Biomedical subjects

Y Xue

Publications and source records attributed to Y Xue.

At least 91 records · Page 5Linked to original sources

PubMed2000

A specificity and targeting subunit of a human SWI/SNF family-related chromatin-remodeling complex.

The SWI/SNF family of chromatin-remodeling complexes facilitates gene activation by assisting transcription machinery to gain access to targets in chromatin. This family includes BAF (also called hSWI/SNF-A) and PBAF (hSWI/SNF-B) from humans and SWI/SNF and Rsc from Saccharomyces cerevisiae. However, the relationship between the human and yeast complexes is unclear because all human subunits published to date are similar to those of both yeast SWI/SNF and Rsc. Also, the two human complexes have many identical subunits, making it difficult to distinguish their structures or functions. Here we describe the cloning and characterization of BAF250, a subunit present in human BAF but not PBAF. BAF250 contains structural motifs conserved in yeast SWI1 but not in any Rsc components, suggesting that BAF is related to SWI/SNF. BAF250 is also a homolog of the Drosophila melanogaster Osa protein, which has been shown to interact with a SWI/SNF-like complex in flies. BAF250 possesses at least two conserved domains that could be important for its function. First, it has an AT-rich DNA interaction-type DNA-binding domain, which can specifically bind a DNA sequence known to be recognized by a SWI/SNF family-related complex at the beta-globin locus. Second, BAF250 stimulates glucocorticoid receptor-dependent transcriptional activation, and the stimulation is sharply reduced when the C-terminal region of BAF250 is deleted. This region of BAF250 is capable of interacting directly with the glucocorticoid receptor in vitro. Our data suggest that BAF250 confers specificity to the human BAF complex and may recruit the complex to its targets through either protein-DNA or protein-protein interactions.

Amino Acid Sequence↗

PubMed2000

[Cytogenetics and clinical studies of hematologic malignancies with 11q23 abnormalities in China].

OBJECTIVE: To evaluate the association between 11q23 abnormalities and the clinical, hematologic, prognostic aspects of hematologic malignancies. METHODS: A total of 6000 cases of hematologic malignancies from our hospital and near regions in China were investigated between October 1985 and November 1998. Chromosome preparations were made on bone marrow cells by using direct method and/or unstimulated short-term cultures. Karyotypes were analyzed by R-banding technique and expressed according to ISCN(1995). RESULTS: 11q23 abnormalities were found in 28 of 6000 cases with hematologic malignancies(0.47%). It may be separated into seven cytonetic categories: t(4;11)(q21;q23)(ten cases), t(11;19)(q23;p13)(five cases), t(9;11)(p12;q23)(two cases), t(10;11)(p15;q23)(two cases), t(6;11)(q27;q23) (one case), del(11)(q23)(seven cases), and t(11;?)(q23;?)(one case). The diagnoses included acute myeloid leukemia in 14 cases (M(2a), three; M(4), two; M(5a), one; M(5b), eight), acute lymphoblastic leukemia(ALL) in 10 cases, myelodysplastic syndrome in three cases and malignant histiocytosis in one case. All 10 cases with t(4;11) anomaly were ALL. Follow-up data were available for 22 of them. Their median survival was 113 days. The patients may be grouped according to the presence or absence of additional abnormalities and/or normal karyotype. The median survival was 75 days for five patients with 11q23 anomaly only, 18 days for two patients with 11q23 and additional abnormalities, 135 days for 10 patients with 11q23 anomaly, additional abnormalities and normal karyotype, and 150 days for 5 patients with 11q23 anomaly and normal karyotype. CONCLUSION: 11q23 abnormalities were mainly seen in ALL and acute monocytic leukemia. Their prognosis was very poor. Both additional abnormalities and lack of normal karyotype had adverse effects on the survival of patients. Thus, they represent a unique clinical-cytogenetic association. 11q23 abnormality; hematologic malignancy; acute monocytic leukemia; acute lymphoblastic leukemia; prognosis

Adolescent↗

PubMed2000

[The common C677T polymorphism in the methylenetetrahydrofolate reductase gene is associated with neural tube defects and preeclampsia].

OBJECTIVE: To assess whether methylenetetrahydrofolate reductase(MTHFR) gene C677T polymorphism is associated with neural tube defects and preeclampsia. METHODS: Twenty- four mothers who had given birth to normal children, 27 mothers who had given birth to NTDs children, 120 normal women, and 57 women who had suffered from preeclampsia were genotyped for C677T polymorphism by using PCR/RFLP method. RESULTS: (1) VV genotype frequency in the normal mothers group it was 0.13, while in the NTDs mothers group it was 0.33; mothers with VV genotype were at 3 times increased risk to have a NTDs child, compared with the normal mothers. (2) In the normal women group VV genotype frequency was 0.15, while in the preeclampsia women group it was 0.31; women with VV genotype were at 2.5 times increased risk to have preeclampsia, compared with the normal women. CONCLUSION: The authors believe that MTHFR VV genotype is associated with the development of NTDs and preeclampsia.

Female↗

PubMed2000

[Investigation of infiltration glass of the machinable infiltrated ceramic(MIC)].

To explore the manufacture arts and determine the properties of the infiltration glass of the MIC. In order to determine the glass forming range of the MIC infiltration glass, molten glass was prepared in Al2O3 crucibles by heating the components to 1450 degrees C. Thermal analytic device was employed to study the thermal properties of the glass. Its crystal phases after micro-crystallization were analyzed with XRD. Flexural strength was measured by means of 3-point bending test. The chemical components of MIC glass were determined. Conventional fluorophlogopite glass was converted into an infiltration glass with low viscosity, good infiltration capability and low fusing temperature by introducing B2O3, La2O3 and Li2O into the glass. Fluorophlogopite crystals formed after crystallization. Conventional mica glass can be changed according to the requirements of properties. Modified mica MIC glass in this study has good infiltration ability in Al2O3 matrix while remains machinability.

Aluminum Silicates↗

PubMed2000

Secondary near-pentaploidy and/or near-tetraploidy characterized by the duplication of 8;21 translocation in the M2 subtype of acute myeloid leukemia.

Hyperploidy, especially near-tetraploidy, is rare in acute myeloid leukemia (AML). We report 2 cases with secondary hyperploidy characterized by double 8;21 translocations. Morphologic observation of bone marrow smears revealed numerous giant blasts in both cases. Chromosome analyses with R-banding technique showed a karyotype of 46,XX,t(8;21)(2%)/92,XXXX, add(7)(q31)x2,t(8;21)x2(7%)/100-117,XXX,-X,-X,-1,+4,+4,-7,+add(7)(q31)x3 , t(8;21)x2,+der(21)t(8;21),+22(90.6%)/46,XX(0.3%) in case 1 and a karyotype of 45,X,-Y,t(8;21)(15%)/90,XX,-Y,-Y,t(8;21)x2(80%)/46,XY(5%) in case 2. DNA ploidy analyses by flow cytometry showed triple peaks (diploid, tetraploid [DI 2.09] and near-pentaploid [DI 2.59]) in case 1, and double peaks (diploid and near-tetraploid [DI 2.07]) in case 2. Reverse-transcriptase polymerase chain reaction detected an AML1/ETO fusion transcript (152 bp) in both cases. This paper brings the total number of cases of secondary hyperploid t(8;21) AML to 6 and further emphasizes a correlation between hyperploidy and t(8;21) translocation.

Bone Marrow↗

PubMed2000

Distribution of a common methylenetetrahydrofolate mutation in six Chinese population groups.

The distribution of the C677T polymorphism was analyzed by the PCR-RFLP technique in the Northeast Han, the Oroqen, the Ewenki, the Daur as well as in Koreans and Mongolians. The results were compared with each other. They revealed that the frequencies of the T allele are quite different (17-47%) among the tested groups and are much higher in Chinese population groups than in others.

Asian People↗

PubMed2000

Analysis of DYS19 and DYS287 polymorphisms in the Han population and three other ethnic groups of northeast China.

The allelic distribution of the Y-chromosome specific microsatellite DYS19 in the Han population and in the Daur, Oroqen and Ewenki ethnic groups (Northeast China) was analyzed by PCR and denatured polyacrylamide gel electrophoresis. The allelic distribution in the Han population group is as follows: A = 2.90%, B = 26.09%, C = 26.09%, D = 29.98%, E = 15.94%. This allelic distribution differs statistically significant from that observed in the three other ethnic groups (p < 0.05). Furthermore the polymorphism of the Y-chromosome specific Alu insert sequence DYS287 was tested in these four groups. However, no Alu sequence insert was found.

Alleles↗

PubMed2000

Analysis of polymorphic mitochondrial DNA in the Han population and three other ethnic groups of northeast China.

By means of the PCR-RFLP technique the polymorphism of a 465 fragment of mtDNA D loop was analyzed in 36 individuals of the Northeast Han, 30 individuals of the Daur, 32 individuals of the Oroqen and 30 individuals of the Ewenki. All these individuals were randomly selected and are healthy. 27 restriction patterns were obtained by assaying the RFLP fragments of the mtDNA D loop. The mean nucleid acid substitute frequencies at each site are the following: Northeast Han = 0.0291, Oroqen = 0.0477, Ewenki = 0.0563, Daur = 0.0541. The genetic relationship between these four populations was analyzed by the UPG cluster analysis.

Asian People↗

PubMed2000

[The application of competitive RT-PCR to detect minimal residual disease in patients with 8;21 translocation].

OBJECTIVE: To construct and evaluate the competitive quantitative RT-PCR method for detecting the fusion gene of AML1-ETO in the patients of t(8;21)AML(acute myeloid leukemia). METHODS: The authors used the method of splicing by overlapping extension (SOE) to obtain the competitive DNA fragment, with which they set up the competitive quantitative RT-PCR assay to detect AML1-ETO chimeric genes in the patients of t(8;21) AML. RESULTS: The competitive DNA fragment has been obtained; the sensitive competitive RT-PCR method is developed, which allows the quantitation of the number of AML1-ETO transcriptions in t(8;21)AML patients at different phases. CONCLUSION: The competitive quantitative RT-PCR method, based on SOE, is simple and convenient; t(8;21) AML patients in different survival conditions express AML1-ETO gene quite differently.

Chromosomes, Human, Pair 21↗

PubMed2000

[Chromosome t (4; 11) acute lymphoblastic leukemia: an analysis of 10 cases].

OBJECTIVE: To characterize morphologically, immunophenotypically, cytogenetically and clinically the acute lymphoblastic leukemia (ALL) with t (4; 11) (q21; q23). METHODS: Ten cases of t (4; 11) ALL were reported. Of them, eight patients were de novo and two relapsed. The patients were treated with combination chemotherapy of DOPL or VP regimen. Immunophenotypic analysis was performed by flow cytometry in seven cases. Cytogenetic analysis was performed using bone marrow cells prepared directly and/or after 24h culture (case 7 using peripheral blood). RHG banding was used for karyotypic analysis. RESULTS: Ten (3.5%) of 285 ALL patients were found to be t (4; 11) ALL. In these 10 patients, increased WBC (> 100 x 10(9)/L) was found in 6 cases. Liver, spleen and/or lymph nodes were involved in all. t (4; 11) was detected as a single abnormality in 5 karyotypes whereas the other 5 showed additional aberration besides t (4; 11). Six patients were CD(19) (+), five were CD(22) (+) and one was HLA-DR (+), CD(5) (+), supporting that most cases of t (4; 11) ALL were B cell origin. Median survival time was 5.5 months in the present series. CONCLUSION: t (4; 11) ALL was a subtype with unique clinical and cytogenetic features, and had a poor prognosis.

Adolescent↗

PubMed2000

[Acute myeloid leukemia M2and t (8; 19) (q22; q13)].

OBJECTIVE: Report for the first time of two cases of acute myeloid leukemia (AML) M(2) with t (8; 19) (q22; q13). METHODS: Chromosome specimens were prepared by short-term culture of bone marrow cells and karyotype analyses were carried out using R-and G-banding techniques. Immunophenotyping of the blast cells was analyzed by flow cytometry with a panel of monoclonal antibodies. AML1/ETO fusion gene was tested by "nested" reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: Karyotype analyses showed 46, XX, t (8; 19) (q22; q13) [28]/46, XX [2] in case 1 and t (8; 19) (q22; q13), del (9) (q12q22) [23]/46, XY [2] in case 2. In case 2, the blast cells expressed CD(13) (38.8%), CD(33) (31.8%), CD(34) (80.9%), and CD(19) (63.9%) and RT-PCR assay revealed no AML1/ETO fusion gene transcript. CONCLUSION: t (8; 19) (q22; q13) is a variant form of t (8; 21) (q22; q22). Its molecular entity remains to be elucidate.

Adolescent↗

PubMed2000

[Detection of trisomy 8 with interphase fluorescence in situ hybridization in myelodysplastic syndromes].

OBJECTIVE: To explore the value of interphase fluorescence in situ hybridization (FISH) in the detection of trisomy 8 in myelodysplastic syndromes (MDS). METHODS: Conventional cytogenetics (CC) and interphase FISH using SpectrumGreen labelled chromosome 8 centromere specific probe were simultaneously carried out to detect trisomy 8 in 69 MDS and 6 normal individuals. RESULTS: Two hundred interphase cells were counted and cells with three green hybridization spots > 3% was assigned. Eleven cases displayed trisomy 8 by CC and were confirmed in 10 by FISH. In 7 cases, the percentage of trisomy 8 cells was significantly lower by FISH than by CC. Seven cases displayed trisomy 8 by FISH in 58 cases who did not show trisomy 8 by CC. Of the 7 cases, two had 2 and 3 marker chromosomes respectively, 4 had normal karyotypes. CONCLUSIONS: Interphase FISH was a useful method for the detection of trisomy 8 in MDS, especially in patients with normal karyotype or marker chromosome. It was a important complement to CC.

Adult↗

PubMed2000

[Study on the clinical characteristics of biphenotypic acute leukemia].

OBJECTIVE: To analyze the biological characteristics and the treatment outcome of adult biphenotypic acute leukemia. METHODS: Immunophenotypes were examined using indirect immunofluorescence method. Biphenotypic acute leukemia (BAL) was diagnosed according to EGIL scoring system. RESULTS: (1) The incidence of BAL in acute leukemia was 3.4%. Percentage for coexpression of B lymphoid and myeloid antigens was 68.4%, for T lymphoid and myeloid antigens 21.1%, for B, T lymphoid and myeloid antigens 10.5%. (2) CD(34) was expressed in 43.75% of the BAL cases. (3) Cytogenetic analysis revealed normal and abnormal karyotypes in 41.7% and 58.3% of the BAL cases, respectively. (4) Six of 19 patients achieved completed remission (CR), but the disease free survivals were all less than 6 months. Treatment outcomes were negatively related to the expression of CD(34) antigen and cytogenetic findings. The BAL patients were poorly responded to therapeutic regimens directed to AML. CONCLUSION: Coexpression of B/M antigens is the commonest subtype in BAL. BAL had a poor prognosis, especially treated with induction regimen directed to AML.

Acute Disease↗

PubMed2000

[Properties and infiltration arts of machinable infiltration ceramic(MIC)].

OBJECTIVE: The purpose of this study is to explore the infiltration arts of MIC and study the effects of different packing density of Al2O3 matrix on the properties of MIC. METHODS: alpha-Al2O3 specimens were fabricated by pouring alpha-Al2O3 slip with different powder/liquid ratios(P/L = 3.5, 7.5, 10.5) into a mold, and subsequently pre-fired at 1160 degrees C for 6 hours to form Al2O3 matrix. The packing density of the matrices were measured. Infiltration concepts were introduced into this study by infiltrating molten mica micro-crystalline glass into the porous Al2O3 matrix at 1160 degrees C for 6 hours to form a continuous interpenetrating composite. The composite then underwent micro-crystallization by nucleating at 550 degrees C for 1 hour and crystallizing at 900 degrees C for 1 hour, which resulted in the MIC. Mechanical properties including three point flexural strength, elastic modulus, Vicker's hardness, indentation fracture toughness and Weibull's modulus of flexural strength were determined. Parameters of machinability(H/KIC)2 of MIC were calculated. XRD and SEM were employed to study its microstructure. RESULTS: The resulted matrices reached packing densities of 63%, 76%, 78% with P/L of 3.5, 7.5 and 10.5. The MIC attained high strength and good machinability after infiltration. Three-point flexural strength and indentation fracture toughness were 342, 431, 374 MPa and 4.05, 4.14, 5.02 MPa m1/2 for MIC with packing density of 63%, 76%, 78% separately. And parameters of machinability were 5.41, 6.84 and 7.39 respectively. Packing density of Al2O3 matrix significantly influenced the mechanical properties. Maximum properties were obtained with a matrix packing density of 75%(P/L = 7.5), with a Weibull's modulus of flexural strength of 6.8. Machinability decreased with the increase of P/L ratio. Micro-crystallizing treatment resulted in the formation of evenly distributed mica crystalline in the composite, which contributed to the high strength of this composite material. CONCLUSION: MIC is a new infiltrated ceramic with favorable strength and machinability which can satisfy the prosthodontic requirements as all ceramic crown and bridge materials, it also shows promising outlook for future developments and clinical usage.

Aluminum Oxide↗

PubMed2000

[Expression and deletion analysis of EcoR II endonuclease and methylase gene].

OBJECTIVE: To clone complete EcoR II restriction endonuclease gene (ecoR II R) and methyl-transferase (ecoR II M) gene into one vector and to analyzing the expression of the whole system. METHODS: Unidirective deletion subclones constructed with Exo III, ecoR II R/M genes were preliminarily located in the cloned fragments according to the enzyme activities of each subclone, exact deletion sites were determined by sequencing, and transcriptional start sites were mapped by S1 mapping. RESULTS: The DNA fragment which was cloned into pBluescript SK+ contained the complete ecoR II R gene and ecoR II M gene, there are two transcriptional start sites in ecoR II R gene, 132 bp to 458 bp from 3' and of ecoR II R gene are indispensable to enzyme activities and deletion of 202 bp from 3' end of ecoR II M gene made it lose the capability to resist specific cut of EcoR II R enzyme, deletion of coding region and flanking sequence of one gene did not affect the expression of the other gene, the recombinant only containing ecoR II R gene appeared to be lethal to dcm + host. CONCLUSIONS: ecoR II M gene closely linking to ecoR II R gene was very important for the existence of the R-M system in process of evolution, but the key to control EcoR II R enzyme acted later than EcoR II M enzyme did not exist in transcriptional level.

Cloning, Molecular↗

PubMed1999

Effects of azimilide, a KV(r) and KV(s) blocker, on canine ventricular arrhythmia models.

Using canine coronary artery ligation/reperfusion and adrenaline arrhythmia models, we determined the effects of azimilide, a class III antiarrhythmic agent, E-1-[[(5-(4-chlorophenyl)-2-furanyl) methylene]-amino]-3-[4-(4-methyl-1-piperazinyl)butyl]-2,4-imidazolidi nedione dihydrochloride. The coronary ligation/reperfusion arrhythmia experiments were divided into two groups, one using low heart rate halothane-anesthetized and the other using high heart rate pentobarbital-anesthetized dogs. Azimilide (6 mg kg(-1) + 0.1 mg kg(-1) min(-1) i.v.) prolonged the corrected QT interval (QTc), decreased the heart rate and suppressed the premature ventricular complexes during ligation (35 +/- 17 beats/30 min as compared with 909 +/- 246 in the control group), and also suppressed ventricular fibrillation induced by coronary ligation/reperfusion in the two groups (1/8 halothane-anesthetized dogs as compared with 7/8 dogs in the control group and 2/8 pentobarbital-anesthetized dogs as compared with 8/8 dogs in the control group). In adrenaline arrhythmia, azimilide hastened the onset of adrenaline arrhythmias and also aggravated the arrhythmias, showing proarrhythmic effects.

Anesthetics↗

PubMed1999

Can histopathology predict treatment outcome following high-energy transurethral microwave thermotherapy of the prostate? Results of a biopsy study.

BACKGROUND: Despite good results of high-energy transurethral microwave thermotherapy (TUMT) in the treatment of benign prostatic hyperplasia, it is still difficult to predict the response to treatment on an individual basis. Besides clinical baseline parameters, intrinsic histological parameters are suggested to play a role in the response variance after TUMT. In this study we analyzed histological parameters (vessel density and epithelium-stroma (E/S) ratio) in patients who were selected for high-energy TUMT and related these parameters to clinical outcome. METHODS: We treated 42 patients with high-energy TUMT, who prior to treatment agreed upon ultrasonographic investigation of the prostate in combination with biopsies of the peripheral and transitional zones of the prostate. For all separate biopsy locations, the histological stained prostate slides were morphometrically quantified with computer assistance and analyzed for E/S ratio and vessel density. Response to treatment was measured by using standardized response evaluation criteria and was correlated with histological outcome. RESULTS: The E/S ratio in the inner gland biopsies tended to be higher in the good response group compared to the very poor responders. Furthermore, a clear trend was seen towards a lower vessel density in good responders. Large prostates and prostates with a high E/S ratio responded well to the high-energy thermotherapy. CONCLUSIONS: Histopathological parameters of the prostate tend to be moderately predictive for clinical response in this research population. Poor responders appeared to have a somewhat higher vessel density in all prostate biopsy sides, and there was also a trend towards a lower E/S ratio in these patients.

Aged↗

PubMed1999

Ultrastructural observations on the expression of axonin-1: implications for the fasciculation of sensory axons during axonal outgrowth into the chick hindlimb.

To help understand how axons interact as they grow into the developing chick hindlimb, we used electron microscopy in conjunction with immunoperoxidase staining for the cell adhesion molecule axonin-1 to label sensory axons. The results showed that sensory axons travel together in bundles, tightly apposed to one another. In contrast, motoneuron axons are more widely spaced, although motoneuron axons situated at the perimeter of sensory axon bundles are found in close contact with neighboring sensory axons. Sensory growth cones and lamellipodia tend to be located centrally within the bundles, with several lamellipodia typically being found stacked together. Strikingly, regions of close axonal apposition are accompanied by axonin-1 expression, suggesting that such contacts are indeed adhesive. Taken together, these observations suggest that groups of sensory axons of a similar age grow together, with some of the older sensory axons fasciculating along motoneuron axons and younger sensory axons later fasciculating along older sensory axons. Axons situated at the periphery of sensory bundles are typically partly labelled, such that axonin-1 is expressed on membranes apposing other labelled axons but not on those facing unlabelled axons or unlabelled Schwann cells. Thus, axonin-1 appears to become redistributed within the membranes of axons growing into the limb, as it does on cultured neurons. In contrast, the neuron-glia cell adhesion molecule (NgCAM), which binds heterophilically to axonin-1, appears uniformly distributed on even those axons that would have an asymmetric distribution of axonin-1. Thus, the localization of axonin-1 strongly suggests that it plays an important role in sensory axon fasciculation, but the relative contributions of its interactions with various potential ligands are unclear. Finally, we found that some sensory growth cones have lamellipodia that are spread over considerable expanses. This suggests that although fasciculation is important in sensory axon guidance, sensory axons may also explore the local environment.

Animals↗