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Biomedical subjects

J Xue

Publications and source records attributed to J Xue.

At least 55 records · Page 3Linked to original sources

[Information behavior of microsatellite loci in genome scanning].

OBJECTIVE: To determine the heterozygosity and polymorphism information content of 139 microsatellite loci in Han population. METHODS: Multiplex approach was used to analyze the 139 loci. The amplified fragments were subjected to electrophoresis in PAGE gel and analyzed with Genescan( TM) and Genotyper(TM). RESULTS: The heterozygosities are between 0.35 to 0.89, with the heterozygosities of 88% loci >0.60. PICs are in the range of 0.32 and 0.88, with PICs of 95% loci >0.50. CONCLUSION: The polymorphism information content of microsatellite loci is very high and their distribution varies in different races and populations.

Aged↗

[In vitro study on transduction of human O(6)-methylguanine-DNA-methyltransferase cDNA into human umbilical cord blood CD34(+) cells].

OBJECTIVE: To explore human umbilical cord blood hematopoietic progenitor cells transduced with human O(6)-methylguanine-DNA-methyltransferase (MGMT) gene increase resistance to 1,3-Bis(2-Chloroethyl)-1-Nitrosourea(BCNU). METHODS: The present authors obtained a full length cDNA fragment encoding the human MGMT from a patient with cholelithiasis liver tissue by RT-PCR method and confirmed by DNA sequencing. The fragment was cloned into pGEM-T vector and further subcloned into G1Na retrovirus vector. Then the G1Na-MGMT was transfected into the packaging cell lines GP+E86 and PA317 by LipofectAMINE method; using the medium containing BCNU for cloning selection and ping-ponging supernatant infection between ecotropic producer clone and amphotropic producer clone, the authors obtained high titer amphotropic PA317 producer clone with the highest titer up to 1.6x10(6) CFU/ml. Cord blood CD34(+) cell were transfected repeatedly with supernatant of retrovirus containing human MGMT cDNA under stimulation of hemopoietic growth factors. RESULTS: PCR, RT-PCR, Southern blot, Northern blot, Western blot and MTT analyses showed that MGMT gene had been integrated into the genomic DNA of cord blood CD34(+) cells and expressed efficiently in the transfected cells. The transgene recipient cells conferred 4 folds stronger resistance to BCNU than that of the non-transduced. CONCLUSION: The retrovirus vector-mediated transfer of MGMT drug resistance gene into human cord blood CD34(+) cells and expression could confer the resistance of transgene cells to BCNU toxicity.

Antigens, CD34↗

[Expression of substance P receptor mRNA in nasal mucosa of rat in allergic rhinitis model].

OBJECTIVE: To study the expression of substance P receptor messenger RNA (SP-R mRNA) in nasal mucosa in allergic rhinitis (AR) rat model. METHODS: Twenty Wistar rats free of disease were randomly divided into two groups. AR model rats were established through repeated intraperitoneal shot of ovalbumin (OV) and consequently confirmed by local challenge with OV. SP-R mRNA in nasal mucosa, obtained from two groups, were used to do reverse transcriptive polymerase chain reaction (RT-PCR) and Southern blot. beta-actin was used as a standard control through out the whole process. RESULTS: The results showed definitely that there were positive expression of SP-R mRNA in normal nasal mucosa. This expressions increased significantly (P < 0.05) during nasal allergy. CONCLUSION: Increased expression SP-R mRNA in nasal mucosa in AR model might play roles in the development of AR.

Animals↗

[Study on the aggregation state of sulfonated phthalimidomethyl zinc phthalocyanine in CEL solution].

Sulfonated Phthalimidomethyl Zinc Phthalocyanine is a new photodynamic therapy reagent, it can be selectively attacked to cell, but how it attacks the target cell is still unknowable. The aggregation state of photosensitizer is significant to its mechanism proved in CEL solution. The aggregation of ZnPcS2P2 in CEL has been studied with absorption spectroscopy and fluorescence spectroscopy. The aggregation state is dimer through theory analysis, monomer molar absorption coefficient as well as equilibrium constant were estimated.

Antineoplastic Agents↗

Phosphorylation of splicing factor SF1 on Ser20 by cGMP-dependent protein kinase regulates spliceosome assembly.

Splicing factor 1 (SF1) functions at early stages of pre-mRNA splicing and contributes to splice site recognition by interacting with the essential splicing factor U2AF65 and binding to the intron branch site. We have identified an 80 kDa substrate of cGMP-dependent protein kinase-I (PKG-I) isolated from rat brain, which is identical to SF1. PKG phosphorylates SF1 at Ser20, which inhibits the SF1-U2AF65 interaction leading to a block of pre-spliceosome assembly. Mutation of Ser20 to Ala or Thr also inhibits the interaction with U2AF65, indicating that Ser20 is essential for binding. SF1 is phosphorylated in vitro by PKG, but not by cAMP-dependent protein kinase A (PKA). Phosphorylation of SF1 also occurs in cultured neuronal cells and is increased on Ser20 in response to a cGMP analogue. These results suggest a new role for PKG in mammalian pre-mRNA splicing by regulating in a phosphorylation-dependent manner the association of SF1 with U2AF65 and spliceosome assembly.

Amino Acid Sequence↗

Prevalence of lesions and body condition scores among female swine at slaughter.

OBJECTIVE: To determine prevalence of foot lesions, dermatitis, shoulder lesions, mammary gland abnormalities, and visceral lesions, and body condition scores among culled female swine at slaughter. DESIGN: Observational study. ANIMALS: Culled gilts and sows killed during a 1-week period at a Midwest slaughterhouse. PROCEDURE: Carcasses were examined, and lesions were recorded. Body condition was scored on the basis of standard criteria. RESULTS: 58.9% (1,029/1,747) of the carcasses had foot lesions, 67.3% (1,178/1,751) had dermatitis, and 4.6% (80/1,751) had shoulder lesions. Body condition score was significantly associated with detection of dermatitis and shoulder lesions. Mean +/- SE number of teats (n = 1,432 carcasses) was 13.86 +/- 0.02. Mean numbers of normal-appearing teats in the left and right mammary chains were 6.57 +/- 0.02 and 6.58 +/- 0.02, respectively. Feet from 48% (688/1,433) of the carcasses were condemned. Visceral lesions were found in 48.8% (624/1,278) of the carcasses; of the carcasses with lesions, 412 (66%) had liver spots, and 268 (42.9%) had pneumonia. CLINICAL IMPLICATIONS: Lesions that potentially could have adversely affected production were found in a large percentage of culled gilts and sows at slaughter. Knowledge of lesions commonly found at slaughter may help direct changes in herd health programs.

Abattoirs↗

The effect of astragapolysaccharide on the lymphocyte proliferation and airway inflammation in sensitized mice.

In order to investigate the regulating role of Astragapolysaccharide (APS) in the mice model of asthmatic airway inflammation, the airway eosinophil number, spleen T lymphocyte proliferation, level of IL-2 production and their relationships were studied in sensitized mice and sensitized mice treated with different concentrations of APS. The results showed that the number of eosinophils as well as lymphocytes in the airway of the sensitized animals were significantly increased, and a marked positive correlation between the inflammation cells and spleen T lymphocyte proliferation was found. Moreover, there was a positive correlation between inflammation cells and the level of IL-2 production. The APS of given dosage could significantly reduce the number of eosinophils in the airway of the sensitized animals. At the same time the level of IL-2 secreted by spleen T lymphocytes stimulated with ConA was also significantly decreased and there was a marked positive correlation between them. Our results suggested that APS of given dosage could prevent antigen-induced the number of eosinophils infiltrating into the airway of sensitized mice and inhibit the proliferation and activation of lymphocyte and IL-2 production. Through its immuno-regulating effect, APS can be helpful in the treatment of asthma.

Animals↗

Distribution of two HIV-1-resistant polymorphisms (SDF1-3'A and CCR2-64I) in East Asian and world populations and its implication in AIDS epidemiology.

Chemokine receptor CCR2 and stromal-derived factor (SDF-1) are involved in HIV infection and AIDS symptom onset. Recent cohort studies showed that point mutations in these two genes, CCR2-64I and SDF1-3'A, can delay AIDS onset > or = 16 years after seroconversions. The protective effect of CCR2-64I is dominant, whereas that of SDF1-3'A is recessive. SDF1-3'A homozygotes also showed possible protection against HIV-1 infection. In this study, we surveyed the frequency distributions of the two alleles at both loci in world populations, with emphasis on those in east Asia. The CCR2-64I frequencies do not vary significantly in the different continents, having a range of 0.1-0.2 in most populations. A decreasing cline of the CCR2-64I frequency from north to south was observed in east Asia. In contrast, the distribution of SDF1-3'A in world populations varies substantially, and the highest frequency was observed in Oceanian populations. Moreover, an increasing cline of the SDF1-3'A frequency from north to south was observed in east Asia. The relative hazard values were computed to evaluate the risk of AIDS onset on the basis of two-locus genotypes in the east Asian and world populations.

Acquired Immunodeficiency Syndrome↗

[Effect of anti-CD4+ human/murine chimeric antibody on the proliferation and apoptosis of lymphocyte in patients with asthma].

OBJECTIVE: To investigate the effects of anti-CD4+ human/murine chimeric antibody on the proliferation and the apoptosis of peripheral blood lymphocytes (PBL) in patients with asthma. METHODS: PBL isolated from patients with asthma were cultured with 50 mg/L, 100 mg/L anti-CD4+ human/murine chimeric antibody and anti-CD3+ McAb (10 mg/L) for 0, 24, 48 h in vitro, the apoptosis cell percentage were detected by flow cytometry and in situ end-labeling technique of fragmental DNA as well as the proliferation of PBL were detected by MTT method. RESULTS: Comparing with normal controls, the apoptosis cell percentage was significantly decreased by stimulation with anti-CD3+ McAb for 24 h and 48 h, the proliferation of lymphocyte was increased in patients with asthma; the apoptosis cell percentage of patients with asthma was significantly increased (P < 0.01, respectively) with the cell cultured with 50 mg/L or 100 mg/L anti-CD4+ human/murine chimeric antibody for 24 h or 48 h At the same time the lymphocyte proliferation was inhabited (P < 0.01, respectively). CONCLUSIONS: It is demonstrated that the proliferation of PBL in patients with asthma were increased and the apoptosis cell percentage were decreased, anti-CD4+ human/murine chimeric antibody had inhibited the proliferation of T lymphocyte and had enhanced the T lymphocyte apoptosis. The anti-CD4+ human/murine chimeric antibody may be potentially useful for the biotherapy of asthma.

Adult↗

[Lymphocyte apoptosis in asthmatic patients and its molecular mechanism].

OBJECTIVE: To assess the apoptosis rate of peripheral blood lymphocytes isolated from patients with asthma and explore its molecular mechanism. METHODS: Lymphocytes were isolated with ficoll-hypaque gradient method and T lymphocytes were further isolated with nylon pili. T lymphocytes were stimulated by anti- CD3+ antibody for 0, 24, 48, 72 hours in vitro and the apoptosis rates were measured with in situ tailing technique. At the same time, Bcl-2 gene expression and Bax gene expression were observed with in situ hybridization. RESULTS: The percentages of apoptosis cell in T lymphocytes from patients with asthma were significantly decreased and the timing delayed in comparison with those in normal controls (P < 0.01). The Bcl-2 mRNA expression in T lymphocytes was significantly increased in different time points than in normal controls (P < 0.01), but Bax mRNA expression in T lymphocytes was remarkably decreased (P < 0.01). The rates of Bcl-2/Bax mRNA could not reach the state of the controls until 72 hours from the begining of the stimulation with the anti-CD3+. CONCLUSIONS: The inhibited apoptosis might be one of the reasons for the chronic persistent inflammation in the airways in asthmatic patients and the imbalance between Bcl-2 gene expression and Bax gene expression may be one of the molecular mechanisms for the inhibited apoptosis.

Adult↗

[Treatment of benign prostatic hyperplasia with laser through the endoscope].

OBJECTIVE: To evaluate the effect of transurethral laser prostatectomy (TULP) and its relation with the size of prostate. METHODS: 469 benign prostatic hyperplasia receiving TULP from 1988 to 1998 were reviewed retrospectively, and the methods of operation and preoperative and postoperative symptom were compared. The effect of 233 patients undergoing TULP was compared with the size of the prostate. RESULTS: The average value for IPSS of 469 patients decreased from 26.7 (preoperation) to 14.2 (postoperation). The mean value of maximum uroflow rate increased from 6.2 ml/s (preoperation) to 11.8 ml/s (postoperation). No difference was seen in postoperative effect between the transurethral contact and noncontact laser prostatectomy. If the estimating weight of prostate exceeded 50 g, the maximum flow rate after 3 years was decreased evidently, the value of IPSS increased to over 20. CONCLUSIONS: If the estimating weight of prostate is less than 50 g, TULP is indicated.

Aged↗

Influence of lactation length and feed intake on reproductive performance and blood concentrations of glucose, insulin and luteinizing hormone in primiparous sows.

Twenty-four pregnant gilts were assigned to four experimental treatments in a 2 x 2 factorial arrangement. The first factor was lactation length (12 vs. 21 days) (LL); the second factor was a provided amount of diet (FF, full feeding vs. low, 2 kg/day). The same diet (1% lysine and 3.27 Mcal ME/kg) was used from farrowing to 1 day after weaning. Sow body weight, backfat thickness (BF), litter weights, and blood samples were measured prior to and 1 day after weaning. Sows were monitored for estrous once daily in the presence of a boar until 35 days after weaning or until estrous was detected. Average feed intake during lactation (ADFI) was 1.9 (low) and 4.0 (FF) kg/day. ADFI among individual sows varied from 1.8 to 4.9 kg/day. Positive effects of both LL and feed intake treatments were found (P < 0.05) on sow body weight loss, backfat loss, glucose concentrations, mean luteinizing hormone (LH) concentrations, and LH pulse frequency prior to weaning, and farrowing-to-estrous interval. Greater concentrations of insulin prior to weaning were associated only with feed intake treatment (P < 0.05). No interactions between LL and feed intake treatments were found in any measures except for sow body weight loss. Using regression analysis, greater lactation feed intake was associated with greater concentrations of insulin and glucose, greater LH pulse frequency prior to weaning and shorter farrowing-to-estrous interval in both LL treatments. We suggest that greater feed intake during lactation improves farrowing-to-estrous interval through LH release regardless of LL treatment.

Animals↗

Management factors associated with swine breeding-herd productivity in the United States.

A database containing 24 key production measurements was created by abstracting data files of 673 U.S. farms which participated in the PigCHAMP data-share program in 1995. Summary statistics for breeding-herd performance data were presented for the Cornbelt and the South or Eastern regions. Eight models were built to assess the association between production system, operation management factors and productivity outcomes. Lactation length, percentage of multiple matings, parity of culled sows, percent gilts in the breeding-female inventory, and female culling rate were the management factors identified as having important associations with productivity outcomes. For example, shorter lactation length, higher percentage of multiple matings, and lower culling rate were associated with more pigs weaned per mated female per year. In addition, a lower percentage of gilts in the breeding-female inventory and a higher percentage of multiple matings were associated with fewer average non-productive female days. We recommend that producers change their management systems to decrease lactation length, the percentage of gilts in the breeding-female inventory, and female culling rate, and increase percentage of multiple matings in order to improve breeding-herd productivity on swine farms.

Animal Husbandry↗

Incomplete embryonic lethality and fatal neonatal hemorrhage caused by prothrombin deficiency in mice.

Deficiency of blood coagulation factor V or tissue factor causes the death of mouse embryos by 10.5 days of gestation, suggesting that part of the blood coagulation system is necessary for development. This function is proposed to require either generation of the serine protease thrombin and cell signaling through protease-activated receptors or an activity of tissue factor that is distinct from blood clotting. We find that murine deficiency of prothrombin clotting factor 2 (Cf2) was associated with the death of approximately 50% of Cf2(-/-) embryos by embryonic day 10.5 (E10.5), and surviving embryos had characteristic defects in yolk sac vasculature. Most of the remaining Cf2(-/-) embryos died by E15.5, but those surviving to E18.5 appeared normal. The rare Cf2(-/-) neonates died of hemorrhage on the first postnatal day. These studies suggest that a part of the blood coagulation system is adapted to perform a developmental function. Other mouse models show that the absence of platelets or of fibrinogen does not cause fetal wastage. Therefore, the role of thrombin in development may be independent of its effects on blood coagulation and instead may involve signal transduction on cells other than platelets.

Animals↗

[Determination of the polymorphism of DXS102 locus and its application in gene diagnosis].

OBJECTIVE: To determine the polymorphism of DXS102 and use it in gene diagnosis in hemophilia B. METHODS: Amp-FLP and linkage analysis on 234 chromosomes. RESULTS: Eight alleles were found at DXS102 locus. The number of AC dinucleotide repeats ranged from 13 to 21. And the observed heterozygosity, calculated heterozygosity and polymorphism information content(PIC) were 0.87, 0.80 and 0.80, respectively. It was noted that the difference of the allele frequencies of DXS102 in Chinese and European populations was significant. By using the linkage analysis of the DXS102 locus, a family with a hemophilia B patient receiving gene therapy in 1994 was analyzed and a carrier in that family was then detected. CONCLUSION: The polymorphism of DXS102 locus reveals significant difference between Chinese and European populations. DXS102 locus can be used as a promising marker for gene diagnosis in hemophilia B family.

Chromosome Mapping↗

Expression and localization of membrane type 1 matrix metalloproteinase in tooth tissues.

Matrix metalloproteinases (MMPs) have been detected in forming dental enamel and are thought to play an important role during enamel biomineralization. Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a membrane bound member of the MMP gene family that has previously been shown to be expressed by cells associated with bone and cartilage formation (osteoclasts, osteoblasts and chondrocytes). Thus, we asked if MT1-MMP was also expressed by the cells responsible for the formation of enamel and dentin. A porcine MT1-MMP cDNA composed of 3284 bp was isolated from an enamel organ-specific cDNA library. Multiple tissue Northern blot analysis revealed that the MT1-MMP message was expressed highly in the enamel organ and pulp organ when compared to the expression levels observed in other non-mineralizing tissues. Northern blot analysis of stage-specific enamel organs (early secretory, late secretory, or maturation stage) and their corresponding pulp organs revealed that MT1-MMP expression increased as the dentin matured. In the enamel organs, however, the MT1-MMP message level became reduced only during the late secretory stage. Immunohistochemical analysis showed that MT1-MMP was present on the surface of the cells (ameloblasts and odontoblasts) responsible for dentin and enamel formation. Thus, MT1-MMP is highly expressed in developing tooth tissues and may play a role in the biomineralization of enamel and dentin.

Ameloblasts↗

Purification, characterization, and cloning of enamel matrix serine proteinase 1.

The maturation of dental enamel succeeds the degradation of organic matrix. Inhibition studies have shown that this degradation is accomplished by a serine-type proteinase. To isolate and characterize cDNA clones encoding this proteinase, we used two degenerate primer approaches to amplify part of the coding region using polymerase chain-reaction (PCR). First, we purified the proteinase from porcine transition-stage enamel matrix and characterized it by partial protein sequencing. The enzyme was isolated from the neutral soluble enamel extract by successive ammonium sulfate precipitations, hydroxyapatite HPLC, reverse-phase HPLC, DEAE ion exchange, and affinity chromatography with a Benzamidine Sepharose 6B column. The intact protein and lysylendopeptidase-generated cleavage products were characterized by amino acid sequence analyses. Degenerate oligonucleotide primers encoding two of the polypeptide sequences were synthesized. In a complementary strategy, degenerate oligonucleotide primers were designed against highly conserved active-site regions of chymotrypsin-like proteinases. Both approaches yielded PCR amplification products that served as probes for screening a porcine enamel organ epithelia-specific cDNA library. The longest full-length clone is 1133 nucleotides and encodes a preproprotein of 254 amino acids. We designate this protein enamel matrix serine proteinase 1 or EMSP1. The active protein has 224 amino acids, an isotope-averaged molecular mass of 24.1 kDa, and an isoelectric point of 6.0. Multiple-tissue Northern analysis indicates that EMSP1 is a tooth-specific protein. Gelatin enzymography shows a dramatic increase in EMSP1 activity in the transition-stage enamel matrix. EMSP1 is most homologous to kallikriens and trypsins.

Amelogenesis↗

Influence of mating frequency on sow reproductive performance.

Gilts and sows were bred one, two, or three times during a single estrous period in a commercial herd for evaluating the effect of mating frequency on reproductive performance. Estrus detection started at approximately 0630 daily by applying back pressure to females with the presence of a mature boar. Natural mating was used. Gilts detected in estrus were mated in the morning of d 1 (AM), the morning of d 1 and 2 (AM-AM), and the morning and afternoon of d 1 and morning of d 2 (AM-PM-AM) for mating frequencies 1, 2, and 3, respectively. Sows were bred in the AM, AM-AM, AM-PM-AM (1), and morning of d 1 and morning and afternoon of d 2 [AM-AM-PM (2)] for mating frequency 1, 2, 3 (1), and 3 (2), respectively. Breeding events in the morning and afternoon started at approximately 0730 and 1530. Females were randomly assigned to a mating frequency. Boars were randomly assigned to each breeding event. In total, 256 gilts and 766 sows were involved in the study. Gilts with a single mating (76.5%, P = .06) and triple matings (80.4%, P < .05) had higher farrowing rates than those with double matings (65.3%). No differences (P > .1) in the farrowing rates of sows were observed between mating frequencies 1, 2, 3 (1), and 3 (2). Double-mated gilts had more (P < .03) total born (9.7 vs 8.6) and pigs born alive (9.3 vs 8.2) than did single-mated gilts. There were no differences (P > .3) in total born and pigs born alive in sows between mating frequencies. We concluded that triple-mating gilts and sows did not improve farrowing rate and litter size compared with single and double matings. There were no differences in farrowing rate and litter size between double- and single-mated sows. Gilts with double matings had a larger litter size than those with a single mating.

Animals↗