Biomedical subjects

Tong Zhao

Publications and source records attributed to Tong Zhao.

At least 19 recordsLinked to original sources

PubMed2026

Identification of Freezing-Responsive microRNAs and Their Targets in Chinese Jujube by Small RNA and Degradome Sequencing.

The jujube tree fruit remains a primary fruit in northern China, yet its geographical distribution and yield are significantly constrained by freezing stress during winter. Numerous studies have highlighted the pivotal regulatory function of microRNAs (miRNAs) in plant responses to low-temperature stress. Nevertheless, the specific miRNAs involved in the response to low temperatures and their associated gene networks in Ziziphus jujuba Mill are not well understood. In this investigation, we utilized high-throughput sequencing to analyze small RNA libraries from branches subjected to temperatures of 4 °C and -30 °C. Our analysis identified a total of 342 miRNAs, comprising 123 known miRNAs and 219 novel miRNAs. The differential expression analysis revealed that under low-temperature conditions, 177 miRNAs underwent significant changes. Among them, specific upregulation of miR319 in the less cold-resistant variety and miR6483 in sensitive variety was observed. By employing degradome sequencing, we identified a total of 1551 target genes corresponding to 3059 unique miRNA target interaction pairs involving 299 miRNAs. Functional analysis using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways indicated that these target genes are primarily associated with transcriptional regulation, metabolic pathways, and genetic information processing. Through a comprehensive analysis, we pinpointed 11 genes corresponding to 9 miRNAs that are implicated in jujube tree cold stress, and 7 target genes of 7 miRNAs were confirmed by 5'-RACE analysis. These miRNAs are likely to exert crucial regulatory functions in the context of jujube tree cold stress. This study is the first to systematically identify miRNAs and their target genes in the response of Ziziphus jujuba Mill to low-temperature stress, which provides important resources for in-depth analysis of the molecular mechanism of jujube tree cold resistance and for cold-resistant breeding.

Ziziphus↗

PubMed2006

Unit-cell scale mapping of ferroelectricity and tetragonality in epitaxial ultrathin ferroelectric films.

Typically, polarization and strain in ferroelectric materials are coupled, leading to the generally accepted direct relation between polarization and unit-cell tetragonality. Here, by means of high-resolution transmission electron microscopy we map, on the unit-cell scale, the degree of tetragonality and the displacements of cations away from the centrosymmetry positions in an ultrathin epitaxial PbZr(0.2)Ti(0.8)O(3) film on a SrRuO(3) electrode layer deposited on a SrTiO(3) substrate. The lattice is highly tetragonal at the centre of the film, whereas it shows reduced tetragonality close to the interfaces. Most strikingly, we find that the maximum off-centre displacements for the central area of the film do not scale with the tetragonality. This challenges the fundamental belief in a strong polarization-tetragonality coupling in PbTiO(3)-based ferroelectrics, at such thicknesses. Furthermore, a systematic reduction of the atomic displacements is measured at the interfaces, suggesting that interface-induced suppression of the ferroelectric polarization plays a critical role in the size effect of nanoscale ferroelectrics.

Journal Article↗

PubMed2006

The role of the VPS4A-exosome pathway in the intrinsic egress route of a DNA-binding anticancer drug.

PURPOSE: This study investigates the subcellular pharmacokinetics of drug efflux in cancer cells and explores the role of the multivesicular body (MVB) in facilitating efflux of doxorubicin, a widely used DNA-targeting anticancer agent, from the nucleus. METHODS: Human erythroleukemic K562 cells were pulsed with doxorubicin and then chased in drug-free media to allow for efflux. Microscopy and biochemical techniques were used to visualize the subcellular localization of the drug and measure drug content and distribution during the efflux period. To explore the role of the MVB in doxorubicin efflux, K562 cells were transfected with dominant negative mutant forms of VPS4a-GFP chimeras. RESULTS: Although the intracellular concentration of drug exceeds the extracellular concentration, nuclear efflux of doxorubicin occurs in living cells at a faster rate than doxorubicin unbinding from isolated nuclei into drug-free buffer. In cells expressing dominant negative VPS4a, doxorubicin accumulates in VPS4a-positive vesicles and drug sequestration is inhibited, directly implicating the MVB pathway in the egress route of doxorubicin in this cell type. CONCLUSIONS: Cellular membranes are a component of the doxorubicin efflux mechanism in K562 cells. Dominant-negative GFP chimeric mutants can be used to elucidate the role of specific membrane trafficking pathways in subcellular drug transport routes.

ATPases Associated with Diverse Cellular Activitie↗

PubMed2006

A new method to make nuclei or cell microarrays.

We invented a new method to make microarrays using nuclei extracted from paraffin-embedded tissues or cultured cells. A blank recipient paraffin block with 10 x 10 cores was constructed and sectioned to make the mold for the cell arrays. The sections of paraffin were mounted on poly-L-lysine-coated slides. Prepared nuclei or cells were injected into the cores of the paraffin mold. The slides were dried and dewaxed and nuclei or cell arrays were made. Using this method, we successfully made microarrays of nuclei extracted from diffuse large B-cell lymphoma paraffin-embedded tissues, nasopharyngeal cancer and lymphoma cell lines. This technique resulted in a paraffin-embedded cell preparation that yielded a cell density of approximately 500 to 1000 or 800 cells on average per 0.6-mm-diameter core. The microarrays were successfully used in fluorescence in situ hybridization, mRNA in situ hybridization, and cytohistochemical staining.

Cell Line, Tumor↗

PubMed2006

Inactivation of enterohemorrhagic Escherichia coli in rumen content- or feces-contaminated drinking water for cattle.

Cattle drinking water is a source of on-farm Escherichia coli O157:H7 transmission. The antimicrobial activities of disinfectants to control E. coli O157:H7 in on-farm drinking water are frequently neutralized by the presence of rumen content and manure that generally contaminate the drinking water. Different chemical treatments, including lactic acid, acidic calcium sulfate, chlorine, chlorine dioxide, hydrogen peroxide, caprylic acid, ozone, butyric acid, sodium benzoate, and competing E. coli, were tested individually or in combination for inactivation of E. coli O157:H7 in the presence of rumen content. Chlorine (5 ppm), ozone (22 to 24 ppm at 5 degrees C), and competing E. coli treatment of water had minimal effects (<1 log CFU/ml reduction) on killing E. coli O157:H7 in the presence of rumen content at water-to-rumen content ratios of 50:1 (vol/wt) and lower. Four chemical-treatment combinations, including (i) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.05% caprylic acid (treatment A); (ii) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.1% sodium benzoate (treatment B); (iii) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 0.5% butyric acid (treatment C); and (iv) 0.1% lactic acid, 0.9% acidic calcium sulfate, and 100 ppm chlorine dioxide (treatment D); were highly effective (>3 log CFU/ml reduction) at 21 degrees C in killing E. coli O157:H7, O26:H11, and O111:NM in water heavily contaminated with rumen content (10:1 water/rumen content ratio [vol/wt]) or feces (20:1 water/feces ratio [vol/wt]). Among them, treatments A, B, and C killed >5 log CFU E. coli O157:H7, O26:H11, and O111:NM/ml within 30 min in water containing rumen content or feces, whereas treatment D inactivated approximately 3 to 4 log CFU/ml under the same conditions. Cattle given water containing treatment A or C or untreated water (control) ad libitum for two 7-day periods drank 15.2, 13.8, and 30.3 liters/day, respectively, and cattle given water containing 0.1% lactic acid plus 0.9% acidic calcium sulfate (pH 2.1) drank 18.6 liters/day. The amounts of water consumed for all water treatments were significantly different from that for the control, but there were no significant differences among the water treatments. Such treatments may best be applied periodically to drinking water troughs and then flushed, rather than being added continuously, to avoid reduced water consumption by cattle.

Animals↗

PubMed2006

Control of Listeria spp. by competitive-exclusion bacteria in floor drains of a poultry processing plant.

In previous studies workers determined that two lactic acid bacterium isolates, Lactococcus lactis subsp. lactis C-1-92 and Enterococcus durans 152 (competitive-exclusion bacteria [CE]), which were originally obtained from biofilms in floor drains, are bactericidal to Listeria monocytogenes or inhibit the growth of L. monocytogenes both in vitro and in biofilms at 4 to 37 degrees C. We evaluated the efficacy of these isolates for reducing Listeria spp. contamination of floor drains of a plant in which fresh poultry is processed. Baseline assays revealed that the mean numbers of Listeria sp. cells in floor drains sampled on six different dates (at approximately biweekly intervals) were 7.5 log(10) CFU/100 cm(2) for drain 8, 4.9 log(10) CFU/100 cm(2) for drain 3, 4.4 log(10) CFU/100 cm(2) for drain 2, 4.1 log(10) CFU/100 cm(2) for drain 4, 3.7 log(10) CFU/100 cm(2) for drain 1, and 3.6 log(10) CFU/100 cm(2) for drain 6. The drains were then treated with 10(7) CE/ml in an enzyme-foam-based cleaning agent four times in 1 week and twice a week for the following 3 weeks. In samples collected 1 week after CE treatments were applied Listeria sp. cells were not detectable (samples were negative as determined by selective enrichment culture) for drains 4 and 6 (reductions of 4.1 and 3.6 log(10) CFU/100 cm(2), respectively), and the mean numbers of Listeria sp. cells were 3.7 log(10) CFU/100 cm(2) for drain 8 (a reduction of 3.8 log(10) CFU/100 cm(2)), <1.7 log(10) CFU/100 cm(2) for drain 1 (detectable only by selective enrichment culture; a reduction of 3.3 log(10) CFU/100 cm(2)), and 2.6 log(10) CFU/100 cm(2) for drain 3 (a reduction of 2.3 log(10) CFU/100 cm(2)). However, the aerobic plate counts for samples collected from floor drains before, during, and after CE treatment remained approximately the same. The results indicate that application of the two CE can greatly reduce the number of Listeria sp. cells in floor drains at 3 to 26 degrees C in a facility in which fresh poultry is processed.

Animals↗

PubMed2006

B cell antigen receptor signaling and internalization are mutually exclusive events.

Engagement of the B cell antigen receptor initiates two concurrent processes, signaling and receptor internalization. While both are required for normal humoral immune responses, the relationship between these two processes is unknown. Herein, we demonstrate that following receptor ligation, a small subpopulation of B cell antigen receptors are inductively phosphorylated and selectively retained at the cell surface where they can serve as scaffolds for the assembly of signaling molecules. In contrast, the larger population of non-phosphorylated receptors is rapidly endocytosed. Each receptor can undergo only one of two mutually exclusive fates because the tyrosine-based motifs that mediate signaling when phosphorylated mediate internalization when not phosphorylated. Mathematical modeling indicates that the observed competition between receptor phosphorylation and internalization enhances signaling responses to low avidity ligands.

Amino Acid Motifs↗

PubMed2006

Reduction of Campylobacter jejuni on chicken wings by chemical treatments.

Eight chemicals, including glycerol monolaurate, hydrogen peroxide, acetic acid, lactic acid, sodium benzoate, sodium chlorate, sodium carbonate, and sodium hydroxide, were tested individually or in combination for their ability to inactivate Campylobacter jejuni at 4 degrees C in suspension. Results showed that treatment for up to 20 min with 0.01% glycerol monolaurate, 0.1% sodium benzoate, 50 or 100 mM sodium chlorate, or 1% lactic acid did not substantially (< or = 0.5 log CFU/ml) reduce C. jejuni populations but that 0.1 and 0.2% hydrogen peroxide for 20 min reduced C. jejuni populations by ca. 2.0 and 4.5 log CFU/ml, respectively. By contrast, treatments with 0.5, 1.0, 1.5, and 2.0% acetic acid, 25, 50, and 100 mM sodium carbonate, and 0.05 and 0.1 N sodium hydroxide reduced C. jejuni populations by >5 log CFU/ml within 2 min. A combination of 0.5% acetic acid plus 0.05% potassium sorbate or 0.5% acetic acid plus 0.05% sodium benzoate reduced C. jejuni populations by >5 log CFU/ml within 1 min; however, substituting 0.5% lactic acid for 0.5% acetic acid was not effective, with a reduction of C. jejuni of <0.5 log CFU/ml. A combination of acidic calcium sulfate, lactic acid, ethanol, sodium dodecyl sulfate, and polypropylene glycol (ACS-LA) also reduced C. jejuni in suspension by >5 log CFU/ml within 1 min. All chemicals or chemical combinations for which there was a >5-log/ml reduction of C. jejuni in suspension were further evaluated for C. jejuni inactivation on chicken wings. Treatments at 4 degrees C of 2% acetic acid, 100 mM sodium carbonate, or 0.1 N sodium hydroxide for up to 45 s reduced C. jejuni populations by ca. 1.4, 1.6, or 3.5 log CFU/g, respectively. Treatment with ACS-LA at 4 degrees C for 15 s reduced C. jejuni by >5 log CFU/g to an undetectable level. The ACS-LA treatment was highly effective in chilled water at killing C. jejuni on chicken and, if recycled, may be a useful treatment in chill water tanks for poultry processors to reduce campylobacters on poultry skin after slaughter.

Animals↗

PubMed2006

[Expression and cloning of mCD99L2 gene from mouse B lymphoma cell line A20 and construction of its eukaryotic expression vector].

OBJECTIVE: To detect and clone mCD99L2 gene from mouse B lymphoma cell line A20 and construct its eukaryotic expression vector pcDNA3.1-mCD99L2. METHODS: The expression of mCD99L2 mRNA in A20 cell line was detected by in situ hybridization. The total RNA of A20 cells was extracted to obtain the full-length cDNA of the coding region of mCD99L2 gene by RT-PCR, the product of which was ligated into pMD18-T vector and the DNA sequence of the insert was detected. The coding regions of mCD99L2 gene was amplified from pMD-mCD99L2 by PCR using primers containing EcoR I and Xho I sites and cloned into the eukaryotic expression vector pcDNA3.1/MycHis(+). RESULTS: In situ hybridization identified positive expression of mCD99L2 gene in the A20 cell line. The full-length cDNA of mCD99L2 coding region of A20 cell line was obtained by RT-PCR, which yielded a product of 712 bp as expected, and the DNA sequence was completely homologus to the mCD99L2 cDNA reported in GenBank. Restriction endonuclease digestion and DNA sequencing indicated that the eukaryotic expression vector pcDNA3.1(+)- mCD99L2 had been constructed successfully. CONCLUSION: mCD99L2 cDNA has been cloned from mouse B lymphoma cell line A20 and its eukaryotic expression vector pcDNA3.1(+)- mCD99L2 successfully constructed, which facilitates further functional study of mCD99L2 gene in mouse B lymphoma cell line A20.

12E7 Antigen↗

PubMed2006

Zinc protoporphyrin aggravates cerebral ischemic injury following experimental subarachnoid hemorrhage.

This study was aimed to evaluate the influence of an antagonist of heme oxygenase, zinc protoporphyrin IX (ZnPPIX), on the production of endogenous carbon monoxide (CO) and the secondary cerebral injury after subarachnoid hemorrhage (SAH). Wistar rats were divided into non-SAH, SAH, and ZnPPIX groups. Autologus arterial hemolysate was injected into rat cisterna magna to induce SAH. CO and cyclic guanosine monophosphate (cGMP) levels in the brain, and lactate dehydrogenase (LDH) activity in serum were determined 24 hours and 72 hours after cisternal injection. It was found that 24 hours and 72 hours after SAH, the CO contents in SAH group were increased by 20.76% and 37.36%, respectively. CO content in ZnPPIX group was statistically lower than that in SAH group. No obvious change of cGMP content in SAH group was found. However, cGMP content in ZnPPIX group was lower than that in SAH group. Serum LDH activity increased significantly after induction of SAH. LDH activity in ZnPPIX group increased to a greater extent. It was concluded that ZnPPIX aggravates the cerebral injury secondary to experimental SAH by inhibiting the production of endogenous CO. The activation of HO/CO pathway is an intrinsic protective mechanism against cerebral ischemic injury after SAH.

Animals↗

PubMed2006

[Value of combinational detection by IgH and IgL primers in improving detection rate of lymphoma gene in paraffin-embedded tissue].

BACKGROUND & OBJECTIVE: Clonality detection through amplifying immunoglobulin heavy chain (IgH) by polymerase chain reaction (PCR) is a useful tool in diagnosis of lymphoma, but the false negative rate is high, especially in paraffin-embedded tissues. This study was to explore the value of tumor tissue microdissection and combinational detection of IgH and immunoglobulin light chain (Ig kappa or Ig lambda) in diagnosis of non-Hodgkin's lymphoma (NHL). METHODS: Two pairs of conventional primers for IgH and T-cell receptor gamma (TCRgamma), 2 novel designed pairs of primers for Ig kappa and Ig lambda were used to detect 58 paraffin-embedded blocks, which had been diagnosed by pathology and histochemistry. Of the 58 cases of lymph node tissues, 39 were B-cell lymphoma, 16 were T-cell lymphoma, and 3 were reactive proliferative lymph node tissue. Lymphoma cell lines DG75 and Jurkat were used as control. RESULTS: The positive rates of IgH primers (P1) and IgL primers (P kappa/P lambda) were 79.5% and 71.8% in the 39 cases of B-cell lymphoma (P>0.05), 6.3% and 12.5% in the 16 cases of T-cell lymphoma, respectively. The positive rate was greatly increased to 92.3% in combinationally detecting the primers for IgH and P kappa/P lambda. There was no positive detection among the reactive proliferative lymph node tissues. CONCLUSION: B-cell lymphoma detection rate can be significantly improved by the combination of IgH and IgL gene rearrangement primers, which provides efficient assistant method for the diagnosis and differential diagnosis of lymphoma.

DNA Primers↗

PubMed2005

Spiral evolution in a confined geometry.

Supported nanoscale lead crystallites with a step emerging from a noncentered screw dislocation on the circular top facet were prepared by rapid cooling from just above the melting temperature. STM observations of the top facet show a nonuniform rotation rate and shape of the spiral step as the crystallite relaxes. These features can be accurately modeled using curvature driven dynamics, as in classical models of spiral growth, with boundary conditions fixing the dislocation core and regions of the step lying along the outer facet edge.

Journal Article↗

PubMed2005

Neurogenesis in the adult rat brain after intermittent hypoxia.

Intermittent hypoxia has been found to prevent brain injury and to have a protective role in the CNS. To address the possible causes of this phenomenon, we made investigative effort to find out whether intermittent hypoxia affects neurogenesis in the adult rat brain by examining the newly divided cells in the subventricular zone (SVZ) and dentate gyrus (DG). The adult rats were treated with 3000 and 5000 m high altitude 4 h per day for 2 weeks consecutively. 5-Bromo-2-deoxyuridine-5-monophosphate (BrdU) immunocytochemistry demonstrated that the BrdU-labeled cells in the SVZ and DG increased after 3000 and 5000 m intermittent hypoxia. The number of BrdU-labeled cells in the SVZ returned to normal level 4 weeks following intermittent hypoxia. However, the BrdU-labeled cells in the DG had a twofold increase 4 weeks subsequent to intermittent hypoxia. From these data, we conclude that intermittent hypoxia facilitates the proliferation of neural stem cells in situ, and that the newly divided cells in the SVZ and DG react differently to hypoxia. We are convinced by these findings that the proliferation of neural stem cells in SVZ and DG may contribute to adaptive changes following intermittent hypoxia.

Altitude↗

PubMed2005

Dedifferentiation of adult human myoblasts induced by ciliary neurotrophic factor in vitro.

Ciliary neurotrophic factor (CNTF) is primarily known for its important cellular effects within the nervous system. However, recent studies indicate that its receptor can be highly expressed in denervated skeletal muscle. Here, we investigated the direct effect of CNTF on skeletal myoblasts of adult human. Surprisingly, we found that CNTF induced the myogenic lineage-committed myoblasts at a clonal level to dedifferentiate into multipotent progenitor cells--they not only could proliferate for over 20 passages with the expression absence of myogenic specific factors Myf5 and MyoD, but they were also capable of differentiating into new phenotypes, mainly neurons, glial cells, smooth muscle cells, and adipocytes. These "progenitor cells" retained their myogenic memory and were capable of redifferentiating into myotubes. Furthermore, CNTF could activate the p44/p42 MAPK and down-regulate the expression of myogenic regulatory factors (MRFs). Finally, PD98059, a specific inhibitor of p44/p42 MAPK pathway, was able to abolish the effects of CNTF on both myoblast fate and MRF expression. Our results demonstrate the myogenic lineage-committed human myoblasts can dedifferentiate at a clonal level and CNTF is a novel regulator of skeletal myoblast dedifferentiation via p44/p42 MAPK pathway.

Animals↗

PubMed2005

Mycobacterium tuberculosis infection and FHIT gene alterations in lung cancer.

Although it is fairly well accepted that pulmonary tuberculosis is a major risk factor of lung cancer, the exact molecular mechanisms involved in its tumorigenesis are unclear. For this purpose, we have examined the relationship between Mycobacterium tuberculosis (M-TB) infection and FHIT gene alteration in lung cancer. Tumors with M-TB infection had a slightly higher abnormal FHIT protein expression compared with tumors without M-TB infection, although not statistically significant (Fisher's exact test, P=0.248). LOH affecting at least one locus of the FHIT gene was significantly more frequent in lung cancer patients with M-TB infection than in patients without M-TB infection whether assessment by univariate testing methods or logistic regression modeling analysis (Fisher's exact test P=0.025, logistic regression analysis P=0.012). These results indicate that M-TB infection is associated with FHIT gene LOH in lung cancer.

Acid Anhydride Hydrolases↗

PubMed2005

[Effect of granulocyte-macrophage colony stimulating factor on the repair of vessel intima damaged by balloon].

OBJECTIVE: To observe the effect of granulocyte-macrophage colony stimulating factor (GM-CSF) on the repair of damaged iliac arteries. METHODS: Twenty-four male New Zealand White rabbits were randomized to two equal groups: GM-CSF group receiving subcutaneous injection of GM-CSF (10 microg.kg(-1).d(-1)), and control group receiving subcutaneous injection of normal saline. Seven days later all rabbits underwent insertion and expansion of balloon into the right iliac arteries so as to cause damage. Four weeks after the operation the operated iliac arteries of the GM-CSF group and the left iliac arteries of the control group were collected to undergo pathological examination. The repair and hyperplasia of intima were observed by microscopy and the indices of restenosis were evaluated by computerized planimetry. RESULTS: Histological examination showed that hyperplasia of neogenetic intima was lighter, numbers of vascular smooth muscle cells and fibrous tissue were less, degree of lumen stenosis was slighter, and the endothelium was more integrated in the GM-CSF group in comparison with the control group. Morphometry showed that the lumen area of the GM-CSF group was 1.27 mm(2) +/- 0.31 mm(2), significantly larger than that of the control group (0.92 mm(2) +/- 0.24 mm(2), P < 0.05). The area of neogenetic intima of the GM-CSF group was 0.85 mm(2) +/- 0.34 mm(2), significant smaller than that of the control group (1.18 +/- 0.38, P < 0.05), and the percentage of intimal hyperplasia of the GM-CSF group was 40% +/- 7%; significantly lower than that of the control group (55% +/- 6%, P < 0.05). CONCLUSION: GM-CSF promotes the repair of intima, reduces the new intima formation, and decreases the rate of restenosis.

Angioplasty, Balloon↗

PubMed2005

Effects of granulocyte-macrophage colony stimulating factor on the repair of vessel intima damaged by balloon.

BACKGROUND: The dysfunction of vascular endothelial cells plays a key role in starting and facilitating restenosis. The acceleration of intima repair and the recovery of endothelial function would reduce the restenosis rate. This study was undertaken to assess the effect of granulocyte-macrophage colony stimulating factor (GM-CSF) on the repair of damaged iliac arteries. METHODS: Twenty-four male New Zealand white rabbits undergoing primary iliac artery deendothelization were randomly divided into two groups (GM-CSF group and control group). The GM-CSF group received a subcutaneous injection of GM-CSF [10 microg x kg(-1) x d(-1)], and the control group was given a subcutaneous injection of equivalent saline. The iliac arteries of all animals were damaged by balloon after 7 days. The levels of nitric oxide (NO) were detected before, 1 week, 2 weeks and 4 weeks after angioplasty. The repair and hyperplasia of the intima were observed microscopically and the indices of stenosis were evaluated by computerized planimetry after 4 weeks of angioplasty. RESULTS: The NO levels of the GM-CSF group were higher than those of the control group 2 weeks and 4 weeks after angioplasty [(91.92 +/- 11.57) micromol/L vs. (81.67 +/- 12.18) micromol/L; (97.67 +/- 10.13) micromol/L vs. (83.16 +/- 12.64) micromol/L]. Four weeks after balloon damage, histological examination showed that neointima formation, vascular smooth muscle cells and fibrous tissue of the GM-CSF group were less than those of the control group. The endothelium of the GM-CSF group was more integrated, and stenosis of lumen was slighter than that of the control group. Morphometry showed the lumen area of the GM-CSF group was larger than that of the control group [(1.27 +/- 0.31) mm(2) vs. (0.92 +/- 0.24) mm(2)], the neointimal area and percent of intima hyperplasia were significantly smaller than those of the control group [(0.85 +/- 0.34) mm(2) vs. (1.18 +/- 0.38) mm(2); (40 +/- 7)% vs. (55 +/- 6)%]. CONCLUSION: GM-CSF could facilitate the repair of the intima, reduce neointima formation, better the function of the endothelium, and decrease the rate of restenosis.

Angioplasty, Balloon↗

PubMed2005

Underlying mechanism of hypoxic preconditioning decreasing apoptosis induced by anoxia in cultured hippocampal neurons.

It is known that hypoxic preconditioning (HP, a brief period of sublethal hypoxia) provides neuroprotection against subsequent severe anoxia, but the mechanisms of this increased tolerance have not been fully elucidated. A hypoxic preconditioning model was established by exposing a 4-day hippocampal culture to 1% O(2) for 20 min/day for 8 days. The preconditioning significantly decreased the number of apoptotic neurons at reoxygenation 24 h after 4 h of severe anoxia (0% O(2)). Further study demonstrated that the degradation of mitochondrial membrane potential (MMP) was greatly inhibited and the expression of B-cell lymphoma protein-2 (Bcl-2) was increased considerably after severe anoxia in the HP groups. These results indicate that the increased anoxic tolerance, which is induced by HP in cultured hippocampal cells, may be correlated with Bcl-2 overexpression and enhanced stability of MMP, which ultimately reduces apoptosis 24 h after reoxygenation.

Animals↗