Biomedical subjects

Ge Li

Publications and source records attributed to Ge Li.

At least 37 records · Page 2Linked to original sources

PubMed2006

[T cell-mediated protective effect in cytomegalovirus infected murine astrocytes].

AIM: To explore T cell-mediated restriction of cytomegalovirus (CMV) in murine astrocytes. METHODS: A T cell-astrocyte coculture system was established, in which astrocytes were infected with mouse cytomegalovirus. Proliferation of T cells was observed under inverted microscope and detected after CFSE staining by flow cytometry. ELISA was used to detect the levels of IFN-gamma and TNF-gamma in coculture supernatants. Observation of astrocyte cytopathic effect (CPE) and PCR assay of cytomegalovirus DNA were also performed. RESULTS: After coculture for 3 d, T cells proliferation was observed under inverted microscope, and flow cytometry assay showed (6.68+/-0.61)% T cells had proliferated (P<0.01 compared with uninfected control). The level of IFN-gamma was (22.9+/-3.4) ng/L in coculture supernatants (P<0.05 compared with uninfected control). While levels of TNF-gamma were under 8 ng/L in both cytomegalovirus infected and uninfected groups. After coculture with T cells 31.25%-75% astrocyte CPE was diminished, and -75% cytomegalovirus DNA load was reduced. Cell-free coculture supernatants also exerted suppressive effect on CPE and viral DNA load. However, the antiviral effect of T cells diminished when added to fresh cytomegalovirus infected astrocytes, accompanied with the decreased level of T cells proliferation and IFN-gamma in coculture supernatants, suggesting the inhibition of T cells' function. CONCLUSION: Cytomegalovirus infected astrocytes could stimulate T cells proliferation and activation. Activated T cells had antiviral effect, which was partly mediated by soluble factors. The function of T cells was rapidly inhibited after activation, of which the underlying complicated mechanisms remain unclear and need further study.

Animals↗

PubMed2006

[Inhibitory effect of murine cytomegalovirus infection on neural stem cells' differentiation and its mechanisms].

OBJECTIVE: Cytomegalovirus (CMV) is the leading infectious cause of congenital anomalies of the central nervous system caused by intrauterine infection. However, the exact pathogenesis of these brain abnormalities has not been fully elucidated. It has been reported that periependymitis, periventricular necrosis and calcification are the most frequent findings in the brains of congenital CMV infection. Because a number of multipotential neural stem cells (NSCs) have been identified from ventricular zone, it is possible that NSCs in this area are primary targets for viral infection, which seems to be primarily responsible for the generation of the brain abnormalities. Therefore, the objective of the present study was to investigate the effect and mechanism of murine cytomegalovirus (MCMV) infection on neural stem cells' differentiation in vitro and its role in the mechanisms of brain abnormalities caused by congenital cytomegalovirus infection. METHODS: NSCs were prepared from fetal BALB/c mouse and were infected with recombinant MCMV RM461 inserted with a report gene LacZ at 1 multiplicity of infection (MOI = 1). The effect of MCMV infection on neural stem cells' differentiation was observed by detecting the ratio of nestin, GFAP and NSE positive cells with immunohistochemistry and flow cytometry on day 2 postinfection. The effects of MCMV infection on gene expression of Wnt-1 and neurogenin 1 (Ngn1) related to neural differentiation were detected by RT-PCR. RESULTS: NSCs isolated from embryonic mouse brains strongly expressed nestin, a specific marker of NSCs and had the capacity to differentiate into NF-200 and NSE positive neurons or GFAP positive astrocytes. At MOI = 1, the results of flow cytometry assay showed that nestin positive cells' proportion in the infection group [(62.2 +/- 1.8)%] was higher than that in the normal group [(37.2 +/- 2.4)%] (t = 4.62, P < 0.01). At the same time, the rates of GFAP and NSE positive cells' in the infection group were significantly lower than those in the normal group (P < 0.01). The scanning densities of Wnt-1 was 0.14 +/- 0.03 in the infection group while 0.32 +/- 0.04 in the control group (t = 7.21, P < 0.01). The scanning densities of Ngn1 were 0.09 +/- 0.01 and 0.21 +/- 0.02 in the two groups (t = 10.7, P < 0.01). CONCLUSIONS: These results suggest that MCMV infection could inhibit neuronal differentiation, which may be primary causes of disorders of brain development in congenital CMV infection. The decreased expression of Wnt-1 and Ngn1 may be involved in the inhibitory effect of murine cytomegalovirus infection on neural stem cells' differentiation, which may lead to a new strategy for preventing and treating brain abnormalities caused by CMV infection through regulating these two signal pathways.

Animals↗

PubMed2005

An experimental study on astrocytes promoting production of neural stem cells derived from mouse embryonic stem cells.

BACKGROUND: The production of neural stem cells (NSCs) derived from embryonic stem (ES) cells was usually very low according to previous studies, which was a major obstacle for meeting the needs of clinical application. This study aimed at investigating whether astrocytes could promote production of NSCs derived from ES cells in vitro. METHODS: Mouse ES cells line-D3 was used to differentiate into NSCs with astrocytes as inducing stromal cells by means of three-stage differentiation procedure. Another group without astrocytes served as control. The totipotency of ES cells was identified by observation of cells' morphology and formation of teratoma in severe combined immunodeficiency disease (SCID) mice. The quantity and purity of NSCs derived from ES cells were analyzed using clonogenic assay, immunohistochemical staining and flow cytometry assay. The plasticity of NSCs was detected by differentiating test. Octamer-binding transcription factor 4 (Oct-4) and nestin, the specific marker genes of ES cells and NSCs respectively, were detected continuously using reverse transcription-polymerase chain reaction (RT-PCR) method to monitor the process of cell differentiation. RESULTS: The ES cells of D3 line could maintain the ability of differentiating into cellular derivations of all three primary germ layers after continuous passage culture. At the end of two-stage of inducing process, 23.2 +/- 3.5 neurospheres per plate formed in astrocyte-induced group and only 0.8 +/- 0.3 per plate in the control group (clonogenic assay, P < 0.01), and the ratio of nestin positive cells was (50.2 +/- 2.8)% in astrocyte-induced group and only (1.4 +/- 0.5)% in the control group (flow cytometry, P < 0.01). With the induction undergoing, the expression of Oct-4 gradually decreased and then disappeared, while the expression of nestin was increased step by step, and the ratio of nestin positive cells was up to 91.4% by the three-stage differentiation. The nestin positive cells could be further induced into neurons, astrocytes, and oligodendrocytes in differentiating medium supplemented with fetal calf serum. The results of differentiating test showed that the ratio of NF-200 and NSE positive cells was (42.7 +/- 2.6)% in astrocyte-induced group and only (11.2 +/- 1.8)% in the control group (P < 0.01). CONCLUSIONS: Astrocytes can not only increase the production of NSCs derived from ES cells but also promote the differentiation of NSCs toward neuronal lineage.

Animals↗

PubMed2005

Guiding farnesyltransferase inhibitors from an ECLiPS library to the catalytic zinc.

Farnesyltransferase inhibitors identified from an ECLiPS library were optimized using solution-phase synthesis. X-ray crystallography of inhibited complexes was used to identify substructures that coordinate to the active site zinc. The X-ray structures were ultimately used to guide the design of second-generation analogs with FTase IC(50)s of less than 1.0 nM.

Animals↗

PubMed2005

Salivary cortisol and memory function in human aging.

OBJECTIVE: To examine the association of salivary cortisol with cognitive changes in a 3 year longitudinal study. Previous studies have suggested that elevated glucocorticoid concentrations alter hippocampal neuronal morphology, inhibit neurogenesis, and impair cognition. METHODS: Salivary cortisol samples were collected at home by 79 cognitively intact older persons (mean age 78+/-7 years) at 08:00, 15:00 and 23:00h, and collections were repeated annually for 3 years. Cognitive function was also assessed annually. RESULTS: The mean cortisol level of samples taken at three times of day and the cortisol concentration at 23:00h were significantly associated with poorer performance on tasks of declarative memory and executive function. Of 46 subjects who completed the entire 3 year study, higher initial cortisol concentration at 23:00h predicted a decline in performance of delayed paragraph recall. CONCLUSION: These results partially confirm previous findings that high cortisol is associated with impaired declarative memory function in non-demented older persons. In addition, our data show that high salivary cortisol concentrations predict a decline in memory function over the next 3 years.

Aged↗

PubMed2005

Activating cystic fibrosis transmembrane conductance regulator channels with pore blocker analogs.

Cystic fibrosis (CF) is caused by mutations that disrupt the surface localization and/or gating of the CF transmembrane conductance regulator (CFTR) chloride channel. The most common CF mutant is deltaF508-CFTR, which inefficiently traffics to the surfaces of most cells. The deltaF508 mutation may also disrupt the opening of CFTR channels once they reach the cell surface, but the extent of this gating defect is unclear. Here, we describe potent activators of wild-type and deltaF508-CFTR channels that are structurally related to 5-nitro-2-(3-phenylpropylamino)benzoate (NPPB), a negatively charged pore blocker that we show to have mixed agonistic activity (channel activation plus voltage-dependent pore block). These CFTR agonists include 1) an uncharged NPPB analog that stimulates channel opening at submicromolar concentrations without blocking the pore and 2) curcumin, a dietary compound recently reported to augment deltaF508-CFTR function in mice by an unknown mechanism. The uncharged NPPB analog enhanced the activities of wild-type and deltaF508-CFTR channels both in excised membrane patches and in intact epithelial monolayers. This compound increased the open probabilities of deltaF508-CFTR channels in excised membrane patches by 10-15-fold under conditions in which wild-type channels were already maximally active. Our results support the emerging view that CFTR channel activity is substantially reduced by the deltaF508 mutation and that effective CF therapies may require the use of channel openers to activate mutant CFTR channels at the cell surface.

Animals↗

PubMed2005

Sequence variants in Toll-like receptor gene cluster (TLR6-TLR1-TLR10) and prostate cancer risk.

BACKGROUND: Chronic inflammation plays an important role in several human cancers and may be involved in the etiology of prostate cancer. Toll-like receptors (TLRs) are important in the innate immune response to pathogens and in cross-talk between innate immunity and adaptive immunity. Our previous finding of an association of TLR4 gene sequence variants and prostate cancer risk provides evidence for a role of TLRs in prostate cancer. In this study, we investigated whether sequence variants in the TLR6-TLR1-TLR10 gene cluster, residing within a 54-kb region on 4p14, were associated with prostate cancer risk. METHODS: We selected 32 single-nucleotide polymorphisms (SNPs) covering these three genes and genotyped these SNPs in 96 control subjects from the Cancer Prostate in Sweden (CAPS) population-based prostate cancer case-control study. Five distinct haplotype blocks were inferred at this region, and we identified 17 haplotype-tagging SNPs (htSNPs) that could uniquely describe >95% of the haplotypes. These 17 htSNPs were then genotyped in the entire CAPS study population (1383 case subjects and 780 control subjects). Odds ratios of prostate cancer for the carriers of a variant allele versus those with the wild-type allele were estimated using unconditional logistic regression. RESULTS: The allele frequencies of 11 of the 17 SNPs were statistically significantly different between case and control subjects (P = .04-.001), with odds ratios for variant allele carriers (homozygous or heterozygous) compared with wild-type allele carriers ranging from 1.20 (95% confidence interval [CI] = 1.00 to 1.43) to 1.38 (95% CI = 1.12 to 1.70). Phylogenetic tree analyses of common haplotypes identified a clade of two evolutionarily related haplotypes that are statistically significantly associated with prostate cancer risk. These two haplotypes contain all the risk alleles of these 11 associated SNPs. CONCLUSION: The observed multiple associated SNPs at the TLR6-TLR1-TLR10 gene cluster were dependent and suggest the presence of a founder prostate cancer risk variant on this haplotype background. The TLR6-TLR1-TLR10 gene cluster may play a role in prostate cancer risk, although further functional studies are needed to pinpoint the disease-associated variants in this gene cluster.

Case-Control Studies↗

PubMed2005

Anti-flt1 peptide, a vascular endothelial growth factor receptor 1-specific hexapeptide, inhibits tumor growth and metastasis.

PURPOSE: The purpose of this study was to develop antagonists specific for the vascular endothelial growth factor receptor 1 (VEGFR1) and to investigate the effects of the antagonists on the VEGF-induced endothelial cell functions and tumor progression. EXPERIMENTAL DESIGN: Hexapeptides that inhibit binding of VEGFR1 and VEGF were identified through screening of synthetic peptide library. A selected peptide, anti-Flt1, was investigated for binding specificity with various receptors and ligand peptides. Effects of the peptide on proliferation, cell migration, and fibrin gel-based angiogenesis of endothelial cells were also investigated. The activity of anti-Flt1, in vivo, was evaluated for inhibition of tumor growth and metastasis in VEGF-secreting cancer cell-implanted mice by s.c. injections of the peptide. RESULTS: Here, we report on a short peptide that binds to VEGFR1 and prevents binding of VEGF. A hexapeptide, anti-Flt1 (Gly-Asn-Gln-Trp-Phe-Ile or GNQWFI), was identified from peptide libraries. The anti-Flt1 peptide shows specificity toward binding to VEGFR1 and it inhibits binding of VEGF, placental growth factor (PlGF), and VEGF/PlGF heterodimer to VEGFR1. This peptide does not inhibit the proliferation of endothelial cells induced by VEGF and VEGF/PlGF heterodimer but it effectively blocks VEGF-induced migration of endothelial cells and their capacity to form capillary-like structures on fibrin gel-based in vitro angiogenesis system. Furthermore, growth and metastasis of VEGF-secreting tumor cells were also significantly inhibited by s.c. injections of anti-Flt1 peptide in nude mice. Accordingly, VEGF-induced migration and capillary formation are mediated through VEGFR1, and these processes may play an important role in the growth and metastasis of VEGF-secreting tumors. CONCLUSIONS: We show that a peptide (anti-Flt1) specific for VEGFR1 inhibits growth and metastasis of tumor that secretes VEGF. The effects on endothelial cell functions, in vitro, indicate that the anticancer activity of anti-Flt1 peptide with reduced blood vessel density could also be due to the blocking of VEGFR1-mediated endothelial cell migration and tube formation. Although the effects of anti-Flt1 peptide still remain to be further characterized, the receptor 1-specific peptide antagonist, anti-Flt1, has potential as a therapeutic agent for various angiogenesis-related diseases, especially cancer.

Amino Acid Sequence↗

PubMed2005

Reversible silencing of CFTR chloride channels by glutathionylation.

The cystic fibrosis transmembrane conductance regulator (CFTR) is a phosphorylation- and ATP-dependent chloride channel that modulates salt and water transport across lung and gut epithelia. The relationship between CFTR and oxidized forms of glutathione is of potential interest because reactive glutathione species are produced in inflamed epithelia where they may be modulators or substrates of CFTR. Here we show that CFTR channel activity in excised membrane patches is markedly inhibited by several oxidized forms of glutathione (i.e., GSSG, GSNO, and glutathione treated with diamide, a strong thiol oxidizer). Three lines of evidence indicate that the likely mechanism for this inhibitory effect is glutathionylation of a CFTR cysteine (i.e., formation of a mixed disulfide with glutathione): (a) channels could be protected from inhibition by pretreating the patch with NEM (a thiol alkylating agent) or by lowering the bath pH; (b) inhibited channels could be rescued by reducing agents (e.g., DTT) or by purified glutaredoxins (Grxs; thiol disulfide oxidoreductases) including a mutant Grx that specifically reduces mixed disulfides between glutathione and cysteines within proteins; and (c) reversible glutathionylation of CFTR polypeptides in microsomes could be detected biochemically under the same conditions. At the single channel level, the primary effect of reactive glutathione species was to markedly inhibit the opening rates of individual CFTR channels. CFTR channel inhibition was not obviously dependent on phosphorylation state but was markedly slowed when channels were first "locked open" by a poorly hydrolyzable ATP analogue (AMP-PNP). Consistent with the latter finding, we show that the major site of inhibition is cys-1344, a poorly conserved cysteine that lies proximal to the signature sequence in the second nucleotide binding domain (NBD2) of human CFTR. This region is predicted to participate in ATP-dependent channel opening and to be occluded in the nucleotide-bound state of the channel based on structural comparisons to related ATP binding cassette transporters. Our results demonstrate that human CFTR channels are reversibly inhibited by reactive glutathione species, and support an important role of the region proximal to the NBD2 signature sequence in ATP-dependent channel opening.

ATP-Binding Cassette Transporters↗

PubMed2005

LL-37 enhances adaptive antitumor immune response in a murine model when genetically fused with M-CSFR (J6-1) DNA vaccine.

DNA vaccine against M-CSFR(J6-1) (macrophage colony-stimulating factor receptor cloned from the J6-1 leukemic cell line) has shown both protective and therapeutic effects. In this study, to explore the adjuvant effects of LL-37 to M-CSFR(J6-1) DNA vaccines, we constructed genetically fused vaccines encoding M-CSFR(J6-1) and LL-37(pF). After immunizing BALB/c mice, specific humoral and cellular immune responses were detected. Compared with pR (encoding the extracellular region of M-CSFR(J6-1)), pF was more effective in inducing humoral and cytotoxic immune response, prolonging survival of mice challenged with SP2/0-CSFR(J6-1) tumor cells, and inducing IFN-gamma and IL-4 release by splenocytes. In this study, we also constructed pLL37 (encoding the mature LL-37) and coadministrated pLL37 and pR to see whether the genetic fusion was necessary. We found that compared with pR alone, pLL37+pR could not prolong survival of mice challenged with SP2/0-CSFR(J6-1) tumor cells. Our results suggest that when genetically fused with M-CSFR(J6-1), LL-37 could enhance adaptive immune response against M-CSFR(J6-1) in a murine model challenged with tumor cells bearing M-CSFR(J6-1).

Adaptation, Physiological↗

PubMed2005

Effects of age and pregnancy on cytochrome P450 induction by octamethyltetracyclosiloxane in female Sprague-Dawley rats.

Dimethylcyclosiloxanes (DMCS) are components of silicone gel containing implants and are known inducers of human drug metabolizing enzymes. The effects of the major DMCS, octamethyltetracyclosiloxane (D4) on cytochrome P450 (CYP) induction were examined in young adult, mature, and pregnant female Sprague-Dawley rats. Also, the ability of D4 administered to pregnant dams to affect CYP expression in fetal liver was examined. Female young, mature, and pregnant Sprague-Dawley rats were administered 0, 5, 20, and 100 mg/kg D4 daily by gavage for 8 days. Liver microsomal CYP (CYP2B, CYP3A, CYP1A) concentrations were evaluated by Western blots using specific antisera, and CYP activities were assayed using CYP selective assays. D4 treatment resulted in a significant induction of CYP2B and CYP3A isoforms. CYP induction was dose and age dependent. A comparison of the inducibility of CYP3A protein by D4 in rats from different age groups showed that the degree of increase was the highest in the pregnant rats at doses of 20 mg/kg D4 or higher. The mature rats had a lesser degree of responsiveness than did the young rats at the dose of 100 mg/ kg D4. Significant increases in CYP2B immunoreactive protein concentrations were observed in young and mature rats given D4 at doses >5 mg/kg and in pregnant rats at doses >20 mg/kg. Maximal CYP2B induction detected with blotting was more than 90-fold in mature rats; however, no significant changes were detected in CYP1A expression. There was a 20% increase of liver to body weight ratio in the mature rats treated with 100 mg/kg D4. D4 has different inductive properties in female rats of different ages and reproductive status. Also, D4 administered to the pregnant dam is capable of inducing CYP expression in fetal liver as well as decreasing fetal body weight.

Age Factors↗

PubMed2005

An improved method for directional differentiation and efficient production of neurons from embryonic stem cells in vitro.

To establish a method of directional differentiation and efficient production of neurons from embryonic stem cells (ES cells) in vitro, based on the 4-/4+ protocol described by Bain, a new method was established to induce ES cells differentiating into neurons by means of three-step differentiation using all-trans retinoic acid (ATRA) combined with astrocyte-conditioned medium (ACM) in Vitro. The totipotency of ES cells was identified by observation of cells' morphology and formations of teratoma in immunocompromised mice. The cells' differentiation was evaluated continuously by the detection of the specific cellular markers of neural stem cells, neurons and astrocytes, including nestin, NSE and GFAP using immunohistochemistry assay. The NSE positive cells' ratio of the differentiated cells was determined by flow cytometry. It was found that the transparent circular clusters surrounding embryoid bodies induced with combining induction protocol formed just after 24 h and gradually enlarged later. This phenomenon could not be observed in EBs induced only by ATRA. The NSE positive cells' ratio in the cells induced with ATRA and ACM was higher than that of the cells induced by ATRA at different time points of differentiation, and finally reached up to 73.5% among the total differentiated population. It was concluded that ES cells could be induced into neurons with high purity and yield by means of inducing method combining with ATRA and ACM.

Animals↗

PubMed2005

Effects of human cytomegalovirus infection on apoptosis and expression of apoptosis-regulating factors.

The present study aimed to find out dynamic changes of apoptosis in human cytomegalovirus (HCMV) infected cells and the influence of HCMV infection on activation of caspase-3 and the expression of apoptosis-regulating genes, bcl-2 and fas mRNA. The sequential changes of apoptotic cell rate in high and low MOI (MOI = 2.5 and 0.25 respectively) of HCMV infected human embryonic lung fibroblasts (HELFs) at 1 h, 12 h, 24 h, 36 h, 48 h, 72 h and 96 h post-infection were measured by flow cytometry. The expression levels of caspase-3 protein and bcl-2 and fas mRNA in HCMV infected cells (MOI = 0.25) at 72 h post-infection were detected by Western blot and in situ hybridization methods, respectively. It was found that the ratio of apoptotic cells in normal controls was consistently lower, but the rates in low and high MOI infected cells were gradually increased with time prolonged, reached peak at 96 h (8.85%) and 72 h (25.63%), respectively. By Western blot analysis, only a narrow band of 32 kD (1 kD = 0.992 1 ku) procaspase-3 was found in normal cells, but a wider procaspase-3 band and a much wider band of 17 kD proteins (p17) appeared in the infected cells. Meanwhile, the expression of bcl-2 mRNA was higher and that of fas mRNA was lower in the normal HELF cells, whereas there were significantly lower bcl-2 mRNA and higher fas mRNA expression levels in HCMV infected cells. It was concluded that HCMV was a stronger inducer of apoptosis in HELF cells. Caspase-3, as the marker of undergoing apoptosis, was expressed increasingly and activated in the infected cells, indicating its action in HCMV-inducing apoptosis. Down-regulating bcl-2 mRNA expression and up-regulating fas mRNA expression were also involved in the mechanism of HCMV-induced apoptosis.

Apoptosis↗

PubMed2005

CD 39-associated high ATPase activity contribute to the loss of P 2 X 7-mediated calcium response in LCL cells.

The P 2 X 7 nucleotide receptor is an adenosine 5'-triphosphate (ATP)-gated ion channel, which induces cation channel opening imparting significant permeability to Ca(2+), and is widely expressed in cells of hematopoietic origin. Our previous report showed that P 2 X 7-mediated calcium response was absent in three Epstein-Barr virus (EBV)-positive and P 2 X 7 positive cell lines. In this report, we detected the cell surface ATPase activity, which contributes to the hydrolysis of extracellular ATP, and the expression of CD 39, which is the main source of ATPase on hematopoietic cells, in these cell lines. Then, we tried to restore the P 2 X 7-mediated calcium response in LCL-H and J 6-1 cells by either increasing the concentration of agonist or suppressing the ATPase activity by betagammaMeATP, a synthetic poorly metabolizable ATP analogue. The results showed that LCL-H and J 6-1 cells had higher levels of ATPase activity and CD 39 expression. The treatment of 300 microM betagammaMeATP efficiently inhibited the ATPase activity on LCL-H and J 6-1 cells. Both elevation of agonist concentration (10mM ATP or 1mM BzATP) and pretreatment with 300 microM betagammaMeATP followed by stimulation with normal concentration of agonists (1mM ATP or 0.1mM BzATP) could cause P 2 X 7-mediated calcium response in LCL-H but neither in J 6-1 cells. These results suggested that multiple mechanisms contributed to the loss of the P 2 X 7-mediated calcium response. CD 39-associated high ATPase activity contributed to the loss of the P 2 X 7-mediated calcium response in LCL-H cells, while additional mechanism(s) existed in J 6-1 cells.

Adenosine Triphosphatases↗

PubMed2005

[Effects of allitridin on the expression of human cytomegalovirus immediate early antigens-IE72 and IE86 in human embryonic lung cells].

OBJECTIVE: To investigate the effect of allitridin injection on the expression of human cytomegalovirus (HCMV) immediate-early antigens (IEAs including IE72 and IE86) in human embryonic lung cells. METHOD: HCMV AD 169 Virus strain infected cell model (MOI = 2.5 and 0.25, respectively) were established, and then treated with ICm5 and MTC doses of allitridin. Western blot was used to analyze the of IE72 and IE86 expression after the treatment, ganciclovir(GCV, IC50 and 2.3 x IC50) treatment as control. RESULT: No matter what kind of MOI was used, both IE86 and IE72 antigens' expression was effectively suppressed by allitridin treatment, and the inhibitory rate of IE86 was almost twice of IE72's. Compared with GCV, allitridin had stronger inhibitory effect on IE86 expressing, although its efficacy on IE72 was weaker than GCV. CONCLUSION: Allitridin could suppress the expression of IE72 and IE86, especially for IE86 expressing, maybe it is ore of key role in the mechanism of allitridin against HCMV.

Allyl Compounds↗

PubMed2005

[BALB/c mice model system of cytomegalovirus-induced myocarditis].

OBJECTIVE: To establish a BALB/c mice model system of cytomegalovirus-induced myocarditis. METHODS: Twenty five specific pathogen-free inbred female BALB/c mice (5 weeks old, 16 - 18 g, seronegative for MCMV) were infected with 1 x 10(4) PFU MCMV by the intraperitoneal (i.p.) route. All experimental mice were sacrificed at 3, 5, 7, 10, 14 days i.p. (n = 5 per time point). Hearts were removed under aseptic conditions, and were transected along the midline. One part of each heart was processed with Bouin's fixative for histological examination. The other part of each heart was immediately frozen in liquid nitrogen and stored at -80 degrees C until MCMV titre was determined by plaque assay. Serum cTnI level was assayed by ELISA. RESULTS: MCMV was detected in the hearts at extremely low levels on 3 days i.p. and could not be detected on 10 days i.p. A mixed cellular infiltrate composed of polymorphonuclear neutrophils and mononuclear lymphocytes was observed on 3 days, which reached a peak at 7 to 10 days after MCMV infection and was maintained for at least 3 - 4 months postinfection. Serum cTnI levels were elevated on 3 days i.p., reaching a peak at 7 to 10 days i.p.. CONCLUSIONS: These data highlight the possible therapeutic uses of antiviral drugs in viral myocarditis as well as further elucidating the pathogenic nature of the disease.

Animals↗

PubMed2005

[Detection of human rhinovirus genes from clinical sample by one-step RT-PCR].

OBJECTIVE: Human rhinovirus (HRV) is the most common respiratory pathogen, which causes not only acute respiratory infection and community acquired pneumonitis in children, but also asthma episode and deterioration. However, the detection of respiratory pathogen, which mainly focuses on respiratory syncytial virus, influenzaviruses A and B, parainfluenza viruses 1-3 and adenoviruses, does not include HRV yet by now in China. The absence of detection method limits the clinical understanding of HRV pathogenicity, and causes unreasonable use of antibiotics. This study aimed to establish a one-step reverse transcription (RT) PCR system for detecting specific fragment of HRV RNA, and to analyze the sequences of amplicons. METHODS: A pair of degenerate primers based on the HRV highly conserved 5'' noncoding region (NCR) were used to develop a one-step RT-PCR system for detecting HRV RNA in nasopharyngeal aspirates from 78 children with acute respiratory tract infections in the spring of 2004. All the positive PCR products were sequenced, and the sequences of the nucleotides were analyzed by using biological software and compared with those in the GeneBank. RESULTS: Eleven (14.1%) of 78 samples were positive on RT-PCR, these patients were clinically diagnozed as upper respiratory tract infection (n = 7), bronchitis (n = 3) and bronchopneumonia (n = 1), respectively. Compared with the sequences of clinical and standard HRV viruses in the GeneBank, the nucleotide sequences of these 11 amplicons shared high homology of 89%-95.5%. Within the 11 amplicons, nucleotide identity varied from 75.2% to 91.8%, and the ratio of genetic variation was from 8.8% to 31.0%, which occurred in highly conserved regions and usually showed single nucleotide mutation in some special locations. These 11 amplicons attribute to the two branches of HRV cladogram, respectively. Most of mutations in highly conservative domain occurred on single ribonucleotide, mainly as transversion (C/G, A/G) and transition (T/C, A/G), some were mutations among 3 bases (A/C/G, A/T/G, A/C/T). And a few mutations involved two nearby ribonucleotide which were also found in highly conservative domain. However, ribonucleotide deletion and insertion were usually found in highly variable domain. CONCLUSION: The findings showed that this one-step RT-PCR system was highly specific, rapid and convenient for the detection of HRV RNA in nasopharyngeal secretions of patients with acute respiratory tract infections and that the genome of HRV viruses was highly variable.

Base Sequence↗

PubMed2004

Protein-bound polysaccharide from Phellinus linteus induces G2/M phase arrest and apoptosis in SW480 human colon cancer cells.

The cytotoxic mechanism of protein-bound polysaccharide isolated from Phellinus linteus (PL, Mesima) has been investigated. PL inhibited the proliferation and colony formation of SW480 human colon cancer cells. Flow cytometry analysis showed that PL increased the populations of both apoptotic sub-G1 and G2/M phase. The result obtained from TUNEL assay corroborated apoptosis which was shown in flow cytometry. Western blot analysis suggested that PL-induced apoptosis and growth inhibition were associated with decrease in Bcl-2, increase of the release of cytochrome c, and reduced expression of cyclin B1. These results suggest that PL has a direct antitumor effect through apoptosis and cell cycle blockade in certain cancer cells.

Antineoplastic Agents↗