry values of IOD, IPD and exophthalmos with a sliding gauge and exophthalmometer. RESULTS: The average value of exophthalmos was (14.48 +/- 1.71) mm. For the 5 - 8 years old children, the value of exophthalmos trended to increase with the increase of age, meanwhile the value of exophthalmos of adolescence aged 9 - 17 years old tended to be stabilized. The average value of IOD was (95.55 +/- 5.32) mm and the average value of IPD was (56.99 +/- 3.93) mm. Both the values of the IOD and IPD of the male were higher than that of the female. The results of the IOD and IDP distance increased with the increase of age and it trended to be periodic. There was positive correlation between the development of IOD and that of IPD, and it could be described by a linear equation. CONCLUSIONS: There is only one rush-increase stage of ocular development which is before the 8 years old in children. The rule of its development is in accordance with the growing and developing mode of neurological system.

Adolescent↗

PubMed2000

[Exploration of gene expression profiles of CD(34)(+) hematopoietic stem/progenitor cells based on large scale sequencing].

OBJECTIVE: To set up a large scale sequencing system and explore the gene expression profiles of CD(34)(+) hematopoietic stem/progenitor cells (HSPCs). METHODS: CD(34)(+) cells were isolated from umbilical cord blood and subjected to cDNA library construction. A primary profile of gene expression in HSPCs was emerged by EST sequencing and bioinformatics analyzing. RESULTS: Among 9,866 ESTs thus obtained, 7 476 meaningful ESTs were clustered into 2,060 unique sequence species (USSs), representing 1,054 known gene species and 1,006 unknown gene fragments. The 1054 known genes were divided into 8 categories: (1) hematopoiesis associated: 73, (2) chromatin structure and cell division/apoptosis: 91, (3) signal transduction and receptors: 111, (4) cell structure/mobility: 48, (5) cell/organism defense/homeostasis: 41; (6) Gene expression (transcription, translation and modification): 265, (7) metabolism: 192; and (8) unclassified: 233. CONCLUSION: A gene expression profile including 1,054 known genes and 1006 new gene fragments of HSPCs was primarily obtained, which may lay a basis for the further study on the molecular mechanism of hematopoiesis regulation and provide candidates for new gene cloning.

Antigens, CD34↗

PubMed1999

Molecular cloning of six novel Krüppel-like zinc finger genes from hematopoietic cells and identification of a novel transregulatory domain KRNB.

To clone zinc finger genes expressed in hematopoietic system, we designed primers based on conserved Cys(2)/His(2) zinc finger sequences to amplify corresponding domains from mRNA of normal bone marrow and leukemia cell line NB4. DNA fragments of novel zinc finger genes were chosen and used as probe pool to screen cDNA libraries or subject to rapid amplification of cDNA ends in order to obtain full-length cDNA. Six cDNAs including whole open reading frame of zinc finger proteins, named as ZNF191, ZNF253 (BMZF-1), ZNF255 (BMZF-2), ZNF256 (BMZF-3), ZNF257 (BMZF-4), and ZNF254 (BMZF-5) were obtained. All six belong to the Krüppel-like zinc finger gene family, and typical transcriptional regulatory motifs exist in the N-terminal moiety, such as the SCAN box in ZNF191, and the KRAB domains in ZNF253, ZNF254, ZNF256, and ZNF257. A previously undefined sequence nominated as Krüppel-related novel box, which may represent a new transregulatory motif, was revealed at the N terminus of ZNF255. The transregulatory function of non-zinc finger regions of ZNF191, ZNF253, and ZNF255 were addressed in yeast and mammalian cells. The results indicated that ZNF255 might be a conditional transactivator, whereas ZNF253 and ZNF191 displayed a suppressive effect on the transcription in yeast and/or mammalian systems.

Amino Acid Sequence↗

PubMed1999

Effects of organic modifiers on retention mechanism and selectivity in micellar electrokinetic capillary chromatography studied by linear solvation energy relationships.

The effects of six organic modifiers (urea, methanol, dioxane, tetrahydrofuran, acetonitrile and 2-propanol) on the retention mechanism and separation selectivity of the bulk buffer in micellar electrokinetic capillary chromatography (MECC) with sodium dodecyl sulfate (SDS) micelles as pseudo-stationary phase have been investigated through linear solvation energy relationships (LSERs). It is found that the retention value in MECC systems with or without organic modifier is primarily dependent on the solvophobic interaction and the hydrogen bonding interaction with the solute as proton acceptor, while the dipolar interaction and the hydrogen bonding interaction with the solute as proton donor play minor roles. The effects of the organic modifiers on the solvophobic, dipolar and hydrogen bonding interactions are evaluated in terms of the relationship between regression coefficient of the LSER equations and the modifier concentration. The variations of the solvophobic interaction and the dipolar interaction with change of the modifier concentration can be approximately explained using the solubility parameter and the dipolarity/polarizability parameter of the organic modifier, respectively. However, the relationships between the hydrogen bond acidity and basicity of the bulk buffer and the organic modifiers are rather complicated. Those results may be caused from the displacement of organic modifiers to the water adsorbed on the micellar surface as well as changes in the acidity and basicity of the bulk buffer with the addition of organic modifiers. In addition, it is found that the phase ratio is influenced significantly by the use of organic modifier.

Benzene Derivatives↗

PubMed1999

Capillary electrochromatography with a silica column with a dynamically modified cationic surfactant.

A novel mode of capillary electrochromatography (CEC), called dynamically modified silica-capillary electrochromatography, is described in this paper. The column packed with bare silica was dynamically modified with long chain quaternary ammonium salt, cetyltrimethylammonium bromide (CTAB), which was added into the mobile phase. CTAB ions were adsorbed onto the surface of bare silica, and the resulted hydrophobic layer on the silica gel was used as the stationary phase. Using the dynamically modified silica column, neutral solutes were separated by CEC. The highest number of theoretical plates obtained was about 71,500/m and the relative standard deviations for t0 and capacity factor of toluene were 4.7% and 4.9% for 20 consecutive runs, respectively. The separation mechanism of neutral solutes and the influence of mobile phase composition on the separation was investigated. The separation of nitrogen-containing solutes was carried out with this mode and the peak tailing of basic solute was effectively eliminated because the adsorption of basic solute on silica was blocked by the preferred adsorption of CTAB.

Cations↗

PubMed1999

Stereochemistry of metabolites of a tobacco-specific lung carcinogen in smokers' urine.

4-(Methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), a tobacco-specific lung carcinogen, is believed to be important as a causative agent for lung cancer in smokers. NNK is extensively metabolized to its carbonyl reduction product 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), which, in turn, can be glucuronidated, producing [4-methylnitrosamino)-1-(3-pyridyl)but-1-yl]-beta-O-D-glucosiduronic+ ++ acid (NNAL-Gluc). Metabolism of NNK to NNAL produces a chiral center. A recent study demonstrated that (R)-NNAL is more tumorigenic in mice than (S)-NNAL and that these enantiomers have substantially different metabolic pathways. Therefore, it is important to determine the stereochemistry of NNAL and NNAL-Gluc in smokers. In this study, we used chiral stationary phase-gas chromatography-nitrosamine-selective detection with confirmation by liquid chromatography-tandem mass spectrometry to determine the stereochemistry of NNAL and NNAL-Gluc in smokers' urine. The two methods agreed well. The results of analyses of urine samples from 30 smokers demonstrated that the enantiomeric distribution of NNAL in urine was 54% (R) and 46% (S) +/- 7.0 (SD), whereas the diastereomeric distribution of NNAL-Gluc was 68% (R) and 32% (S) +/- 8.1. These results conclusively demonstrate that both (R)- and (S)-NNAL are formed metabolically from NNK in smokers. These data are essential for furthering our understanding of the role of NNK as a cause of lung cancer in smokers.

Carcinogens↗

PubMed1999

Study of physically absorbed stationary phases for open tubullar capillary electrochromatography.

A novel method based on the adsorption of positively charged compounds on the wall of a fused-silica capillary was applied to prepare stationary phases for open tubular capillary electrochromatography (OTCEC). The positively charged substances including cationic surfactant such as cetyltrimethylammonium bromide (CTAB) and basic chiral selectors such as protein, peptide and amino acid were physically adsorbed onto the capillary wall under specially selected conditions. The adsorbed stationary phase of CTAB was used to separate neutral compounds, while the others were used for chiral separations. The run-to-run reproducibility of retention time was rather good with relative standard deviation (RSD) values of less than 2.3%. The separation efficiency was excellent with the highest theoretical plate number of up to 590000/m and the average one above 250000/m. Stored at 2-8 degrees C in the refrigerator, the adsorbed stationary phase can last at least one month. It was observed that the UV spectra for the enantiomers are significantly different due to the diastereomeric interactions of enantiomers with the chiral stationary phase in the detection window. With the use of the same capillary, the same instrument, and the same mobile phase, the superiority of OTCEC over open tubular liquid chromatography (OTLC) and capillary zone electrophoresis (CZE) was illustrated.

Animals↗

PubMed1999

Effects of organic modifiers on solute retention and electrokinetic migrations in micellar electrokinetic capillary chromatography.

Influences of seven organic modifiers, including urea, methanol (MeOH), dioxane (DIO), tetrahydrofuran (THF), acetonitrile (ACN), 1-propanol (1-PrOH) and 2-propanol (2-PrOH), on the solute retention and the electrokinetic migrations in micellar electrokinetic capillary chromatography (MEKC) are investigated with sodium dodecyl sulfate (SDS) micelle as pseudostationary phase. It is observed that in the limited concentration ranges used in the MEKC systems the effect of organic modifier concentration on the retention can be described by the equation logk1=logk1w-SC for most binary aqueous-organic buffer, but deviations from this retention equation are observed at ACN and particularly THF as organic modifiers. With parameter S as a measure of the elutropic strength, the elutropic strength of the organic modifiers is found to follow a general order urea <MeOH<ACN<2-PrOH<DIO, while THF is found to be the most abundant modifier in selectivity among the organic modifiers studied. The electroosmotic mobility decreases linearly with increasing modifier concentrations. The strength of modifiers to suppress the electroosmotic mobility follows the order urea < MeOH, ACN < DIO, THF, 1-PrOH, 2-PrOH. The addition of ACN affects the electrophoretic mobility of the SDS micelle in different patterns depending on the buffer composition used, while the addition of the other modifiers leads to a rough linear decrease of the electrophoretic mobility of the SDS micelle. The suppressing strength of THF on the electrophoretic mobility of the SDS micelle is strongly related to the buffer composition, whereas the suppressing strength for the other modifiers follows the sequence urea < MeOH < DIO, 1-PrOH, 2-PrOH. The migration time window is expanded by the use of organic modifiers. Urea and MeOH have the least expanding strength while ACN, DIO, THF, 1-PrOH and 2-PrOH have the highest expanding strength on the migration time window.

Chromatography, Micellar Electrokinetic Capillary↗

PubMed1999

Role of motor unit number estimate electromyography in experimental canine laryngeal reinnervation.

Laryngeal electromyography has been used clinically to differentiate neuromuscular pathology from other causes of vocal fold immobility such as arytenoid dislocation, tumor invasion, or cricoarytenoid joint fixation. Electromyography has also been used to predict the prognosis for nerve recovery in laryngeal paralysis. Existing electromyographic techniques either record activity with voluntary motion or study nerve conduction. In this study a new technique, motor unit number estimation, a commercially available quantitative method of electromyographic analysis, is used to study the progress of recovery of vocal fold function after recurrent laryngeal nerve injury. Four dogs underwent transection and immediate reanastomosis of selected branches of the adductor and abductor branches of the recurrent laryngeal nerve on 1 side; the opposite side served as a control. Baseline electromyographic and videolaryngoscopic studies were performed. These measures were then repeated in a longitudinal fashion every 6 weeks after denervation. The motor unit number estimation technique indicated a return of motor unit numbers with time, along with estimates of their size. This was consistent with the expected progress of laryngeal reinnervation. These data and their predictive value for nerve recovery will be discussed.

Anastomosis, Surgical↗

PubMed1999

Temporal profile of serum-induced S-phase entry and retinoblastoma protein phosphorylation in human skin fibroblasts.

Cultured skin fibroblasts from type 1 diabetic patients with nephropathy have a hyperplastic growth phenotype in comparison with diabetics without nephropathy and controls. We studied the G1 phase cyclins in skin fibroblasts from control subjects to define the temporal profile of serum-induced pRB phosphorylation, cyclin D1 protein expression, and cyclin D1/CDK4(6) kinase activity as well as S-phase entry by FACS analysis. Our preliminary studies indicate that cultured skin fibroblasts from type 1 diabetic patients with nephropathy have an enhanced pRB phosphorylation, cyclin D1 protein expression, and cyclin D1/CDK4(6) kinase activity. This finding may become useful to identify patients at risk for the development of nephropathy.

Blood Proteins↗