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Q Ji

Publications and source records attributed to Q Ji.

At least 19 recordsLinked to original sources
PubMed2006

Single-nucleotide polymorphism identification in the caprine myostatin gene.

Polymerase chain reaction (PCR) products of MSTN gene amplified from 35 goats representing 17 Chinese indigenous goat breeds and five imported goat breeds were sequenced to identify the single-nucleotide polymorphisms (SNPs) of a 379-bp fragment including part of intron 2 and exon 3 of MSTN gene. A total of eight SNPs (A1980G, G1981C, A1982G, G1984T, A2121G, T2124C, G2174A and A2246G) were identified among the sequenced goats. The SNPs found are all located in intron 2 except for A2246G, which was a synonymous mutation in exon 3. Four haplotypes were sorted from these eight SNPs, of which, haplotype I (AGAGATGA) and haplotype II (GCGTGTAA) are the two main haplotypes with the frequency of 77.8% and 14.8% respectively. The SNPs found at positions 1980, 1981, 1982, 1984 and 2121 might be linked to inheritance completely.

Animals↗
PubMed2006

Platelet-lymphocyte conjugation differs between lymphocyte subpopulations.

BACKGROUND: Platelets can bind to, and thereby influence, lymphocyte function. OBJECTIVE: The propensities of different lymphocyte subpopulations to form platelet-lymphocyte conjugates/aggregates (P-Lym) was investigated using four-color whole blood flow cytometry. RESULTS: P-Lym constituted approximately 3% of circulating lymphocytes. Platelet conjugation was most common among large (monocyte-sized) lymphocytes. Platelet activation by ADP slightly increased platelet-T-cell conjugation, mainly to T-cytolytic (Tc) cells, but markedly elevated platelet-natural killer (NK)-cell conjugation. T-cell activation by phytohemagglutinin increased heterotypic conjugation among both T-helper (TH) and Tc cells, whilst NK-cell activation by interleukin-2 affected platelet-NK-cell aggregation little. Neither platelet activation nor lipopolysaccharides-induced B-cell activation enhanced platelet-B-cell aggregation. Activation-dependent heterotypic conjugation was mainly found among large cells, with increased percentages of conjugated cells and more platelets bound per lymphocyte. P-Lym formation initiated by platelet activation was abolished by P-selectin blockade, and tended to be reduced by inhibition of GPIIb/IIIa, CD11b, or CD40L. P-Lym formation initiated by lymphocyte activation was partially inhibited by each of these blocking agents, but more markedly inhibited when the blocking agents were combined. CONCLUSIONS: Platelets selectively bind to larger and activated lymphocytes. T-lymphocyte activation enhances platelet-T-cell aggregation. Platelet activation enhances platelet-Tc aggregation slightly and platelet-NK-cell aggregation markedly, while cellular activation affects platelet-B-cell aggregation little. P-selectin ligation is essential, but GPIIb/IIIa, CD40L, and CD11b also contribute to the heterotypic conjugation.

Adult↗
PubMed2001

Different protective roles in vitro of alpha- and beta-domains of growth inhibitory factor (GIF) on neuron injuries caused by oxygen free radicals.

It was well known that beta-amyloid (Abeta) and tau protein play an important role in pathological procedure of Alzheimer's disease (AD), a senile dementia. The growth inhibitory factor (GIF, also named metallothionein-3, MT-3) had been demonstrated to inhibit the outgrowth of cortex neurons in the medium with extract of the AD patient brain. In our experiments, it was found that the neurons of cortex and the PC12 (pheochromocytoma) cells could be protected from the cytotoxicity of beta-amyloid 25-35 in presence of GIF and its domains. Additionally, GIF can scavenge the hydroxyl radical efficiently in CytC-VitC radical producing system and its alpha-domain shown more effective potentials than its beta-domain. The electron paramagnetic resonance spectra also show that the alpha-domain has more potential ability for eliminating reactive oxygen free radicals than its beta-domain. The results suggest that GIF could act as an efficient scavenger against free radicals in vitro and the alpha-domain in GIF molecule shows more potential in protecting against reactive oxygen species injury than the beta-domain.

Alzheimer Disease↗
PubMed2001

Further characterization and population data for the pentanucleotide STR polymorphism D10S2325.

Pentanucleotide tandem repeat markers are interesting for forensic sciences, because they may present less stutter on the electrophoretic pattern. We focused on the analysis of the DNA sequence for each allele at the pentanucleotide STR locus D10S2325 in order to understand their structures in the human genome and to construct human allelic ladder, which is necessary for forensic DNA typing. In order to evaluate the forensic applicability of D10S2325 and to construct a preliminary database, the genotype distributions and allele frequencies in three major ethnic groups were investigated. The population samples included Caucasians (Germans), Africans (African Americans), and Asians (Chinese). A total of 520 samples from unrelated individuals was analyzed by Amp-FLP. An example of each allele and new alleles were sequenced. Allele determination was carried out by comparison with a sequenced human allelic ladder made in-house. This pentanucleotide STR provided easily interpretable results. A total of 15 alleles was found in our population samples. Three new alleles were observed and named as alleles 19 and 21 based on the number of repeat motifs, while allele 19 can be divided further into two alleles, 19a and 19 according to analysis of the sequence. No evidence of deviation from Hardy-Weinberg equilibrium was observed. In 64 confirmed father/mother/child triplets no mutation event was observed. Using a maximum likelihood method, the mutation rate was indirectly estimated as 2.5 x 10(-5). These results suggest that D10S2325 is a useful marker for forensic casework and paternity analysis.

Black or African American↗
PubMed2001

Dissolution behavior of porcine somatotropin with simultaneous gel formation and lysine Schiff-base hydrolysis.

The primary goal of this work was to develop a reliable in vitro dissolution model to evaluate the effects of Schiff-base hydrolysis and gel formation on the dissolution kinetics of pellets of porcine somatotropin (pST) and pST conjugated with ortho-vanillin (ov-pST) via Schiff-base formation, in an effort to develop an extended-release pST implant. Experimentally, dissolution was investigated as a function of ov concentration in pH 7.4, phosphate buffered saline under sink conditions where steady-state (constant flux) dissolution is typically observed. However, the resulting dissolution profiles displayed variable release rates due to gel formation at the solid-liquid interface, which impeded pST release. Chemical modification of pST with ov reduced gel formation and also resulted in much lower release rates. A mathematical model was developed that quantitatively accounts for changes in dissolution rates due to transient gel formation via irreversible aggregation, along with the effects of reversible Schiff-base hydrolysis involving ov, and predicts dissolution rates in the presence of ov decrease due to the much lower solubility of ov-pST. Our results indicate that although ov-pST is less prone to aggregate, pST/ov-pST equilibration is rapid compared to dissolution and therefore aggregation remains the limiting factor, and ultimately precludes this approach as a viable extended-release delivery system.

Animals↗
PubMed2001

The distribution of integumentary structures in a feathered dinosaur.

Non-avian theropod dinosaurs with preserved integumentary coverings are becoming more common; but apart from the multiple specimens of Caudipteryx, which have true feathers, animals that are reasonably complete and entirely articulated that show these structures in relation to the body have not been reported. Here we report on an enigmatic small theropod dinosaur that is covered with filamentous feather-like structures over its entire body.

Animals↗
PubMed2001

[Expression of apoptosis-related proteins in Hashimoto's thyroiditis and its pathological significance].

OBJECTIVE: To explore the role and significance of apoptosis-related proteins in the pathogenesis and pathological changes in Hashimoto's thyroiditis (HT). METHODS: Apoptotic level in thyroid tissue specimens from 17 patients with HT and 17 patients with nontoxic goiter (NTG) was evaluated by TUNEL method. Expression and distribution of Fas, FasL, Bcl-2 and Bax proteins in the specimens were investigated with immunohistochemical methods. RESULTS: A high percentage of apoptosis (32.5% +/- 12.3%) was observed by TUNEL method in thyroid follicles from HT specimens in comparison with that from NTG specimens (1.3% +/- 0.7%, P < 0.01). Positive rates of Fas, FasL, Bcl-2 and Bax in thyroid cells of NTG (35% approximately 47%) were significantly lower than those in thyroid cells of HT (88% approximately 94%, P < 0.01). The intensity of positive immunostaining for Fas, FasL, Bcl-2 and Bax in thyroid cells of HT was significantly higher than that of the controls (P < 0.01). Apoptosis and strongly positive immunostained thyroid cells with HT for Fas, FasL and Bax were mainly distributed in follicles adjacent to lymphocytic infiltrates, whereas strongly positive stained thyroid cells for Bcl-2 were mainly located in the area remote from the infiltrating lymphocytes. Staining of infiltrating lymphocytes for Fas, FasL, Bcl-2 and Bax was weak. CONCLUSION: Thyroid follicles in HT specimens exhibited high apoptotic levels. The high expression of apoptosis-related proteins Fas, FasL, Bcl-2 and Bax in thyrocytes of HT and weak expression in infiltrating lymphocytes accounted for thyroid follicle destruction and diffuse lymphocytic infiltration in HT.

Adult↗
PubMed2001

Vitamin C transport in human lens epithelial cells: evidence for the presence of SVCT2.

Vitamin C [ascorbic acid (AA)] is an important antioxidant present in m M amounts in the aqueous humor. Recently, two specific transporters for vitamin C (SVCT1, SVCT2) have been cloned in the rat and the human. The aim of the present study was to characterize vitamin C transport in an immortalized human lens epithelial cell line (HLE-B3). AA uptake was linear for 120 min in experiments conducted with 14C AA + 40 microM unlabelled AA. Uptake was measured at varying AA concentrations (0.04-1 m M) in Na+-containing and Na+-free buffers for 30 min at 37 degrees C. Effect of potential inhibitors of AA transport was also examined. Presence (or absence) of SVCT1 and SVCT2 was studied by RT-PCR of HLE-B3 poly (A)+ RNA using gene specific primers. Uptake studies revealed that AA uptake was highly Na+-dependent and exhibited saturation. Na+-dependent 14C-AA uptake was strongly inhibited (85-90%) by 10 m M unlabelled AA. Incubation of HLE-B3 cells with cAMP (0.1 m M), cytocholasin B (0.1 m M) and phorbol dibutyrate (1 microM) resulted in partial inhibition (36-51%) of AA uptake. Under similar conditions, D -glucose (10 m M) and staurosporine (0.1 microM) had no effect. RT-PCR showed the presence of SVCT2 while SVCT1 could not be amplified. Exposure to the chemical oxidant tert-butylhydroperoxide (TBH) up-regulated SVCT2 gene expression in HLE-B3 cells. Our data suggest that Na+-dependent transport of AA in normal lens epithelium is most likely mediated by SVCT2 rather than by SVCT1. This transport system may be subject to regulation by oxidant stress and by various second messenger signals.

Antioxidants↗
PubMed2001

Cyclic AMP-dependent protein kinase mediates ocular dominance shifts in cat visual cortex.

Visual experience during a critical period early in postnatal development can change connections within mammalian visual cortex. In a kitten at the peak of the critical period (approximately P28-42), brief monocular deprivation can lead to complete dominance by the open eye, an ocular dominance shift. This process is driven by activity from the eyes, and depends on N-methyl-D-aspartate (NMDA) receptor activation. The components of the intracellular signaling cascade underlying these changes have not all been identified. Here we show that inhibition of protein kinase A (PKA) by Rp-8-Cl-cAMPS blocks ocular dominance shifts that occur following monocular deprivation early in the critical period. Inhibition of protein kinase G by Rp-8-Br-PET-cGMPS had no effect, indicating a specificity for the PKA pathway. Enhancement of PKA activity late in the critical period with Sp-8-Cl-cAMPS did not increase plasticity. PKA is a necessary component of the pathway leading to cortical plasticity during the critical period.

Animals↗
PubMed2001

Effect of the group I metabotropic glutamate agonist DHPG on the visual cortex.

Metabotropic glutamate receptors have a variety of effects in visual cortex that depend on the age of the animal, the layer of the cortex, and the group of the receptor. Here we describe these effects for group I receptors, using both in vivo and in vitro preparations. The metabotropic group I glutamate receptor agonist 3,5 dihydroxyphenylglycine (DHPG) potentiates the responses to N-methyl-D-aspartate (NMDA) and alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) in slices of rat visual cortex. It also increases, initially, the visual response in the cat visual cortex. Both these effects are largest at 3-4 wk of age and decline to insignificance by 10 wk of age. Both are also largest in lower layers of cortex, which explains why the facilitatory effects found with the general metabotropic glutamate agonist 1S,3R aminocyclopentane-1,3-dicarboxylic acid (ACPD) are observed only in lower layers. Prolonged application of DHPG in the cat visual cortex, after the initial excitatory effect, produces depression. We also found that DHPG facilitates the NMDA response in fast-spiking cells, which are inhibitory, providing a partial explanation for this. Thus there are multiple effects of group I metabotropic glutamate receptors, which vary with layer and age in visual cortex.

Action Potentials↗