Sterility changeover induced by low temperature in male sterility line CMS7311 of heading Chinese cabbage ( Brassica campestris L. ssp. penkinsis) was investigated under constant temperature, day/night alternating tem...Sterility changeover induced by low temperature in male sterility line CMS7311 of heading Chinese cabbage ( Brassica campestris L. ssp. penkinsis) was investigated under constant temperature, day/night alternating temperature in light-growth-incubator and outdoor natural day/night alternating temperature respectively. It showed that the sterility of CMS7311 has significant change with temperature. The constant temperature of 6 - 12 degreesC was suitable to induce the changeover of sterility (CGS) of CMS7311 ; the shortest treatment time for CGS induction at this temperature was 3 d. The significant value of sterility changeover of CMS7311 occurred at the constant temperature of 6 - 9 degreesC after treatment for 6 - 9 d. The intensity of CGS was stronger under constant temperature than under alternate temperature, but the shortest treatment time inducing CGS has no difference between them. When treated for 9 d under the day/night alternating temperature of 11/7 degreesC, its sterility could also turn to normal fertility (near to sterile grade I or zero). In normal condition, the interval from the end of temperature treatment to the beginning of CGS induction was 10 - 16 d. In the condition of natural day/night alternating temperature, the lower limit of temperature for effective CGS induction was at the daily mean temperature ( DMT) of 3. 5 - 6. 8 degreesC, and the shortest treatment time which could induce the sterility changeover was also longer than that under constant temperature, being 11d at DMT of 1.5 - 3.1 degreesC. In addition, for the apical dominance, the flower bud on the first lateral branch showed the CGS 8 - 10 d later than the flower bud on the main stem under the same temperature with the same days of treatment. The intensity of CGS of CMS7311 on the first lateral branch was also weaker than the flower bud on the main stem.展开更多
[Objective] The aim of the research was to study the effect of the ice bath time after heat shock and the incubation time on the transformation efficacy,and to establish a simple and quick transformation method.[Metho...[Objective] The aim of the research was to study the effect of the ice bath time after heat shock and the incubation time on the transformation efficacy,and to establish a simple and quick transformation method.[Method]Competent cells were prepared with two buffer solutions;with the ice bath time after heat shock and the recovery time as the variables,the relationship between these two factors and transformation efficacy was studied.[Result]The transformation efficacy was the best when the ice bath time was 2 min and the recovery time was 30 or 40 min;when the ice bath time and the recovery time was 0 min,a certain amount of transformants still could be obtained.[Conclusion]The ice bath time after heat shock and the recovery time had certain impact on transformation efficacy,but they were not the decisive factors.Therefore,in the general transformation experiment,these two steps could be omitted.展开更多
Objective: To detect the expression of hMSH2, hMLH1 and p53 in gastric epithelial cells with and without Helicobactcr pylori (H. pylori) infection and investigate the relationship between H. pylori infection and th...Objective: To detect the expression of hMSH2, hMLH1 and p53 in gastric epithelial cells with and without Helicobactcr pylori (H. pylori) infection and investigate the relationship between H. pylori infection and these genes in gastric carcinogenesis. Methods: H. pylori infection was detected by rapid urease tests. Expression of hMSH2, hMLHland p53 in gastric cancer (GC) tissue, its adjacent mucosa, gastritic mucosa and normal mucosa was assessed by immunohistochemistry SP method. Results: Positive expression rate of hMSH2 in GC tissue (62.7%) was higher than those in adjacent mucosa (29.4%), gastritic mucosa (32.4%) and normal mucosa (30.0%) (P〈0.001). Positive rate of hMSH2 in poorly differentiated adenocarcinoma (76.4%) was higher than those in other carcinomas (54.3%, 53.1%) (P〈0.05). Positive expression rate of hMLH1 in GC tissue (64.3%) mucosa (82.4%) and normal mucosa (80.0%) was lower than those in adjacent mucosa (84.4%), gastritic (P〈0.01). Positive rate of hMLH1 in mucoid carcinoma (43.7%) was lower than those in other carcinomas (78.2%, 64.7%) (P〈0.01). Positive expression rate of p53 in GC tissue (51.9%) was higher than those in adjacent mucosa (3.1%), gastritic mucosa (0.0%) and normal mucosa (0.0%) (P〈0.001). Positive rate of p53 in well differentiated adenocarcinoma (32.6%) was lower than those in other carcinomas (58.8%, 68.7%) (P〈0.01). Positive rates of hMSH2 and hMLH1 in GC with H. pylori infection were lower than those without the infection, respectively (P〈0.05). Positive rate of p53 in GC with H. pylori infection (61.4%) was higher than that without the infection (40.6%) (P〈0.05). Conclusion: Gastric carcinogenesis may be associated with abnormal expression of hMSH2, hMLH1 and p53; H. pylori infection affecting expression of these genes may be one of its carcinogenic mechanisms.展开更多
AIMS To establish the prevalence of bacterial infection in cir- rhotic patients with hepatocellular carcinoma(HCC). METHODS All 719 cirrhotic patients with HCC were investigat- ed retrospectively for the prevalence of...AIMS To establish the prevalence of bacterial infection in cir- rhotic patients with hepatocellular carcinoma(HCC). METHODS All 719 cirrhotic patients with HCC were investigat- ed retrospectively for the prevalence of bacterial infections. RESULTS The incidence of bacterial infection was 15.4% (111/719).According to Child-Pugh classification,the inci- dences of bacterial infection in class A,B and C were 2.3%,8. 0%,and 26.4 %,respectively.The bacterial infection increased with the severity of cirrhosis and severe bacterial infections usual- ly occurred in Child-Pugh class B and C patients. CONCLUSIONS The susceptibility of HCC patients to bacterial infection is mainly due to the underlying cirrhosis and not to the HCC itself.展开更多
Psychophysical experiments on human and animal subjects have proven that aged individuals show significantly reduced visual contrast sensitivity compared with young adults.To uncover the possible neural mechanisms,we ...Psychophysical experiments on human and animal subjects have proven that aged individuals show significantly reduced visual contrast sensitivity compared with young adults.To uncover the possible neural mechanisms,we used extracellular single-unit recording techniques to examine the response of V1(primary visual cortex) neurons as a function of visual stimulus contrast in both old and young adult cats(Felis catus).The mean contrast sensitivity of V1 neurons to visual stimuli in old cats decreased significantly relative to young adult cats,consistent with findings reported in old primates.These results indicate that aging can affect contrast sensitivity of visual cortical cells in both primate and non-primate mammalian animals,and might contribute to the reduction of perceptual visual contrast sensitivity in aged individuals.Further,V1 cells of old cats exhibited increased responsiveness,decreased signal-to-noise ratio,and enlarged receptive field(RF) size compared with that of young adult cats,which indicated that decreased contrast sensitivity of V1 neurons accompanied a reduction of intracortical inhibition during senescence.展开更多
[Objective]The aim of this study was to investigate whether communication signal C6-HSL among individual bacteria can influence plant growth and disease resistance ability. [Method]With potato virus-free plantlets as ...[Objective]The aim of this study was to investigate whether communication signal C6-HSL among individual bacteria can influence plant growth and disease resistance ability. [Method]With potato virus-free plantlets as the test materials and C6-HSL as the inducer,the potato's growth and the ability of resistance against Erwinia carotovora subp carotovora were tested after being treated by C6-HSL with different concentrations. The effects of C6-HSL on plant landmark defense enzyme activities and H2O2 content in potato leaves were measured especially. [Result]C6-HSL with different concentrations could obviously inhibit the growth rate of root and the number of roots,but had no effect on plant height,number of nodes and leaf size. POD or SOD activity and H2O2 content in plant landmark defense enzymes significantly increased after induction of C6-HSL,but PAL and PPO activity had no obvious change. In the resistant test,potato plants induced by C6-HSL could inhibit the infection of Erwinia carotovora subp carotovora effectively,and its incidence was significantly lower than the control group. [Conclusion]Bacteria AHL can be possibly used as a new kind of plant disease-resistant activator.展开更多
Study of marine noctilucence in marine is important to fishery, environmental monitoring and military affairs. A luminous bacterial strain D2 was isolated from the marine sediment samples collected near Donghai Island...Study of marine noctilucence in marine is important to fishery, environmental monitoring and military affairs. A luminous bacterial strain D2 was isolated from the marine sediment samples collected near Donghai Island in Zhanjiang, China. The primary cultural and luminescent conditions of luminous bacterium D2 which was identified as Vibrio sp. were determined in liquid culture. The results showed that pH 7.0, 35 ℃, with 2.0 % NaCI, were the best growth conditions, and pH5 - 6, 20℃, OD600 0.08, with 3.0 % NaCI, were the optimal luminescent conditions.展开更多
Objective: To investigated the e?ect of inhibition of telomerase with hTERT antisense on leukemic cells (HL-60 and K562) to CDDP-induced apoptosis. Methods: Antisense phosphorothioate oligodeox...Objective: To investigated the e?ect of inhibition of telomerase with hTERT antisense on leukemic cells (HL-60 and K562) to CDDP-induced apoptosis. Methods: Antisense phosphorothioate oligodeoxynucleotide (AS PS-ODN) was synthesized and puri?ed. Telomerase activity was detected by Telomerase PCR ELASA kit and cell apoptosis was observed by morphological method and determined by ?owcytometry. Results: AS PS-ODN could signi?cantly inhibit telomerase activity by down regulat- ing the hTERT expression, and increase the susceptibility of leukemic cells to CDDP-induced apoptosis. Conclusion: Inhibition of telomerase with hTERT antisense can increases the susceptibility of leukemic cells to CDDP-induced apoptosis.展开更多
The prevalence of antibiotic susceptibility and disinfectant resistance in bacterial pathogens causes a serious problem not only to food safety but also to public health, which directly or indirectly leads to treatmen...The prevalence of antibiotic susceptibility and disinfectant resistance in bacterial pathogens causes a serious problem not only to food safety but also to public health, which directly or indirectly leads to treatment and disinfection failures. In this review, multidrug resistance, the mechanism of disinfectant resistance, the methods for detecting disinfectant resistance and the cross-resistance between an- tibiotics and disinfectants are summarized. More efforts should be devoted to explor- ing the professional guidance of using antibiotics and disinfectants, and to develop- ing the comprehensive detection with genetic and molecular methods is highly ex- pected.展开更多
Numerous cellular and molecular events have been described in development of gastric cancer. In this artide, we overviewed roles of Helicobacter pylori (H pylori) infection on some of the important events in gastric...Numerous cellular and molecular events have been described in development of gastric cancer. In this artide, we overviewed roles of Helicobacter pylori (H pylori) infection on some of the important events in gastric carcinogenesis and discussed whether these cellular and molecular events are reversible after cure of the infection. There are several bacterial components affecting gastric epithelial kinetics and promotion of gastric carcinogenesis. The bacterium also increases risks of genetic instability and mutations due to NO and other reactive oxygen species. Epigenetic silencing of tumor suppressor genes such as RUNX3 may alter the frequency of phenotype change of gastric glands to those with intestinal metaplasia. Host factors such as increased expression of growth factors, cytokines and COX-2 have been also reported in non-cancerous tissue in Hpylori-positive subjects. It is noteworthy that most of the above phenomena are reversed after the cure of the infection. However, some of them including overexpression of COX-2 continue to exist and may increase risks for carcinogenesis in metaplastic or dysplastic mucosa even after successful H pylori eradication. Thus, H pylori eradication may not completely abolish the risk for gastric carcinogenesis. Efficiency of the cure of the infection in suppressing gastric cancer depends on the timing and the target population, and warrant further investigation.展开更多
Apoptosis is central for the control and elimination of viral infections. In chronic hepatitis C virus (HCV) infection, enhanced hepatocyte apoptosis and upregulation of the death inducing ligands CD95/Fas, TRAIL and ...Apoptosis is central for the control and elimination of viral infections. In chronic hepatitis C virus (HCV) infection, enhanced hepatocyte apoptosis and upregulation of the death inducing ligands CD95/Fas, TRAIL and TNFα occur. Nevertheless, HCV infection persists in the majority of patients. The impact of apoptosis in chronic HCV infection is not well understood. It may be harmful by triggering liver fibrosis, or essential in interferon (IFN) induced HCV elimination. For virtually all HCV proteins, pro- and anti-apoptotic effects have been described, especially for the core and NS5A protein. To date, it is not known which HCV protein affects apoptosis in vivo and whether the infectious virions act pro- or anti- apoptotic. With the availability of an infectious tissue culture system, we now can address pathophysiologically relevant issues. This review focuses on the effect of HCV infection and different HCV proteins on apoptosis and of the corresponding signaling cascades.展开更多
Type I interferons (IFN) are well studied cytokines with anti-viral and immune-modulating functions. Type I IFNsare produced following viral infections, but until recently, the mechanisms of viral recognition leading ...Type I interferons (IFN) are well studied cytokines with anti-viral and immune-modulating functions. Type I IFNsare produced following viral infections, but until recently, the mechanisms of viral recognition leading to IFN productionwere largely unknown. Toll like receptors (TLRs) have emerged as key transducers of type I IFN during viral infectionsby recognizing various viral components. Furthermore, much progress has been made in defining the signaling path-ways downstream of TLRs for type I IFN production. TLR7 and TLR9 have become apparent as universally importantin inducing type I IFN during infection with most viruses, particularly by plasmacytoid dendritic cells. New intracellularviral pattern recognition receptors leading to type I IFN production have been identified. Many bacteria can also inducethe up-regulation of these cytokines. Interestingly, recent studies have found a detrimental effect on host cells if type IIFN is produced during infection with the intracellular gram-positive bacterial pathogen, Listeria monocytogenes. Thisreview will discuss the recent advances made in defining the signaling pathways leading to type I IFN production.展开更多
The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/APO2L) is a member of the TNF gene superfamily that induces apoptosis upon engagement of cognate death receptors. While TRAIL is relatively ...The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/APO2L) is a member of the TNF gene superfamily that induces apoptosis upon engagement of cognate death receptors. While TRAIL is relatively non-toxic to normal cells, it selectively induces apoptosis in many transformed cells. Nevertheless, breast tumor cells are particularly resistant to the effects of TRAIL. Here we report that, in combination with the cyclin-dependent kinase inhibitor roscovitine, exposure to TRAIL induced marked apoptosis in the majority of TRAIL-resistant breast cancer cell lines examined. Roscovitine facilitated TRAIL death-inducing signaling complex formation and the activation of caspase-8. The cFLIPL and cFLIPs FLICE-inhibitory proteins were significantly down-regulated following exposure to roscovitine and, indeed, the knockdown of cFLIP isoforms by siRNA sensitized breast tumor cells to TRAIL-induced apoptosis. In addition, we demonstrate that roscovitine strongly suppressed Mcl-1 expression and up-regulated E2F1 protein levels in breast tumor ceils. Significantly, the silencing of Mci-1 by siRNA sensitized breast tumor cells to TRAIL-induced apoptosis. Furthermore, the knockdown of E2F1 protein by siRNA reduced the sensitizing effect of roscovitine in TRAIL-induced apoptosis. In summary, our results reveal a pleitropic mechanism for the pro-apoptotic influence of roscovitine, highlighting its potential as an antitumor agent in breast cancer in combination with TRAIL.展开更多
AIM: To investigate the effects of exogenous melatonin on bacterial translocation and apoptosis in a rat ulcerati-ve colitis model. METHODS: Rats were randomly assigned to three groups: groupⅠ: control, group Ⅱ: exp...AIM: To investigate the effects of exogenous melatonin on bacterial translocation and apoptosis in a rat ulcerati-ve colitis model. METHODS: Rats were randomly assigned to three groups: groupⅠ: control, group Ⅱ: experimental colitis, group Ⅲ: colitis plus melatonin treatment. On d 11 after colitis, plasma tumor necrosis factor-α, portal blood endotoxin levels, colon tissue myeloperoxidase and caspase-3 activity were measured. Bacterial translocation was quantified by blood, lymph node, liver and spleen culture. RESULTS: We observed a significantly reduced inciden-ce of bacterial translocation to the liver, spleen, mesen-teric lymph nodes, portal and systemic blood in animals treated with melatonin. Treatment with melatonin signifi-cantly decreased the caspase-3 activity in colonic tissues compared to that in trinitrobenzene sulphonic acid-trea-ted rats (16.11 ± 2.46 vs 32.97 ± 3.91, P < 0.01). CONCLUSION: Melatonin has a protective effect on ba-cterial translocation and apoptosis.展开更多
Despite advances in preoperative evaluation and postoperative care, intervention, especially surgery, for relief of obstructive jaundice still carries high morbidity and mortality rates, mainly due to sepsis and renal...Despite advances in preoperative evaluation and postoperative care, intervention, especially surgery, for relief of obstructive jaundice still carries high morbidity and mortality rates, mainly due to sepsis and renal dysfunction. The key event in the pathophysiology of obstructive jaundice-associated complications is endotoxemia of gut origin because of intestinal barrier failure. This breakage of the gut barrier in obstructive jaundice is multi-factorial, involving disruption of the immunologic, biological and mechanical barrier. Experimental and clinical studies have shown that obstructive jaundice results in increased intestinal permeability. The mechanisms implicated in this phenomenon remain unresolved, but growing research interest during the last decade has shed light in our knowledge in the field. This review summarizes the current concepts in the pathophysiology of obstructive jaundice-induced gut barrier dysfunction, analyzing pivotal factors, such as altered intestinal tight junctions expression, oxidative stress and imbalance of enterocyte proliferation and apoptosis. Clinicians handling patients with obstructive jaundice should not neglect protecting the intestinal barrier function before, during and after intervention for the relief of this condition, which may improve their patients’ outcome.展开更多
AIM: To determine how glucocorticoids (GCs) may affect the growth and chemosensitivity of common carcinoma cells. METHODS: The effect of dexamethasone (DEX) on growth and chemosensitivity was assessed in 14 carc...AIM: To determine how glucocorticoids (GCs) may affect the growth and chemosensitivity of common carcinoma cells. METHODS: The effect of dexamethasone (DEX) on growth and chemosensitivity was assessed in 14 carcinoma cell lines. The function of GC receptors (GR) was assessed by MMTV reporter assay. Overexpression of GR was done by in vitro transfection and expression of a GR-expressing vector. Immunohistochemical stain of tissues and ceils were done by PA1-511A, an anti-GR monodonal antibody. RESULTS: DEX inhibited cell growth of four (MCF-7, MCF- 7/MXR1, MCF-7/TPT300, and HeLa), increased cisplatin cytoxicity of one (SiHa), and decreased dsplatin cytotoxicity of two (H460 and Hep3B) cell lines. The GR content of the seven cell lines affected by DEX was significantly higher than those of the seven cell lines unaffected by DEX (5.2±2.5×10^4 sites/cell vs1.3±1.4×10^4 sites/cell, P= 0.005). Only two DEX-unresponsive cell lines {NPC-TW01 and NPC- TW04) oontained high GR amounts in the range (1.9-8.1×10^4 sites/cell) of the seven DEX-responsive cell lines. The GR function of NPC-TW01 and NPC-TW04, however, was foundto be impaired. The importance of high cellular amount of GR in mediating DEX susceptibility of the cells was further exemplified by GR dose-dependent drug resistance to cisplatin of AGS, a cell line with low GR content and was unaffected by DEX before transfection of GR-expressing vector. Immunohistochemical studies of human cancer tissues showed that 5 of the 45 (11.1%) breast cancer and 43 of the 85 (50.6%) non-small cell lung cancer had high GR contents at the ranges of the GC-responsive carcinoma cell lines. CONCLUSION: The growth and chemosensitivity of human carcinomas with high GR contents may be affected by GC. However, in light of the heterogeneous and even contradictive effects of GC on these cells, routine examination of GR contents of human carcinoma tissues may not be clinically useful until other markers that help predict the ultimate effect of GC on individual patients are identified.展开更多
This paper considers a model of cell-to-cell spread of HIV-I with CTL immune response. By using a discrete delay to model the intracellular delay, it is shown that the uninfected equilibrium is globally asymptotical s...This paper considers a model of cell-to-cell spread of HIV-I with CTL immune response. By using a discrete delay to model the intracellular delay, it is shown that the uninfected equilibrium is globally asymptotical stable in some conditions and the sufficient condition to ensure the stability of the infected equilibrium does not change would be enlarged by Sturm sequence. Numerical simulations are presented to illustrate the results.展开更多
Helicobacter pylori(H.pylori) infection is among the most common human infections and the major risk factor for peptic ulcer disease and gastric cancer.With-in this work we present the implication of C-terminal region...Helicobacter pylori(H.pylori) infection is among the most common human infections and the major risk factor for peptic ulcer disease and gastric cancer.With-in this work we present the implication of C-terminal region of H.pylori neutrophil activating protein in the stimulation of neutrophil activation as well as the evi-dence that the C-terminal region of H.pylori activating protein is indispensable for neutrophil adhesion to endothelial cells,a step necessary to H.pylori inflammation.In addition we show that arabino galactan proteins derived from chios mastic gum,the natural resin of the plant Pistacia lentiscus var.Chia inhibit neutrophil activation in vitro.展开更多
文摘Sterility changeover induced by low temperature in male sterility line CMS7311 of heading Chinese cabbage ( Brassica campestris L. ssp. penkinsis) was investigated under constant temperature, day/night alternating temperature in light-growth-incubator and outdoor natural day/night alternating temperature respectively. It showed that the sterility of CMS7311 has significant change with temperature. The constant temperature of 6 - 12 degreesC was suitable to induce the changeover of sterility (CGS) of CMS7311 ; the shortest treatment time for CGS induction at this temperature was 3 d. The significant value of sterility changeover of CMS7311 occurred at the constant temperature of 6 - 9 degreesC after treatment for 6 - 9 d. The intensity of CGS was stronger under constant temperature than under alternate temperature, but the shortest treatment time inducing CGS has no difference between them. When treated for 9 d under the day/night alternating temperature of 11/7 degreesC, its sterility could also turn to normal fertility (near to sterile grade I or zero). In normal condition, the interval from the end of temperature treatment to the beginning of CGS induction was 10 - 16 d. In the condition of natural day/night alternating temperature, the lower limit of temperature for effective CGS induction was at the daily mean temperature ( DMT) of 3. 5 - 6. 8 degreesC, and the shortest treatment time which could induce the sterility changeover was also longer than that under constant temperature, being 11d at DMT of 1.5 - 3.1 degreesC. In addition, for the apical dominance, the flower bud on the first lateral branch showed the CGS 8 - 10 d later than the flower bud on the main stem under the same temperature with the same days of treatment. The intensity of CGS of CMS7311 on the first lateral branch was also weaker than the flower bud on the main stem.
基金Supported by Foundation for Returned Scholars of Hebei Province(2010)Research Fund for the Doctoral Program of Hebei Normal University(L2009B13)~~
文摘[Objective] The aim of the research was to study the effect of the ice bath time after heat shock and the incubation time on the transformation efficacy,and to establish a simple and quick transformation method.[Method]Competent cells were prepared with two buffer solutions;with the ice bath time after heat shock and the recovery time as the variables,the relationship between these two factors and transformation efficacy was studied.[Result]The transformation efficacy was the best when the ice bath time was 2 min and the recovery time was 30 or 40 min;when the ice bath time and the recovery time was 0 min,a certain amount of transformants still could be obtained.[Conclusion]The ice bath time after heat shock and the recovery time had certain impact on transformation efficacy,but they were not the decisive factors.Therefore,in the general transformation experiment,these two steps could be omitted.
文摘Objective: To detect the expression of hMSH2, hMLH1 and p53 in gastric epithelial cells with and without Helicobactcr pylori (H. pylori) infection and investigate the relationship between H. pylori infection and these genes in gastric carcinogenesis. Methods: H. pylori infection was detected by rapid urease tests. Expression of hMSH2, hMLHland p53 in gastric cancer (GC) tissue, its adjacent mucosa, gastritic mucosa and normal mucosa was assessed by immunohistochemistry SP method. Results: Positive expression rate of hMSH2 in GC tissue (62.7%) was higher than those in adjacent mucosa (29.4%), gastritic mucosa (32.4%) and normal mucosa (30.0%) (P〈0.001). Positive rate of hMSH2 in poorly differentiated adenocarcinoma (76.4%) was higher than those in other carcinomas (54.3%, 53.1%) (P〈0.05). Positive expression rate of hMLH1 in GC tissue (64.3%) mucosa (82.4%) and normal mucosa (80.0%) was lower than those in adjacent mucosa (84.4%), gastritic (P〈0.01). Positive rate of hMLH1 in mucoid carcinoma (43.7%) was lower than those in other carcinomas (78.2%, 64.7%) (P〈0.01). Positive expression rate of p53 in GC tissue (51.9%) was higher than those in adjacent mucosa (3.1%), gastritic mucosa (0.0%) and normal mucosa (0.0%) (P〈0.001). Positive rate of p53 in well differentiated adenocarcinoma (32.6%) was lower than those in other carcinomas (58.8%, 68.7%) (P〈0.01). Positive rates of hMSH2 and hMLH1 in GC with H. pylori infection were lower than those without the infection, respectively (P〈0.05). Positive rate of p53 in GC with H. pylori infection (61.4%) was higher than that without the infection (40.6%) (P〈0.05). Conclusion: Gastric carcinogenesis may be associated with abnormal expression of hMSH2, hMLH1 and p53; H. pylori infection affecting expression of these genes may be one of its carcinogenic mechanisms.
文摘AIMS To establish the prevalence of bacterial infection in cir- rhotic patients with hepatocellular carcinoma(HCC). METHODS All 719 cirrhotic patients with HCC were investigat- ed retrospectively for the prevalence of bacterial infections. RESULTS The incidence of bacterial infection was 15.4% (111/719).According to Child-Pugh classification,the inci- dences of bacterial infection in class A,B and C were 2.3%,8. 0%,and 26.4 %,respectively.The bacterial infection increased with the severity of cirrhosis and severe bacterial infections usual- ly occurred in Child-Pugh class B and C patients. CONCLUSIONS The susceptibility of HCC patients to bacterial infection is mainly due to the underlying cirrhosis and not to the HCC itself.
基金Supported by National Natural Science Foundation of China(31171082)Natural Science Foundation of Anhui Province(070413138)the Key Research Foundation of Anhui Province Education Department(KJ2009A167)
文摘Psychophysical experiments on human and animal subjects have proven that aged individuals show significantly reduced visual contrast sensitivity compared with young adults.To uncover the possible neural mechanisms,we used extracellular single-unit recording techniques to examine the response of V1(primary visual cortex) neurons as a function of visual stimulus contrast in both old and young adult cats(Felis catus).The mean contrast sensitivity of V1 neurons to visual stimuli in old cats decreased significantly relative to young adult cats,consistent with findings reported in old primates.These results indicate that aging can affect contrast sensitivity of visual cortical cells in both primate and non-primate mammalian animals,and might contribute to the reduction of perceptual visual contrast sensitivity in aged individuals.Further,V1 cells of old cats exhibited increased responsiveness,decreased signal-to-noise ratio,and enlarged receptive field(RF) size compared with that of young adult cats,which indicated that decreased contrast sensitivity of V1 neurons accompanied a reduction of intracortical inhibition during senescence.
基金Supported by Natural Science Foundation in Hebei Province(C200600707)~~
文摘[Objective]The aim of this study was to investigate whether communication signal C6-HSL among individual bacteria can influence plant growth and disease resistance ability. [Method]With potato virus-free plantlets as the test materials and C6-HSL as the inducer,the potato's growth and the ability of resistance against Erwinia carotovora subp carotovora were tested after being treated by C6-HSL with different concentrations. The effects of C6-HSL on plant landmark defense enzyme activities and H2O2 content in potato leaves were measured especially. [Result]C6-HSL with different concentrations could obviously inhibit the growth rate of root and the number of roots,but had no effect on plant height,number of nodes and leaf size. POD or SOD activity and H2O2 content in plant landmark defense enzymes significantly increased after induction of C6-HSL,but PAL and PPO activity had no obvious change. In the resistant test,potato plants induced by C6-HSL could inhibit the infection of Erwinia carotovora subp carotovora effectively,and its incidence was significantly lower than the control group. [Conclusion]Bacteria AHL can be possibly used as a new kind of plant disease-resistant activator.
文摘Study of marine noctilucence in marine is important to fishery, environmental monitoring and military affairs. A luminous bacterial strain D2 was isolated from the marine sediment samples collected near Donghai Island in Zhanjiang, China. The primary cultural and luminescent conditions of luminous bacterium D2 which was identified as Vibrio sp. were determined in liquid culture. The results showed that pH 7.0, 35 ℃, with 2.0 % NaCI, were the best growth conditions, and pH5 - 6, 20℃, OD600 0.08, with 3.0 % NaCI, were the optimal luminescent conditions.
基金This project was supported by grants from Foundation of Science and Technology of Guangzhou city (2001-Z-037-01) and Guangdong Province (021195).
文摘Objective: To investigated the e?ect of inhibition of telomerase with hTERT antisense on leukemic cells (HL-60 and K562) to CDDP-induced apoptosis. Methods: Antisense phosphorothioate oligodeoxynucleotide (AS PS-ODN) was synthesized and puri?ed. Telomerase activity was detected by Telomerase PCR ELASA kit and cell apoptosis was observed by morphological method and determined by ?owcytometry. Results: AS PS-ODN could signi?cantly inhibit telomerase activity by down regulat- ing the hTERT expression, and increase the susceptibility of leukemic cells to CDDP-induced apoptosis. Conclusion: Inhibition of telomerase with hTERT antisense can increases the susceptibility of leukemic cells to CDDP-induced apoptosis.
基金Supported by the National Key Research and Development Program of China(2016YFD0501208)the Social Development Program of Yangzhou(YZ2016058)+1 种基金the National Major Project for Agro-product Quality&Safety Risk Assessment(GJFP2017007)the Project for the Construction of Science and Technology Service Platform for Poultry Quality and Safety of Yangzhou(yz2015162)~~
文摘The prevalence of antibiotic susceptibility and disinfectant resistance in bacterial pathogens causes a serious problem not only to food safety but also to public health, which directly or indirectly leads to treatment and disinfection failures. In this review, multidrug resistance, the mechanism of disinfectant resistance, the methods for detecting disinfectant resistance and the cross-resistance between an- tibiotics and disinfectants are summarized. More efforts should be devoted to explor- ing the professional guidance of using antibiotics and disinfectants, and to develop- ing the comprehensive detection with genetic and molecular methods is highly ex- pected.
文摘Numerous cellular and molecular events have been described in development of gastric cancer. In this artide, we overviewed roles of Helicobacter pylori (H pylori) infection on some of the important events in gastric carcinogenesis and discussed whether these cellular and molecular events are reversible after cure of the infection. There are several bacterial components affecting gastric epithelial kinetics and promotion of gastric carcinogenesis. The bacterium also increases risks of genetic instability and mutations due to NO and other reactive oxygen species. Epigenetic silencing of tumor suppressor genes such as RUNX3 may alter the frequency of phenotype change of gastric glands to those with intestinal metaplasia. Host factors such as increased expression of growth factors, cytokines and COX-2 have been also reported in non-cancerous tissue in Hpylori-positive subjects. It is noteworthy that most of the above phenomena are reversed after the cure of the infection. However, some of them including overexpression of COX-2 continue to exist and may increase risks for carcinogenesis in metaplastic or dysplastic mucosa even after successful H pylori eradication. Thus, H pylori eradication may not completely abolish the risk for gastric carcinogenesis. Efficiency of the cure of the infection in suppressing gastric cancer depends on the timing and the target population, and warrant further investigation.
文摘Apoptosis is central for the control and elimination of viral infections. In chronic hepatitis C virus (HCV) infection, enhanced hepatocyte apoptosis and upregulation of the death inducing ligands CD95/Fas, TRAIL and TNFα occur. Nevertheless, HCV infection persists in the majority of patients. The impact of apoptosis in chronic HCV infection is not well understood. It may be harmful by triggering liver fibrosis, or essential in interferon (IFN) induced HCV elimination. For virtually all HCV proteins, pro- and anti-apoptotic effects have been described, especially for the core and NS5A protein. To date, it is not known which HCV protein affects apoptosis in vivo and whether the infectious virions act pro- or anti- apoptotic. With the availability of an infectious tissue culture system, we now can address pathophysiologically relevant issues. This review focuses on the effect of HCV infection and different HCV proteins on apoptosis and of the corresponding signaling cascades.
基金A. K. Perry is supported by the Howard Hughes Medi-cal Institute predoctoral fellowship (Grant No. 59003787).Part of this work was also supported by National Insti-tutes of Health research grants RO1 CA87924, RO1AI056154, and R37 AI47868 to G. Cheng and from the MajorResearch Plan (30170461, 30430640) +1 种基金Natural ScienceFoundation of China, and the National Basic ResearchProgram of MOST (2002CB513001, 2001CB-510002)H. Tang. H. Tang is also a fellow of Outstanding YoungInvestigators of National Naturual Science Foundation ofChina (30025010).
文摘Type I interferons (IFN) are well studied cytokines with anti-viral and immune-modulating functions. Type I IFNsare produced following viral infections, but until recently, the mechanisms of viral recognition leading to IFN productionwere largely unknown. Toll like receptors (TLRs) have emerged as key transducers of type I IFN during viral infectionsby recognizing various viral components. Furthermore, much progress has been made in defining the signaling path-ways downstream of TLRs for type I IFN production. TLR7 and TLR9 have become apparent as universally importantin inducing type I IFN during infection with most viruses, particularly by plasmacytoid dendritic cells. New intracellularviral pattern recognition receptors leading to type I IFN production have been identified. Many bacteria can also inducethe up-regulation of these cytokines. Interestingly, recent studies have found a detrimental effect on host cells if type IIFN is produced during infection with the intracellular gram-positive bacterial pathogen, Listeria monocytogenes. Thisreview will discuss the recent advances made in defining the signaling pathways leading to type I IFN production.
文摘The tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL/APO2L) is a member of the TNF gene superfamily that induces apoptosis upon engagement of cognate death receptors. While TRAIL is relatively non-toxic to normal cells, it selectively induces apoptosis in many transformed cells. Nevertheless, breast tumor cells are particularly resistant to the effects of TRAIL. Here we report that, in combination with the cyclin-dependent kinase inhibitor roscovitine, exposure to TRAIL induced marked apoptosis in the majority of TRAIL-resistant breast cancer cell lines examined. Roscovitine facilitated TRAIL death-inducing signaling complex formation and the activation of caspase-8. The cFLIPL and cFLIPs FLICE-inhibitory proteins were significantly down-regulated following exposure to roscovitine and, indeed, the knockdown of cFLIP isoforms by siRNA sensitized breast tumor cells to TRAIL-induced apoptosis. In addition, we demonstrate that roscovitine strongly suppressed Mcl-1 expression and up-regulated E2F1 protein levels in breast tumor ceils. Significantly, the silencing of Mci-1 by siRNA sensitized breast tumor cells to TRAIL-induced apoptosis. Furthermore, the knockdown of E2F1 protein by siRNA reduced the sensitizing effect of roscovitine in TRAIL-induced apoptosis. In summary, our results reveal a pleitropic mechanism for the pro-apoptotic influence of roscovitine, highlighting its potential as an antitumor agent in breast cancer in combination with TRAIL.
文摘AIM: To investigate the effects of exogenous melatonin on bacterial translocation and apoptosis in a rat ulcerati-ve colitis model. METHODS: Rats were randomly assigned to three groups: groupⅠ: control, group Ⅱ: experimental colitis, group Ⅲ: colitis plus melatonin treatment. On d 11 after colitis, plasma tumor necrosis factor-α, portal blood endotoxin levels, colon tissue myeloperoxidase and caspase-3 activity were measured. Bacterial translocation was quantified by blood, lymph node, liver and spleen culture. RESULTS: We observed a significantly reduced inciden-ce of bacterial translocation to the liver, spleen, mesen-teric lymph nodes, portal and systemic blood in animals treated with melatonin. Treatment with melatonin signifi-cantly decreased the caspase-3 activity in colonic tissues compared to that in trinitrobenzene sulphonic acid-trea-ted rats (16.11 ± 2.46 vs 32.97 ± 3.91, P < 0.01). CONCLUSION: Melatonin has a protective effect on ba-cterial translocation and apoptosis.
文摘Despite advances in preoperative evaluation and postoperative care, intervention, especially surgery, for relief of obstructive jaundice still carries high morbidity and mortality rates, mainly due to sepsis and renal dysfunction. The key event in the pathophysiology of obstructive jaundice-associated complications is endotoxemia of gut origin because of intestinal barrier failure. This breakage of the gut barrier in obstructive jaundice is multi-factorial, involving disruption of the immunologic, biological and mechanical barrier. Experimental and clinical studies have shown that obstructive jaundice results in increased intestinal permeability. The mechanisms implicated in this phenomenon remain unresolved, but growing research interest during the last decade has shed light in our knowledge in the field. This review summarizes the current concepts in the pathophysiology of obstructive jaundice-induced gut barrier dysfunction, analyzing pivotal factors, such as altered intestinal tight junctions expression, oxidative stress and imbalance of enterocyte proliferation and apoptosis. Clinicians handling patients with obstructive jaundice should not neglect protecting the intestinal barrier function before, during and after intervention for the relief of this condition, which may improve their patients’ outcome.
基金Supported by grants from the National Science Council No.NSC 93-2314-B-002-006, Taiwan, and grants from National Taiwan University Hospital 91-N006
文摘AIM: To determine how glucocorticoids (GCs) may affect the growth and chemosensitivity of common carcinoma cells. METHODS: The effect of dexamethasone (DEX) on growth and chemosensitivity was assessed in 14 carcinoma cell lines. The function of GC receptors (GR) was assessed by MMTV reporter assay. Overexpression of GR was done by in vitro transfection and expression of a GR-expressing vector. Immunohistochemical stain of tissues and ceils were done by PA1-511A, an anti-GR monodonal antibody. RESULTS: DEX inhibited cell growth of four (MCF-7, MCF- 7/MXR1, MCF-7/TPT300, and HeLa), increased cisplatin cytoxicity of one (SiHa), and decreased dsplatin cytotoxicity of two (H460 and Hep3B) cell lines. The GR content of the seven cell lines affected by DEX was significantly higher than those of the seven cell lines unaffected by DEX (5.2±2.5×10^4 sites/cell vs1.3±1.4×10^4 sites/cell, P= 0.005). Only two DEX-unresponsive cell lines {NPC-TW01 and NPC- TW04) oontained high GR amounts in the range (1.9-8.1×10^4 sites/cell) of the seven DEX-responsive cell lines. The GR function of NPC-TW01 and NPC-TW04, however, was foundto be impaired. The importance of high cellular amount of GR in mediating DEX susceptibility of the cells was further exemplified by GR dose-dependent drug resistance to cisplatin of AGS, a cell line with low GR content and was unaffected by DEX before transfection of GR-expressing vector. Immunohistochemical studies of human cancer tissues showed that 5 of the 45 (11.1%) breast cancer and 43 of the 85 (50.6%) non-small cell lung cancer had high GR contents at the ranges of the GC-responsive carcinoma cell lines. CONCLUSION: The growth and chemosensitivity of human carcinomas with high GR contents may be affected by GC. However, in light of the heterogeneous and even contradictive effects of GC on these cells, routine examination of GR contents of human carcinoma tissues may not be clinically useful until other markers that help predict the ultimate effect of GC on individual patients are identified.
基金Supposed by the National Science Fund of China(10571143)
文摘This paper considers a model of cell-to-cell spread of HIV-I with CTL immune response. By using a discrete delay to model the intracellular delay, it is shown that the uninfected equilibrium is globally asymptotical stable in some conditions and the sufficient condition to ensure the stability of the infected equilibrium does not change would be enlarged by Sturm sequence. Numerical simulations are presented to illustrate the results.
基金Supported by A Grant from the General Secretariat of Research and Technology, Ministry of Development of Greece, by the Program HERAKLITOS I as well as by Chios Gum Mastic Growers Association
文摘Helicobacter pylori(H.pylori) infection is among the most common human infections and the major risk factor for peptic ulcer disease and gastric cancer.With-in this work we present the implication of C-terminal region of H.pylori neutrophil activating protein in the stimulation of neutrophil activation as well as the evi-dence that the C-terminal region of H.pylori activating protein is indispensable for neutrophil adhesion to endothelial cells,a step necessary to H.pylori inflammation.In addition we show that arabino galactan proteins derived from chios mastic gum,the natural resin of the plant Pistacia lentiscus var.Chia inhibit neutrophil activation in vitro.