Risk knowledge,product knowledge,and brand benefits for purchase intentions: Experiences with air purifiers against city smog in China

The present study is based on the theoretical framework of protective action decision model. This study aims to explain the relationship among the risk knowledge, product knowledge, risk perception, and brand benefits and the consumers’ purchase intentions of a specific air purifier compared with alternative brands. The research context is city smog. Results show that consumers’ risk knowledge and product knowledge significantly affect their purchase of an air purifier brand as well as play a considerable role in predicting their risk perception and in foreseeing their purchase intentions under the influence of the manufacturer's advertising strategies. Furthermore, consumers’ risk perception is a critical psychological factor that has a significantly positive influence on brand's experiential benefits, instead of functional and symbolic benefits. In particular, when comparing with brand's functional and symbolic benefits, the brand's experiential benefits is more attractive to consumers and has a stronger effect on consumers’ air purifier purchase intentions in the context of city smog.     

Detection of cell-cycle stage by fluorescence in situ hybridization: its application in human interphase cytogenetics.

Distinct cell-cycle-dependent changes in the conformation of centromeric chromatin in a specific human chromosome containing alpha-satellite DNA have been demonstrated by fluorescence in situ hybridization (FISH). This method, based upon specific FISH signal morphology, allows simultaneous analysis of chromosomal aneuploidy and detection of specific cell-cycle stage(s) of human tumor and/or normal cell populations in a single preparation of interphase cells. This interphase cytogenetic procedure might prove useful for both basic and clinical research involving human cells.     

Cell kinetic studies of chick brain cells in culture: an autoradiographic study with [3H]- and [14C]-thymidine

Labelling index, S-phase duration and cell-cycle time of proliferating brain cells from 6-day-old chick embryos in culture were investigated autoradiographically after labelling with [3H]- and/or [14C]-thymidine. The dissociated cells were cultured in the absence or in the presence of brain extract from 8-day-old chick embryos. Cultures contained essentially two cell types, which could be easily distinguished by the size of their nuclei: small nuclei identified as belonging to precursor cells of neurons and large nuclei corresponding to astroglial cells. The labelling index of astroglial cells (16.4%) was about 2 times higher than that of the neuronal cells (9.9%). Under the influence of brain extract the labelling index of neuroblasts was nearly doubled while that of the astroglial cells remained nearly unchanged. From double-labelling experiments with [3H]- and [14C]-thymidine, the same S-phase duration of about 7 hr was found for both cell types cultured with or without brain extract. A cell-cycle duration of 39 hr for neuronal and of 29 hr for astroglial cells was found. The cycle times remained constant under the influence of brain extract. From the measured data mentioned above, a growth fraction of 50% (neuroblasts) and 68% (astroglial cells) was calculated in control cultures without brain extract. After addition of brain extract, the growth fraction increased for both cell types (neuroblasts: 92%; astroglial cells: 80%). The results demonstrate that more cells proliferate in the presence of brain extract, but the durations of the S-phase and the cell cycle remain unchanged.     

Emission of isoprenoids from natural vegetation in the Beijing region (Northern China)

ABSTRACT

A survey was conducted to identify plants emitting isoprenoids in the Beijing area which could potentially contribute to smog episodes when combined with anthropogenic pollutants. The emission pattern was similar to that observed in the previously surveyed boreal ecosystems (Europe, North America). Most deciduous oaks are strong isoprene emitters; however, some of them do not emit isoprenoids and are therefore more suitable for the urban environment of Beijing. No emission of monoterpenes was found in Chinese oaks, and this trait seems therefore confined to the Mediterranean environment. The emission of isoprene was found in poplars and in some of the bamboo widespread in city parks and in the riparial vegetation surrounding the city. Chinese pine species emit monoterpenes when wounded, and the emission is not qualitatively different among species. Pinus tabulaeformis, one of the most important trees in China, is a low emitter compared to other pine species.     

In vivo cytogenetic studies on mice exposed to ethylene dibromide

The pesticide, ethylene dibromide (EDB), was evaluated with in vivo cytogenetic assays to determine its genotoxicity. CD1 male mice were exposed to EDB through intraperitoneal injections. Bone marrow cells isolated from femora were analyzed for sister-chromatid exchange (SCE), chromosome aberration and micronucleus formation. The results showed that only certain concentrations of EDB tested caused a slight but significant increase in SCEs and chromosome aberrations. However, these increases were not dose-related. No increase in the polychromatic erythrocytes with micronuclei was observed following EDB exposure. Also, EDB did not cause cell-cycle delay in comparison with controls. Thus, it appears that EDB is not an effective genotoxic agent in vivo in mice.     

p27(Kip1) ubiquitination and degradation is regulated by the SCF(Skp2) complex through phosphorylated Thr187 in p27.

Many tumorigenic processes affect cell-cycle progression by their effects on the levels of the cyclin-dependent kinase inhibitor p27(Kip1) [1,2]. The phosphorylation- and ubiquitination-dependent proteolysis of p27 is implicated in control of the G1-S transition in the cell cycle [3-6]. To determine the factors that control p27 stability, we established a cell-free extract assay that recapitulates the degradation of p27. Phosphorylation of p27 at Thr187 was essential for its degradation. Degradation was also dependent on SCF(Skp2), a protein complex implicated in targeting phosphorylated proteins for ubiquitination [7-10]. Immunodepletion of components of the complex - Cul-1, Skp1, or Skp2 - from the extract abolished p27 degradation, while addition of purified SCF(Skp2) to Skp2- depleted extract restored the capacity to degrade p27. A specific association was observed between Skp2 and a p27 carboxy-terminal peptide containing phosphorylated Thr187, but not between Skp2 and the non-phosphorylated peptide. Skp2-dependent associations between Skp1 or Cul-1 and the p27 phosphopeptide were also detected. Isolated SCF(Skp2) contained an E3 ubiquitin ligase activity towards p27. Our data thus suggest that SCF(Skp2) specifically targets p27 for degradation during cell-cycle progression.     

Cell Kinetic Studies of Chick Brain Cells In Culture: an Autoradiographic Study With [3H]- and [14C]-Thymidine

Labelling index, S-phase duration and cell-cycle time of proliferating brain cells from 6-day-old chick embryos in culture were investigated autoradiographically after labelling with [³H]- and/or [¹⁴C]-thymidine. the dissociated cells were cultured in the absence or in the presence of brain extract from 8-day-old chick embryos. Cultures contained essentially two cell types, which could be easily distinguished by the size of their nuclei: small nuclei identified as belonging to precursor cells of neurons and large nuclei corresponding to astroglial cells. the labelling index of astroglial cells (16.4%) was about 2 times higher than that of the neuronal cells (9.9%). Under the influence of brain extract the labelling index of neuroblasts was nearly doubled while that of the astroglial cells remained nearly unchanged. From double-labelling experiments with [³H]- and [¹⁴C]-thymidine, the same S-phase duration of about 7 hr was found for both cell types cultured with or without brain extract. A cell-cycle duration of 39 hr for neuronal and of 29 hr for astroglial cells was found. the cycle times remained constant under the influence of brain extract. From the measured data mentioned above, a growth fraction of 50% (neuroblasts) and 68% (astroglial cells) was calculated in control cultures without brain extract. After addition of brain extract, the growth fraction increased for both cell types (neuroblasts: 92%; astroglial cells: 80%). the results demonstrate that more cells proliferate in the presence of brain extract, but the durations of the S-phase and the cell cycle remain unchanged.     

Public smog knowledge,risk perception,and intention to reduce car use: Evidence from China

ABSTRACT

Smog pollution has received widely attention in recent years due to its negative effects. There is consensus that the motor vehicle exhaust emission is one of the sources of smog pollution and reduced private car use would significantly improve the air quality and alleviate the smog pollution problem. In this research, we aim to investigate how public smog knowledge and risk perception (physical health risk perception and mental health risk perception) affect public attitude and intention to reduce car use. A questionnaire survey of 334 randomly sampled respondents was designed to test these relationships. The results show that public smog knowledge is positively and significantly related to physical health risk perception, mental health risk perception, attitude and intention to reduce car use. Public smog knowledge has the largest impact on intention to reduce car use. Furthermore, physical health risk perception and mental health risk perception are positively and significantly associated with attitude and intention to reduce car use. In addition, the results also indicated that public smog knowledge is at a low level. Based on the results, implications and suggestions for future research were discussed.     

Protective effect of Hemidesmus indicus R.Br. root extract against cisplatin-induced cytogenetic damage in mouse bone marrow cells

The aqueous extract of Hemidesmus indicus roots was investigated for its in vivo antigenotoxic effect against cisplatin-induced cytogenetic damage. Swiss albino mice were administered with various doses of the extract either singly (50, 100 and 200 mg/kg body weight) or as split doses (10, 20 and 40 mg/kg bw/day) for five consecutive days by oral gavage. As endpoints, chromosome aberrations, micronuclei in polychromatic erythrocytes, mitotic index and PCE/NCE ratio were estimated. The extract protected the bone marrow cells from cisplatin-induced genotoxicity in an inverse dose-dependent manner. However, the extract was cytotoxic at all doses. But, under split dose regime it conferred a higher level of genoprotection and was not cytotoxic at the lower two doses. The presence of saponins, tannins, phenols, terpenoids, flavonoids and coumarins in the crude extract could explain these effects.     

Iron chelation and related properties of Podophyllum hexandrum, a possible role in radioprotection

Aqueous extract of Podophyllum species has been reported to render significant protection against radiation induced mortality, cytogenetic damage and cell death. In view of this, present study was undertaken to investigate its antioxidant properties. Chelation, oxidation and reduction of Fe2+ and Fe3+ were measured using chelating agents 2-2' bipiridyl and potassium thiocyanate respectively. Podophyllum extract, in a dose dependent manner, chelated Fe2+ more efficiently than Fe3+ and also modulated Fe2+/Fe3+ ratio. Homogenate of mouse liver was used to measure TBARS for estimating lipid peroxidation. Podophyllum extract also inhibited lipid peroxidation in a dose dependent manner and maximum inhibition (92%) was achieved at 1000 micrograms/ml concentration. These results demonstrates that Podophyllum exhibits antioxidant properties as seen through chelation and modulation of redox state of iron ions and these may primarily contribute towards its radioprotective manifestation.     

Interaction of low-dose irradiation with subsequent mutagenic treatment: role of mitotic delay

Experiments were carried out with human lymphocytes to test whether there was any relation between the changes that conditioning treatment can produce in cell progression or in mitotic delay induced by the challenge dose and the presence of an ‘adaptive response’ (AR). In experiments in which the cells were successively fixed after the challenge dose, the interaction between conditioning treatment and challenge was of the same sign for all the fixation times: therefore it is likely that modifications of the cytogenetic damage in primed cells is not a mere reflection of stage sensitivity. In experiments in which using 1 Gy as conditioning treatment we induced a drastic extension of G₂, we did not observe any AR; therefore, even if conditioning treatment can induce modifications in the cell-cycle phases before and/or after challenge, there is probably no link between these modifications and the presence of an AR.     

Studies on the plant cytoskeleton using miniprotoplasts of tobacco BY-2 cells

Vacuoles in plant cells can be eliminated by centrifugation of protoplasts through a density gradient. In this review, properties of evacuolated protoplasts, named ‘miniprotoplasts’, and the significant roles in plant cytoskeleton studies are described. Miniprotoplasts, prepared from tobacco BY-2 cells whose cell-cycle had been synchronized at late anaphase, continued to divide to form two daughter cells. In the presence of cytochalasin B cytokinetic cleavage was enhanced, suggesting a role of actin filaments in plant cytokinesis. In the cytoplasmic extract of miniprotoplasts both tubulin and actin could be polymerized to form microtubules (MTs) and actin filaments (AFs), respectively. A purification method for tubulin, actin and related proteins was developed using the extract. To investigate the interaction between cortical microtubules and the plasma membrane, an experimental system in which MTs were reconstructed on membrane ghosts was developed by combination of membrane ghosts and the extract.     

Lymphocyte proliferation kinetics and genotoxic findings in a pilot study on individuals chronically exposed to arsenic in Mexico

In the search for early biological markers to detect genetic damage, a pilot study on a hydroarsenicism-exposed group was designed. Blood and urine samples were taken from 11 individuals chronically exposed and from 13 individuals with lower exposure to the metal. Lymphocyte cultures for cytogenetic studies and HGPRT assay were done with coded peripheral blood samples, while arsenic levels and the “rec assay” in B. subtilis were determined in urine samples. The highly exposed group excreted greater amounts of As, nevertheless the rec assay showed negative results. An interesting finding is that the cell-cycle kinetics exhibited a significant difference between the groups studied, the average generation time (AGT) was longer in the highly exposed group. The percentages of chromosomal aberrations and the frequencies of sister-chromatid exchanges were similar in both populations, although complex aberrations were more frequent in the highly exposed group, which also showed a higher average variation frequency in the HGPRT assay, but the 2 latter observations were not statistically significant. The lag in lymphocyte proliferation could mean an impairment of the immune response due to arsenic exposure.     

Twenty years of cell-cycle conferences in Roscoff

At the end of April 2008, the cell-cycle community celebrated the twentieth anniversary of the Jacques-Monod cell-cycle conferences in Roscoff (France), where the discovery of Cdk1 as a key cell-cycle regulator was first discussed in 1988.     

Efficiency of Coleus aromaticus extract in modifying cyclophosphamide and mitomycin-C induced clastogenicity in mouse bone marrow cells

The anticlastogenic potency of the ethanolic extract of a medicinal plant, C. aromaticus was investigated by taking bone marrow chromosomal aberration assay and micronucleus (MN) test as the test parameters. Swiss albino mice were fed orally with different doses (10,15, 25, 50 and 100 mg/kg body weight) of ethanolic extract for 7 days and on the 7th day, two doses each of anticancer drugs cyclophosphamide (CP; 25 and 50 mg/kg body weight) and mitomycin-C (MMC; 4 and 8 mg/kg body weight) were injected, ip, to different groups of animals. Bone marrow MN preparations were made at 24 and 48 hr time intervals. Coleus extract reduced CP and MMC induced MN and lower doses of the extract were found to be more effective than higher doses. The effective doses of extract in MN test were selected to study the anticlastogenic effects against CP (25 and 50 mg/kg body weight) and MMC (2 and 4 mg/kg body weight) induced chromosomal aberrations. The results indicate the protective effect of C. aromaticus against CP and MMC induced cytogenetic damage.     

广州城市的氧化型污染及其对植物的影响

广州城市大气的氧化型污染日趋严重;在植物伤害症状、超微结构、生长发育及生理生化效应等几方面阐述了光化学烟雾的主要污染物质ＮＯｘ、Ｏ３、ＰＡＮ及其同族体对植物的危害,最后讨论了利用植物防治广州的光化学烟雾污染的一些问题。     

Identifying the spatial effects and driving factors of urban PM2.5 pollution in China

Exploring exactly where air pollution comes from, and identifying the key factors that influence it, can provide a scientific basis for the rational formulation and effective implementation of air pollution policies in China. Based on the data from 2001 to 2012 covering PM_2.5 concentrations in 285 Chinese cities, we use dynamic spatial panel models to empirically analyze the key driving factors of this air pollution. Results show that China’s urban smog demonstrates both obvious global spatial autocorrelation and local spatial agglomeration. There is a significant inverted “U-shaped” curve between economic development level and air pollution, and most cities are in the phase in which pollution is increasing in conjunction with improvements to the economy. Due to a rapid increase in population in built up areas, a high-proportion of secondary industry, a coal-dominated energy structure and increasing traffic intensity, China’s smog problem is becoming more and more serious. FDI probably will not play a future role in mitigating the air pollution. Central heating in winter in northern China further aggravates local smog to a certain extent. Because China’s haze pollution presents path-dependent characteristics and spatial spillover effects in the time dimension and in the space dimension respectively, so smog alleviation policies should be implemented based both on the strategies of maximizing effort and regional joint prevention and control.     

Seroprevalence of antibodies against Anisakis simplex larvae among health-examined residents in three hospitals of southern parts of Korea

The present study was performed to estimate the seroprevalence of larval Anisakis simplex infection among the residents health-examined in 3 hospitals in southern parts of Korea. A total of 498 serum samples (1 serum per person) were collected in 3 hospitals in Busan Metropolitan city, Masan city, and Geoje city in Gyeongsangnam-do (Province) and were examined by IgE-ELISA and IgE-western blotting with larval A. simplex crude extract and excretory-secretory products (ESP). The prevalence of antibody positivity was 5.0% and 6.6% with ELISA against crude extracts and ESP, respectively. It was also revealed that infection occurred throughout all age groups and higher in females than in males. A specific protein band of 130 kDa was detected from 10 patients with western blot analysis against crude extract and ESP among those who showed positive results by ELISA. Our study showed for the first time the seroprevalence of anisakiasis in Korea. The allergen of 130 kDa can be a candidate for serologic diagnosis of anisakiasis.     

TOR-mediated cell-cycle activation causes neurodegeneration in a Drosophila tauopathy model

BACKGROUND: Previous studies have demonstrated reexpression of cell-cycle markers within postmitotic neurons in neurodegenerative tauopathies, including Alzheimer's disease (AD). However, the critical questions of whether cell-cycle activation is causal or epiphenomenal to tau-induced neurodegeneration and which signaling pathways mediate cell-cycle activation in tauopathy remain unresolved. RESULTS: Cell-cycle activation accompanies wild-type and mutant tau-induced neurodegeneration in Drosophila, and genetically interfering with cell-cycle progression substantially reduces neurodegeneration. Our data support a role for cell-cycle activation downstream of tau phosphorylation, directly preceding apoptosis. We accordingly show that ectopic cell-cycle activation leads to apoptosis of postmitotic neurons in vivo. As in AD, TOR (target of rapamycin kinase) activity is increased in our model and is required for neurodegeneration. TOR activation enhances tau-induced neurodegeneration in a cell cycle-dependent manner and, when ectopically activated, drives cell-cycle activation and apoptosis in postmitotic neurons. CONCLUSIONS: TOR-mediated cell-cycle activation causes neurodegeneration in a Drosophila tauopathy model, identifying TOR and the cell cycle as potential therapeutic targets in tauopathies and AD.