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Jing Li

Publications and source records attributed to Jing Li.

At least 73 records · Page 4Linked to original sources
PubMed2006

Identification and function of the growth hormone gene in Rongjiang pig of China.

Growth of animal is largely regulated by growth hormone (GH). In this study, the GH gene was isolated and cloned from the genomic DNA library from Rongjiang pig, a Chinese local swine, using polymerase chain reaction technique. The complete nucleotide sequence of a 1.903 kb genomic fragment containing Rongjiang swine GH gene has been determined. The GH gene contained five exons and four introns similar to the GH genes of other mammalians and exhibited 97%~99% identity to the GH genes of the four western meat-type breeds and nine Chinese local pigs. Polymorphism of GH genes was analyzed by using the restriction enzymes Dde I, Nar I and BsmN I in four western meat-type breeds and ten Chinese local pigs. Five polymorphic restriction sites, with Dde I at the base 622 (G/A) in exon 2 and 274 (T/C) in 5o-flank, with Nar I at 631 (G/A) in exon 2, and with BsmN I at the base 841 (T/C) in intron 2 and 1358 (A/G) in exon 4, were identified. The polymorphic restriction site at 1358 (A/G) leaded to the GH mature protein of Rongjiang pig differing from that of four western meat-type breeds and eight Chinese local breeds at the residue Val108 substituted by Ile108. According to the crystal structure of human GH mature protein, this Ile108 substitution might result in a lower affinity of GH for its receptor in Rongjiang breed.

Animals↗
PubMed2006

Saccharomyces cerevisiae Mer2, Mei4 and Rec114 form a complex required for meiotic double-strand break formation.

In budding yeast, at least 10 proteins are required for formation of the double-strand breaks (DSBs) that initiate meiotic recombination. Spo11 is the enzyme responsible for cleaving DNA and is found in a complex that also contains Ski8, Rec102, and Rec104. The Mre11/Rad50/Xrs2 complex is required for both DSB formation and DSB processing. In this article we investigate the functions of the remaining three proteins--Mer2, Mei4, and Rec114--with particular emphasis on Mer2. The Mer2 protein is present in vegetative cells, but it increases in abundance and becomes phosphorylated specifically during meiotic prophase. Mer2 localizes to distinct foci on meiotic chromosomes, with foci maximally abundant prior to the formation of synaptonemal complex. If DSB formation is blocked (e.g., by a spo11 mutation), dephosphorylation of Mer2 and its dissociation from chromosomes are delayed. We have also found that the Mei4 and Rec114 proteins localize to foci on chromosomes and these foci partially colocalize with each other and with Mer2. Furthermore, the three proteins co-immunoprecipitate. Mer2 does not show significant colocalization with Mre11 or Rec102 and Mer2 does not co-immunoprecipitate with Rec102. We propose that Mer2, Mei4, and Rec114 form a distinct complex required for DSB formation.

Chromosome Breakage↗
PubMed2006

[Screening of sleep apnea syndrome by ECG derived respiration of ambulatory electrocardiogram].

OBJECTIVE: To evaluate the feasibility of screening sleep apnea-hypopnea syndrome (SAHS) by from electrocardiogram derived respiration (EDR) of ambulatory electrocardiogram (AECG) monitoring. METHODS: The overnight sleep investigation was administered to 80 subjects by polysomnogram (PSG) and 24 hours AECG monitoring simultaneously during February through November, 2004. The electrocardiogram analyzers did not know the PSG results at all, They were both asked to give the apnea hypopnea index (AHI) by EDR and PSG respectively. The PSG result was considered as the gold standard so as to evaluate the feasibility of screening SAHS by EDR of AECG monitoring. RESULTS: The average age, male gender, body mass index, history of hypertension were higher in the SAHS(+) patients than those of the SAHS(-) patients. Automatic analysis was performed with software in a sensitivity of 75%, 87.5% and 100% respectively. When software sensitivity adjusted to 75%, the sensitivity of screening SAHS with EDR was 26.7%, with the specificity of 80%, the positive predictive value of 80%, the negative predictive value of 26.7%, the diagnose accordance rate of 40%. When software sensitivity was adjusted to 87.5%, the sensitivity of screening SAHS with EDR was 55%, with the specificity of 45%, the positive predictive value of 75%, the negative predictive value of 25%, and the diagnose accordance rate of 52.5%. When software sensitivity was adjusted to 100%, the sensitivity of screening SAHS with EDR was 88.3%, with the specificity of 35%, the positive predictive value of 84.1%, the negative predictive value of 50%, and the diagnose accordance rate of 75%. CONCLUSION: EDR technique of AECG was useful to screen the suspicious SAHS patients, sensitivity and the diagnosis coincidence rate was higher when the sensitivity of automatic analysis software was adjusted to 100%.

Adolescent↗
PubMed2006

The surface display of haemolysin from Vibrio harveyi on yeast cells and their potential applications as live vaccine in marine fish.

HL1 gene encoding haemolysin from Vibrio harveyi SF-1 was expressed in yeast cells and the expressed haemolysin was displayed on the cell surface. After induction for 36h in galactose-containing medium, one-third of the cells contained the displayed protein and the displayed cells had haemolytic activity on erythrocytes from flounder. The double diffusion agar analysis showed that the sera from the flounder immunized with the displayed yeast cells having the haemolytic activity could form precipitate with the purified haemolysin. ELISA analysis indicated that immunization times had great influence on increased production of the specific antibody against haemolysin in turbot immunized with the displayed yeast cells having the haemolytic activity. After the challenge with V. harveyi SF-1, it was found that earlier protection in flounder and significant protection in turbot, both of which were immunized with the displayed yeast cells having the haemolytic activity, were achieved. These results suggested that the displayed yeast cells with the haemolytic activity could be used as potential live vaccine in marine fish.

Animals↗
PubMed2006

Proliferation and differentiation of bone marrow stromal cells under hypoxic conditions.

Low oxygen tension is a potent differentiation inducer of numerous cell types and an effective stimulus of many gene expressions. Here, we described that under 8% O(2), bone marrow stromal cells (MSCs) exhibited proliferative and morphologic changes. The level of differentiated antigen H-2Dd and the number of G(2)/S/M phase cells increased evidently under 8% O(2) condition. Also, the proportion of wide, flattened, and epithelial-like cells (which were alkaline phosphatase staining positive) in MSCs increased significantly. When cultured in adipogenic medium, there was a 5- to 6-fold increase in the number of lipid droplets under hypoxic conditions compared with that in normoxic culture. We also demonstrated the existence of MSC differentiation under hypoxic conditions by electron microscopy. Expression of Oct4 was inhibited under 8% O(2) condition, but after adipocyte differentiation in normoxic culture and hypoxia-mimicking agents cobalt chloride (CoCl(2)) and deferoxamine mesylate (DFX) treatments, Oct4 was still expressed in MSCs. These results indicate hypoxia accelerates MSC differentiation and hypoxia and hypoxia-mimicking agents exert different effects on MSC differentiation.

Animals↗
PubMed2006

[Exon rearrangement analysis of parkin gene in patients with isolated early-onset parkinsonism using semi-quantitative PCR].

OBJECTIVE: To investigate the value of fluorescence semi-quantitative PCR in analysis of the exon rearrangement of parkin gene in Chinese patients with isolated early-onset parkinsonism (EOP). METHODS: fluorescence semi-quantitative PCR was used to analyze the exon rearrangements of parkin gene in 61 isolated patients with EOP. RESULTS: Exon deletions in parkin gene were found in 4 of the 61 isolated patients with EOP. One of them failed to show the PCR product of exon 4 and had homozygous deletions of exon 4. The normalized ratios (NRs) of exon 2, exon 3, and exon 4 of the other 3 patients were 0.47, 0.52, and 0.49 respectively, showing that they had heterozygous deletions of exon 2, 3, and 4 respectively. No exon multiplication was found in this study. CONCLUSION: Exon rearrangement of parkin gene exists in Chinese patients with isolated EOP.

Adolescent↗
PubMed2006

Effects of estrogen receptor subtype-selective agonists on immune functions in ovariectomized mice.

Estrogens have multiple influences on immune functions. Estrogen receptors (ERs) have two distinct subtypes - alpha and beta. To explore the specific roles of each ER subtype in estrogen-mediated immunomodulation, we investigated the effects of ER subtype-selective agonists on immune functions in ovariectomized Balb/c mice. Treatment with ERalpha-selective agonist propyl pyrazole triol (PPT) caused thymic atrophy and significant changes in thymic CD4/CD8 phenotypic profile. In contrast, ERbeta-selective agonist diarylpropionitrile (DPN) alone had no effect on thymic weight, cellularity or CD4/CD8 phenotype expression. When coadministered with PPT, DPN partially antagonized PPT-evoked decrease in thymic cellularity and also partially attenuated PPT-induced shifts in thymic T-cell phenotype. These results indicate that ERalpha plays a predominant role in estrogen-induced thymic atrophy and ERbeta activation may partially down-regulate ERalpha-mediated effects on thymic cellularity and T-cell phenotype expression. In addition, PPT administration induced a reduction in the percentage of mature B cells in the spleen, and enhanced IFN-gamma production but suppressed IL-6 production from in vitro Con A-stimulated splenocytes as estradiol (E(2)) did, whereas DPN treatment had no effects either alone or with PPT, suggesting ERalpha mediates these estrogen actions. Treatment with PPT or DPN did not augment anti-DNP antibody production after DNP-KLH immunization as E(2) did, implying that not merely one ER signaling pathway is involved in mediating estrogen's effects on specific humoral immune responses. Our study further indicates ER subtype-selective agonists provide a novel approach to explore each ER subtype-mediated immunomodulation.

Animals↗
PubMed2006

Haplotype-based quantitative trait mapping using a clustering algorithm.

BACKGROUND: With the availability of large-scale, high-density single-nucleotide polymorphism (SNP) markers, substantial effort has been made in identifying disease-causing genes using linkage disequilibrium (LD) mapping by haplotype analysis of unrelated individuals. In addition to complex diseases, many continuously distributed quantitative traits are of primary clinical and health significance. However the development of association mapping methods using unrelated individuals for quantitative traits has received relatively less attention. RESULTS: We recently developed an association mapping method for complex diseases by mining the sharing of haplotype segments (i.e., phased genotype pairs) in affected individuals that are rarely present in normal individuals. In this paper, we extend our previous work to address the problem of quantitative trait mapping from unrelated individuals. The method is non-parametric in nature, and statistical significance can be obtained by a permutation test. It can also be incorporated into the one-way ANCOVA (analysis of covariance) framework so that other factors and covariates can be easily incorporated. The effectiveness of the approach is demonstrated by extensive experimental studies using both simulated and real data sets. The results show that our haplotype-based approach is more robust than two statistical methods based on single markers: a single SNP association test (SSA) and the Mann-Whitney U-test (MWU). The algorithm has been incorporated into our existing software package called HapMiner, which is available from our website at http://www.eecs.case.edu/~jxl175/HapMiner.html. CONCLUSION: For QTL (quantitative trait loci) fine mapping, to identify QTNs (quantitative trait nucleotides) with realistic effects (the contribution of each QTN less than 10% of total variance of the trait), large samples sizes (>or= 500) are needed for all the methods. The overall performance of HapMiner is better than that of the other two methods. Its effectiveness further depends on other factors such as recombination rates and the density of typed SNPs. Haplotype-based methods might provide higher power than methods based on a single SNP when using tag SNPs selected from a small number of samples or some other sources (such as HapMap data). Rank-based statistics usually have much lower power, as shown in our study.

Algorithms↗
PubMed2006

Effect of inhibition of nitric oxide synthase on renal cyclooxygenase in the diabetic rat.

Renal cyclooxygenase (COX)-2 expression and arachidonic acid-stimulated prostaglandin release are increased in streptozotocin-diabetic rats and are reduced by tempol treatment, indicating a role for superoxide. Generation of nitric oxide (NO) and its product with superoxide, peroxynitrite, is also increased in diabetes and can induce COX-2. To investigate a role of NO, rats were treated with L-nitroarginine methyl ester (L-NAME; 100 mg/kg/day) to inhibit NO synthase (NOS) for 14-18 days. In isolated perfused kidneys from diabetic rats, prostaglandin release and vasoconstrictor responses to arachidonic acid were increased and renal cortical expression of COX-2 was 2-fold that of control rats. Treatment of diabetic rats with L-NAME reduced arachidonic acid-stimulated release of prostaglandins and the expression of COX-2. L-NAME increased vasoconstrictor responses to AA in diabetic and non-diabetic rats but abolished the differences between the two. These results, coupled with those using tempol, suggest that NO or its product with superoxide may contribute to the induction of renal COX-2 in the diabetic rat.

Angiotensin II↗
PubMed2006

A sphingosine-1-phosphate-activated calcium channel controlling vascular smooth muscle cell motility.

In a screen of potential lipid regulators of transient receptor potential (TRP) channels, we identified sphingosine-1-phosphate (S1P) as an activator of TRPC5. We explored the relevance to vascular biology because S1P is a key cardiovascular signaling molecule. TRPC5 is expressed in smooth muscle cells of human vein along with TRPC1, which forms a complex with TRPC5. Importantly, S1P also activates the TRPC5-TRPC1 heteromultimeric channel. Because TRPC channels are linked to neuronal growth cone extension, we considered a related concept for smooth muscle. We find S1P stimulates smooth muscle cell motility, and that this is inhibited by E3-targeted anti-TRPC5 antibody. Ion permeation involving TRPC5 is crucial because S1P-evoked motility is also suppressed by the channel blocker 2-aminoethoxydiphenyl borate or a TRPC5 ion-pore mutant. S1P acts on TRPC5 via two mechanisms, one extracellular and one intracellular, consistent with its bipolar signaling functions. The extracellular effect appears to have a primary role in S1P-evoked cell motility. The data suggest S1P sensing by TRPC5 calcium channel is a mechanism contributing to vascular smooth muscle adaptation.

Calcium Channels↗
PubMed2006

Amperometric glucose biosensor based on layer-by-layer assembly of multilayer films composed of chitosan, gold nanoparticles and glucose oxidase modified Pt electrode.

A new strategy for fabricating glucose biosensor was presented by layer-by-layer assembled chitosan (CS)/gold nanoparticles (GNp)/glucose oxidase (GOD) multilayer films modified Pt electrode. First, a cleaned Pt electrode was immersed in poly(allylamine) (PAA), and then transferred to GNp, followed by the adsorption of GOD (GOD/GNp/PAA/Pt). Second, the GOD/GNp/PAA/Pt electrode was immersed in CS, and then transferred to GNp, followed by the adsorption of GOD (GOD/GNp/CS/GOD/GNp/PAA/Pt). Third, different layers of multilayer films modified Pt electrodes were assembled by repeating the second process. Film assembling and characterization were studied by quart crystal microbalance, and properties of the resulting glucose biosensors were measured by electrochemical measurements. The results confirmed that the assembling process of multilayer films was simple to operate, the immobilized GOD displayed an excellent catalytic property to glucose, and GNp in the biosensing interface efficiently improved the electron transfer between analyte and electrode surface. The amperometric response of the biosensors uniformly increased from one to six layers of multilayer films, and then reached saturation after the seven layers. Among the resulting biosensors, the biosensor based on the six layers of multilayer films was best. It showed a wide linear range of 0.5-16 mM, with a detection limit of 7.0 microM estimated at a signal-to-noise ratio of 3, fast response time (within 8s). Moreover, it exhibited good reproducibility, long-term stability and interference free. This method can be used for constructing other thin films, which is a universal immobilization method for biosensor fabrication.

Biosensing Techniques↗
PubMed2006

Creation of engineered cardiac tissue in vitro from mouse embryonic stem cells.

BACKGROUND: Embryonic stem (ES) cells can terminally differentiate into all types of somatic cells and are considered a promising source of seed cells for tissue engineering. However, despite recent progress in in vitro differentiation and in vivo transplantation methodologies of ES cells, to date, no one has succeeded in using ES cells in tissue engineering for generation of somatic tissues in vitro for potential transplantation therapy. METHODS AND RESULTS: ES-D3 cells were cultured in a slow-turning lateral vessel for mass production of embryoid bodies. The embryoid bodies were then induced to differentiate into cardiomyocytes in a medium supplemented with 1% ascorbic acid. The ES cell-derived cardiomyocytes were then enriched by Percoll gradient centrifugation. The enriched cardiomyocytes were mixed with liquid type I collagen supplemented with Matrigel to construct engineered cardiac tissue (ECT). After in vitro stretching for 7 days, the ECT can beat synchronously and respond to physical and pharmaceutical stimulation. Histological, immunohistochemical, and transmission electron microscopic studies further indicate that the ECTs both structurally and functionally resemble neonatal native cardiac muscle. Markers related to undifferentiated ES cell contamination were not found in reverse transcriptase-polymerase chain reaction analysis of the Percoll-enriched cardiomyocytes. No teratoma formation was observed in the ECTs implanted subcutaneously in nude mice for 4 weeks. CONCLUSIONS: ES cells can be used as a source of seed cells for cardiac tissue engineering. Additional work remains to demonstrate engraftment of the engineered heart tissue in the case of cardiac defects and its functional integrity within the host's remaining healthy cardiac tissue.

Animals↗
PubMed2006

Targeted and shielded adenovectors for cancer therapy.

Conditionally replicative adenovirus (CRAd) vectors are novel vectors with utility as virotherapy agents for alternative cancer therapies. These vectors have already established a broad safety record in humans and overcome some of the limitations of non-replicative adenovirus (Ad) vectors. In addition, one potential problem with these vectors, attainment of tumor or tissue selectivity has widely been addressed. However, two confounding problems limiting efficacy of these drug candidates remains. The paucity of the native Ad receptor on tumor tissues, and host humoral response due to pre-existing titers of neutralizing antibodies against the vector itself in humans have been highlighted in the clinical context. The well-characterized CRAd, AdDelta24-RGD, is infectivity enhanced, thus overcoming the lack of coxsackievirus and adenovirus receptor (CAR), and this agent is already rapidly progressing towards clinical translation. However, the perceived host humoral response potentially will limit gains seen from the infectivity enhancement and therefore a strategy to blunt immunity against the vector is required. On the basis of this caveat a novel strategy, termed shielding, has been developed in which the genetic modification of a virion capsid protein would provide uniformly shielded Ad vectors. The identification of the pIX capsid protein as an ideal locale for genetic incorporation of shielding ligands to conceal the Ad vector from pre-existing neutralizing antibodies is a major progression in the development of shielded CRAds. Preliminary data utilizing an Ad vector with HSV-TK fused to the pIX protein indicates that a shield against neutralizing antibodies can be achieved. The utility of various proteins as shielding molecules is currently being addressed. The creation of AdDelta24S-RGD, an infectivity enhanced and shielded Ad vector will provide the next step in the development of clinically and commercially feasible CRAds that can be dosed multiple times for maximum effectiveness in the fight against cancers in humans.

Adenoviridae↗
PubMed2006

Zn(tbip) (H2tbip= 5-tert-butyl isophthalic acid): a highly stable guest-free microporous metal organic framework with unique gas separation capability.

A novel guest-free metal organic framework (GFMMOF) is synthesized and structurally characterized. It contains one-dimensional close-packed open channels with a pore diameter of 4.5 A. It demonstrates a remarkable thermal stability, a unique ability to separate methanol from dimethyl ether or water, and is among the microporous MOFs having the highest adsorbed hydrogen density (0.054 g/cm3 at 77 K and 1 atm).

Journal Article↗
PubMed2006

Determination of zonisamide by a coated monolithic column.

In this paper, a monolithic ODS-silica gel column dynamically coated with cetylpyridinium chloride (CPC) was used to demonstrate the high-speed and efficient separation of zonisamide (1,2-benzisoxazole-3-methanesulfonamide, ZNS), its raw material (1,2-benzisoxazole-3-methanecarbonic acid) and intermediate (sodium 1,2-benzisoxazole-3-methanesulfonate) in drugs. Using a 40 mmol/L sodium perchlorate solution (pH 7.0) containing 10% acetonitrile as eluent, the analytes were eluted with a sharp and symmetrical peak within 3.0 min, detected with UV detection at 210 nm. The column demonstrates excellent stability over time, and exhibits unusual selectivity for pharmaceutical analysis. Thus, by this developed method, zonisamide in drug samples can be determined rapidly with high recoveries and good selectivity.

Anticonvulsants↗
PubMed2006

Population pharmacokinetics of troxacitabine, a novel dioxolane nucleoside analogue.

PURPOSE: To develop and validate a population pharmacokinetic model for troxacitabine, a novel l-nucleoside analogue, administered by short infusion; to characterize clinical covariates that influence pharmacokinetic variability; and to design a dosage rate for continuous infusion administration to achieve low micromolar concentrations, which may be more efficacious than shorter infusions. EXPERIMENTAL DESIGN: Plasma samples from 111 cancer patients receiving troxacitabine (0.12-12.5 mg/m(2)) as a 30-minute infusion in phase I trials were used to develop the model with NONMEM. Clinical covariates evaluated included creatinine clearance, body surface area, age, and sex. From the model, a troxacitabine dosage rate of 2.0 to 3.0 mg/m(2)/d was expected to achieve a target concentration of 0.1 micromol/L; plasma samples were obtained during the infusion from eight patients receiving troxacitabine as a 3-day infusion. RESULTS: Troxacitabine pharmacokinetics were characterized by a three-compartment linear model. The mean value for systemic clearance [interindividual variability (CV%)] from the covariate-free model was 9.1 L/h (28%). Creatinine clearance and body surface area accounted for 36% of intersubject variation in clearance. Troxacitabine 2.0 mg/m(2)/d (n = 3) and 3.0 mg/m(2)/d (n = 5) for 3 days produced mean +/- SD end of infusion concentrations of 0.12 +/- 0.03 and 0.15 +/- 0.03 micromol/L, respectively. CONCLUSIONS: Renal function and body surface area were identified as sources of troxacitabine pharmacokinetic variability. The population pharmacokinetic model model-derived dosage rates for continuous infusion administration successfully achieved predetermined target plasma concentrations. The present model may be used to optimize treatment with troxacitabine by developing a dosing strategy based on both renal function and body size.

Antineoplastic Agents↗