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Sample records for metal carcinogenesis physicochemical

  1. Recent advances in metal carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Sunderman, F.W. Jr.

    Recent advances in metal carcinogenesis are comprehensively reviewed, including (a) epidemiological and clinical aspects, (b) carcinogenesis bioassays, (c) bacterial mutagenesis, (d) mammalian cell mutagenesis, (e) chromosomal damage, (f) mammalian cell transformation, (g) microsomal metabolism, (h) DNA strandbreaks and crosslinks, (i) DNA polymerase infidelity, (j) RNA strand initiation, and (k) helical transition of B-DNA to Z-DNA. Based upon these observations, several hypotheses are proposed for the molecular pathogenesis of carcinogenesis by metal compounds. These hypotheses are amenable to experimental test by existing techniques of molecular biology.

  2. Heavy metal levels, physicochemical properties and microbial ...

    African Journals Online (AJOL)

    Journal of Applied Sciences and Environmental Management ... out to assess the microbial, physicochemical and heavy metal characteristics of soil samples from five different waste collection sites within the University of Benin, Benin City and evaluated using standard analytical and classical microbiological methods.

  3. Physicochemical, bacteriological and metal analysis of some ...

    African Journals Online (AJOL)

    This study was investigates the physicochemical, microbial and metal contents of water samples obtained from three different surface waters (Ala river, Onyearugbulem stream and FUTA stream).The samples were collected in the early the early morning during the late rainy season of August 2010. The streams are all ...

  4. Evaluation of Physicochemical Properties and Heavy Metals ...

    African Journals Online (AJOL)

    Physicochemical properties of municipal dumpsite compost in Kano metropolis and concentration of heavy metals were investigated. Analysis was carried out by atomic absorption spectrometry (Buck Scientific VPG 210). The results shows that the compost pH (6.63-8.19), electric conductivity of compost (638-933μs/cm), ...

  5. Carcinogenesis

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1975-01-01

    The long-term aims are concerned with various aspects of the natural history and biology of cancer, the mechanism of induction and of the advancement of time of appearance of tumors, the development of systems suitable for the assay of oncogenesis and cocarcinogenesis, and the elucidation of some of the factors important to the problem of extrapolation of estimates of risk made in experimental systems to the estimate of risk in man. It is necessary to have a number of test systems in order to study the various factors related to cocarcinogenesis; some of these are clearly tissue specific. The liver tumor system is clearly useful for certain compounds, and the liver is an excellent tissue for the study of the mechanisms of cocarcinogenesis. This year we report on the relatively rapid induction of what appears histologically to be carcinoma of the thyroid by aminotriazole. In a collaborative study with the Neutron and Gamma-Ray Toxicity Group, we have established a new example of synergism in carcinogenesis, namely between radiation and pituitary hormone(s) in the production of Harderian gland tumors. Not only does a synergistic effect on incidence occur, but also on the degree of malignancy of the tumor induced. We thus have three different model systems for the study of various aspects of cocarcinogenesis: various chemicals, including nononcogenic polycyclic hydrocarbons, in liver tumorigenesis; ionizing radiation and aminotriazole in thyroid tumorigenesis; and in conjunction with the JANUS Program, the interaction of radiation and hormones in the production of Harderian gland, mammary gland, and other tumors

  6. Determination of physico-chemical parameters and heavy metals in ...

    African Journals Online (AJOL)

    EJIRO

    Water samples from selected hand-dug wells and Ona River in Itaogbolu area of Akure, Ondo State,. Nigeria were collected, physico-chemical parameters and heavy metals were determined using standard analytical procedure. The results of the physico-chemical analysis were obtained in the following range; PH ...

  7. Physicochemical Characteristics and Levels of Some Heavy Metals ...

    African Journals Online (AJOL)

    Michael Horsfall

    ABSTRACT: Some physicochemical characteristics and heavy metal levels in soil samples around metal scrap dumps at Abraka and Agbor vicinities of Delta State, Nigeria, were analysed in order to assess the effects of the dumps on the soils. Conventional analytical methods were employed for the determination of these ...

  8. The 9th Conference on Metal Toxicity and Carcinogenesis: The conference overview.

    Science.gov (United States)

    Wise, James T F; Wang, Lei; Zhang, Zhuo; Shi, Xianglin

    2017-09-15

    Heavy metals, such as arsenic, chromium, cadmium, nickel, mercury, and uranium are known to cause many human diseases and health complications after occupational or environmental exposure. Consequently, metals are environmental health concerns. This manuscript is an overview of the 9th Conference on Metal Toxicity and Carcinogenesis held in October 2016 in Lexington, Kentucky. Since 2000, this biennial meeting brings together experts in the field to discuss current and prospective research in an effort to advance research pertaining to metal toxicity and carcinogenesis. In this review we summarize the major topics discussed and provide insight regarding current research in the field and an account of the direction in which the field is progressing. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Physico-chemical characteristics and Heavy metal levels in Drinking ...

    African Journals Online (AJOL)

    Physico-chemical characteristics and Heavy metal levels in Drinking Water sources in Sokoto metropolis in North-western Nigeria. ... Tap water samples had similar conductivity values (180 -190μS/m), sachet water samples had conductivity values ranging from 80μS/m to 260μS/m while well water samples had highest ...

  10. Determination of physico-chemical parameters and heavy metals in ...

    African Journals Online (AJOL)

    EJIRO

    Full Length Research Paper. Determination of physico-chemical parameters and heavy metals in water samples from Itaogbolu area of. Ondo-State, Nigeria. S. O. Adefemi* and E. E. Awokunmi. Department of Chemistry, University of Ado Ekiti, P. M. B. 5363, Nigeria. Accepted 22 December, 2009. Water samples from ...

  11. Evaluation of Some Metals Content and Physicochemical Properties ...

    African Journals Online (AJOL)

    ADOWIE PERE

    Chemical as well as physical and biological properties may change significantly during a year particularly as demand increases on a ground well and water table is lowered (James, 2010). The aim of this research was therefore to evaluate the metal contents and physicochemical parameters in some major rivers.

  12. An appraisal of physicochemical parameters and some trace metals ...

    African Journals Online (AJOL)

    Industrial effluent samples collected from the disposal point of five different companies in Trans-Amadi industrial area of Port Harcourt were analyzed to investigate effect on the environment. The analyzed effluent samples showed results of the physicochemical parameters and trace metals in the ranges : (pH 3.60 - 6.90), ...

  13. Physico-chemical parameters and heavy metal contents of Ibuya ...

    African Journals Online (AJOL)

    The physico-chemical parameters and heavy metal contents of Ibuya River were investigated between September 2012 and August 2013 from four stations using standard methods to etermine acceptable water quality standards and evaluate possible sustainability of a thriving fisheries cum tourist sport fishing venture.

  14. Heavy Metal Levels, Physicochemical Properties and Microbial ...

    African Journals Online (AJOL)

    ADOWIE PERE

    induced immobilization of heavy metals in contaminated soil and water: Implication on simultaneous remediation of contaminated soil and groundwater. Environ. Sci. Pollut. Res. 21(6): 4665-4674. Mahar, A; Wang, P; Ali, A; Awasthi, MK; Lahori,.

  15. [The biochemical carcinogenesis of selected heavy metals in bladder cancer].

    Science.gov (United States)

    Rorbach-Dolata, Anna; Marchewka, Zofia; Piwowar, Agnieszka

    2015-01-01

    Bladder cancer takes the second place in the classification of morbidity of urinary system cancers. Many chemical factors take part in cancerogenesis. It is suggested that exposure to heavy metals such as arsenic, chromium, nickel and cadmium as well as its metabolites may trigger the bladder cancer through inducing excessive reactive oxygen species production and oxidative stress formation which are responsible for DNA damage. In patients with bladder cancer is observed the disorder of processes regulated by p-53, including apoptosis. There are many patients with bladder cancer with confirmed absence of retinoblastoma protein, which is responsible of holding on the process of coming up the cells with mutation into synthesis, where the replication process undergoes. It is mentioned that excessive expression of proto-oncogenes may also cause the bladder cancer. The article concerns biochemical effects of exposure to chosen heavy metals and their potential role in bladder cancer progression.

  16. Assessment of physicochemical qualities, heavy metal ...

    African Journals Online (AJOL)

    Ogbe

    2012-08-23

    Aug 23, 2012 ... Despite recognizing the life sustaining importance of water, man's approaches to water usage has always ... were protected from direct sunlight and transported in a cooler box containing ice packs to the laboratory for ..... mals and plants while many other metals such as Cd, Cr,. Pb and Co have no known ...

  17. Assessment of physicochemical qualities, heavy metal ...

    African Journals Online (AJOL)

    Ogbe

    2012-08-23

    Aug 23, 2012 ... flame and single element hollow cathode lamp. Isolation, detection and estimation of bacteria ..... Earth Sci. 1:45-53. Aktar MW, Paramasivam M, Ganguly M, Purkait S, Sengupta D (2010). Assessment and occurrence of various heavy metals in surface water of Ganga river around Kolkata: a study for toxicity ...

  18. Heavy Metals and Physicochemical Properties of Soils in Kano ...

    African Journals Online (AJOL)

    Heavy Metals and Physicochemical Properties of Soils in Kano Urban Agricultural Lands. ... The mean ranges of total Cu, Cr, Ni, Zn, Pb and Cd were 4.95 – 5.99, 5.85 – 165.66, 54.03 – 57.77, 55.07 – 255.52, 42.84 – 68.12 and 0.59 – 11.81mg/kg respectively. All the values were lower than the maximum allowable ...

  19. Physicochemical and biological properties of new steroid metal complexes

    International Nuclear Information System (INIS)

    Huber, R.

    1980-04-01

    The aim of this investigation was to prepare stable steroid metal chelates by chemical conversion of the natural steroid hormones testerone, 5α-dihydrotestosterone (5α-DHT) and estradiol and to characterize these by means of their spectroscopic and other physico-chemical properties. In addition, various measuring techniques for the qualitative and quantitative study of complex stabilities and hydrolytic properties were employed. The distribution of some tritiated steroid metal complexes in the tissues of rats was tested using whole animal autoradiography, mainly with a view to identifying whether selective concentration occurs in certain organs. (orig.) [de

  20. Assessment of heavy metal removal technologies for biowaste by physico-chemical fractionation

    NARCIS (Netherlands)

    Veeken, A.H.M.; Hamelers, H.V.M.

    2003-01-01

    In the Netherlands, the heavy metal content of biowaste-compost frequently exceeds the legal standards for heavy metals. In order to assess heavy metal removal technologies, a physico-chemical fractionation scheme was developed to gain insight into the distribution of heavy metals (Cd, Cu, Pb and

  1. Physico-chemical characteristics and Heavy metal levels in Drinking ...

    African Journals Online (AJOL)

    Michael Horsfall

    ABSTRAC: This study investigated the physico-chemical characteristics of drinking waters collected from tap, well and sachet in Sokoto metropolis in North Western Nigeria. Conductivity and pH values were determined by standard methods while elemental composition was analysed using X-ray Fluorescence spectroscopy ...

  2. Study on physicochemical and heavy metals (Pb, Fe, Mn ...

    African Journals Online (AJOL)

    The highest mean value for dissolved oxygen observed was 4.33 mg/L. The results of physicochemical study upon comparison with WHO and NIS standards of drinking water show that, the values were all within permissible limits. The concentration of lead, iron and manganese ranged between 0.09 – 0.27 mg/L, 0.25 –0.32 ...

  3. Physicochemical Characteristics and Levels of Some Heavy Metals ...

    African Journals Online (AJOL)

    Michael Horsfall

    indicated a significant degree of soil contamination for Pd, Cd, Co, Cu and Zn in the soils studied showing a higher ... disposed waste. These metals which are not biodegradable are accumulated in living organisms when released into the environment. Although trace ... heavy metals in Nigerian soils if such solid waste.

  4. Assessment of some heavy metals and physicochemical properties ...

    African Journals Online (AJOL)

    aghomotsegin

    tolerable levels set by FAO and WHO for agricultural soil. It is suggested that the dumpsite and the control area with their adequate soil ... However, metallic materials from damaged vehicle parts, electronics, computers, cans, etc, are also disposed in the same way as the other non-metallic materials, thereby constituting a.

  5. Physicochemical Characteristics and Trace Metal Levels of Locally ...

    African Journals Online (AJOL)

    Michael Horsfall

    Mohr titration methods. Atomic absorption spectroscopy (Buck model 20. VGP) model was used for the analysis of the pre- treated samples for the following trace metals-Fe, Cu,. Zn, Cr, Pb and Cd which are among the nine (9) listed toxic metals by the United State Environmental. Protection Agency (1998) with the exception ...

  6. Physicochemical Characteristics and Heavy Metal Levels in Water ...

    African Journals Online (AJOL)

    MICHAEL

    makes them a source of concern. Sources of heavy metals includes industrial activates (mining, oil exploration activities, manufacturing and agricultural practices), domestics and commercial practices that generates wastes, and natural factors. Metal content in rivers may vary between the water column and bed sediments.

  7. Physicochemical characteristics and heavy metal levels in soil ...

    African Journals Online (AJOL)

    Distribution pattern of heavy metals in petrol stations, abattoirs, mechanic workshops and hospital incinerator sites were Mn > Zn > Pb > Cd, while for dumpsites Zn > Mn > Pb > Cd. Pollution index indicated that soil qualities varied between slightly contaminated to severely polluted status. This showed that the heavy metal ...

  8. Physicochemical Characteristics and Levels of Some Heavy Metals ...

    African Journals Online (AJOL)

    These soils therefore constitute a major health risk to the local population. This study successfully related and attributed the presence of heavy metals with anomalous concentration in the soils to anthropogenic inputs from the metal scrap dumps. @JASEM. J. Appl. Sci. Environ. Manage. December, 2010, Vol. 14 (4) 57 - 60 ...

  9. Physicochemical Characteristics and Heavy Metal Levels in Soil ...

    African Journals Online (AJOL)

    ADOWIE PERE

    associated mainly with industrial, agricultural, mining, land disposal of waste, waste incineration, mechanic workshop and fuel filling station (Fernando et al., 2012). Heavy metals contamination of topsoil has been a major concern regarding their toxicity, persistence and non-degradability in the environment. Toxicity of these ...

  10. Physicochemical and heavy metals values of Nigerian crude oil ...

    African Journals Online (AJOL)

    NPDC) Benin City representing three different oil wells each for Onshore and Offshore and labeled A, B, C for Onshore and D, E, F for offshore were analyzed for their ash content, volatile matter, pH, relative density and metal content. The results ...

  11. Physicochemical and nutraceutical properties of moringa (Moringa oleifera) leaves and their effects in an in vivo AOM/DSS-induced colorectal carcinogenesis model.

    Science.gov (United States)

    Cuellar-Nuñez, M L; Luzardo-Ocampo, I; Campos-Vega, R; Gallegos-Corona, M A; González de Mejía, E; Loarca-Piña, G

    2018-03-01

    Moringa (Moringa oleifera) is a plant that has generated great interest in recent years because of its attributed medicinal properties. The aim of this study was to characterize the bioactive compounds of moringa leaves (MO) and evaluate their effect on a colorectal carcinogenesis model. Twenty-four male CD-1 mice were divided into 4 groups: Group 1 fed with basal diet (negative control/NC); Group 2 received AOM/DSS (positive control); Groups 3 and 4 were fed with basal diet supplemented with moringa leaves (2.5% w/w and 5% w/w, respectively) for 12weeks. Moringa leaves exhibited a high content of dietary fiber (~18.75%) and insoluble dietary fiber (2.29%). There were identified 9 phenolic compounds whereas the chlorogenic and ρ-coumaric acid showed the higher contents (44.23-63.34μg/g and 180.45-707.42μg/g, respectively). Moringa leaves decreased the activity of harmful fecal enzymes (β-glucosidase, β-glucuronidase, tryptophanase and urease up to 40%, 43%, 103% and 266%, respectively) as well tumors incidence in male CD1-mice (~50% with 5% w/v of moringa dose). These findings suggest that the bioactive compounds of moringa such as total dietary fiber and phenolic compounds may have chemopreventive capacity. This is the first study of the suppressive effect of moringa leaves in an in vivo model of AOM/DSS-induced colorectal carcinogenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Evolutionary patterns and physicochemical properties explain macroinvertebrate sensitivity to heavy metals.

    Science.gov (United States)

    Malaj, Egina; Guénard, Guillaume; Schäfer, Ralf B; von der Ohe, Peter C

    2016-06-01

    Ecological risk assessment depends strongly on species sensitivity data. Typically, sensitivity data are based on laboratory toxicity bioassays, which for practical constraints cannot be exhaustively performed for all species and chemicals available. Bilinear models integrating phylogenetic information of species and physicochemical properties of compounds allow to predict species sensitivity to chemicals. Combining the molecular information (DNA sequences) of 31 invertebrate species with the physicochemical properties of six bivalent metals, we built bilinear models that explained 70-80% of the variability in species sensitivity to heavy metals. Phylogeny was the most important component of the bilinear models, as it explained the major part of the explained variance (> 40%). Predicted values from bilinear modeling were in agreement with experimental values (> 50%); therefore, this approach is a good starting point to build statistical models which can potentially predict heavy metal toxicity for untested invertebrate species based on empirical values for similar species. Despite their good performance, development of the presented bilinear models would benefit from improved phylogenetic and toxicological datasets. Our analysis is an example for linking evolutionary biology with applied ecotoxicology. Its future applications may encompass other stress factors or traits influencing the survival of aquatic organisms in polluted environments.

  13. Analysis of heavy metals during composting of the tannery sludge using physicochemical and spectroscopic techniques.

    Science.gov (United States)

    Haroun, Mahdi; Idris, Azni; Omar, Syed

    2009-06-15

    The major limitation of direct application of tannery sludge compost in agriculture is the total heavy metal contents and their bioavailability to the soil-plant system. This study focused on the heavy metal characterization and the influence of changing the physicochemical properties of the medium throughout the composting on the concentrations, bioavailability or chemical forms of Cr, Cu, Zn, Pb and Cd in tannery sludge. The study shows that throughout the 60 days of composting, physicochemical analysis and Fourier-transformed infrared (FTIR) spectroscopic characterization show that all parameters elaborated and reached relatively stable levels reflecting the stability and maturity of the final product, and revealed the biodegradation of components that can be easily assimilated by microorganism. The C/N ratio reaches the optimal range of stable compost; inorganic nitrogen is transformed into stable organic forms. The total concentration of Cr, Zn, Cu, Pb and Cd is very low rendering final compost acceptable for agricultural use. The germination index for both Chinese cabbage and lettuce was 97% after 60 days of composting, showing that the final compost was not phytotoxic. Furthermore, in using a sequential extraction method in sludge compost at different phases of treatment, a less than 2% of metals bound to bioavailable fractions X-(KNO(3)+H(2)O). A large proportion of the heavy metals were associated to the residual fraction (75-85%) and more resistant fractions to extraction X-NaOH, X-EDTA, X-HNO(3) (15-25%). Mobile fractions of metals are poorly predictable from the total content. Bioavailability of all fractions of elements tends to decrease.

  14. Human bronchial epithelial BEAS-2B cells, an appropriate in vitro model to study heavy metals induced carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Park, Youn-hee; Kim, Donghern; Dai, Jin; Zhang, Zhuo, E-mail: zhuo.zhang@uky.edu

    2015-09-15

    Occupational and environmental exposure to arsenic (III) and chromium VI (Cr(VI)) have been confirmed to cause lung cancer. Mechanisms of these metals carcinogenesis are still under investigation. Selection of cell lines to be used is essential for the studies. Human bronchial epithelial BEAS-2B cells are the cells to be utilized by most of scientists. However, due to p53 missense mutation (CCG → TCG) at codon 47 and the codon 72 polymorphism (CGC → CCC) in BEAS-2B cells, its usage has frequently been questioned. The present study has examined activity and expression of 53 and its downstream target protein p21 upon acute or chronic exposure of BEAS-2B cells to arsenic and Cr(VI). The results show that short-term exposure of BEAS-2B cells to arsenic or Cr(VI) was able to activate both p53 and p21. Chronic exposure of BEAS-2B cells to these two metals caused malignant cell transformation and tumorigenesis. In arsenic-transformed BEAS-2B cells reductions in p53 promoter activity, mRNA expression, and phosphorylation of p53 at Ser392 were observed, while the total p53 protein level remained the same compared to those in passage-matched parent ones. p21 promoter activity and expression were decreased in arsenic-transformed cells. Cr(VI)-transformed cells exhibit elevated p53 promoter activity, mRNA expression, and phosphorylation at Ser15, but reduced phosphorylation at Ser392 and total p53 protein level compared to passage-matched parent ones. p21 promoter activity and expression were elevated in Cr(VI)-transformed cells. These results demonstrate that p53 is able to respond to exposure of arsenic or Cr(VI), suggesting that BEAS-2B cells are an appropriate in vitro model to investigate arsenic or Cr(VI) induced lung cancer. - Highlights: • Short-term exposure of BEAS-2B cells to arsenic or Cr(VI) activates p53 and p21. • Chronic exposure of BEAS-2B cells to arsenic or Cr(VI) causes cell transformation and tumorigenesis. • Arsenic-transformed cells exhibit

  15. Metal ion leachates and the physico-chemical stability of biotherapeutic drug products.

    Science.gov (United States)

    Kumar, Sandeep; Zhou, Shuxia; Singh, Satish K

    2014-01-01

    Metal ions that leach into biotherapeutic drug product solution during manufacturing and storage, result in contamination that can cause physico-chemical degradation of the active molecule. In this review, we describe various mechanisms by which metal ion leachates can interact with therapeutic proteins and antibodies. Site-specific modifications due to metal catalyzed oxidation (MCO) of the therapeutic proteins cause them to become destabilized and potentially increasingly aggregation prone. We have examined the molecular sequences and structures for three case studies, human relaxin (hRlx), human growth hormone (hGH) and an IgG2 mAb to rationalize the experimental findings related to their MCO. The analysis indicates that metal-binding sites lie in close spatial proximities to predicted aggregation prone regions in these molecules. From the perspective of pharmaceutical development of biotherapeutic drugs, this link between molecular origins of MCO and subsequent aggregation is undesirable. This article further suggests molecular design strategies involving disruption of APRs that may also help mitigate the impact of metal ion leachates on biotherapeutic drug products as well as improving their solubility.

  16. Radiation carcinogenesis

    International Nuclear Information System (INIS)

    Adams, G.E.

    1987-01-01

    In this contribution about carcinogenesis induced by ionizing radiation some radiation dose-response relationships are discussed. Curves are shown of the relation between cell survival and resp. low and high LET radiation. The difference between both curves can be ascribed to endogenous repair mechanisms in the cell. The relation between single-gen mutation frequency and the surviving fractions of irradiated cells indicates that these repairing mechanisms are not error free. Some examples of reverse dose-response relationships are presented in which decreasing values of dose-rate (LET) correspond with increasing radiation induced cell transformation. Finally some molecular aspects of radiation carcinogenesis are discussed. (H.W.). 22 refs.; 4 figs

  17. PHYSICO-CHEMICAL PROPERTIES OF THE SOLID AND LIQUID WASTE PRODUCTS FROM THE HEAVY METAL CONTAMINATED ENERGY CROPS GASIFICATION PROCESS

    Directory of Open Access Journals (Sweden)

    Sebastian Werle

    2017-02-01

    Full Text Available The paper presents the results of basic physico-chemical properties of solid (ash and liquid (tar waste products of the gasification process of the heavy metal contaminated energy crops. The gasification process has carried out in a laboratory fixed bed reactor. Three types of energy crops: Miscanthus x giganteus, Sida hermaphrodita and Spartina Pectinata were used. The experimental plots were established on heavy metal contaminated arable land located in Bytom (southern part of Poland, Silesian Voivodship.

  18. River Water Pollution in Developed and Developing Countries: Judge and Assessment of Physicochemical Characteristics and Selected Dissolved Metal Concentration

    OpenAIRE

    Sikder, M. Tajuddion; Kihara, Yusuke; Yasuda, Masaomi; Yustiawati; Mihara, Yoshihiro; Tanaka, Shunitz; Odgerel, Dalkhav; Mijiddorj, Badamtsetseg; Syawal, Suhaemi M.; Hosokawa, Toshiyuki; Saito, Takeshi; Kurasaki, Masaaki

    2013-01-01

    To compare water quality in rivers of developed and developing countries, a study based on physicochemical parameters and dissolved metals levels was conducted. Water samples were collected from selected sites in Dhaka, Bangladesh; Hokkaido and Osaka, Japan; Erdenet, Mongolia and West Java, Indonesia. Analysis of least significant differences revealed that most water quality parameters were within comparable low levels in both developed and developing countries. The dissolved metals concentra...

  19. Chemical carcinogenesis

    Directory of Open Access Journals (Sweden)

    Paula A. Oliveira

    2007-12-01

    Full Text Available The use of chemical compounds benefits society in a number of ways. Pesticides, for instance, enable foodstuffs to be produced in sufficient quantities to satisfy the needs of millions of people, a condition that has led to an increase in levels of life expectancy. Yet, at times, these benefits are offset by certain disadvantages, notably the toxic side effects of the chemical compounds used. Exposure to these compounds can have varying effects, ranging from instant death to a gradual process of chemical carcinogenesis. There are three stages involved in chemical carcinogenesis. These are defined as initiation, promotion and progression. Each of these stages is characterised by morphological and biochemical modifications and result from genetic and/or epigenetic alterations. These genetic modifications include: mutations in genes that control cell proliferation, cell death and DNA repair - i.e. mutations in proto-oncogenes and tumour suppressing genes. The epigenetic factors, also considered as being non-genetic in character, can also contribute to carcinogenesis via epigenetic mechanisms which silence gene expression. The control of responses to carcinogenesis through the application of several chemical, biochemical and biological techniques facilitates the identification of those basic mechanisms involved in neoplasic development. Experimental assays with laboratory animals, epidemiological studies and quick tests enable the identification of carcinogenic compounds, the dissection of many aspects of carcinogenesis, and the establishment of effective strategies to prevent the cancer which results from exposure to chemicals.A sociedade obtém numerosos benefícios da utilização de compostos químicos. A aplicação dos pesticidas, por exemplo, permitiu obter alimento em quantidade suficiente para satisfazer as necessidades alimentares de milhões de pessoas, condição relacionada com o aumento da esperança de vida. Os benefícios estão, por

  20. Heavy Metal Levels and Physico-Chemical Quality of Potable Water Supply in Warri, Nigeria

    International Nuclear Information System (INIS)

    Nduka, K.C.; Orisakwe, E.O.

    2007-01-01

    The interaction between man's activities and the environment is gaining world wide attention. Warri an oil producing community in Delta State of Nigeria is faced with environmental oil pollution. Since open and underground water bodies are regarded as final recipients of most environmental pollutants, this study sought to provide data on the levels of the physico-chemical parameters and contaminants in Warri metropolitan water supply. This study investigated the cadmium, lead and chromium using Atomic Absorption Spectrophotometer, physico - chemical properties such as pH, temperature, total suspended solid TSS, total dissolved solid TDS, electrical conductivity EC, biological oxygen demand BOD, dissolved oxygen DO, chemical oxygen demand COD, and total coliform count of potable water sources in Warri. Ekpan River was found to have 1.2 mg/L of cadmium, 1.0mg/L of chromium, 1.20 mg/L of lead and 2.0 mg/L of manganese. The heavy metals levels and the pollution parameters were lowest in the borehole water samples, except pH which is more acidic in borehole water samples and conductivity which is more in well water samples in all the sampling stations. Some of the parameters were above WHO standards

  1. Microbiological, physicochemical, and heavy metals assessment of groundwater quality in the Triffa plain (eastern Morocco)

    Science.gov (United States)

    Yahya, Hameed Saleh Ali; Jilali, Abdelhakim; Mostareh, Mohammed Mohammed Mohammed; Chafik, Zouheir; Chafi, Abdelhafid

    2017-12-01

    The focus of this study is the physicochemical and bacteriological characteristics of groundwater in the Triffa plain, Morocco. In total, 34 groundwater samples were analyzed for major elements (Tp, pH, EC, K+, Na+, Ca2+, Mg2+, Cl-, SO4 2-, NO3 -, NO2 -, NH4 +, H2PO4 -, CO3, and HCO3 -) and trace metal (Al, Cd, Cu, Fe, and Zn) content. The results show that the pH values range between 6.7 and 8.9, electrical conductivity ranges between 740 and 7340 µS/cm, and nitrate content ranges between 1.7 and 212 mg/l. Hydrochemical facies represented using a Piper diagram indicate an Na-K-Cl type water. All the trace metal concentrations are within the admissible standard range except for Cd. The bacteriological analysis showed that the majority of groundwater samples are contaminated. Generally, the content of total coliforms, fecal coliforms, and fecal streptococci ranged from 0 to 140, 0 to 125, and 0 to 108 CFU/100 ml, respectively. The samples are grouped according to three factors. Factor 1 shows strong positive loadings of EC, Mg, Cl, Na and K with 51.91% of total variance (TV); factor 2 shows strong negative loadings of NO3, SO4 and Ca with 17.98% of TV; and factor 3 shows strong negative loading of HCO3 with 15.56 of TV. We conclude that the quality of this groundwater is suitable for irrigation and domestic use (cleaning house, ect).

  2. Monitoring trace metals and organohalogens in shellfish (2014) and physicochemical parameters and trace metals in seawater (2015) under the Shellfish Waters Directive

    OpenAIRE

    Institute, Marine

    2017-01-01

    Directive 2006/113/EC on the Quality Required of Shellfish Waters, also referred to as the Shellfish Waters Directive (SWD) requires the monitoring of, inter alia, certain physicochemical parameters including trace metal contaminants in order to assess and protect the quality of shellfish growing waters and the shellfish harvested from them. Sixty-four areas have been designated as Shellfish Waters (SWs) under SI 268 of 2006, SI 55 of 2009 and SI 464 of 2009. The SWD is concerned the quality ...

  3. Quantifying restoration success and recovery in a metal-polluted stream: A 17-year assessment of physicochemical and biological responses

    Science.gov (United States)

    Clements, W.H.; Vieira, N.K.M.; Church, S.E.

    2010-01-01

    Evaluating the effectiveness of stream restoration is often challenging because of the lack of pre-treatment data, narrow focus on physicochemical measures and insufficient post-restoration monitoring. Even when these fundamental elements are present, quantifying restoration success is difficult because of the challenges associated with distinguishing treatment effects from seasonal variation, episodic events and long-term climatic changes.2. We report results of one of the most comprehensive and continuous records of physical, chemical and biological data available to assess restoration success for a stream ecosystem in North America. Over a 17 year period we measured seasonal and annual changes in metal concentrations, physicochemical characteristics, macroinvertebrate communities, and brown trout Salmo trutta populations in the Arkansas River, a metal-contaminated stream in Colorado, USA.3. Although we observed significant improvements in water quality after treatment, the effectiveness of restoration varied temporally, spatially and among biological response variables. The fastest recovery was observed at stations where restoration eliminated point sources of metal contamination. Recovery of macroinvertebrates was significantly delayed at some stations because of residual sediment contamination and because extreme seasonal and episodic variation in metal concentrations prevented recolonization by sensitive species. Synthesis and applications. Because recovery trajectories after the removal of a stressor are often complex or nonlinear, long-term studies are necessary to assess restoration success within the context of episodic events and changes in regional climate. The observed variation in recovery among chemical and biological endpoints highlights the importance of developing objective criteria to assess restoration success. Although the rapid response of macroinvertebrates to reduced metal concentrations is encouraging, we have previously demonstrated that

  4. Water physico-chemical characteristics and trace heavy metal contamination status in sediment and waters of Kpeshie Lagoon, La, Accra

    International Nuclear Information System (INIS)

    Addo, M.A.; Okley, G.M.; Gbadago, J.K.; Avi, C.; Osae, S.; Sanu, J.K.

    2007-01-01

    Some physico-chemical water quality parameter (pH, temperature, conductivity, TDS, salinity, DO, major ions, nutrients, etc.) have been measured in the Kpeshie Lagoon, Accra. In addition trace heavy metal contamination status of water and bottom sediment were investigated. Some of the water quality parameters including conductivity (19370-28500mg/I), TDS (9750-14180mg/l), Chlorine (5725.2-8277.6mg/l) and Total Alkalinity (800-2000mg/l) were characterised as being high. However, nutrient contents of the water were within specified water quality regulatory limits for natural waters. The high presence of some heavy metals in the water and sediment especially Ni (71.8-1568μg/g), Pb (0.5-27.10μg/g) in the sediment was adjudged to pose a potential health risk to humans and the aquatic life of the lagoon's ecosystem. (au)

  5. Optimization Aspects of Carcinogenesis

    OpenAIRE

    Brutovsky, B.; Horvath, D.

    2009-01-01

    Any process in which competing solutions replicate with errors and numbers of their copies depend on their respective fitnesses is the evolutionary optimization process. As during carcinogenesis mutated genomes replicate according to their respective qualities, carcinogenesis obviously qualifies as the evolutionary optimization process and conforms to common mathematical basis. The optimization view accents statistical nature of carcinogenesis proposing that during it the crucial role is actu...

  6. Effects of heavy metals and soil physicochemical properties on wetland soil microbial biomass and bacterial community structure.

    Science.gov (United States)

    Zhang, Chang; Nie, Shuang; Liang, Jie; Zeng, Guangming; Wu, Haipeng; Hua, Shanshan; Liu, Jiayu; Yuan, Yujie; Xiao, Haibing; Deng, Linjing; Xiang, Hongyu

    2016-07-01

    Heavy metals (HMs) contamination is a serious environmental issue in wetland soil. Understanding the micro ecological characteristic of HMs polluted wetland soil has become a public concern. The goal of this study was to identify the effects of HMs and soil physicochemical properties on soil microorganisms and prioritize some parameters that contributed significantly to soil microbial biomass (SMB) and bacterial community structure. Bacterial community structure was analyzed by polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Relationships between soil environment and microorganisms were analyzed by correlation analysis and redundancy analysis (RDA). The result indicated relationship between SMB and HMs was weaker than SMB and physicochemical properties. The RDA showed all eight parameters explained 74.9% of the variation in the bacterial DGGE profiles. 43.4% (contain the variation shared by Cr, Cd, Pb and Cu) of the variation for bacteria was explained by the four kinds of HMs, demonstrating HMs contamination had a significant influence on the changes of bacterial community structure. Cr solely explained 19.4% (pstructure, and Cd explained 17.5% (pstructure changes. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Synthesis and physicochemical study of 6B subgroup metal complexes with aminoalcohols

    Energy Technology Data Exchange (ETDEWEB)

    Spitsyn, V.I.; Mozgin, S.V.; Subbotina, N.A.; Felin, M.G. (Moskovskij Gosudarstvennyj Univ. (USSR))

    1982-04-01

    Number of new complexes of molybdenum (VI) and tungsten (VI) with ethanolamines and aminopropanols are prepared. Physicochemical investigation of the prepared complexes by different methods is carried out. The structure of coordination sphere of the extracted complexes is proposed and the dependence of the forming products composition on the nature of the central atom and properties of the used ligands is explained. All the substances have the thermogramms on which initial endoeffect can be disclosed (removal of the solvent coordinated molecule); then the decomposition of the organic part of the molecule takes place. The corresponding trioxide is the final product during decomposition in the open air.

  8. Synthesis and physicochemical study of complexes of metals of subgroup VIB with amino alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Spitsyn, V.I.; Mozgin, S.V.; Subbotina, N.A.; Felin, M.G.

    1982-04-01

    New mixed-ligand complexes of chromium(III) with glycine and mono- and diethanolamines and a number of new complexes of molybdenum(VI) and of tungsten(VI) with ethanolamines and aminopropanols have been obtained; the physicochemical investigation of the complexes obtained by various methods has been made. A structure has been proposed for the coordination sphere of the complexes isolated and the dependence of the composition of the products formed on the nature of the central atom and on the properties of the ligands used have been explained.

  9. Physicochemical characteristics and sorption capacities of heavy metal ions of activated carbons derived by activation with different alkyl phosphate triesters

    Science.gov (United States)

    Wang, Jing; Liu, Hai; Yang, Shaokun; Zhang, Jian; Zhang, Chenglu; Wu, Haiming

    2014-10-01

    Five alkyl phosphate triesters (APTEs), including trimethyl phosphate (TMP), triethyl phosphate (TEP), triisopropyl phosphate (TPP), tributyl phosphate (TBP) and trioctyl phosphate (TOP), were used as activating agents for preparing activated carbons (AC-APTEs) with high surface acidity and metal ion sorption capacity. N2 adsorption/desorption isotherms, surface morphologies, elemental compositions, results of Boehm's titration and sorption capacities of heavy metal ions of the carbons were investigated. AC-APTEs contained much more acidic groups and exhibited much less surface area (phosphoric acid activation. For the AC-APTEs, AC-TOP had the highest surface area (488 m2/g), AC-TMP showed the highest yield (41.1%), and AC-TBP possessed the highest acidic groups (2.695 mmol/g), oxygen content (47.0%) and metal ion sorption capacities (40.1 mg/g for Ni(II) and 53.5 mg/g for Cd(II)). For the carbons, AC-APTEs showed much larger Ni(II) and Cd(II) sorption capacities than AC-PPA, except AC-TPP. The differences of the carbons in the physicochemical and sorption properties suggested surface chemistry of the carbons was the main factor influencing their sorption capacities whereas the pore structure played a secondary role.

  10. An Assessment Of Physicochemical Properties, Heavy Metal Enrichment And Fungal Characterization Of Refined Kerosene Impacted Soil In Anand, Gujarat, India

    Directory of Open Access Journals (Sweden)

    Shamiyan R Khan

    2013-12-01

    Full Text Available The present study was carried out to assess the physico-chemical properties, heavy metal enrichment and fungal isolation and characterization of the top soil samples collected in-situ from aged refined kerosene contaminated as well as uncontaminated garden soil sites in Anand, Gujarat, India. The total petroleum hydrocarbon (TPH concentrations were 17,510 mg/kg in kerosene contaminated soil against 142.65 mg/kg for uncontaminated soils. The contamination increased the soil organic carbon, nitrogen and clay to 2.95 %, 0.612 %, 36.22 % as compared to 1.5%, 0.153%, 32.4% respectively in the uncontaminated soil. Increased concentration of heavy metals like Cobalt, Copper, Iron, Zinc and Lead against the uncontaminated soil was encountered. Ten native fungal speciesbelonging to a total of five genera include Aspergillus (A. terreus, A. versicolor, A. niger; Fusarium oxysporum; Penicilliumjanthinellum from the uncontaminated garden soil, whereas the contaminated soil included Aspergillus (A. terreus, A. versicolor , A. niger Candida tropicalis,Cladosporiumbruhnei and Fusarium oxysporum, identified based on 18S rRNA and the nucleotide sequences were submitted to the NCBI, GenBank database. The changes created by kerosene contamination resulted in variation in individual concentrations of physicochemical properties, soil conductivity, pH and soil fertility indices probably dwindle the growth of fungal strains causing a reduction in the fungal population in the kerosene contaminated soil. International Journal of Environment, Volume-2, Issue-1, Sep-Nov 2013, Pages 164-174 DOI: http://dx.doi.org/10.3126/ije.v2i1.9219

  11. Rapid diffusion method for physicochemical characterization of metal ligands in soils and sediments

    International Nuclear Information System (INIS)

    Garland, T.R.; Wildung, R.E.; Pelroy, R.A.

    1975-01-01

    A diffusion method is described that allows preliminary characterization of metals in soils and sediments while minimizing the potential for alteration of metal form. In addition, examples of the application of the method to model compounds of Pu in the soil are given

  12. Evaluation of the physicochemical properties of structured materials: metallic, polymeric and ceramic, for the treatment of sour gases

    International Nuclear Information System (INIS)

    Salazar, A.; Chavez, R. H.; Olea, O.; Solis, D.

    2013-01-01

    in this work the physicochemical properties of three structured materials: metallic, polymeric and ceramic, from Sulzer Brothers Limited brand, are studied in order to removal sour gases, by absorption process, in aqueous solution of Monoethanolamine (Mea), at 30% weight. Mechanical properties, chemical composition, morphology and corrosion resistance were determined, using different characterization techniques, such as: 1) mechanically, according to standard procedures Astm E-384-1990, 2) chemically, by the corrosion resistance in the presence of an electrochemical cell, in aqueous solution of H 2 SO 4 , 1 N by Astm G-5-1999, 3) morphologically by scanning electron microscopy technique, and 4) efficiency of separation, by the gas chromatography technique in order to determine the chemical absorption of CO 2 by Mea. The ceramic material was the hardest with 700 Hk value and tensile strength of 90 MPa, likewise showed resistance to corrosion of 10.28 m py, separation efficiency of 74% CO 2 , at 10 minutes. The metallic material had a hardness of 190 Hk and it was the most resistant of tension, with 831 MPa, and corrosion resistance of 780.4 x 10 -6 m py, likewise promoted CO 2 separation efficiency of 90% during the evaluation. The polymeric material presented hardness of 20 Hk and 35 MPa and it was not suffered surface change with electrochemical attack, with 282.4 x 10 -6 m py, and separation efficiency of 88%. Therefore the polymer was the most ductile, with smooth surface and greater resistance with H 2 SO 4 . The metal material was more resistant to plastic deformation and more corrugated surface and the second resistance in the presence of acid medium in aqueous solutions. For all the above, the metallic material is recommended by its greater separation in the reduction of acid gases and the polymer due to its greater chemical resistance. (Author)

  13. Applying physicochemical approaches to control phosphogypsum heavy metal releases in aquatic environment.

    Science.gov (United States)

    Ammar, Rawaa; El Samrani, Antoine G; Kazpard, Véronique; Bassil, Joseph; Lartiges, Bruno; Saad, Zeinab; Chou, Lei

    2013-12-01

    One of the most important sources of solid waste in the Mediterranean Basin ecosystem originated from the phosphate fertilizer industries, which discharge phosphogypsum (PG) directly into aquatic environments or are stacked on stockpiles. The present study investigates metal release from PG under the influence of variable pH, increasing PG mass content, and complexing organic matter ligands. Major ions from PG leachates, grain size and charge, main functional groups along with metal leachability (Pb, Cd, Cr, Cu, and Zn) were determined using ion chromatography, laser diffraction, zetameter, Fourier transform infrared spectroscopy, and atomic absorption spectroscopy, respectively. The complete dissolution of PG recorded is at 2 g/L. Saturation and supersaturation with respect to PG may occur at concentrations of 3 and 4 g/L, respectively, revealing a clustering phenomenon leading to heavy metal encapsulation within the aggregates. Organic ligands such as citrate may trigger the cationic exchange within the PG suspension leading to ion release. As these factors are considered as specific process involving the release of contaminants from PG during storage under natural conditions, this study could set the foundations for PG remediation in aquatic environment. Organic ligands under controlled pH conditions could be utilized in treating fertilizer industrial wastes by taking into consideration the particularity of the receiving area, thus decreasing metal hazardous impact on natural media.

  14. Synthesis, physico-chemical characterization and biological activity of 2-aminobenzimidazole complexes with different metal ions

    Directory of Open Access Journals (Sweden)

    Podunavac-Kuzmanović Sanja O.

    2004-01-01

    Full Text Available Complexes of 2-aminobenzimidazole (L with nitrates of cobalt(II nickel(II, copper (II, zinc(II and silver(I were synthesized. The molar ratio metal:ligand in the reaction of the complex formation was 1:2. It should be noticed, that the reaction of all the metal salts yielded bis(ligand complexes of the general formula M(L2(NO32 × nH2O (M=Co, Ni Cu, Zn or Ag; n=0, 1, 2 or 6. The complexes were characterized by elemental analysis of the metal, molar conductivity, magnetic susceptibility measurements and IR spectra. Co(II, Ni(II and Cu(II complexes behave as non-electrolytes, whilst Zn(II and Ag(I are 1:1 electrolytes. Cu(II complex has a square-planar stereochemistry, Ag(I complex is linear, whilst the Co(II, Ni(II and Zn(II complexes have a tetrahedral configuration. In all the complexes ligand is coordinated by participation of the pyridine nitrogen of the benzimidazole ring. The antimicrobial activity of the ligand and its complexes against Pseudomonas aeruginosa, Bacillus sp. Staphylococcus aureus and Saccharomyces cerevisiae was investigated. The effect of metal on the ligand antimicrobial activity is discussed.

  15. A Study of Physicochemical Parameters and Nine Heavy Metals in the Euphrates River, Iraq

    Directory of Open Access Journals (Sweden)

    Fikrat M. Hassan

    2010-01-01

    Full Text Available This study was conducted to reveal possible environmental effects on the Euphrates River from the Al-Hindiya barrage to the downstream end of Al-Kufa city in the middle of Iraq. Seven sites were selected along the study area and sampled during March 2004 to February 2005. We measured physical and chemical properties (air and water temperature, pH, electrical conductivity, TDS, TSS and dissolved oxygen as well as, concentration and distribution of some heavy metals (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn in both dissolved and particulate phases, in the water and sediments (exchangeable and residual phases. The studied area was slightly alkaline, with very hard water and high BOD5. The nutrients showed clear seasonal fluctuations in their concentrations. It was shown that the concentrations of metals in the particulate phase were higher than those in dissolved phase in water. In sediments, the mean concentrations of heavy metals as exchangeable phase were less than in the residual phase.

  16. Physicochemical characteristics of the coconut pulp (Acrocomia aculeata) for use as support of proteins and metal material

    International Nuclear Information System (INIS)

    Yubero, F.; Ayala, J.; Lopez, M.; Valdovinos, V.; Monteiro, M.; Gonzalez, Y.; Thompson, W.; Arguello, J.

    2016-01-01

    The fruit of the Acrocomia aculeata, native palm tree typical of the tropical region, is exploited mainly for the manufacture of oils and animal consumption. This study was aimed to determine the physicochemical characteristics of the residue of the Acrocomia aculeata coconut pulp in order to apply it in the development of new materials. Therefore fruits collected for the production of pulp were drying and pulverized, the chemical and mineral compositions were studied by GAFTA standardized techniques for the analysis of crude fiber, protein, fat and calories and INAA respectively. Subsequently, the initial material was chemically modified and assessed the solubilities of the native material and the obtained modified material proving to be completely insoluble in solvents organic and aqueous (water, ethanol, terbutanol, isobutanol and hexane), the materials were analyzed by IR with Transformed Fourier and the results showed the existence of changes in the double link lengthening conjugated and aromatic; and link double nitrogen C=N/N=O. EPR analysis indicated that the materials obtained are not paramagnetic at room temperature, however can incorporate magnetite and Fe 0 . These preliminary studies concluded that this eco material could be applied as support of proteins and metals. (author)

  17. Utilization of steel, pulp and paper industry solid residues in forest soil amendment: relevant physicochemical properties and heavy metal availability.

    Science.gov (United States)

    Mäkelä, Mikko; Watkins, Gary; Pöykiö, Risto; Nurmesniemi, Hannu; Dahl, Olli

    2012-03-15

    Industrial residue application to soil was investigated by integrating granulated blast furnace or converter steel slag with residues from the pulp and paper industry in various formulations. Specimen analysis included relevant physicochemical properties, total element concentrations (HCl+HNO3 digestion, USEPA 3051) and chemical speciation of chosen heavy metals (CH3COOH, NH2OH·HCl and H2O2+H2O2+CH3COONH4, the BCR method). Produced matrices showed liming effects comparable to commercial ground limestone and included significant quantities of soluble vital nutrients. The use of converter steel slag, however, led to significant increases in the total concentrations of Cr and V. Subsequently, total Cr was attested to occur as Cr(III) by Na2CO3+NaOH digestion followed by IC UV/VIS-PCR (USEPA 3060A). Additionally, 80.6% of the total concentration of Cr (370 mg kg(-1), d.w.) occurred in the residual fraction. However, 46.0% of the total concentration of V (2470 mg kg(-1), d.w.) occurred in the easily reduced fraction indicating potential bioavailability. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Optimization aspects of carcinogenesis.

    Science.gov (United States)

    Brutovsky, B; Horvath, D

    2010-05-01

    Any process in which competing solutions replicate with errors and numbers of their copies depend on their respective fitnesses is the evolutionary optimization process. As during carcinogenesis mutated genomes replicate according to their respective qualities, carcinogenesis obviously qualifies as the evolutionary optimization process and conforms to common mathematical basis. The optimization view accents statistical nature of carcinogenesis proposing that during it the crucial role is actually played by the allocation of trials. Optimal allocation of trials requires reliable schemas' fitnesses estimations which necessitate appropriate, fitness landscape dependent, statistics of population. In the spirit of the applied conceptual framework, features which are known to decrease efficiency of any evolutionary optimization procedure (or inhibit it completely) are anticipated as "therapies" and reviewed. Strict adherence to the evolutionary optimization framework leads us to some counterintuitive implications which are, however, in agreement with recent experimental findings, such as sometimes observed more aggressive and malignant growth of therapy surviving cancer cells.

  19. Experimental radiation carcinogenesis

    International Nuclear Information System (INIS)

    Walburg, H.E. Jr.

    1974-01-01

    Literature on radioinduced carcinogenesis in experimental animals is reviewed with emphasis on the basic principles which could lead to a better predictability of radiation effects in man. It was concluded that the animal systems studied thus far are quantitatively inadequate for determining radiation risk estimates in man. (350 references.) (U.S.)

  20. Carcinogenesis of cutaneous malignancies.

    Science.gov (United States)

    Buzzell, R A

    1996-03-01

    Over the past several years significant progress has been made in identifying the cellular and biochemical mechanisms underlying carcinogenesis. This review summarizes recent advances that have helped clarify the process of malignant transformation in cutaneous tumors. Ultraviolet radiation-induced mutations in the p53 tumor suppressor gene and human papilloma virus inhibition of the p53 and retinoblastoma tumor suppressor gene products appear to play significant roles in the development of many cutaneous squamous cell carcinomas. Studies of patients with the nevoid basal cell carcinoma syndrome suggest the existence of an additional regulatory gene that may be involved in the development of basal cell carcinomas. Carcinogenesis is multistep process involving genetic and epigenetic alterations to specific proto-oncogene and tumor suppressor gene products that progressively release the cell from normal controlled growth and replication.

  1. Radiation carcinogenesis, laboratory studies

    International Nuclear Information System (INIS)

    Shellabarger, C.J.

    1974-01-01

    Laboratory studies on radioinduced carcinogenesis are reviewed. Some topics discussed are: radioinduced neoplasia in relation to life shortening; dose-response relationships; induction of skin tumors in rats by alpha particles and electrons; effects of hormones on tumor response; effects of low LET radiations delivered at low dose-rates; effects of fractionated neutron radiation; interaction of RBE and dose rate effects; and estimates of risks for humans from animal data. (U.S.)

  2. Carcinogenesis. Genetics and circumstances

    International Nuclear Information System (INIS)

    Hino, Okio

    2005-01-01

    Described are the author's study and aspect concerning carcinogenesis and radiation carcinogenesis, where he thinks cancer is not automatic, has a process and takes time. For radiation carcinogenic studies, he has used a model of the rat with genetically determined kidney cancer which is highly radiosensitive. That is, mutation by the so-called 2nd-hit of the causal gene (tumor suppressing gene Tsc2) is studied in the animal where the 1st-hit has been done by retrotransposon insertion, with and without exposure to radiations (X-ray, heavy particle beam and cosmic ray) for elucidating the mutation spectrum of the causal gene, the carcinogenic target, for the ultimate aim to prevent human cancer. He discusses the drama-type molecular mechanisms leading to cancer, gene abnormality and disease crisis, discontinuity in continuity in cancer formation, and importance of the timely diagnosis and appropriate therapy, and concludes the present age is becoming such one as that the nature of cancer even if genetic can be controlled by circumstances like timely and appropriate intervention. (S.I.)

  3. Evaluation of the capacity of Raman Microscopy in the mineralogical and physico-chemical characterization of archaeological material: corroded metals, stained-glass and pigments

    International Nuclear Information System (INIS)

    Bouchard-Abouchacra, Michel

    2001-01-01

    This study is based on the evaluation of the capacity of non-destructive physico-chemical analysis by Raman Microscopy in three artistic and archaeological domains: metal corrosion, stained-glass and Prehistoric pigments. The study presents different levels of results depending on the field of application. In relation to Prehistoric pigments the results show clearly the capacity of distinguishing in black pigments, manganese oxide from amorphous carbon, or, the facility of identification of hematite in red pigments. Concerning the study of the corrosion products of metals, RM is indubitably an ideal technique for the identification and differentiation of the diverse alteration products observed on archaeological metallic material (sulphates, chlorides, oxides...). Finally, in the case of stained-glass, the positive results obtained in the study of the glass itself or in the study of the superficial coloration is counterbalanced by the complexity of identification of glass coloration due to metallic colloid particles, or by the fluorescent problem particularly important in this last application. However, the global result is clearly optimistic and demonstrate the utility of such a non-destructive technique for archaeologists, restorers or conservators. (author) [fr

  4. Cell proliferation in carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Cohen, S.M.; Ellwein, L.B. (Univ. of Nebraska Medical Center, Omaha (USA))

    1990-08-31

    Chemicals that induce cancer at high doses in animal bioassays often fail to fit the traditional characterization of genotoxins. Many of these nongenotoxic compounds (such as sodium saccharin) have in common the property that they increase cell proliferation in the target organ. A biologically based, computerized description of carcinogenesis was used to show that the increase in cell proliferation can account for the carcinogenicity of nongenotoxic compounds. The carcinogenic dose-response relationship for genotoxic chemicals (such as 2-acetylaminofluorene) was also due in part to increased cell proliferation. Mechanistic information is required for determination of the existence of a threshold for the proliferative (and carcinogenic) response of nongenotoxic chemicals and the estimation of risk for human exposure.

  5. Metal and physico-chemical variations at a hydroelectric reservoir analyzed by Multivariate Analyses and Artificial Neural Networks: environmental management and policy/decision-making tools.

    Science.gov (United States)

    Cavalcante, Y L; Hauser-Davis, R A; Saraiva, A C F; Brandão, I L S; Oliveira, T F; Silveira, A M

    2013-01-01

    This paper compared and evaluated seasonal variations in physico-chemical parameters and metals at a hydroelectric power station reservoir by applying Multivariate Analyses and Artificial Neural Networks (ANN) statistical techniques. A Factor Analysis was used to reduce the number of variables: the first factor was composed of elements Ca, K, Mg and Na, and the second by Chemical Oxygen Demand. The ANN showed 100% correct classifications in training and validation samples. Physico-chemical analyses showed that water pH values were not statistically different between the dry and rainy seasons, while temperature, conductivity, alkalinity, ammonia and DO were higher in the dry period. TSS, hardness and COD, on the other hand, were higher during the rainy season. The statistical analyses showed that Ca, K, Mg and Na are directly connected to the Chemical Oxygen Demand, which indicates a possibility of their input into the reservoir system by domestic sewage and agricultural run-offs. These statistical applications, thus, are also relevant in cases of environmental management and policy decision-making processes, to identify which factors should be further studied and/or modified to recover degraded or contaminated water bodies. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. a Baseline Study of Physico-Chemical Parameters and Trace Metals in Waters of Manakudy, South-West Coast of India

    Science.gov (United States)

    Subramanian, M.; Muthumanikkam, J.

    2013-05-01

    The transport of trace metals from the land to ocean has a number of different routes and efficiencies. The sources of toxic elements into the rivers to be debouched into the sea through estuaries are either weathered naturally from the soils and rocks or introduced anthropogenically from point or non-point sources, in labile form or in particulate form. However, recent studies indicate that the transport of trace elements to the aquatic environment is much more complex than what has been thought. The chemistry and ecology of an estuarine system are entirely different from the fluvial as well as the marine system. Estuarine environment is characterized by a constantly changing mixture of salt and freshwater. In the present study area Manakudy estuary is situated about 8 kilometres north west of Kanyakumari (Latitude N 08 05 21.8 and Longitude E 077 29 03.7). To gain a better understanding of the geochemical behavior of physico-chemical parameters and trace elements in the estuary and to examine variations in associated chemical changes, 20 water samples were collected throughout the Manakudy estuary, a minor river in south-western India. These samples, collected in typical dry season during 2012, were analyzed for physico-chemical parameters, dissolved major and trace elements. Our results show that dissolved Na, Mg, Ca and Cl behave conservatively along the salinity gradient. The concentration of nutrients is normal and they are due to the higher organic activity in soils as well as faster rates of chemical weathering reaction in the source region. The concentration of major ions is due to tidal influence and it increases with salinity and the nutrients do behave non-conservatively due to biogenic removal. The conservative behaviour of the trace metals with salinity has been strongly affected by the introduction of these metals by external sources. Even though the trace metals in the contaminated water have been removed and incorporated in sediments due to

  7. Physico-chemical characterisation of particulate heavy metals from municipal solid waste incinerator emissions and their contributions to ambient air quality. Case of Toulon MSWI (South of France)

    International Nuclear Information System (INIS)

    Le Floch, M.

    2004-07-01

    The aims of this study are the physico-chemical characterisation, the apportionment and the following of particulate heavy metals from MSWI emissions. Various methods (in situ data treatment, unmixing models and codes, UNMIX or CMB, sequential extractions and extended X-ray absorption fine structure (EXAFS) agree in the following: - identification of the MSWI source in two profiles (Zn - Ca and Ba - Cu - Fe - Zn - Pb - Ca); - estimation of its contribution of up to 25% of the total sources contribution; - showing the seasonal variability in term of profile and contribution of this source; - suggest the potential of emitted elements to enter the food chain; This EXAFS first approach on atmospheric particulate matter shows that zinc and lead are in an atomic environment with calcium, silicon and aluminum. In spite of disputable conclusions, isotopic lead ratios define a 'MSWI' end-member and confirm that the town-center of Toulon is outside the MSWI plume influence. (author)

  8. Gene amplification in carcinogenesis

    Directory of Open Access Journals (Sweden)

    Lucimari Bizari

    2006-01-01

    Full Text Available Gene amplification increases the number of genes in a genome and can give rise to karyotype abnormalities called double minutes (DM and homogeneously staining regions (HSR, both of which have been widely observed in human tumors but are also known to play a major role during embryonic development due to the fact that they are responsible for the programmed increase of gene expression. The etiology of gene amplification during carcinogenesis is not yet completely understood but can be considered a result of genetic instability. Gene amplification leads to an increase in protein expression and provides a selective advantage during cell growth. Oncogenes such as CCND1, c-MET, c-MYC, ERBB2, EGFR and MDM2 are amplified in human tumors and can be associated with increased expression of their respective proteins or not. In general, gene amplification is associated with more aggressive tumors, metastases, resistance to chemotherapy and a decrease in the period during which the patient stays free of the disease. This review discusses the major role of gene amplification in the progression of carcinomas, formation of genetic markers and as possible therapeutic targets for the development of drugs for the treatment of some types of tumors.

  9. contribution to carcinogenesis

    Directory of Open Access Journals (Sweden)

    Aneta Białkowska

    2014-01-01

    Full Text Available The centrosomes are subcellular organelles composed of two centrioles surrounded by a pericentriolar material. In animal cells they are responsible for the organization of the interphase microtubule cytoskeleton including microtubule nucleation and elongation, their attachment and release. The centrosomes are also involved in the construction of the mitotic spindle and chromosome segregation. More than a century ago it was suggested that these structures might be involved in human diseases, including cancer. Cancer cells show a high frequency of centrosome aberrations, especially amplification. Centrosome defects may increase the incidence of multipolar mitoses that lead to chromosomal segregation abnormalities and aneuploidy, which is the predominant type of genomic instability found in human solid tumors. The number of these organelles in cells is strictly controlled and is dependent on the proper process of centrosome duplication. Multiple genes that are frequently found mutated in cancers encode proteins which participate in the regulation of centrosome duplication and the numeral integrity of centrosomes. In recent years there has been growing interest in the potential participation of centrosomes in the process of carcinogenesis, especially because centrosome abnormalities are observed in premalignant stages of cancer development. The common presence of abnormal centrosomes in cancer cells and the role these organelles play in the cells suggest that the factors controlling the number of centrosomes may be potential targets for cancer therapy.

  10. Physico-chemical assessment of paper mill effluent and its heavy metal remediation using aquatic macrophytes--a case study at JK Paper mill, Rayagada, India.

    Science.gov (United States)

    Mishra, Swayamprabha; Mohanty, Monalisa; Pradhan, Chinmay; Patra, Hemanta Kumar; Das, Ritarani; Sahoo, Santilata

    2013-05-01

    The present investigation aims to assess the phytoremediation potential of six aquatic macrophytes, viz. Eichhornia crassipes, Hydrilla verticillata, Jussiaea repens, Lemna minor, Pistia stratiotes and Trapa natans grown in paper mill effluent of JK Paper mill of Rayagada, Orissa, for remediation of heavy metals. The experiment was designed in pot culture experiments. Assessment of physico-chemical parameters of paper mill effluent showed significant decrease in pH, conductivity, total dissolved solids, total suspended solids, chlorine, sulphur, biological and chemical oxygen demand after growth of macrophytes for 20 days. Phytoremediation ability of these aquatic macrophytic species for copper (Cu) and mercury (Hg) was indicated by assessing the decrease in the levels of heavy metals from effluent water. Maximum reduction (66.5 %) in Hg content of untreated paper mill effluent was observed using L. minor followed by T. natans (64.8 %). L. minor showed highest reduction (71.4 %) of Cu content from effluent water followed by E. crassipes (63.6 %). Phytoextraction potential of L. minor was remarkable for Hg and Cu, and bioaccumulation was evident from bioconcentration factor values, i.e. 0.59 and 0.70, respectively. The present phytoremediation approach was considered more effective than conventional chemical treatment method for removing toxic contaminants from paper mill effluent.

  11. Physicochemical Characteristics and Ecological Risk Assessment of Heavy Metals Contaminated Soils in Copper Mining of Nulasai, Xinjiang, China

    Directory of Open Access Journals (Sweden)

    Dina·Tursenjan

    2017-12-01

    Full Text Available Taking the mining areas, tailings and surrounding farmland soil of the Nulasai copper mine in Xinjiang as the research object, the characteristics of soil physical and characteristics of heavy metal contents in this area were studied, and their ecological and environmental risks were preliminarily evaluated. The results showed that due to the long-term impact of mining wastewater, soil pH in the Nulasai mining area was relatively low. Soil conductivity and salt content were higher than those in the surrounding farmland, while soil organic matter, available nitrogen, available potassium and available phosphorus were lower than those in the surrounding farmland. The contents of heavy metals Cr, Cd, Pb, Cu, Ni and Zn in the mining area, tailing area and farmland soil were all lower than those in Xinjiang except for Cu. Overall, the heavy metal content of the soil manifested the area > tailing area > farmland. Single factor(Pi, Nemerow comprehensive pollution index(I and potential ecological risk index(RI indicated that the ecological risk of heavy metals in the soil around the mining area was manifested tailings > mining area > farmland. The potential ecological risk index of heavy metals in 0~30 cm topsoil was higher than that in 30~70 cm deep soil, but the overall ecological risk was lower in different land use types.

  12. Synthesis, Characterization, and Physicochemical Studies of Mixed Ligand Complexes of Inner Transition Metals with Lansoprazole and Cytosine

    Directory of Open Access Journals (Sweden)

    Sarika Verma

    2013-01-01

    Full Text Available Few complexes of inner transition metals [Th(IV, Ce(IV, Nd(III, Gd(III] have been synthesized by reacting their metal salts with lansoprazole, 2-([3-methyl-4-(2,2,2-trifluoroethoxypyridin-2-yl]methylsulfinyl-1H-benzoimidazole and cytosine. All the complexes were synthesized in ethanolic medium. The yield percentage rangs from 80 to 90%. The complexes are coloured solids. The complexes were characterized through elemental analyses, conductance measurements, and spectroscopic methods (FT IR, FAB Mass, 1H NMR and UV. An IR spectrum indicates that the ligand behaves as bidentate ligands. The metal complexes have been screened for their antifungal activity towards Aspergillus niger fungi. The interaction of inner transition metals with lansoprazole, in presence of cytosine, has also been investigated potentiometrically at two different temperatures 26±1°C and 36±1°C and at 0.1 M (KNO3 ionic strength. The stability constants of ternary complexes indicate the stability order as Th(IV < Ce(IV < Gd(III < Nd(III. logK values obtained are positive and suggest greater stabilization of ternary complexes. The values of thermodynamic parameters (free energy (ΔG, enthalpy (ΔH, and entropy (ΔS are also calculated.

  13. Brain acetylcholinesterase of jaguar cichlid (Parachromis managuensis): From physicochemical and kinetic properties to its potential as biomarker of pesticides and metal ions.

    Science.gov (United States)

    Araújo, Marlyete Chagas de; Assis, Caio Rodrigo Dias; Silva, Luciano Clemente; Machado, Dijanah Cota; Silva, Kaline Catiely Campos; Lima, Ana Vitória Araújo; Carvalho, Luiz Bezerra; Bezerra, Ranilson de Souza; Oliveira, Maria Betânia Melo de

    2016-08-01

    This contribution aimed to characterize physicochemical and kinetic parameters of the brain cholinesterases (ChEs) from Parachromis managuensis and investigate the in vitro effects of pesticides and metal ions on its activity intending to propose as biomarker. This species is suitable for this investigation because (1) it was recently introduced in Brazil becoming invasive (no restrictions on capture) and (2) occupies the top of the food chain (being subject to bioaccumulation). The enzyme extract was exposed to 10 metal ions (Al(3+), Ba(2+), Cd(2+), Cu(2+), Hg(2+), Mg(2+), Mn(2+), Pb(2+), Fe(2+) and Zn(2+)) and ChEs selective inhibitors (BW284c51, Iso-OMPA, neostigmine and serine). The extract was also incubated with organophosphate (dichlorvos) and carbamate pesticides (carbaryl and carbofuran). Inhibition parameters (IC20, IC50 and ki) were determined. Selective inhibitors and kinetic parameters confirmed acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) -like as responsible for the ChE activities, most AChE. The IC50 values for pesticides were: 1.68μM (dichlorvos); 4.35μM (carbaryl) and 0.28μM (carbofuran). Most of the analyzed ions did not show significant effect at 1mM (p=0.05), whereas the following ions inhibited the enzyme activity in the order: Hg(2+)>Cu(2+)>Cd(2+)>Zn(2+). Mercury ion strongly inhibited the enzyme activity (IC20=0.7μM). The results about allow to conclude that P. managuensis brain AChE is a potential biomarker for heavy metals and pesticides under study, mainly for the carbamate carbofuran once it was capable to detect 6-fold lower levels than the limit concentration internationally recommended. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Physico-Chemical parameters and trace-metals concentration in effluents from various industries in vicinity of Lahore

    International Nuclear Information System (INIS)

    Gulfraz, M.; Ahmad, T.; Afzal, H.

    2003-01-01

    Increasing problem of pollution has become serious in almost all big cities of Pakistan. The industrial effluents (Liquid waste) discharged by different industries are drained into streams/nallahs, which ultimately join the waterways (streams, lakes, rivers or sea). The effluent samples from five industries, like Tanneries, Chemicals, Pharmaceuticals, Fertilizers and metal/electroplating, working in Lahore, Sheikhupura and Kalashahkaku were selected for analysis. The parameters, like Temperature, pH, conductivity, hardness, alkalinity, total dissolved solids, chemical oxygen demands, phosphate, nitrate, nitrite, major cations (Na, K, Ca, Mg) and heavy/trace metals, were studied. The results were compared with National environmental Quality standards (NEQS). It was further observed that when effluents of industries join fresh water of stream, lakes or rivers, this causes severe water-pollution and damages the flora and fauna. Suggestions for effective control of water-pollution are also given. (author)

  15. Epigenetic mechanism of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Niwa, Ohtsura

    1995-01-01

    Carcinogenic action of radiations has long been thought to be due to its mutagenic activity. Since DNA damage is induced and distributes in a stochastic fashion, radiation induction of cancers was also assumed to follow a stochastic kinetics. However, recent progress in radiation research has revealed that some features of radiation carcinogenesis are not explainable by the simple action of radiation as a DNA damaging and mutagenic agent. Firstly, frequencies of radiation-induced transformation in vitro and radiation-induced mammary cancers in rats are too high to be accounted for by the frequency of radiation-induced mutation. Secondly, trans-generation carcinogenesis among F1 mice born to irradiated parents occurs also much more frequently than to be predicted by the frequency of radiation induced germline mutation. Thirdly, multistage carcinogenesis theory predicts that carcinogens give hits to the target cells so as to shorten the latency of cancers. However, latencies of radiation induced solid cancers among atomic bomb survivors are similar to those of the control population. Fourthly, although radiation elevates the frequency of cancers, the induced cancers seem to share the same spectrum of cancer types as in the unirradiated control populations. This suggests that radiation induces cancer by enhancement of the spontaneous carcinogenesis process. These data suggest that the first step of radiation carcinogenesis may not be the direct induction of mutation. Radiation may induce genetic instability which increases the spontaneous mutation rate in the cells to produce carcinogenic mutations. Growth stimulatory effect of radiation may also contribute to the process. Thus, epigenetic, but not genetic effect of radiation might better contribute in the process of carcinogenesis. (author)

  16. SYNTHESIS AND PHYSICO-CHEMICAL STUDIES OF HETEROMETALLIC NITRILOTRIACETATES OF CHROMIUM(III WITH SOME 3d METALS

    Directory of Open Access Journals (Sweden)

    Victor Ciorne

    2006-06-01

    Full Text Available Heterometallic complexes of chromium (III with some 3d metals have been synthesized based on nitrilotriacetic acid (H3nta, like M(bpy2Cr2(OH2(nta2·nH2O, where M = Mn2+, Co2+, Ni2+ and Zn2+; bpy = α,α′- bipyridine; n = 8 or 9. Their chemical composition has been determined from the results of the elemental analysis and thermogravimetric study. The coordination modes of the nta3 ̄ ligand and the type of chemical bonds have been proposed basing on IR spectra.

  17. Experimental radiation carcinogenesis is studies at NIRS

    International Nuclear Information System (INIS)

    Sado, Toshihiko

    1992-01-01

    Experimental radiation carcinogenesis studies conducted during the past decade at NIRS are briefly reviewed. They include the following: 1) Age dependency of susceptibility to radiation carcinogenesis. 2) Radiation-induced myeloid leukemia. 3) Mechanism of fractionated X-irradiation (FX) induced thymic lymphomas. 4) Significance of radiation-induced immunosuppression in radiation carcinogenesis in vivo. 5) Other ongoing studies. (author)

  18. Radiation carcinogenesis: radioprotectors and photosensitizers

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1982-01-01

    This paper outlines 1) some of the salient features of radiation carcinogenesis that are pertinent to the questions of how the carcinogenic effects might be influenced, 2) the effects of radioprotectors on ionizing radiation-induced cancer, and 3) the effect of photosensitizers on UVR-induced skin cancer

  19. Radiation carcinogenesis: radioprotectors and photosensitizers

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1982-01-01

    This paper outlines 1) some of the salient features of radiation carcinogenesis that are pertinent to the questions of how the carcinogenic effects might be influenced, 2) the effects of radioprotectors on ionizing radiation-induced cancer, and 3) the effect of photosensitizers on UVR-induced skin cancer.

  20. Influence of physicochemical-electronic properties of transition metal ion doped polycrystalline titania on the photocatalytic degradation of Indigo Carmine and 4-nitrophenol under UV/solar light

    Energy Technology Data Exchange (ETDEWEB)

    Devi, L. Gomathi, E-mail: gomatidevi_naik@yahoo.co.in [Department of Post Graduate Studies in Chemistry, Central College City Campus, Dr. Ambedkar street, Bangalore University, Bangalore 560001 (India); Kumar, S. Girish [Department of Post Graduate Studies in Chemistry, Central College City Campus, Dr. Ambedkar street, Bangalore University, Bangalore 560001 (India)

    2011-01-15

    To understand the role of dopant inside TiO{sub 2} matrix, anatase TiO{sub 2} was doped with transition metal ions like Mn{sup 2+}, Fe{sup 3+}, Ru{sup 3+} and Os{sup 3+} having unique half filled electronic configuration and their photocatalytic activity was probed in the degradation of Indigo Carmine (IC) and 4-nitrophenol (NP) under UV/solar light. For comparison, TiO{sub 2} was also doped with V{sup 5+}, Ni{sup 2+} and Zn{sup 2+} metal ions having d{sup 0}, d{sup 8} and d{sup 10} electronic configuration respectively. Irrespective of excitation source UV/solar light and nature of the organic pollutant, photocatalytic activities of doped photocatalysts followed the order: Mn{sup 2+}-TiO{sub 2} > Fe{sup 3+}-TiO{sub 2} > Ru{sup 3+}-TiO{sub 2} {>=} Os{sup 3+}-TiO{sub 2} > Zn{sup 2+}-TiO{sub 2} > V{sup 5+}-TiO{sub 2} > Ni{sup 2+}-TiO{sub 2} at an optimum concentration of dopant. Based on the experimental results obtained, it is proposed that the existence of dopant with half filled electronic configuration in TiO{sub 2} matrix which is known to enhance the photocatalytic activity is not universal{exclamation_point} Rather it is a complex function of several physicochemical-electronic properties of doped titania. Enhanced photocatalytic activity of Mn{sup 2+} (0.06 at.%)-TiO{sub 2} was attributed to the combined factors of high positive reduction potential of Mn{sup 2+}/Mn{sup 3+} pairs, synergistic effects in the mixed polymorphs of anatase and rutile, smaller crystallite size with high intimate contact between two phases and favorable surface structure of the photocatalyst. Despite the intense research devoted to transition metal ion doped TiO{sub 2}, it is rather difficult to make unifying conclusion which is highlighted in this study.

  1. Carcinogenesis mechanisms of Fusobacterium nucleatum.

    Science.gov (United States)

    Gholizadeh, Pourya; Eslami, Hosein; Kafil, Hossein Samadi

    2017-05-01

    Transformed cells of cancers may be related to stromal cells, immune cells, and some bacteria such as Fusobacterium nucleatum. This review aimed to evaluate carcinogenesis mechanisms of Fusobacterium spp. in the oral cavity, pancreatic and colorectal cancers. These cancers are the three of the ten most prevalence cancer in the worldwide. Recent findings demonstrated that F. nucleatum could be considered as the risk factor for these cancers. The most important carcinogenesis mechanisms of F. nucleatum are chronic infection, interaction of cell surface molecules of these bacteria with immune system and stromal cells, immune evasion and immune suppression. However, there are some uncertainty carcinogenesis mechanisms about these bacteria, but this review evaluates almost all the known mechanisms. Well-characterized virulence factors of F. nucleatum such as FadA, Fap2, LPS and cell wall extracts may act as effector molecules in the shift of normal epithelial cells to tumor cells. These molecules may provide new targets, drugs, and strategies for therapeutic intervention. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  2. Molecular insight of arsenic-induced carcinogenesis and its prevention.

    Science.gov (United States)

    Mandal, Paramita

    2017-05-01

    Population of India and Bangladesh and many other parts of the world are badly exposed to arsenic through drinking water. Due to non-availability of safe drinking water, they are dependent on arsenic-contaminated water. Generally, poverty level is high in those areas with lack of proper nutrition. Arsenic is considered to be an environmental contaminant and widely distributed in the environment due to its natural existence and anthropogenic applications. Contamination of arsenic in both human and animal could occur through air, soil, and other sources. Arsenic exposure mainly occurs in food materials through drinking water with high levels of arsenic in it. High levels of arsenic in groundwater have been found to be associated with various health-related problems including arsenicosis, skin lesions, cardiovascular diseases, reproductive problems, psychological, neurological, immunotoxic, and carcinogenesis. The mechanism of arsenic toxicity consists in its transformation in metaarsenite, which acylates protein sulfhydryl groups, affect on mitochondria by inhibiting succinic dehydrogenase activity and can uncouple oxidative phosphorylation with production of active oxygen species by tissues. A variety of dietary antioxidant supplements are useful to protect the carcinogenetic effects of arsenic. They play crucial role for counteracting oxidative damage and protect carcinogenesis by chelating with heavy metal moiety. Phytochemicals and chelating agents will be beneficial for combating heavy metal-induced carcinogenesis through its biopharmaceutical properties.

  3. Analysis of physico-chemical properties and heavy metals in drinking water from different sources in and around Ranchi, Jharkhand, India

    Directory of Open Access Journals (Sweden)

    Priscilla Kerketta

    Full Text Available Aim: The present study was undertaken to determine the physico-chemical properties and heavy metals in drinking water samples collected from different sources in and around Ranchi, Jharkhand, India. Materials and Methods: A total number of 100 water samples were collected from different sources like hand pumps (44, wells (27, taps (20, rivers (3 and ponds (6. The gross appearance, taste, odour, temperature, pH, dissolved oxygen, biochemical oxygen demand, alkalinity, conductivity, total dissolved solid, salinity and the concentration of lead and cadmium were analyzed. Results: Water samples were transparent, odourless and taste was agreeable except rivers and ponds. The mean value of temperature (24.8±0.416 to 30.7±0.819, pH (6.4±0.1 to 7.3±0.1, dissolved oxygen (3.9±0.05 to 8.95±0.15, biochemical oxygen demand (2.3±0.7 to 7.5±0.409, alkalinity (35±1 to 144.75±40.359, conductivity (83±1.15 to1508±0, total dissolved solid (73±1 to 1422±0 and salinity (0.016±.014. Mean levels (ppm of lead (Pb was (0.01±0.00 to 0.11±0.03 and cadmium (Cd was (0.04±0.01 to 0.11±0.03. Conclusion: Out of water samples collected from above mentioned sources, samples from ponds and rivers were highly contaminated. The pH of 6 water samples was more than prescribed level, dissolved oxygen in 11 was samples was below than 5 ppm, biochemical oxygen demand in 19 water samples was above 6 ppm, alkalinity in 14 samples were above 120 ppm, conductivity in 2 water samples were above1400 μS/cm, The levels of lead and cadmium was more than the permissible limits. [Vet World 2013; 6(7.000: 370-375

  4. Carcinogenesis

    International Nuclear Information System (INIS)

    Reilly, C.A. Jr.

    1979-01-01

    This section contains summaries of research in the following areas: use of liver for mechanistic studies of multistage hepatocarcinogenesis and for screening of environmental contaminants for tumor initiating and promoting activity; molecular properties of rat liver ornithine aminotransferase; regulation of gene expression in rat liver; methods of tumor detection; mechanisms of radiation and viral oncogenesis; biphenyl metabolism by rat liver microsomes; and studies on aryl hydrocarbon hydroxylase activity

  5. Carcinogenesis

    International Nuclear Information System (INIS)

    Buess, E.M.; Cerny, E.A.; Chan, E.W.

    1977-01-01

    The first section deals with the assessment of carcinogens and cocarcinogens and the underlying mechanisms of their actions. The second concerns cancer induction by bone-seeking radionuclides and seeks to provide a firm foundation for estimating cancer risks to human populations in the event of accidental incorporation of radionuclides. The third is aimed at defining the role of oncornavirus activation in tumor induction by radiation and other environmental pollutants. The other two sections describe the new studies, one dealing with the development of an in vitro cell system (murine teratocarcinoma cells) to screen chemicals rapidly for carcinogenic and mutagenic capacity, and the other investigating the potential use of plasma isozymes as indicators of mutagenesis in mammals. Accomplishments and projections for each of these studies follow

  6. Liver Development, Regeneration, and Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Janet W. C. Kung

    2010-01-01

    Full Text Available The identification of putative liver stem cells has brought closer the previously separate fields of liver development, regeneration, and carcinogenesis. Significant overlaps in the regulation of these processes are now being described. For example, studies in embryonic liver development have already provided the basis for directed differentiation of human embryonic stem cells and induced pluripotent stem cells into hepatocyte-like cells. As a result, the understanding of the cell biology of proliferation and differentiation in the liver has been improved. This knowledge can be used to improve the function of hepatocyte-like cells for drug testing, bioartificial livers, and transplantation. In parallel, the mechanisms regulating cancer cell biology are now clearer, providing fertile soil for novel therapeutic approaches. Recognition of the relationships between development, regeneration, and carcinogenesis, and the increasing evidence for the role of stem cells in all of these areas, has sparked fresh enthusiasm in understanding the underlying molecular mechanisms and has led to new targeted therapies for liver cirrhosis and primary liver cancers.

  7. Synthesis, physicochemical and antimicrobial studies of first row transition metal complexes with quinoline derivatives nitroquinolino (3,2-b(1,5benzodixazepine and nitroquinolino(3,2-b(1,5benzoxazepine

    Directory of Open Access Journals (Sweden)

    Neeraj Sharma

    2011-03-01

    Full Text Available div align="justify">Metal complexes of Mn (II, Cu (II, Ni (II & Co (II with quinoline derivatives have been synthesized and characterized by elemental analysis, molar conductance, magnetic movement, electronic spectra, thermal analysis and IR spectral data. The molecular formula of complexes corresponds to [ML(NO32] where M = Mn ,Cu , Ni , Co , Zn , Fe, and Cr. The physicochemical and IR spectral data shows that the ligand coordinates to the metal ion in bidentate fashion (through the C=N and N-H groups. The antimicrobial studies of ligand and its metal, metal complexes have been screened for selected bacteria (E. Coli , S. typhi , B. subtilis and S. aureus and fungi (A. flavous, A. niger, P. triticena and F. species. Antimicrobial studies shows that the Mn (II complexes are more toxic than other metal complexes. Magnetic susceptibility measurements reveal octahedral geometry around the metal ion. The complexes were found to be non electrolyte in nature on the basis of low value of molar conductance.

  8. Biological aspects of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Upton, A.C.

    1984-01-01

    Ionizing radiation has been observed to increase the incidence of virtually every type of neoplasm, and carcinogenic effects have been noted in all species investigated. Susceptibility varies markedly, however, with species, strain, organ, cell type, sex, age at irradiation, physiological condition, exposure to other physical or chemical agents, and additional variables. Because of the multicausal, multistage nature of the cancer process, and the diversity of mechanisms through which carcinogenesis may be influenced by irradiation, the variety of observed dose-incidence relationships is not unexpected. The data are consistent with the concept that cancer arises from a single transformed cell, through a stepwise succession of undefined changes, and that the process of transformation may be initiated by radiation-induced damage to the DNA of the affected cell. There is also evidence that intercellular interactions may play an important role in the evolution of the neoplastic process, the nature and radiobiology of which remain to be determined

  9. Genetic factors for breast carcinogenesis

    Directory of Open Access Journals (Sweden)

    Pedro Enrique Miguel-Soca

    2016-12-01

    Full Text Available Breast cancer is a multifactorial genenetic disease in which oncogenes derived from normal cellular genes intervene, which constitute positive signals of cellular proliferation and tumour suppressor genes and represent negative signals of cells multiplication and differentiation. Although these alterations which affect germinal cells produce inherited cancers, in most of the cases somatic cell genes are affected. To the susceptibility of cancer due to genes as BRCA1 and BCRA2, the effect of factors associated to environment, life style and toxic habits are added, these determine a complex interrelation genes-environment which imply an activation of oncogenes and inactivation of tumour suppressors. The objective of this review in to offer an updated view about the main genes implied in breast carcinogenesis. The topic is controversial y currently deeply investigated.

  10. Environmental carcinogenesis and genetic variability

    International Nuclear Information System (INIS)

    Knudsen, A.G. Jr

    1977-01-01

    It was found that carcinogenesis in man may involve the interaction of genetic and environmental forces, and that mutation, whether germinal or somatic, seems to be involved in the origin of many, perhaps all cancers. The cancers of man may be visualized as occurring in four groups of individuals according to whether (1) neither genetic nor environmental factors are dominant, i.e. 'background' or 'spontaneous' cancer, (2) heredity alone is dominant, (3) environment alone is important, or (4) both are operating (Knudsen, 1977). The last two groups together are widely thought to contribute 70-80% of cancer cases in the United States; the relative contribution of each group is a major question to be answered

  11. Time factors in radiation carcinogenesis

    International Nuclear Information System (INIS)

    Sasaki, Shunsaku

    1995-01-01

    Results of experiments using B6C3F 1 female mice were made subject of analysis on the time factors in radiation carcinogenesis. In the experiment for examination of influence of age at irradiation on the lifetime risk and on distribution of ages at death, mice were irradiated at day 12, 14 or 17 of the prenatal period, or day 0, 7, 35, 105, 240 or 365 of the postnatal period with doses ranging from 0.48 to 5.7 Gy gamma-rays from 137 Cs. In the experiment to examine the reduction factor for carcinogenic effect by multiple fractionation of gamma-rays dose 1.9 or 3.8 Gy was divided into 10 fractions, which were delivered once a week during period from 5 to 15 weeks of age. All mice were allowed to live out their life spans under a specific pathogen free condition. The cumulative relative risk for mortality from all causes except lymphoma and leukemia was shown to decrease with age when mice were irradiated at the fetal, neonatal, suckling, adolescent or young adult period, whereas, the decrease in the cumulative relative risk was very little when gamma-rays were given at the intermediate adult period. The lifetime risk for the increase in mortality and for the induction of solid tumors was highest in mice irradiated during neonatal, suckling or adolescent period. Age-dependence of susceptibility to radiation carcinogenesis was different for each type of neoplasm. However, the most susceptible period for induction of each type of neoplasm concentrated in the age from neonatal to adolescent period. Radiation-induced late effects were apparently reduced by multiple fractionation of radiation dose, but the reduction factor for the increase in the long-term mortality did not exceed 2.0. (author)

  12. Statistical modeling and extrapolation of carcinogenesis data

    International Nuclear Information System (INIS)

    Krewski, D.; Murdoch, D.; Dewanji, A.

    1986-01-01

    Mathematical models of carcinogenesis are reviewed, including pharmacokinetic models for metabolic activation of carcinogenic substances. Maximum likelihood procedures for fitting these models to epidemiological data are discussed, including situations where the time to tumor occurrence is unobservable. The plausibility of different possible shapes of the dose response curve at low doses is examined, and a robust method for linear extrapolation to low doses is proposed and applied to epidemiological data on radiation carcinogenesis

  13. Recent progress in nickel carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Sunderman, F.W. Jr.

    1984-01-01

    Positive bacterial mutagenesis tests have been obtained with Ni(II) in Corynybacterium, but not in E. coli, S. typhimurium, or B. subtilis. Transformation assays of several soluble and crystalline Ni compounds have been positive in Syrian hamster embryo cells. Ni(II) binds to DNA, RNA, and nucleoproteins, and becomes localized in nucleoli. Genotoxic effects of Ni include: (a) chromosomal aberrations, including sister-chromatid exchanges, (b) DNA strandbreaks and DNA-protein crosslinks, (c) inhibition of DNA and RNA synthesis, (d) infidelity of DNA transcription, and (e) mutations at the HGPRTase locus in Chinese hamster cells and the TK locus in mouse lymphoma cells. These findings are consistent with somatic mutation as the mechanism for initiation of nickel carcinogenesis. Ni compounds cause reversible transition of double-stranded poly(dG-dC) DNA from the right-handed B-helix to the left-handed Z-helix, suggesting a mechanism whereby nickel might modulate oncogene expression. 99 references, 4 tables.

  14. Assessment of the Physicochemical Quality of Challawa Gorge Dam ...

    African Journals Online (AJOL)

    Dr Maimuna

    analyzed for some physicochemical parameters, heavy metals (Cd, Cr, Mn, Pb, Zn) and minerals (Na and K) using Atomic Absorption Spectrophotometric and Flame Photometric techniques. The results showed the following ranges of the physicochemical parameters; pH (7.78±1.1 to 7.82±0.2), Conductivity (45.0±3.2.

  15. Physico-Chemical Characterization and Pollution Index ...

    African Journals Online (AJOL)

    MICHAEL HORSFALL

    inorganic macro components (common cations and .... Table 2: Concentration of Physicochemical Parameters of leachates from Igbudu Market waste dumpsite ..... general, the condition in each of the dumpsites investigated determines the concentration of heavy metals in later years. The lead concentration a mean value of ...

  16. Assessment of Physicochemical Characteristics of Selected ...

    African Journals Online (AJOL)

    ADOWIE PERE

    ABSTRACT: The physicochemical parameters of seven different borehole waters in Oke-Oyi, Ilorin East Local ... water source due to its lower tendency to be polluted ... samples were collected into polythene bottles prewashed with detergent, diluted HNO3 and distilled de-ionised water. Samples for heavy metal analysis.

  17. Assessment of Physicochemical Characteristics of Produced Water ...

    African Journals Online (AJOL)

    This study evaluated the physico-chemical characteristics, total hydrocarbon concentration (THC) and some heavy metal levels of produced water from terminals of two oil industry facilities in Nigeria, using standard methods. Appropriate sample bottles were used in the collection of samples for analyses of BOD, other ...

  18. Determination of Selected Physicochemical Parameters and Heavy ...

    African Journals Online (AJOL)

    This was evident in lack of plant growth noticed in the study area as a result of depletion of NPK values below specified value by USDA Standards for plant growth. The high level of contamination of some of the physicochemical parameters and heavy metals as seen in this project underscores the need for due diligence in ...

  19. Role of bacteria in oral carcinogenesis

    Directory of Open Access Journals (Sweden)

    R Rajeev

    2012-01-01

    Full Text Available Oral cancer is the most common cancer diagnosed in Indian men and is the leading cause of cancer deaths. It is considered as a multistep and multifactorial disease. Besides accumulation of genetic mutations, numerous other carcinogens are involved. In this category, viral and chemical carcinogens are well studied and documented. However, in the oral cavity, the role of microbiota in carcinogenesis is not known. Microbial populations on mouth mucosa differ between healthy and malignant sites, and certain oral bacterial species have been linked with malignancies, but the evidence is still weak in this respect. Nevertheless, oral microorganisms inevitably up-regulate cytokines and other inflammatory mediators that affect the complex metabolic pathways, and may thus be involved in carcinogenesis. Poor oral health associates statistically with prevalence of many types of cancer such as pancreatic and gastrointestinal cancer. This review presents possible carcinogenesis pathway involved in bacterial carcinogenesis, commonly implicated bacteria in oral carcinogenesis, and their role in cancer therapeutics as well.

  20. Modeling Multiple Causes of Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Jones, T D

    1999-01-24

    multiple causes of carcinogenesis and shifts the risk-assessment logic to considerations of "what dose does?" in contrast to the current process of the substance-specific question of "what dose is?" Whether reactive oxygen is the proximate or contributing cause of disease or simply a better estimate of biologically effective dose, it has enormous advantages for improved risk- and policy-based decisions. Various estimates of immune system modulation will be given based on radiobiology.

  1. Bacterionomics and vironomics in carcinogenesis

    Directory of Open Access Journals (Sweden)

    Pratiwi Sudarmono

    2017-02-01

    Full Text Available Virus and bacteria are microbes which are very common cause human infection. Most of the bacterial infection can be eradicated by antibiotics and infection symptoms disappear. But for virus infection, once infected, the virus will persistently stay in the host, even undergo not only a lytic cycle but also integrated into host genome. Nowadays, at least 6 virus type are consistently related to human cancer, such as EBV,HPV,HTLV,HBV,HCV,HKSV, and the new one Merkel Virus (MCV. Although not every infected people will get cancer, but around 20% of the whole cancer in human are caused by viral oncogene. Class one oncogenic bacterial is Helicobacter pylori. Infection with this bacteria can cause persistent gastro duodenal inflammation which cause some alteration in gastric cell growth into transformation. Expression of Cag gene and Vac gene and some expression of OMP protein usually link to gastric cancer. Molecular mechanisms of carcinogenesis for every virus which cause infection  is a very complex , which include several processes caused by cell transformation. Besides, other host and environmental factors are also play a significant role in cancer development. Some scientist put a Hallmark analysis as a model to quickly summarize what pathobiology process will happen and what gene or protein caused the process. The Hallmark analysis comprise of several process which may happen simultaneously because some of the Hallmark is caused by the same protein. The Hallmark consists of various virus strategies in oncogenesis such as promoting angiogenesis, avoiding immune destruction, genome instability and mutation, deregulating cellular energetic, resisting cell death, sustaining proliferative signaling, evading growth suppressors, enabling cellular immortality, promoting inflammation and activation metastasis. For example, infection by HPV, will cause low grade dysplasia which can continue to invasive cervical cancer. After host cell transformation, in

  2. Evaluation of the physicochemical properties of structured materials: metallic, polymeric and ceramic, for the treatment of sour gases; Evaluacion de las propiedades fisicoquimicas de materiales estructurados: metalico, polimerico y ceramico, para el tratamiento de gases acidos

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, A.; Chavez, R. H. [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico); Olea, O.; Solis, D., E-mail: rosahilda.chavez@inin.gob.mx [Universidad Autonoma del Estado de Mexico, Facultad de Quimica, Cerro de Coatepec s/n, Ciudad Universitaria, 50100 Toluca, Estado de Mexico (Mexico)

    2013-07-01

    in this work the physicochemical properties of three structured materials: metallic, polymeric and ceramic, from Sulzer Brothers Limited brand, are studied in order to removal sour gases, by absorption process, in aqueous solution of Monoethanolamine (Mea), at 30% weight. Mechanical properties, chemical composition, morphology and corrosion resistance were determined, using different characterization techniques, such as: 1) mechanically, according to standard procedures Astm E-384-1990, 2) chemically, by the corrosion resistance in the presence of an electrochemical cell, in aqueous solution of H{sub 2}SO{sub 4}, 1 N by Astm G-5-1999, 3) morphologically by scanning electron microscopy technique, and 4) efficiency of separation, by the gas chromatography technique in order to determine the chemical absorption of CO{sub 2} by Mea. The ceramic material was the hardest with 700 Hk value and tensile strength of 90 MPa, likewise showed resistance to corrosion of 10.28 m py, separation efficiency of 74% CO{sub 2}, at 10 minutes. The metallic material had a hardness of 190 Hk and it was the most resistant of tension, with 831 MPa, and corrosion resistance of 780.4 x 10{sup -6} m py, likewise promoted CO{sub 2} separation efficiency of 90% during the evaluation. The polymeric material presented hardness of 20 Hk and 35 MPa and it was not suffered surface change with electrochemical attack, with 282.4 x 10{sup -6} m py, and separation efficiency of 88%. Therefore the polymer was the most ductile, with smooth surface and greater resistance with H{sub 2}SO{sub 4}. The metal material was more resistant to plastic deformation and more corrugated surface and the second resistance in the presence of acid medium in aqueous solutions. For all the above, the metallic material is recommended by its greater separation in the reduction of acid gases and the polymer due to its greater chemical resistance. (Author)

  3. Diet, lifestyle, and molecular alterations that drive colorectal carcinogenesis

    NARCIS (Netherlands)

    Diergaarde, B.

    2004-01-01

    Environmental factors have been repeatedly implicated in the etiology of colorectal cancer, and much is known about the molecular events involved in colorectal carcinogenesis. The relationships between environmental risk factors and the molecular alterations that drive colorectal carcinogenesis are

  4. Strategies to prepare TiO2 thin films, doped with transition metal ions, that exhibit specific physicochemical properties to support osteoblast cell adhesion and proliferation

    International Nuclear Information System (INIS)

    Dhayal, Marshal; Kapoor, Renu; Sistla, Pavana Goury; Pandey, Ravi Ranjan; Kar, Satabisha; Saini, Krishan Kumar; Pande, Gopal

    2014-01-01

    Metal ion doped titanium oxide (TiO 2 ) thin films, as bioactive coatings on metal or other implantable materials, can be used as surfaces for studying the cell biological properties of osteogenic and other cell types. Bulk crystallite phase distribution and surface carbon–oxygen constitution of thin films, play an important role in determining the biological responses of cells that come in their contact. Here we present a strategy to control the polarity of atomic interactions between the dopant metal and TiO 2 molecules and obtain surfaces with smaller crystallite phases and optimal surface carbon–oxygen composition to support the maximum proliferation and adhesion of osteoblast cells. Our results suggest that surfaces, in which atomic interactions between the dopant metals and TiO 2 were less polar, could support better adhesion, spreading and proliferation of cells. - Highlights: • Electrochemical properties of dopants control the nature of TiO 2 thin films. • A model explains the correlation of dopant properties and behaviour of TiO 2 films. • Dopants with less polar interaction with TiO 2 exhibit better biological activity

  5. Experimental radiation carcinogenesis: what have we learned

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1980-01-01

    The author reviews the need for animal experiments in development of a biological model for radioinduced carcinogenesis. He concludes they are vital for: (1) study of mechanisms; (2) establishment of generalizations; (3) elucidation of dose-response and time-dose relationships; and (4) determination of dose-distributions and their results, particularly for radionuclides

  6. Molecular mechanisms in radiation carcinogenesis: introduction

    International Nuclear Information System (INIS)

    Setlow, R.B.

    1975-01-01

    Molecular studies of radiation carcinogenesis are discussed in relation to theories for extrapolating from cellular and animal models to man. Skin cancer is emphasized because of sunlight-induced photochemical damage to DNA. It is emphasized that cellular and animal models are needed as well as molecular theories for quantitative evaluation of hazardous environmental agents. (U.S.)

  7. Radiation carcinogenesis and related radiobiology. Special listing

    International Nuclear Information System (INIS)

    1980-01-01

    The special listing of Current Cancer Research Projects is a publication of the International Cancer Research Data Bank (ICRDB) Program of the National Cancer Institute. Each Listing contains descriptions of ongoing projects in one selected cancer research area. The research areas include: Human cancer and exposure to radiation; Experimental radiation carcinogenesis and radiation biology

  8. Studies by nuclear and physico-chemical methods of tissue's metallic contamination located around biomaterials. Toxicity measurements of several biomaterials residual radioactivity

    International Nuclear Information System (INIS)

    Guibert, Geoffroy

    2004-01-01

    Implants used as biomaterials fulfill conditions of functionality, compatibility and occasionally bio-activity. There are four main families of biomaterials: metals and metal alloys, polymers, bio-ceramics and natural materials. Because of corrosion and friction in the human body, implants generate debris. These debris develop different problems: toxicity, inflammatory reactions, prosthetic unsealing by osseous dissolution. Nature, size, morphology and amount of debris are the parameters which have an influence on tissue response. We characterize metallic contamination coming from knee prosthesis into surrounding capsular tissue by depth migration, in vivo behaviours, content, size and nature of debris. The PIXE-RBS and STEM-EDXS methods, that we used, are complementary, especially about characterization scale. Debris contamination distributed in the whole articulation is very heterogeneous. Debris migrate on several thousands μm in tissue. Solid metallic particles, μm, are found in the most polluted samples, for both kinds of alloys TA6V and CrCoMo. In the mean volume analysed by PIXE, the in vivo mass ratios [Ti]/[V] and [Co]/[Cr] confirm the chemical stability of TA6V debris and chemical evolution of CrCoMo debris. Complementary measures of TA6V grains, on a nano-metric scale by STEM-EDXS, show a dissolution of coarse grain (μm) in smaller grains (nm). Locally, TA6V grains of a phase are detected and could indicate a preferential dissolution of β phase (grain boundaries) with dropping of Al and V, both toxic and carcinogenic elements. A thin target protocol development correlates PIXE and histological analysis on the same zone. This protocol allows to locate other pathologies in relationship with weaker metal contamination, μg/g, thanks to the great sensitivity of PIXE method. Harmlessness with respect to the residual radioactivity of several natural or synthetic biomaterials is established, using ultra low background noise γ detection system. (author)

  9. Oral mucosal carcinogenesis in SENCAR mice.

    Science.gov (United States)

    Kim, Tae-Won; Chen, Qianming; Shen, Xiaodong; Regezi, Joseph A; Ramos, Daniel M; Tanaka, Hironori; Jordan, Richard C K; Kramer, Randall H

    2002-01-01

    Animal models of oral carcinogenesis have been developed but most use the hamster buccal pouch or rat oral mucosa. With completion of human and murine genome sequencing, the development of a mouse model of oral carcinogenesis may prove useful for future genomic studies of oral carcinogenesis. To achieve this objective, 30 SENCAR mice were initiated by brush application of palatal, buccal and tongue mucosa with 200 nmol 7,12-dimethylbenz[a]anthracene (DMBA) using 3 treatment regimens, and promoted by brush application with 5 nmol 12-O-tetradecanoylphorbol-13-acetate (TPA) for a total of 28 weeks. Alternatively, 5 mice were treated with 0.5% 4-nitroquinoline-1-oxide (4NQO) alone by brush application for 28 weeks. There were another 6 control mice treated with vehicle alone. The tumor samples were analyzed for the presence of H-ras codon 61 gene mutations using a mutant-allele-specific amplification-polymerase chain reaction (MASA-PCR) technique. The results showed that among the group of 24 mice initiated with DMBA for 2 or 6 weeks, a range of papilliferous lesions were seen on the buccal mucosa comprising papillomas, papillomas with dysplasia and 7 squamous cell carcinomas (SCC). In those 6 mice initiated with 1 week of DMBA, only papillomas developed. In the 5 mice treated with 4NQO, one developed papillomas with dysplasia and two had SCCs in the tongue mucosa but not the buccal mucosa. Both carcinogens induced codon 61 mutation of the H-ras gene at a high frequency. The results indicated that DMBA/TPA and 4NQO in SENCAR mice reliably produced preneoplastic and malignant oral cavity lesions, which resemble the multistages for human oral carcinogenesis, and targeted to site-specific zones of the oral mucosa, namely the buccal mucosa and tongue, respectively. These results show that SENCAR mice can be used as a unique model of oral carcinogenesis with the potential for detailed molecular studies of neoplastic progression to SCC.

  10. Somatic Host Cell Alterations in HPV Carcinogenesis

    OpenAIRE

    Tamara R. Litwin; Megan A. Clarke; Michael Dean; Nicolas Wentzensen

    2017-01-01

    High-risk human papilloma virus (HPV) infections cause cancers in different organ sites, most commonly cervical and head and neck cancers. While carcinogenesis is initiated by two viral oncoproteins, E6 and E7, increasing evidence shows the importance of specific somatic events in host cells for malignant transformation. HPV-driven cancers share characteristic somatic changes, including apolipoprotein B mRNA editing catalytic polypeptide-like (APOBEC)-driven mutations and genomic instability ...

  11. Radiation carcinogenesis and related radiobiology. Special listing

    International Nuclear Information System (INIS)

    1978-01-01

    This Special Listing of Current Cancer Research Projects is a service of the International Cancer Research Data Bank (ICRDB) program of the National Cancer Institute. Each listing contains descriptions of ongoing projects in one selected cancer research area. The descriptions are provided by cancer scientists in about 50 different countries. Research areas covered in this listing are: Human cancer and exposure to radiation; experimental radiation carcinogenesis and radiation biology

  12. Physico-chemical behaviour of a metal/polymer contact subject to a low amplitude friction in a chlorinated medium. Effect of ionitriding and ion implantation surface treatment

    International Nuclear Information System (INIS)

    Rabbe, L.M.

    1993-10-01

    The fretting-corrosion behaviour of two tribological couples (TA6V/PMMA and 316L/PMMA) had been studied in order to better understand the degradation mechanisms observed on pivot prosthesis sealed in bones. Pressure appears to have a major role; at high contact pressure, the PMMA wear is the main degradation mechanism with PMMA debris acting as a metal surface protecting agent; at low contact pressure, both material deterioration is involved, and titanium has a corrosion-dominated degradation. An optimal resistance to fretting is achieved when TA6V is coated with Ti N (ion implantation) and Ti N, Ti 2 N (ionitriding). When nitriding, processing temperature appears as a critical factor to ensure thickness and homogeneity of the nitride coatings. 181 p., 106 figs., 110 refs

  13. Inhibition of carcinogenesis by retinoids. [Review

    Energy Technology Data Exchange (ETDEWEB)

    Nettesheim, P.

    1979-01-01

    Progress made in recent years in the search for retinoids with anticarcinogenic activity is reviewed. There are many studies to be found in the literature which show no substantial effect of retinoids on carcinogenesis or tumor growth. Some of these negative findings may be related to the carcinogen dose used, the type of retinoid used, the dose, dose schedule or mode of administration of the retinoid. Others may indicate that the particular type of tumor or tumor system is, indeed, refractory to retinoids in general or to those retinoids that were tested. A great gap still exists in our knowledge concerning the pharmake-kinetics of most retinoids their availability to various normal and cancerous tissues, and the role and existence of transport and binding proteins. There are studies which indicate that under certain conditions, particularly conditions of topical application, some retinoids may even enhance carcinogenesis. It seems, however, indisputable by now that some retinoids are effective inhibitors of carcinogenesis in some organ systems and can even inhibit the growth of some established tumors. While the mechanisms of these inhibitory effects are presently not understood, it does seem clear that they are not mediated via the cytotoxic mechanisms typical of chemotherapeutic agents. The hope that retinoids might become an effective tool to halt the progression of some neoplastic diseases, seems to be justified.

  14. Genetic alterations during radiation-induced carcinogenesis

    International Nuclear Information System (INIS)

    Kodama, Seiji

    1995-01-01

    This paper reviews radiation-induced genetic alterations and its carcinogenesis, focusing on the previous in vitro assay outcome. A colony formation assay using Syrian hamster fetal cells and focus formation assay using mouse C3H10T1/2 cells are currently available to find malignant transformation of cells. Such in vitro assays has proposed the hypothesis that radiation-induced carcinogenesis arises from at least two-stage processes; i.e., that an early step induced by irradiation plays an important role in promoting the potential to cause the subsequent mutation. A type of genetic instability induced by radiation results in a persistently elevated frequency of spontaneous mutations, so-called the phenomenon of delayed reproductive death. One possible mechanism by which genetic instability arises has been shown to be due to the development of abnormality in the gene group involved in the maintenance mechanism of genome stability. Another possibility has also been shown to stem from the loss of telomere (the extremities of a chromosome). The importance of search for radiation-induced genetic instability is emphasized in view of the elucidation of carcinogenesis. (N.K.)

  15. Oxidative stress in prostate hypertrophy and carcinogenesis

    Directory of Open Access Journals (Sweden)

    Waldemar M. Przybyszewski

    2009-07-01

    Full Text Available Aging, significant impairment of the oxidation/reduction balance, infection, and inflammation are recognized risk factors of benign hyperplasia and prostate cancer. Chronic symptomatic and asymptomatic prostate inflammatory processes generate significantly elevated levels of reactive oxygen and nitrogen species, and halogenated compounds. Prostate cancer patients showed significantly higher lipid peroxidation and lower antioxidant levels in peripheral blood than healthy controls, whereas patients with prostate hyperplasia did not show such symptoms. Oxidative/nitrosative/halogenative stress causes DNA modifications leading to genome instability that may initiate carcinogenesis; however, it was shown that oxidative damage alone is not sufficient to initiate this process. Peroxidation products induced by reactive oxygen and nitrogen species seem to take part in epigenetic mechanisms regulating genome activity. One of the most common changes occurring in more than 90�0of all analyzed prostate cancers is the silencing of GSTP1 gene activity. The gene encodes glutathione transferase, an enzyme participating in detoxification processes. Prostate hyperplasia is often accompanied by chronic inflammation and such a relationship was not observed in prostate cancer. The participation of infection and inflammation in the development of hyperplasia is unquestionable and these factors probably also take part in initiating the early stages of prostate carcinogenesis. Thus it seems that therapeutic strategies that prevent genome oxidative damage in situations involving oxidative/nitrosative/halogenative stress, i.e. use of antioxidants, plant steroids, antibiotics, and non-steroidal anti-inflammatory drugs, could help prevent carcinogenesis.

  16. PHYSICOCHEMICAL CHARACTERIZATION OF COMPOST OF THE

    OpenAIRE

    MAHDI AHMED; AZNI IDRIS; S. R. SYED OMAR

    2007-01-01

    It is very important that tannery wastes in the form of sludge are managed in an environmentally sound manner. This study focused on the heavy metal characterization and the influence of changing the physico-chemical properties of the medium throughout the composting on the concentrations, bioavailability or chemical forms of Cr, Cu, Zn, Pb and Cd in tannery sludge. The physical and chemical properties of the composted sludge during treatment show the stability and maturity of end product. To...

  17. Electrical conduction in solid materials physicochemical bases and possible applications

    CERN Document Server

    Suchet, J P

    2013-01-01

    Electrical Conduction in Solid Materials (Physicochemical Bases and Possible Applications) investigates the physicochemical bases and possible applications of electrical conduction in solid materials, with emphasis on conductors, semiconductors, and insulators. Topics range from the interatomic bonds of conductors to the effective atomic charge in conventional semiconductors and magnetic transitions in switching semiconductors. Comprised of 10 chapters, this volume begins with a description of electrical conduction in conductors and semiconductors, metals and alloys, as well as interatomic bon

  18. MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC ...

    African Journals Online (AJOL)

    Peters

    MICROSCOPIC, PHYSICOCHEMICAL AND CHROMATOGRAPHIC. FINGERPRINTS OF LEAVES OF NIGERIAN CASSIA TORA LINN. Fatokun Omolola T1*., EsievoKevwe B2., Ugbabe Grace E3. and Kunle Oluyemisi F4. Department of Medicinal Plant Research and Traditional Medicine, National Institute for.

  19. Physico-chemical properties

    Indian Academy of Sciences (India)

    Unknown

    Abstract. Xenogeneic bone procured from the slaughterhouse waste was deproteinated by heat treatment method intended for use as a bone substitute. The effect of heat treatment was investigated by thermal ana- lysis and by physico-chemical methods such as X-ray powder diffraction (XRD) and Fourier transformed.

  20. The Role of the Stroma in Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Nurija Bilalović

    2006-02-01

    Full Text Available This systematic review considers the most recent attitudes and news regarding the influence of the stroma on tumor initiation and progression. It is now widely accepted that tumor stroma plays an active role in carcinogenesis. Many different signaling molecules, ligands and signaling pathways recently have been discovered. This review considers the complexity of interactions between malignant cells and its stroma (cross-talk. The recent advances and better understanding of the tumor-stroma interactions will have important impact on the new and combined therapeutic approaches and modalities.

  1. Mechanisms of carcinogenesis prevention by flavonoids

    Directory of Open Access Journals (Sweden)

    G. A. Belitsky

    2014-01-01

    Full Text Available The mechanisms of anticancerogenic effects of flavanoids and isocyanates from the plants widely consumed in the midland belt of Russia were reviewed. Data of studies both in vitro and in vivo were analyzed. Special attention was paid to inhibition of targets responsible for carcinogen metabolic activation, carcinogenesis promotion and tumor progression as well as neoangiogenesis. Besides that the antioxidant properties of flavonoids and their effects on cell cycle regulation, apoptosis initiation and cell mobility were considered.

  2. Curcumin: the spicy modulator of breast carcinogenesis.

    Science.gov (United States)

    Banik, Urmila; Parasuraman, Subramani; Adhikary, Arun Kumar; Othman, Nor Hayati

    2017-07-19

    Worldwide breast cancer is the most common cancer in women. For many years clinicians and the researchers are examining and exploring various therapeutic modalities for breast cancer. Yet the disease has remained unconquered and the quest for cure is still going on. Present-day strategy of breast cancer therapy and prevention is either combination of a number of drugs or a drug that modulates multiple targets. In this regard natural products are now becoming significant options. Curcumin exemplifies a promising natural anticancer agent for this purpose. This review primarily underscores the modulatory effect of curcumin on the cancer hallmarks. The focus is its anticancer effect in the complex pathways of breast carcinogenesis. Curcumin modulates breast carcinogenesis through its effect on cell cycle and proliferation, apoptosis, senescence, cancer spread and angiogenesis. Largely the NFkB, PI3K/Akt/mTOR, MAPK and JAK/STAT are the key signaling pathways involved. The review also highlights the curcumin mediated modulation of tumor microenvironment, cancer immunity, breast cancer stem cells and cancer related miRNAs. Using curcumin as a therapeutic and preventive agent in breast cancer is perplexed by its diverse biological activity, much of which remains inexplicable. The information reviewed here should point toward potential scope of future curcumin research in breast cancer.

  3. Oncogenomic disruptions in arsenic-induced carcinogenesis.

    Science.gov (United States)

    Sage, Adam P; Minatel, Brenda C; Ng, Kevin W; Stewart, Greg L; Dummer, Trevor J B; Lam, Wan L; Martinez, Victor D

    2017-04-11

    Chronic exposure to arsenic affects more than 200 million people worldwide, and has been associated with many adverse health effects, including cancer in several organs. There is accumulating evidence that arsenic biotransformation, a step in the elimination of arsenic from the human body, can induce changes at a genetic and epigenetic level, leading to carcinogenesis. At the genetic level, arsenic interferes with key cellular processes such as DNA damage-repair and chromosomal structure, leading to genomic instability. At the epigenetic level, arsenic places a high demand on the cellular methyl pool, leading to global hypomethylation and hypermethylation of specific gene promoters. These arsenic-associated DNA alterations result in the deregulation of both oncogenic and tumour-suppressive genes. Furthermore, recent reports have implicated aberrant expression of non-coding RNAs and the consequential disruption of signaling pathways in the context of arsenic-induced carcinogenesis. This article provides an overview of the oncogenomic anomalies associated with arsenic exposure and conveys the importance of non-coding RNAs in the arsenic-induced carcinogenic process.

  4. Modifying factors in urinary bladder carcinogenesis

    Science.gov (United States)

    Ito, Nobuyuki; Fukushima, Shoji; Shirai, Tomoyuki; Nakanishi, Keisuke; Hasegawa, Ryohei; Imaida, Katsumi

    1983-01-01

    N-Butyl-N-(4-hydroxybutyl)nitrosamine (BBN) is a potent carcinogen in the urinary bladder of animals. The BBN model of bladder cancer is an excellent model of human urinary bladder cancer and has already led to a greater knowledge of its pathogenesis. In our studies, histogenesis and morphological characteristics of BBN urinary bladder cancer were analyzed in different animal species such as rats, mice, hamsters and guinea pigs and also in different rat strains. Papillary or nodular hyperplasia (PN hyperplasia) is found to be a preneoplastic lesion of the rat urinary bladder. Therefore, the promoting and inhibitory effects of various chemicals in two-stage urinary bladder carcinogenesis were judged by measuring PN hyperplasia in rats. Dose-dependent and organ-specific effects of the urinary bladder promoter, saccharin, in the induction of PN hyperplasia were shown in rats after initiation by BBN. The promoting effect of saccharin was seen more clearly in the urinary bladder of rats after potent initiation. A strain difference in susceptibility of the urinary bladder to the promoter was also shown. These results suggest that the above various factors may also have modifying activities on urinary bladder carcinogenesis in man. PMID:6832095

  5. Radiation carcinogenesis: Epidemiology and biological significance

    International Nuclear Information System (INIS)

    Boice, J.D.; Fraumeni, J.F.

    1984-01-01

    Epidemiologic studies of populations exposed to radiation have led to the identification of a preventable cause of cancer, but in the long run perhaps the most important contribution of radiation studies will be to provide insights into the basic processes of human carcinogenesis. In this volume, key investigators of major epidemiologic projects summarize their observations to date, including information to help assess the effects of low-level exposures. Experimentalists and theorists emphasize the relevance of laboratory and epidemiologic data in elucidating carcinogenic risks and mechanisms in man. This volume was prepared with several objectives in mind: (a) organize and synthesize knowledge on radiation carcinogenesis through epidemiologic and experimental approaches; (b) illustrate and explore ways of utilizing this information to gain insights into the fundamental mechanisms of cancer development; (c) stimulate the formation of hypotheses suited to experimental or epidemiologic testing, theoretical modeling, and multidisciplinary approaches; and (d) identify recent advances that clarify dose-response relationships and the influence of low-dose exposures, provide leads to carcinogenic mechanisms and host-environmental interactions, and suggest strategies for future research and preventive action

  6. Transgenerational teratogenesis and carcinogenesis by radiation

    International Nuclear Information System (INIS)

    Nomura, Taisei

    2000-01-01

    This paper thoroughly reviews studies on transgenerational teratogenesis and carcinogenesis induced by radiation and summarizes currently available data from animal studies. The discussions focus on the incidence of tumors, malformations, and mutations in the offspring after parental exposure to radiation, as well as estimated relative risks of congenital malformations and stillbirths in the offspring after parental X-ray exposure. The data suggest that different types of tumors are induced in offspring, because of strain differences in the experimental animals. The results of epidemiological studies in human populations, such as the children of atomic bomb survivors, conflict with the findings in animal studies. The author points to the following reasons for the differences between the results in animals and humans: differences in radiation doses, timing of exposure, and genetic predisposition, etc. While pointing out issues that need to be investigated further, the author indicates that clear strain differences exist in types of tumors induced and in tumor incidences in the offspring of animals that were irradiated before the offspring were conceived, and that genetic predisposition is therefore important in transgenerational carcinogenesis. (K.H.)

  7. Transgenerational teratogenesis and carcinogenesis by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Taisei [Osaka Univ., Suita (Japan). Graduate School of Medicine

    2000-07-01

    This paper thoroughly reviews studies on transgenerational teratogenesis and carcinogenesis induced by radiation and summarizes currently available data from animal studies. The discussions focus on the incidence of tumors, malformations, and mutations in the offspring after parental exposure to radiation, as well as estimated relative risks of congenital malformations and stillbirths in the offspring after parental X-ray exposure. The data suggest that different types of tumors are induced in offspring, because of strain differences in the experimental animals. The results of epidemiological studies in human populations, such as the children of atomic bomb survivors, conflict with the findings in animal studies. The author points to the following reasons for the differences between the results in animals and humans: differences in radiation doses, timing of exposure, and genetic predisposition, etc. While pointing out issues that need to be investigated further, the author indicates that clear strain differences exist in types of tumors induced and in tumor incidences in the offspring of animals that were irradiated before the offspring were conceived, and that genetic predisposition is therefore important in transgenerational carcinogenesis. (K.H.)

  8. Physico-chemical analysis of Logone River water at Moundou City ...

    African Journals Online (AJOL)

    The physico-chemical parameters and some heavy metal concentrations in the Logone River water at Moundou City, Chad, are studied for two stations from July 2013 to December 2014, one upstream and another downstream of the city. Standard methods are used. A total of twenty-two physico-chemical parameters were ...

  9. MECHANISM OF CARCINOGENESIS OF THE POLYCYCLIC AROMATICHYDROCARBONS

    Energy Technology Data Exchange (ETDEWEB)

    Cavalieri, E.; Calvin, M.

    1970-08-01

    The carcinogenic activity of the benzo[a]pyrene 1, the 7,12-dimethylbenz[a]anthracene 2 and the 3-methylcholanthrene 3 is suggested to be determine by the electrophilic attack of the active oxygen, induced by the hydroxylating enzyme systems, on the most reactive substituting carbon atom(s). The cationic intermediate(s) with the charge mainly localized on a complementary, interrelated position(s) of the hydroxyl substituted position(s) reacts further with the cellular nucleophiles. The electrophilic nature of the ultimate chemical carcinogens constitutes the common distinctive feature that correlates their different structures and allows us to understand their carcinogenicity. The formation of a covalent bond with the nucleophiles of the biological macromolecules, nucleic acids and proteins, appears to be the essential requirement in the primary process of carcinogenesis.

  10. Angiogenesis, Thrombospondin-1 and Cervical Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Ming-Ping Wu

    2005-06-01

    Full Text Available Angiogenesis, the growth of new vessels from existing vasculature, plays an essential role in tumor development. The process involves interaction among cancer cells, endothelial cells, and components of the extracellular matrix, and is regulated by the balance of angiogenesis activators and angiogenesis inhibitors. This review profiles some fundamental concepts of angiogenesis, the importance of angiogenesis in cervical neoplasm, and the role of thrombospondin-1 as an angiogenesis inhibitor in cervical carcinogenesis. The usefulness and limitations of microvessel density in evaluation of angiogenic status are also discussed. Recent research and evolving concepts have led to a paradigm shift in anticancer therapy, from conventional cancer-centered chemotherapy to angiogenic or “metronomic” chemotherapy and/or combined angiogenesis inhibitors. The epigenetic strategy, which views the tumor system as a whole, transcends the cancer gene-centered approach.

  11. (Radiation carcinogenesis in the whole body system)

    Energy Technology Data Exchange (ETDEWEB)

    Fry, R.J.M.

    1990-12-14

    The objectives of the trip were: to take part in and to give the summary of a Symposium on Radiation Carcinogenesis at Tokyo, and to give a talk at the National Institute of Radiological Sciences at Chiba. The breadth of the aspects considered at the conference was about as broad as is possible, from effects at the molecular level to human epidemiology, from the effects of tritium to cancer induction by heavy ions. The events induced by cancer that lead to cancer and the events that are secondary are beginning to come into better focus but much is still not known. Interest in suppressor genes is increasing rapidly in the studies of human tumors and many would predict that the three or four suppressor genes associated with cancer are only the first sighting of a much larger number.

  12. Parasite Infection, Carcinogenesis and Human Malignancy

    Directory of Open Access Journals (Sweden)

    Hoang van Tong

    2017-02-01

    Full Text Available Cancer may be induced by many environmental and physiological conditions. Infections with viruses, bacteria and parasites have been recognized for years to be associated with human carcinogenicity. Here we review current concepts of carcinogenicity and its associations with parasitic infections. The helminth diseases schistosomiasis, opisthorchiasis, and clonorchiasis are highly carcinogenic while the protozoan Trypanosoma cruzi, the causing agent of Chagas disease, has a dual role in the development of cancer, including both carcinogenic and anticancer properties. Although malaria per se does not appear to be causative in carcinogenesis, it is strongly associated with the occurrence of endemic Burkitt lymphoma in areas holoendemic for malaria. The initiation of Plasmodium falciparum related endemic Burkitt lymphoma requires additional transforming events induced by the Epstein-Barr virus. Observations suggest that Strongyloides stercoralis may be a relevant co-factor in HTLV-1-related T cell lymphomas. This review provides an overview of the mechanisms of parasitic infection-induced carcinogenicity.

  13. Assessment of the Physicochemical Quality of Challawa Gorge Dam ...

    African Journals Online (AJOL)

    Dr Maimuna

    Water and sediment samples were collected from Challawa Gorge dam during the wet and dry seasons and analyzed for some physicochemical parameters, heavy metals (Cd, Cr, Mn, Pb, Zn) and minerals (Na and K) using Atomic Absorption Spectrophotometric and Flame Photometric techniques. The results showed the.

  14. Assessment of the Physicochemical Quality of Challawa Gorge Dam ...

    African Journals Online (AJOL)

    Water and sediment samples were collected from Challawa Gorge dam during the wet and dry seasons and analyzed for some physicochemical parameters, heavy metals (Cd, Cr, Mn, Pb, Zn) and minerals (Na and K) using Atomic Absorption Spectrophotometric and Flame Photometric techniques. The results showed the ...

  15. Elucidation of physico-chemical characteristics and mycoflora of ...

    African Journals Online (AJOL)

    Elucidation of physico-chemical characteristics and mycoflora of bovine milk available in selected area of Karachi, Pakistan. ... The concentrations of metals considered were estimated after wet digestion of samples using atomic absorption spectroscopy. The ranges of average concentration of Mg, Fe, Cu and Zn were found ...

  16. evaluation of physico-chemical parameters of agricultural soils

    African Journals Online (AJOL)

    Benlkhoubi N, Saber S, Lebkiri A, Rifi El and Fahime El

    2016-05-01

    May 1, 2016 ... industries and which is estimated by 2000 units [4], can generate a metal pollution drained along these rivers that will be transferred to the soil through irrigation waters and subsequently into the crops. This work lists the physicochemical parameters of evaluation of agricultural soils in the city of Kenitra (Sidi ...

  17. physico-chemical and bacteriological analyses of drinking water

    African Journals Online (AJOL)

    2012-07-02

    Jul 2, 2012 ... Physicochemical, heavy metals and bacteriological analysis of drinking water samples from ten. (10) geo-referenced points in five ... Analysis of Drinking Water in Ibeno LGA Akwa Ibom State. 117 ment Area is one of the coastal .... using mercury-in-glass broth thermometer. Water pH was taken in-situ using ...

  18. Effect of flooding on the physicochemical quality of Mehmeh stream ...

    African Journals Online (AJOL)

    The effect of flooding on the physicochemical quality of Mehmeh River in Lokoja Nigeria was studied. The metallic content of the river was carried out using flame atomic absorption spectrometry. Results of this study indicated an increase in the concentrations of the parameters studied. A comparative study on the ...

  19. Comfrey (Symphytum officinale. L. and Experimental Hepatic Carcinogenesis: A Short-Term Carcinogenesis Model Study

    Directory of Open Access Journals (Sweden)

    Maria Fernanda Pereira Lavieri Gomes

    2010-01-01

    Full Text Available Comfrey or Symphytum officinale (L. (Boraginaceae is a very popular plant used for therapeutic purposes. Since the 1980s, its effects have been studied in long-term carcinogenesis studies, in which Comfrey extract is administered at high doses during several months and the neoplastic hepatic lesions are evaluated. However, the literature on this topic is very poor considering the studies performed under short-term carcinogenesis protocols, such as the ‘resistant hepatocyte model’ (RHM. In these studies, it is possible to observe easily the phenomena related to the early phases of tumor development, since pre-neoplastic lesions (PNLs rise in about 1–2 months of chemical induction. Herein, the effects of chronic oral treatment of rats with 10% Comfrey ethanolic extract were evaluated in a RHM. Wistar rats were sequentially treated with N-nitrosodiethylamine (ip and 2-acetilaminofluorene (po, and submitted to hepatectomy to induce carcinogenesis promotion. Macroscopic/microscopic quantitative analysis of PNL was performed. Non-parametric statistical tests (Mann–Whitney and χ2 were used, and the level of significance was set at P ≤ 0.05. Comfrey treatment reduced the number of pre-neoplastic macroscopic lesions up to 1 mm (P ≤ 0.05, the percentage of oval cells (P = 0.0001 and mitotic figures (P = 0.007, as well as the number of Proliferating Cell Nuclear Antigen (PCNA positive cells (P = 0.0001 and acidophilic pre-neoplastic nodules (P = 0.05. On the other hand, the percentage of cells presenting megalocytosis (P = 0.0001 and vacuolar degeneration (P = 0.0001 was increased. Scores of fibrosis, glycogen stores and the number of nucleolus organizing regions were not altered. The study indicated that oral treatment of rats with 10% Comfrey alcoholic extract reduced cell proliferation in this model.

  20. Comfrey (Symphytum Officinale. l.) and Experimental Hepatic Carcinogenesis: A Short-term Carcinogenesis Model Study.

    Science.gov (United States)

    Gomes, Maria Fernanda Pereira Lavieri; de Oliveira Massoco, Cristina; Xavier, José Guilherme; Bonamin, Leoni Villano

    2010-06-01

    Comfrey or Symphytum officinale (L.) (Boraginaceae) is a very popular plant used for therapeutic purposes. Since the 1980s, its effects have been studied in long-term carcinogenesis studies, in which Comfrey extract is administered at high doses during several months and the neoplastic hepatic lesions are evaluated. However, the literature on this topic is very poor considering the studies performed under short-term carcinogenesis protocols, such as the 'resistant hepatocyte model' (RHM). In these studies, it is possible to observe easily the phenomena related to the early phases of tumor development, since pre-neoplastic lesions (PNLs) rise in about 1-2 months of chemical induction. Herein, the effects of chronic oral treatment of rats with 10% Comfrey ethanolic extract were evaluated in a RHM. Wistar rats were sequentially treated with N-nitrosodiethylamine (ip) and 2-acetilaminofluorene (po), and submitted to hepatectomy to induce carcinogenesis promotion. Macroscopic/microscopic quantitative analysis of PNL was performed. Non-parametric statistical tests (Mann-Whitney and χ(2)) were used, and the level of significance was set at P ≤ 0.05. Comfrey treatment reduced the number of pre-neoplastic macroscopic lesions up to 1 mm (P ≤ 0.05), the percentage of oval cells (P = 0.0001) and mitotic figures (P = 0.007), as well as the number of Proliferating Cell Nuclear Antigen (PCNA) positive cells (P = 0.0001) and acidophilic pre-neoplastic nodules (P = 0.05). On the other hand, the percentage of cells presenting megalocytosis (P = 0.0001) and vacuolar degeneration (P = 0.0001) was increased. Scores of fibrosis, glycogen stores and the number of nucleolus organizing regions were not altered. The study indicated that oral treatment of rats with 10% Comfrey alcoholic extract reduced cell proliferation in this model.

  1. Exocrine pancreatic carcinogenesis and autotaxin expression.

    Directory of Open Access Journals (Sweden)

    Sandeep Kadekar

    Full Text Available Exocrine pancreatic cancer is an aggressive disease with an exceptionally high mortality rate. Genetic analysis suggests a causative role for environmental factors, but consistent epidemiological support is scarce and no biomarkers for monitoring the effects of chemical pancreatic carcinogens are available. With the objective to identify common traits for chemicals inducing pancreatic tumors we studied the National Toxicology Program (NTP bioassay database. We found that male rats were affected more often than female rats and identified eight chemicals that induced exocrine pancreatic tumors in males only. For a hypothesis generating process we used a text mining tool to analyse published literature for suggested mode of actions (MOA. The resulting MOA analysis suggested inflammatory responses as common feature. In cell studies we found that all the chemicals increased protein levels of the inflammatory protein autotaxin (ATX in Panc-1, MIA PaCa-2 or Capan-2 cells. Induction of MMP-9 and increased invasive migration were also frequent effects, consistent with ATX activation. Testosterone has previously been implicated in pancreatic carcinogenesis and we found that it increased ATX levels. Our data show that ATX is a target for chemicals inducing pancreatic tumors in rats. Several lines of evidence implicate ATX and its product lysophosphatidic acid in human pancreatic cancer. Mechanisms of action may include stimulated invasive growth and metastasis. ATX may interact with hormones or onco- or suppressor-genes often deregulated in exocrine pancreatic cancer. Our data suggest that ATX is a target for chemicals promoting pancreatic tumor development.

  2. Inflammation, oxidative DNA damage, and carcinogenesis

    International Nuclear Information System (INIS)

    Lewis, J.G.; Adams, D.O.

    1987-01-01

    Inflammation has long been associated with carcinogenesis, especially in the promotion phase. The mechanism of action of the potent inflammatory agent and skin promoter 12-tetradecanoyl phorbol-13-acetate (TPA) is unknown. It is though that TPA selectively enhances the growth of initiated cells, and during this process, initiated cells progress to the preneoplastic state and eventually to the malignant phenotype. The authors and others have proposed that TPA may work, in part, by inciting inflammation and stimulating inflammatory cells to release powerful oxidants which then induce DNA damage in epidermal cells. Macrophages cocultured with target cells and TPA induce oxidized thymine bases in the target cells. This process is inhibited by both catalase and inhibitors of lipoxygenases, suggesting the involvement of both H 2 O 2 and oxidized lipid products. In vivo studies demonstrated that SENCAR mice, which are sensitive to promotion by TPA, have a more intense inflammatory reaction in skin that C57LB/6 mice, which are resistant to promotion by TPA. In addition, macrophages from SENCAR mice release more H 2 O 2 and metabolites of AA, and induce more oxidative DNA damage in cocultured cells than macrophages from C57LB/6 mice. These data support the hypothesis that inflammation and the release of genotoxic oxidants may be one mechanism whereby initiated cells receive further genetic insults. They also further complicate risk assessment by suggesting that some environmental agents may work indirectly by subverting host systems to induce damage rather than maintaining homeostasis

  3. Somatic Host Cell Alterations in HPV Carcinogenesis.

    Science.gov (United States)

    Litwin, Tamara R; Clarke, Megan A; Dean, Michael; Wentzensen, Nicolas

    2017-08-03

    High-risk human papilloma virus (HPV) infections cause cancers in different organ sites, most commonly cervical and head and neck cancers. While carcinogenesis is initiated by two viral oncoproteins, E6 and E7, increasing evidence shows the importance of specific somatic events in host cells for malignant transformation. HPV-driven cancers share characteristic somatic changes, including apolipoprotein B mRNA editing catalytic polypeptide-like (APOBEC)-driven mutations and genomic instability leading to copy number variations and large chromosomal rearrangements. HPV-associated cancers have recurrent somatic mutations in phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha ( PIK3CA ) and phosphatase and tensin homolog ( PTEN ), human leukocyte antigen A and B ( HLA-A and HLA-B ) -A/B , and the transforming growth factor beta (TGFβ) pathway, and rarely have mutations in the tumor protein p53 ( TP53 ) and RB transcriptional corepressor 1 ( RB1 ) tumor suppressor genes. There are some variations by tumor site, such as NOTCH1 mutations which are primarily found in head and neck cancers. Understanding the somatic events following HPV infection and persistence can aid the development of early detection biomarkers, particularly when mutations in precancers are characterized. Somatic mutations may also influence prognosis and treatment decisions.

  4. Somatic Host Cell Alterations in HPV Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Tamara R. Litwin

    2017-08-01

    Full Text Available High-risk human papilloma virus (HPV infections cause cancers in different organ sites, most commonly cervical and head and neck cancers. While carcinogenesis is initiated by two viral oncoproteins, E6 and E7, increasing evidence shows the importance of specific somatic events in host cells for malignant transformation. HPV-driven cancers share characteristic somatic changes, including apolipoprotein B mRNA editing catalytic polypeptide-like (APOBEC-driven mutations and genomic instability leading to copy number variations and large chromosomal rearrangements. HPV-associated cancers have recurrent somatic mutations in phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA and phosphatase and tensin homolog (PTEN, human leukocyte antigen A and B (HLA-A and HLA-B-A/B, and the transforming growth factor beta (TGFβ pathway, and rarely have mutations in the tumor protein p53 (TP53 and RB transcriptional corepressor 1 (RB1 tumor suppressor genes. There are some variations by tumor site, such as NOTCH1 mutations which are primarily found in head and neck cancers. Understanding the somatic events following HPV infection and persistence can aid the development of early detection biomarkers, particularly when mutations in precancers are characterized. Somatic mutations may also influence prognosis and treatment decisions.

  5. Hypoxia and Angiogenesis in Endometrioid Endometrial Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Nicole Horrée

    2007-01-01

    Full Text Available Background: Hypoxia-inducible factor 1α (HIF-1α plays an essential role in the adaptive response of cells to hypoxia, triggering biologic events associated with aggressive tumor behavior. Methods: Expression of HIF-1α and proteins in the HIF-1α pathway (Glut-1, CAIX, VEGF in paraffin-embedded specimens of normal (n = 17, premalignant (n = 17 and endometrioid endometrial carcinoma (n = 39 was explored by immunohistochemistry, in relation to microvessel density (MVD. Results: HIF-1α overexpression was absent in inactive endometrium but present in hyperplasia (61% and carcinoma (87%, with increasing expression in a perinecrotic fashion pointing to underlying hypoxia. No membranous expression of Glut-1 and CAIX was noticed in inactive endometrium, in contrast with expression in hyperplasia (Glut-1 0%, CAIX 61%, only focal and diffuse and carcinoma (Glut-1 94.6%, CAIX 92%, both mostly perinecrotically. Diffuse HIF-1α was accompanied by activation of downstream targets. VEGF was significantly higher expressed in hyperplasias and carcinomas compared to inactive endometrium. MVD was higher in hyperplasias and carcinomas than in normal endometrium (p < 0.001. Conclusion: HIF-1α and its downstream genes are increasingly expressed from normal through premalignant to endometrioid adenocarcinoma of the endometrium, paralleled by activation of its downstream genes and increased angiogenesis. This underlines the potential importance of hypoxia and its key regulator HIF-1α in endometrial carcinogenesis.

  6. Carcinogenesis induced by low-dose radiation

    Directory of Open Access Journals (Sweden)

    Piotrowski Igor

    2017-11-01

    Full Text Available Although the effects of high dose radiation on human cells and tissues are relatively well defined, there is no consensus regarding the effects of low and very low radiation doses on the organism. Ionizing radiation has been shown to induce gene mutations and chromosome aberrations which are known to be involved in the process of carcinogenesis. The induction of secondary cancers is a challenging long-term side effect in oncologic patients treated with radiation. Medical sources of radiation like intensity modulated radiotherapy used in cancer treatment and computed tomography used in diagnostics, deliver very low doses of radiation to large volumes of healthy tissue, which might contribute to increased cancer rates in long surviving patients and in the general population. Research shows that because of the phenomena characteristic for low dose radiation the risk of cancer induction from exposure of healthy tissues to low dose radiation can be greater than the risk calculated from linear no-threshold model. Epidemiological data collected from radiation workers and atomic bomb survivors confirms that exposure to low dose radiation can contribute to increased cancer risk and also that the risk might correlate with the age at exposure.

  7. Multistage chemical carcinogenesis in mouse skin

    Energy Technology Data Exchange (ETDEWEB)

    Slaga, T.J.; Fischer, S.M.; Weeks, C.E.; Klein-Szanto, A.J.P.

    1979-01-01

    Skin tumors in mice can be induced by the sequential application of a subthreshold dose of a carcinogen (initiation phase) followed by repetitive treatment with a noncarcinogenic tumor promoter. The initiation phase requires only a single application of either a direct acting carcinogen or a procarcinogen which has to be metabolized before being active and is essentially an irreversible step which probably involves a somatic cell mutation. There is a good correlation between the skin tumor initiating activites of several polycyclic aromatic hydrocarbons (PAH) and their ability to bind covalently to epidermal DNA. Laboratory results suggest that bay region diol-epoxides are the ultimate carcinogenic form of PAH carcinogens. Potent inhibitors and stimulators of PAH tumor initiation appear to affect the level of the PAH diol-epoxide reacting with specific DNA bases. Reecent data suggests that the tumor promotion stage involves at least three important steps: (1) the induction of embryonic looking cells (dark cells) in adult epidermis; (2) an increased production of epidermal prostaglandins and polyamines; (3) sustained proliferation of dark cells. Retinoic acid specifically inhibits step two whereas the anti-inflammatory steriod fluocinolone acetonide is a potent inhibitor of steps one and three. The mechanism and the importance of a specific sequence for each step in chemical carcinogenesis in mouse skin are detailed.

  8. Experimental carcinogenesis induced by incorporated plutonium

    Energy Technology Data Exchange (ETDEWEB)

    Oghiso, Yoichi [National Inst. of Radiological Sciences, Chiba (Japan)

    1999-06-01

    The carcinogenic effects of an alpha-emitter, {sup 239}Pu, were investigated by animal experiments as focused on both pulmonary tumors after inhalation exposures to insoluble oxide aerosols and tumor spectra induced by injection of soluble citrate. The life-span study using Wistar strain rats exposed to Pu dioxide aerosols has shown differential dose-related responses of malignancies and histopathological phenotypes of lung tumors, suggesting a threshold dose around 1.0 Gy of the lung dose. As abnormality of tumor-related genes could be supposed for the background of pulmonary carcinogenesis, the mutations of p53 tumor suppressor gene were examined by PCR-SSCP analysis using DNA fragments extracted from lung tumors. While mutations were detected in 23 cases (about 28%) among 82 lung tumors, their relations to either malignancies, histological phenotypes, dose, or oncogenesis are not yet to be elucidated. The life-span study using C3H strain mice injected with Pu citrate has shown contrast dose responses between osteosarcomas and lymphoid tumors around 10 Gy of the skeletal dose, and further indicated specific tumor spectra differed from low LET radiation exposures as shown by much more frequency of B cell type leukemic lymphomas and none of myeloid leukemias. (author)

  9. Loss of HLTF function promotes intestinal carcinogenesis

    Directory of Open Access Journals (Sweden)

    Sandhu Sumit

    2012-03-01

    Full Text Available Abstract Background HLTF (Helicase-like Transcription Factor is a DNA helicase protein homologous to the SWI/SNF family involved in the maintenance of genomic stability and the regulation of gene expression. HLTF has also been found to be frequently inactivated by promoter hypermethylation in human colon cancers. Whether this epigenetic event is required for intestinal carcinogenesis is unknown. Results To address the role of loss of HLTF function in the development of intestinal cancer, we generated Hltf deficient mice. These mutant mice showed normal development, and did not develop intestinal tumors, indicating that loss of Hltf function by itself is insufficient to induce the formation of intestinal cancer. On the Apcmin/+ mutant background, Hltf- deficiency was found to significantly increase the formation of intestinal adenocarcinoma and colon cancers. Cytogenetic analysis of colon tumor cells from Hltf -/-/Apcmin/+ mice revealed a high incidence of gross chromosomal instabilities, including Robertsonian fusions, chromosomal fragments and aneuploidy. None of these genetic alterations were observed in the colon tumor cells derived from Apcmin/+ mice. Increased tumor growth and genomic instability was also demonstrated in HCT116 human colon cancer cells in which HLTF expression was significantly decreased. Conclusion Taken together, our results demonstrate that loss of HLTF function promotes the malignant transformation of intestinal or colonic adenomas to carcinomas by inducing genomic instability. Our findings highly suggest that epigenetic inactivation of HLTF, as found in most human colon cancers, could play an important role in the progression of colon tumors to malignant cancer.

  10. Pulmonary carcinogenesis from plutonium-containing particles

    International Nuclear Information System (INIS)

    Thomas, R.G.; Smith, D.M.; Anderson, E.C.

    1980-01-01

    Induction of lung tumors by various types of radiation is of paramount concern to the nuclear industry. The data presented were obtained by exposing the pulmonary system of Syrian hamsters to particles of zirconium oxide containing various amounts of either plutonium-238 or -239 as the alpha radiation source. These particles were injected intravenously and lodged permanently in the capillary bed of the lung. When less than 20% of the lung tissue was irradiated, simulating the ''hot particle'' mode, tumors were not evident with lung burdens up to 500 nCi plutonium. More diffuse irradiation significantly increased the tumor incidence, with lung burdens of 50 to 150 nCi. When plutonium-laden microspheres were administered intratracheally, tumor production was considerably increased and the addition of 3 mg of iron oxide intratracheally further increased the incidence. Using the zirconium oxide matrix for the carrier of plutonium in aerosol particles produced tumor incidences of up to 50% in Syrian hamsters exposed by inhalation. Initial pulmonary (alveolar) burdens reached 100 nCi of plutonium. Similar inhalation studies using plutonium dioxide alone (no matrix) failed to produce any increase in lung tumorigenesis. The results are discussed in terms of possible mechanisms necessary for lung carcinogenesis. (H.K.)

  11. Nanochemistry of metals

    International Nuclear Information System (INIS)

    Sergeev, Gleb B

    2001-01-01

    The results of studies on the nanochemistry of metals published in recent years are generalised. Primary attention is centred on the methods for the synthesis of nanoparticles and their chemical reactions. The means of stabilisation of nanoparticles which involve individual metals and incorporate atoms of several metals are considered as well as their physicochemical properties. Self-assembling processes of nanoparticles are described. The prospects of using metal nanoparticles in semiconductor devices, catalysis, biology and medicine are discussed. The bibliography includes 165 references.

  12. PHYSICOCHEMICAL CHARACTERIZATION OF COMPOST OF THE

    Directory of Open Access Journals (Sweden)

    MAHDI AHMED

    2007-04-01

    Full Text Available It is very important that tannery wastes in the form of sludge are managed in an environmentally sound manner. This study focused on the heavy metal characterization and the influence of changing the physico-chemical properties of the medium throughout the composting on the concentrations, bioavailability or chemical forms of Cr, Cu, Zn, Pb and Cd in tannery sludge. The physical and chemical properties of the composted sludge during treatment show the stability and maturity of end product. Total metal content in the final compost were much lower than the limit values of composts to be used as good soil fertilizer. Furthermore, it was observed in using a sequential extraction method in sludge compost at different phases of treatment, that a large proportion of the heavy metals were associated to the residual fraction (70– 80% and more resistant fractions to extraction X–NaOH, X–EDTA, X–HNO3 (12–29%. Less than 2% of metals bound to bioavailable fractions X–(KNO3 + H2O. Bioavailable fractions of all elements tend to decrease. Mobile fractions of metals are poorly predictable from the total content.

  13. Implications of tyrosine phosphoproteomics in cervical carcinogenesis

    Directory of Open Access Journals (Sweden)

    DeFord James

    2008-01-01

    Full Text Available Abstract Background Worldwide cervical cancer remains a leading cause of mortality from gynecologic malignancies. The link between cervical cancer and persistent infection with HPV has been established. At a molecular level little is known about the transition from the precancerous state to invasive cancer. To elucidate this process, cervical biopsies from human specimens were obtained from precancerous state to stage III disease. Methods Cervical biopsies were obtained from patients with a diagnosis of cervical cancer undergoing definitive surgery or staging operation. Biopsies were obtained from patients with precancerous lesions at the time of their excisional procedure. Control samples were obtained from patients undergoing hysterectomy for benign conditions such as fibroids. Samples were subjected to proteomic profiling using two dimensional gel electrophoresis with subsequent trypsin digestion followed by MALDI-TOF protein identification. Candidate proteins were then further studied using western blotting, immunoprecipitation and immunohistochemistry. Results Annexin A1 and DNA-PKcs were found to be differentially expressed. Phosphorylated annexin A1 was up regulated in diseased states in comparison to control and its level was strongly detected in the serum of cervical cancer patients compared to controls. DNA-PKcs was noted to be hyperphosphorylated and fragmented in cancer when compared to controls. By immunohistochemistry annexin A1 was noted in the vascular environment in cancer and certain precancerous samples. Conclusion This study suggests a probable role for protein tyrosine phosphorylation in cervical carcinogenesis. Annexin A1 and DNA-PK cs may have synergistic effects with HPV infection. Precancerous lesions that may progress to cervical cancer may be differentiated from lesions that will not base on similar immunohistochemical profile to invasive squamous cell carcinoma.

  14. Mustard gas exposure and carcinogenesis of lung.

    Science.gov (United States)

    Hosseini-khalili, Alireza; Haines, David D; Modirian, Ehsan; Soroush, Mohammadreza; Khateri, Shahriar; Joshi, Rashmi; Zendehdel, Kazem; Ghanei, Mostafa; Giardina, Charles

    2009-08-01

    Sulfur mustard (SM), also known as mustard gas, is an alkylating compound used as a chemical weapon in World War I and by Iraqi forces against Iranians and indigenous Iraqi Kurds during the Iran-Iraq War of the 1980s. Although SM is a proven carcinogen there are conflicting views regarding the carcinogenicity of a single exposure. The present study characterizes lung cancers formed in mustard gas victims from the Iran-Iraq War. Demographic information and tumor specimens were collected from 20 Iranian male lung cancer patients with single high-dose SM exposures during the Iran-Iraq War. Formalin-fixed, paraffin-embedded lung cancers were analyzed by immunohistochemistry for p53 protein. In addition, DNA was extracted from the tissues, PCR amplified and sequenced to identify mutations in the p53 and KRAS genes associated with SM exposure. A relatively early age of lung cancer onset (ranging from 28 to 73 with a mean of 48) in mustard gas victims, particularly those in the non-smoking population (mean age of 40.7), may be an indication of a unique etiology for these cancers. Seven of the 20 patients developed lung cancer before the age of 40. Five of 16 cancers from which DNA sequence data was obtainable provided information on eight p53 mutations (within exons 5-8). These mutations were predominately G to A transitions; a mutation consistent with the DNA lesion caused by SM. Two of the lung cancers had multiple p53 point mutations, similar to results obtained from factory workers chronically exposed to mustard agent. No mutations were detected in the KRAS gene. The distinguishing characteristics of lung carcinogenesis in these mustard gas victims suggest that a single exposure may increase the risk of lung cancer development in some individuals.

  15. Iron and thiols as two major players in carcinogenesis: friends or foes?

    Science.gov (United States)

    Toyokuni, Shinya

    2014-01-01

    Iron is the most abundant metal in the human body and mainly works as a cofactor for proteins such as hemoglobin and various enzymes. No independent life forms on earth can survive without iron. However, excess iron is intimately associated with carcinogenesis by increasing oxidative stress via its catalytic activity to generate hydroxyl radicals. Biomolecules with redox-active sulfhydryl function(s) (thiol compounds) are necessary for the maintenance of mildly reductive cellular environments to counteract oxidative stress, and for the execution of redox reactions for metabolism and detoxification. Involvement of glutathione S-transferase and thioredoxin has long attracted the attention of cancer researchers. Here, I update recent findings on the involvement of iron and thiol compounds during carcinogenesis and in cancer cells. It is now recognized that the cystine/glutamate transporter (antiporter) is intimately associated with ferroptosis, an iron-dependent, non-apoptotic form of cell death, observed in cancer cells, and also with cancer stem cells; the former with transporter blockage but the latter with its stabilization. Excess iron in the presence of oxygen appears the most common known mutagen. Ironically, the persistent activation of antioxidant systems via genetic alterations in Nrf2 and Keap1 also contributes to carcinogenesis. Therefore, it is difficult to conclude the role of iron and thiol compounds as friends or foes, which depends on the quantity/distribution and induction/flexibility, respectively. Avoiding further mutation would be the most helpful strategy for cancer prevention, and myriad of efforts are being made to sort out the weaknesses of cancer cells.

  16. Colorectal Carcinogenesis: Role of Oxidative Stress and Antioxidants.

    Science.gov (United States)

    Carini, Francesco; Mazzola, Margherita; Rappa, Francesca; Jurjus, Abdo; Geagea, Alice Gerges; Al Kattar, Sahar; Bou-Assi, Tarek; Jurjus, Rosalyn; Damiani, Provvidenza; Leone, Angelo; Tomasello, Giovanni

    2017-09-01

    One of the contributory causes of colon cancer is the negative effect of reactive oxygen species on DNA repair mechanisms. Currently, there is a growing support for the concept that oxidative stress may be an important etiological factor for carcinogenesis. The purpose of this review is to elucidate the role of oxidative stress in promoting colorectal carcinogenesis and to highlight the potential protective role of antioxidants. Several studies have documented the importance of antioxidants in countering oxidative stress and preventing colorectal carcinogenesis. However, there are conflicting data in the literature concerning its proper use in humans, since these studies did not yield definitive results and were performed mostly in vitro on cell populations, or in vivo in experimental animal models. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  17. Experimental, statistical, and biological models of radon carcinogenesis

    International Nuclear Information System (INIS)

    Cross, F.T.

    1991-09-01

    Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared to domestic environments and from uncertainties about the interaction between cigarette-smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research program that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models), and the relationship of radon to smoking and other copollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. 20 refs., 1 fig

  18. Experimental, statistical and biological models of radon carcinogenesis

    International Nuclear Information System (INIS)

    Cross, F.T.

    1992-01-01

    Risk models developed for underground miners have not been consistently validated in studies of populations exposed to indoor radon. Imprecision in risk estimates results principally from differences between exposures in mines as compared with domestic environments and from uncertainties about the interaction between cigarette smoking and exposure to radon decay products. Uncertainties in extrapolating miner data to domestic exposures can be reduced by means of a broad-based health effects research programme that addresses the interrelated issues of exposure, respiratory tract dose, carcinogenesis (molecular/cellular and animal studies, plus developing biological and statistical models) and the relationship of radon to smoking and other co-pollutant exposures. This article reviews experimental animal data on radon carcinogenesis observed primarily in rats at Pacific Northwest Laboratory. Recent experimental and mechanistic carcinogenesis models of exposures to radon, uranium ore dust, and cigarette smoke are presented with statistical analyses of animal data. (author)

  19. Risk, assessment and multiple stages in radiation carcinogenesis

    International Nuclear Information System (INIS)

    Burns, F.J.; Sawey, M.J.; Hosselet, S.; Garte, S.J.

    1989-01-01

    The authors discuss the multistage theory of carcinogenesis in terms of time-response and dose-response function, considering various workers' studies using irradiated rat skin. The authors' own results of experiments conducted to determine if two or more individual radiation doses add together to produce carcinogenic effects are presented (no such effect was observed due to skin cell repair), together with their data comparing the induction and repair kinetics of DNA breaks with carcinogenesis in the rat skin, which indicated that single strand breaks are not the initial lesion in the dual action theory. (UK)

  20. Characterization of physicochemical properties of ivy nanoparticles for cosmetic application

    OpenAIRE

    Huang, Yujian; Lenaghan, Scott C; Xia, Lijin; Burris, Jason N; Stewart, C Neal Jr; Zhang, Mingjun

    2013-01-01

    Abstract Background Naturally occurring nanoparticles isolated from English ivy (Hedera helix) have previously been proposed as an alternative to metallic nanoparticles as sunscreen fillers due to their effective UV extinction property, low toxicity and potential biodegradability. Methods This study focused on analyzing the physicochemical properties of the ivy nanoparticles, specifically, those parameters which are crucial for use as sunscreen fillers, such as pH, temperature, and UV irradia...

  1. Carcinogenesis related to intense pulsed light and UV exposure

    DEFF Research Database (Denmark)

    Hedelund, L; Lerche, C; Wulf, H C

    2006-01-01

    This study examines whether intense pulsed light (IPL) treatment has a carcinogenic potential itself or may influence ultraviolet (UV)-induced carcinogenesis. Secondly, it evaluates whether UV exposure may influence IPL-induced side effects. Hairless, lightly pigmented mice (n=144) received three...

  2. Chronology of p53 protein accumulation in gastric carcinogenesis

    NARCIS (Netherlands)

    Craanen, M. E.; Blok, P.; Dekker, W.; Offerhaus, G. J.; Tytgat, G. N.

    1995-01-01

    p53 Protein accumulation in early gastric carcinoma was studied in relation to the histological type (Lauren classification) and the type of growth pattern, including the chronology of p53 protein accumulation during carcinogenesis. Forty five, paraffin embedded gastrectomy specimens from early

  3. Lack of cyclin D1 overexpression in gastric carcinogenesis

    NARCIS (Netherlands)

    Blok, P.; Craanen, M. E.; van Diest, P. J.; Dekker, W.; Tytgat, G. N.

    2000-01-01

    Cyclin D1 overexpression was examined in early gastric carcinomas and precursor lesions with the following aims; (1) to assess the chronology of cyclin D1 overexpression in various stages of gastric carcinogenesis, (2) to correlate cyclin D1 overexpression with the Lauren type, the grade of

  4. Hypoxia and cell cycle deregulation in endometrial carcinogenesis

    NARCIS (Netherlands)

    Horrée, N.

    2007-01-01

    Because uterine endometrial carcinoma is the most common malignancy of the female genital tract and 1 of every 5 patients dies of this disease, understanding the mechanisms of carcinogenesis and progression of endometrial carcinoma is important. In general, this thesis can be summarized as a study

  5. Breast cancer as heterogeneous disease: contributing factors and carcinogenesis mechanisms.

    Science.gov (United States)

    Kravchenko, Julia; Akushevich, Igor; Seewaldt, Victoria L; Abernethy, Amy P; Lyerly, H Kim

    2011-07-01

    The observed bimodal patterns of breast cancer incidence in the U.S. suggested that breast cancer may be viewed as more than one biological entity. We studied the factors potentially contributing to this phenomenon, specifically focusing on how disease heterogeneity could be linked to breast carcinogenesis mechanisms. Using empirical analyses and population-based biologically motivated modeling, age-specific patterns of incidence of ductal and lobular breast carcinomas from the SEER registry (1990-2003) were analyzed for heterogeneity and characteristics of carcinogenesis, stratified by race, stage, grade, and estrogen (ER)/progesterone (PR) receptor status. The heterogeneity of breast carcinoma age patterns decreased after stratification by grade, especially for grade I and III tumors. Stratification by ER/PR status further reduced the heterogeneity, especially for ER(+)/PR(-) and ER(-)/(-) tumors; however, the residual heterogeneity was still observed. The number of rate-limiting events of carcinogenesis and the latency of ductal and lobular carcinomas differed, decreasing from grade I to III, with poorly differentiated tumors associated with the least number of carcinogenesis stages and the shortest latency. Tumor grades play important role in bimodal incidence of breast carcinoma and have distinct mechanisms of carcinogenesis. Race and cancer subtype could play modifying role. ER/PR status contributes to the observed heterogeneity, but is subdominant to tumor grade. Further studies on sources of "remaining" heterogeneity of population with breast cancer (such as genetic/epigenetic characteristics) are necessary. The results of this study could suggest stratification rather than unification of breast cancer prevention strategies, risk assessment, and treatment.

  6. Preliminary Phytochemical and Physicochemical Characterization of ...

    African Journals Online (AJOL)

    Purpose: To carry out phytochemical and physicochemical studies on the leaves of Gynura segetum. Methods: Preliminary phytochemical and physicochemical studies using chromatographic techniques,were carried out, Parameters evaluated include ash value, loss on drying and extractive value, amongst others.

  7. Molecular and cellular mechanisms of cadmium carcinogenesis

    International Nuclear Information System (INIS)

    Waisberg, Michael; Joseph, Pius; Hale, Beverley; Beyersmann, Detmar

    2003-01-01

    Cadmium is a heavy metal, which is widely used in industry, affecting human health through occupational and environmental exposure. In mammals, it exerts multiple toxic effects and has been classified as a human carcinogen by the International Agency for Research on Cancer. Cadmium affects cell proliferation, differentiation, apoptosis and other cellular activities. Cd 2+ does not catalyze Fenton-type reactions because it does not accept or donate electrons under physiological conditions, and it is only weakly genotoxic. Hence, indirect mechanisms are implicated in the carcinogenicity of cadmium. In this review multiple mechanisms are discussed, such as modulation of gene expression and signal transduction, interference with enzymes of the cellular antioxidant system and generation of reactive oxygen species (ROS), inhibition of DNA repair and DNA methylation, role in apoptosis and disruption of E-cadherin-mediated cell-cell adhesion. Cadmium affects both gene transcription and translation. The major mechanisms of gene induction by cadmium known so far are modulation of cellular signal transduction pathways by enhancement of protein phosphorylation and activation of transcription and translation factors. Cadmium interferes with antioxidant defense mechanisms and stimulates the production of reactive oxygen species, which may act as signaling molecules in the induction of gene expression and apoptosis. The inhibition of DNA repair processes by cadmium represents a mechanism by which cadmium enhances the genotoxicity of other agents and may contribute to the tumor initiation by this metal. The disruption of E-cadherin-mediated cell-cell adhesion by cadmium probably further stimulates the development of tumors. It becomes clear that there exist multiple mechanisms which contribute to the carcinogenicity of cadmium, although the relative weights of these contributions are difficult to estimate

  8. Harnessing Aquatic Physicochemical Parameters Influencing ...

    African Journals Online (AJOL)

    The management-oriented background for harnessing aquatic physicochemical parameters influencing macro invertebrate fauna of Anambra River basin for sustainable fish productivity was studied. The intra seasonal variability in the water quality of the river revealed mean transparency of 1.79 cm, Conductivity of 28.81 ...

  9. Synthesis, physicochemical characterization, and functional ...

    African Journals Online (AJOL)

    subjected to modification by acetylation. The acetylated acha starch with degree of modification 0.78 had reduced foaming capacity and amylose contents. The starches have similar organoleptic properties ranging from white, gritty, non sticky to bland tastes. Physicochemical indices investigated such as true density, bulk ...

  10. Physico-chemical wastewater treatment

    NARCIS (Netherlands)

    Mels, A.R.; Teerikangas, E.

    2002-01-01

    Wastewater reclamation strategies aimed at closing industrial water cycles and recovery of valuable components will in most cases require a combination of wastewater treatment unit operations. Biological unit operations are commonly applied as the core treatment. In addition, physico-chemical unit

  11. Physicochemical impact studies of gamma rays on "aspirin" analgesics drug and its metal complexes in solid form: Synthesis, spectroscopic and biological assessment of Ca(II), Mg(II), Sr(II) and Ba(II) aspirinate complexes

    Science.gov (United States)

    Refat, Moamen S.; Sharshar, T.; Elsabawy, Khaled M.; Heiba, Zein K.

    2013-09-01

    Metal aspirinate complexes, M2(Asp)4, where M is Mg(II), Ca(II), Sr(II) or Ba(II) are formed by refluxed of aspirin (Asp) with divalent non-transition metal ions of group (II) and characterized by elemental analysis and spectroscopic measurements (infrared, electronic, 1H NMR, Raman, X-ray powder diffraction and scanning electron microscopy). Elemental analysis of the chelates suggests the stoichiometry is 1:2 (metal:ligand). Infrared spectra of the complexes agree with the coordination to the central metal atom through three donation sites of two oxygen atoms of bridge bidentate carboxylate group and oxygen atom of sbnd Cdbnd O of acetyl group. Infrared spectra coupled with the results of elemental analyzes suggested a distorted octahedral structure for the M(II) aspirinate complexes. Gamma irradiation was tested as a method for stabilization of aspirin as well as their complexes. The effect of gamma irradiation, with dose of 80 Gy, on the properties of aspirinate complexes was studied. The aspirinate chelates have been screened for their in vitro antibacterial activity against four bacteria, gram-positive (Bacillus subtilis and Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) and two strains of fungus (Aspergillus flavus and Candida albicans). The metal chelates were shown to possess more antibacterial activity than the free aspirin chelate.

  12. Cervical Carcinogenesis and Immune Response Gene Polymorphisms: A Review

    Directory of Open Access Journals (Sweden)

    Akash M. Mehta

    2017-01-01

    Full Text Available The local immune response is considered a key determinant in cervical carcinogenesis after persistent infection with oncogenic, high-risk human papillomavirus (HPV infections. Genetic variation in various immune response genes has been shown to influence risk of developing cervical cancer, as well as progression and survival among cervical cancer patients. We reviewed the literature on associations of immunogenetic single nucleotide polymorphism, allele, genotype, and haplotype distributions with risk and progression of cervical cancer. Studies on HLA and KIR gene polymorphisms were excluded due to the abundance on literature on that subject. We show that multiple genes and loci are associated with variation in risk of cervical cancer. Rather than one single gene being responsible for cervical carcinogenesis, we postulate that variations in the different immune response genes lead to subtle differences in the effectiveness of the antiviral and antitumour immune responses, ultimately leading to differences in risk of developing cervical cancer and progressive disease after HPV infection.

  13. Regulatory miRNAs in Colorectal Carcinogenesis and Metastasis.

    Science.gov (United States)

    Guo, Yongchen; Bao, Yonghua; Yang, Wancai

    2017-04-22

    Colorectal cancer is one of the most common malignancies and is the second-leading cause of cancer-related death world-wide, which is linked to genetic mutations, epigenetic alterations, and oncogenic signaling activation. MicroRNAs, one of the categories of epigenetics, have been demonstrated significant roles in carcinogenesis and progression through regulating of oncogenic signaling pathways, stem cells, epithelial-mesenchymal transition, and metastasis. This review summarizes the roles of microRNAs in the regulating of Wnt, Ras, TGF-β, and inflammatory signaling pathways, stemness, and epithelial-mesenchymal transition, for carcinogenesis and metastasis in colorectal cancer. Improving our understanding of the mechanisms of regulatory interactions of microRNAs with signaling pathways in colorectal cancer formation and progression will aid in determining the genes responsible for colorectal cancer initiation, progression, metastasis, and recurrence and, finally, in developing personalized approaches for cancer prevention and therapy.

  14. Nucleophilic targets in carcinogenesis, mutagenesis and chemotherapy of cancer.

    Science.gov (United States)

    Raikov, Z D; Christova-Georgieva, N I; Raikova, E T

    1987-01-01

    A hypothesis is suggested, which emphasizes the role in carcinogenesis of the attack on low molecular nucleophilic substances (LMN) by electrophilic agents - chemical carcinogens, phisical factors, and antitumor alkylating agents. The significance of the degree of nucleophilicity (electronic charge, order of bonds, index of valence) as a locus minoris resistentiae of the LMN in the electrophilic attack on the latter is emphasized as well as the probable role of the hydrogenated pteridines in influencing carcinogenesis by means of ascorbate, tocopherol, SH-containing compounds etc. In support of this hypothesis the preference of electrophilic agents (derivatives of nitrogen mustard and nitrosoureas) for the places with highest degree of nucleophilicity as targets, in experiments in vitro with nucleic bases and pteridines is emphasized.

  15. Plastics and carcinogenesis: The example of vinyl chloride

    Directory of Open Access Journals (Sweden)

    Paul Wesley Brandt-Rauf

    2012-01-01

    Full Text Available The manufacture, use and disposal of various plastics can pose numerous health risks, including the risk of cancer. A model example of carcinogenic risk from plastics is provided by polyvinyl chloride, since it is composed of the known human carcinogen vinyl chloride (VC. In recent years, much has been learned about the molecular biological pathways of VC carcinogenesis. This has led to molecular epidemiologic studies of VC carcinogenesis in exposed human populations which have identified useful biomarkers of exposure, effect and susceptibility for VC. These studies have in turn provided the basis for new molecular approaches for the prevention and treatment of VC cancers. This model could have much wider applicability for many other carcinogenic exposures and many other human cancers.

  16. Inhibitory effects of acetylsalicylic acid on exocrine pancreatic carcinogenesis.

    Science.gov (United States)

    Yıldız, H; Oztas, H; Yıldız, D; Koc, A; Kalipci, E

    2013-05-01

    We investigated short (6 months) and long (12 months) term inhibitory effects of low (200 ppm) and high (400 ppm) dosages of acetylsalicylic acid (aspirin) on exocrine pancreatic carcinogenesis. It is known that exocrine pancreatic carcinogenesis can be detected by the presence of atypical acinar cell foci (AACF) in pancreas. We investigated possible inhibitory effects of acetylsalicylic acid in an azaserine-treated rat model. AACF were produced in rats by injection with azaserine according to previous studies. Our findings showed that the number, volume and diameter of pancreatic AACF were reduced after acetylsalicylic acid application. These observations suggest that acetylsalicylic acid may exert a protective effect against neoplastic development of pancreatic acinar cells in azaserine injected rats. Our findings corroborate reports in the literature concerning the effects of aspirin in reducing neoplastic development.

  17. Basic concepts of inflammation and its role in carcinogenesis.

    Science.gov (United States)

    Maher, Stephen G; Reynolds, John V

    2011-01-01

    While the normal inflammatory cascade is self-limiting and crucial for host protection against invading pathogens and in the repair of damaged tissue, a wealth of evidence suggests that chronic inflammation is the engine driving carcinogenesis. Over a period of almost 150 years the link between inflammation and cancer development has been well established. In this chapter we discuss the fundamental concepts and mechanisms behind normal inflammation as it pertains to wound healing. We further discuss the association of inflammation and its role in carcinogenesis, highlighting the different stages of cancer development, namely tumour initiation, promotion and progression. With both the innate and adaptive arms of the immune system being central to the inflammatory process, we examine the role of a number of immune effectors in contributing to the carcinogenic process. In addition, we highlight the influences of host genetics in altering cancer risk.

  18. Synergistic chemopreventive effects of nobiletin and atorvastatin on colon carcinogenesis.

    Science.gov (United States)

    Wu, Xian; Song, Mingyue; Qiu, Peiju; Rakariyatham, Kanyasiri; Li, Fang; Gao, Zili; Cai, Xiaokun; Wang, Minqi; Xu, Fei; Zheng, Jinkai; Xiao, Hang

    2017-04-01

    Different cancer chemopreventive agents may act synergistically and their combination may produce enhanced protective effects against carcinogenesis than each individual agent alone. Herein, we investigated the chemopreventive effects of nobiletin (NBT, a citrus polymethoxyflavone) and atorvastatin (ATST, a lipid-lowering drug) in colon cancer cells/macrophages and an azoxymethane (AOM)-induced colon carcinogenesis rat model. The results demonstrated that co-treatments of NBT/ATST produced enhanced growth inhibitory and anti-inflammatory effects on the colon cancer cells and macrophages, respectively. Isobologram analysis confirmed that these interactions between NBT and ATST were synergistic. NBT/ATST co-treatment also synergistically induced extensive cell cycle arrest and apoptosis in colon cancer cells. Oral administration of NBT (0.1%, w/w in diet) or ATST (0.04%, w/w in diet) significantly decreased colonic tumor incidence and multiplicity in AOM-treated rats. Most importantly, co-treatment of NBT/ATST at their half doses (0.05% NBT + 0.02% ATST, w/w in diet) resulted in even stronger inhibitory effects on colonic tumor incidence and multiplicity than did NBT or ATST alone at higher doses. Statistical analysis confirmed that the enhanced chemopreventive activities against colon carcinogenesis in rats by the NBT/ATST combination were highly synergistic. Our results further demonstrated that NBT/ATST co-treatment profoundly modulated key cellular signaling regulators associated with inflammation, cell proliferation, cell cycle progression, apoptosis, angiogenesis and metastasis in the colon of AOM-treated rats. In conclusion, for the first time, our results demonstrated a strong synergy in inhibiting colon carcinogenesis produced by the co-treatment of NBT and ATST, which provided a scientific basis for using NBT in combination with ATST for colon cancer chemoprevention in humans. © The Author 2017. Published by Oxford University Press. All rights reserved

  19. The relevance of cell transformation to carcinogenesis in vivo

    International Nuclear Information System (INIS)

    Little, J.B.

    1989-01-01

    Despite the caveats concerning rodent as opposed to human cell transformation systems, the author concludes there are several areas in which cell transformation studies with rodent cells have shown clear relevance to carcinogenesis in vivo, especially studies of carcinogenic effects of high LET radiation, particularly dependence on dose rate. In vitro studies firmly established the generality of promotion by phorbol esters tumour promotors. Initial studies on suppression of transformation, notably by protease inhibitors, has led to the confirmation of this phenomenon in in vivo carcinogenesis; development of inhibitor preparations from natural sources suitable for long-term supplementation in human diet, is under investigation. The potential importance of these modifiers is further emphasized by mechanistic studies suggesting that radiation may initiate a large fraction of exposed cell population, and expression of transformation may be controlled to a large extent by environmental conditions including the presence of promoting or suppressing agents. Finally, cell transformation systems offer the opportunity for mechanistic studies of the initial stages of carcinogenesis. Provocative results have arisen in several areas consistent with findings in experimental animals. (author)

  20. Wnt Lipidation and Modifiers in Intestinal Carcinogenesis and Cancer

    Directory of Open Access Journals (Sweden)

    Elke Kaemmerer

    2016-07-01

    Full Text Available The wingless (Wnt signaling is suggested as a fundamental hierarchical pathway in regulation of proliferation and differentiation of cells. The Wnt ligands are small proteins of about 40 kDa essentially for regulation and initiation of the Wnt activity. They are secreted proteins requiring acylation for activity in the Wnt signaling cascade and for functional interactivity with transmembrane proteins. Dual lipidation is important for posttranslational activation of the overwhelming number of Wnt proteins and is probably involved in their spatial distribution. The intestinal mucosa, where Wnt signaling is essential in configuration and maintenance, is an established model to study Wnt proteins and their role in carcinogenesis and cancer. The intestinal crypt-villus/crypt-plateau axis, a cellular system with self-renewal, proliferation, and differentiation, is tightly coordinated by a Wnt gradient. In the review, some attention is given to Wnt3, Wnt3A, and Wnt2B as important members of the Wnt family to address the role of lipidation and modifiers of Wnt proteins in intestinal carcinogenesis. Wnt3 is an important player in establishing the Wnt gradient in intestinal crypts and is mainly produced by Paneth cells. Wnt2B is characterized as a mitochondrial protein and shuttles between mitochondria and the nucleus. Porcupine and ACSL5, a long-chain fatty acid activating enzyme, are introduced as modifiers of Wnts and as interesting strategy to targeting Wnt-driven carcinogenesis.

  1. Role of the Vanins–Myeloperoxidase Axis in Colorectal Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Francesco Mariani

    2017-04-01

    Full Text Available The presence of chronic inflammation in the colonic mucosa leads to an increased risk of cancer. Among proteins involved in the regulation of mucosal inflammation and that may contribute both to structural damage of the intestinal mucosa and to intestinal carcinogenesis, there are myeloperoxidase (MPO and vanins. The infiltration of colonic mucosa by neutrophils may promote carcinogenesis through MPO, a key enzyme contained in the lysosomes of neutrophils that regulates local inflammation and the generation of reactive oxygen species (ROS and mutagenic species. The human vanin gene family consists of three genes: vanin-1, vanin-2 and vanin-3. All vanin molecules are pantetheinases, that hydrolyze pantetheine into pantothenic acid (vitamin B5, and cysteamine, a sulfhydryl compound. Vanin-1 loss confers an increased resistance to stress and acute intestinal inflammation, while vanin-2 regulates adhesion and transmigration of activated neutrophils. The metabolic product of these enzymes has a prominent role in the inflammation processes by affecting glutathione levels, inducing ulcers through a reduction in mucosal blood flow and oxygenation, decreasing local defense mechanisms, and in carcinogenesis by damaging DNA and regulating pathways involved in cell apoptosis, metabolism and growth, as Nrf2 and HIF-1α.

  2. Heel spur radiotherapy and radiation carcinogenesis risk estimation.

    Science.gov (United States)

    Surenkok, Serdar; Dirican, Bahar; Beyzadeoglu, Murat; Oysul, Kaan

    2006-10-01

    Radiotherapy is a nonsurgical alternative therapy of painful heel spur patients. Nonetheless, cancer induction is the most important somatic effect of ionizing radiation. This study was designed to evaluate the carcinogenesis risk factor in benign painful heel spur patients treated by radiotherapy. Between 1974 and 1999, a total of 20 patients received mean 8.16 Gy total irradiation dose in two fractions. Thermoluminescent dosimeters (TLD(100)) were placed on multiple phantom sites in vivo within the irradiated volume to verify irradiation accuracy and carcinogenesis risk factor calculation. The 20 still-alive patients, who had a minimum 5-year and maximum 29-year follow-up (mean 11.9 years), have been evaluated by carcinogenic radiation risk factor on the basis of tissue weighting factors as defined by the International Commission on Radiological Protection Publication 60. Reasonable pain relief has been obtained in all 20 patients. The calculated mean carcinogenesis risk factor is 1.3% for radiation portals in the whole group, and no secondary cancer has been clinically observed. Radiotherapy is an effective treatment modality for relieving pain in calcaneal spur patients. The estimated secondary cancer risk factor for irradiation of this benign lesion is not as high as was feared.

  3. Cellular adaptation as an important response during chemical carcinogenesis

    International Nuclear Information System (INIS)

    Farber, E.

    1992-01-01

    Since disease processes are largely expressions of how living organisms react and respond to perturbations in the external and internal environments, adaptive or protective responses and their modulations and mechanisms are of the greatest concern in fundamental studies of disease pathogenesis. Such considerations are also of the greatest relevance in toxicology, including how living organisms respond to low levels of single and multiple xenobiotics and radiations. As the steps and mechanisms during cancer development are studied in greater depth, phenomena become apparent that suggest that adaptive reactions and responses may play important or even critical roles in the process of carcinogenesis. The question becomes whether the process of carcinogenesis is fundamentally an adversarial one (i.e., an abnormal cell in a vulnerable host), or is it more in the nature of a physiological selection or differentiation, which has survival value for the host as an adaptive phenomena? The very early initial interactions of mutagenic chemical carcinogens, radiations and viruses with DNA prejudice most to consider the adversarial 'abnormal' view as the appropriate one. Yet, the unusually common nature of the earliest altered rare cells that appear during carcinogenesis, their unusually bland nature, and their spontaneous differentiation to normal-appearing adult liver should be carefully considered

  4. Pharmacological inhibition of MAGL attenuates experimental colon carcinogenesis.

    Science.gov (United States)

    Pagano, Ester; Borrelli, Francesca; Orlando, Pierangelo; Romano, Barbara; Monti, Martina; Morbidelli, Lucia; Aviello, Gabriella; Imperatore, Roberta; Capasso, Raffaele; Piscitelli, Fabiana; Buono, Lorena; Di Marzo, Vincenzo; Izzo, Angelo A

    2017-05-01

    Colorectal cancer (CRC) is a major health problem in Western countries. The endocannabinoid 2-arachidonoyl-glycerol (2-AG) exerts antiproliferative actions in a number of tumoral cell lines, including CRC cells. Monoacylglycerol lipase (MAGL), a serine hydrolase that inactivates 2-AG, is highly expressed in aggressive human cancer cells. Here, we investigated the role of MAGL in experimental colon carcinogenesis. The role of MAGL was assessed in vivo by using the xenograft and the azoxymethane models of colon carcinogenesis; MAGL expression was evaluated by RT-PCR and immunohistochemistry; 2-AG levels were measured by liquid chromatography mass spectrometry; angiogenesis was evaluated in tumor tissues [by microvessel counting and by investigating the expression of vascular endothelial growth factor (VEGF) and fibroblast growth factor-2 (FGF-2) proteins] as well as in human umbilical vein endothelial cells (HUVEC); cyclin D1 was evaluated by RT-PCR. MAGL and 2-AG were strongly expressed in tumor tissues. The MAGL inhibitor URB602 reduced xenograft tumor volume, this effect being associated to down-regulation of VEGF and FGF-2, reduction in the number of vessels and down-regulation of cyclin D1. In HUVEC, URB602 exerted a direct antiangiogenic effect by inhibiting FGF-2 induced proliferation and migration, and by modulating pro/anti-angiogenic agents. In experiments aiming at investigating the role of MAGL in chemoprevention, URB602 attenuated azoxymethane-induced preneoplastic lesions, polyps and tumors. MAGL, possibly through modulation of angiogenesis, plays a pivotal role in experimental colon carcinogenesis. Pharmacological inhibition of MAGL could represent an innovative therapeutic approach to reduce colorectal tumor progression. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. A review of current techniques of Physico-chemical and biological ...

    African Journals Online (AJOL)

    In spite of this fact, the soil is constantly subjected to various forms of abuse, including heavy metals pollution. The ecological destructive effect, high cost, and intensive labour requirement associated with ex situ physico-chemical remediation methods make the search for in situ remediation techniques inevitable. This paper ...

  6. Pathogenesis and biomarkers of carcinogenesis in ulcerative colitis

    DEFF Research Database (Denmark)

    Thorsteinsdottir, Sigrun; Gudjonsson, Thorkell; Nielsen, Ole Haagen

    2011-01-01

    -driven mechanisms of DNA damage, including the generation and effects of reactive oxygen species, microsatellite instability, telomere shortening and chromosomal instability, are reviewed, as are the molecular responses to genomic stress. We also discuss how these mechanisms can be translated into usable biomarkers....... Although progress has been made in the understanding of inflammation-driven carcinogenesis, markers based on these findings possess insufficient sensitivity or specificity to be usable as reliable biomarkers for risk of colorectal cancer development in patients with ulcerative colitis. However, screening...

  7. Bacterial infection increases risk of carcinogenesis by targeting mitochondria

    DEFF Research Database (Denmark)

    Strickertsson, Jesper A.B.; Desler, Claus; Rasmussen, Lene Juel

    2017-01-01

    pathways, and compares the impact of the bacterial alteration of mitochondrial function to that of cancer. Bacterial virulence factors have been demonstrated to induce mutations of mitochondrial DNA (mtDNA) and to modulate DNA repair pathways of the mitochondria. Furthermore, virulence factors can induce...... or impair the intrinsic apoptotic pathway. The effect of bacterial targeting of mitochondria is analogous to behavior of mitochondria in a wide array of tumours, and this strongly suggests that mitochondrial targeting of bacteria is a risk factor for carcinogenesis....

  8. The dimethylhydrazine induced colorectal tumours in rat - experimental colorectal carcinogenesis

    International Nuclear Information System (INIS)

    Perse, M.; Cerar, A.

    2005-01-01

    Animal models of colorectal carcinogenesis represent invaluable research tool for investigating colorectal cancer (CRC). Experimentally induced tumours in laboratory animals provide opportunity for studying certain aspects of tumours that cannot be effectively studied in humans. Significant information on human CRC aetiology or factors influencing it has derived from studies using dimethylhydrazine (DMH) model that is one of the experimental models appreciated for its morphological similarity to human CRC. Today, DMH model represents useful research tool for the studies of colon carcinogens and chemopreventive agents. The review offers insight into morphogenesis and genetic alterations of DMH induced colorectal epithelial tumours in rats. (author)

  9. Perspectives in the paradigm of radiation-induced carcinogenesis

    International Nuclear Information System (INIS)

    Sugakhara, T.; Vatanabe, M.; Niva, O.; Nikajdo, O.

    1995-01-01

    Carcinogenesis is analysed as a multistage process consisting of initiation, promotion and progression. This model includes the mutation of oncogenes and the loss of hetrezygosity by tumor-suppressor genes. The threshold concept of radiation cancerogenesis is proposed, under which ionizing radiation can induce in somatic cell genetic effects a s result of DNA damage and epigenetic changes as well. The epigenetic changes (through DNA or cytoplasma) can be stabilized as mutations observed in many cancer cells and play a dominant role in radiation cancerogenesis induction. The ration of epigenetic and genetic effects largely depends on radiation doses

  10. Toxicity of Nanomaterials-Physicochemical Effects

    Directory of Open Access Journals (Sweden)

    A Rahi

    2015-02-01

    Full Text Available Nanomaterials involve the structures with at least one dimension of <100 nm. Recently, development in nanotechnology has led to the use of nanomaterials in many different fields. On the other hand, increasing use of nanomaterials has resulted in release of these materials to the environment. Therefore, before employing these materials in biological and living systems, they should be evaluated in terms of biocompatibility and distribution. Although the toxic effects of nanomaterials on living organisms, human health and the environment have been studied by some researchers, there are too much uncertainty regarding the effects and mechanisms of toxicity of nanomaterials. Therefore, understanding the toxicity effects of nanomaterials is highly desirable. Cellular uptake mechanisms and dispersion of nanomaterials in biological environments depend on their physicochemical properties. Therefore, knowledge of the unique characteristics of nanomaterials and the interactions of nanomaterials with biological systems, are important criteria for the safe use of nanomaterials. Properties of nanomaterials such as size, shape, aspect ratio, density, surface and structural defects and dissolving rate are the main causes of cytotoxicity and side effects of these materials in the body. Exposure to nanomaterials may cause a range of acute and chronic effects, including inflammation, exacerbation of asthma, metal fume fever, fibrosis, chronic inflammatory diseases and cancer. The present paper, reviews the previous studies aiming at the investigation of the relation between the physiochemical properties of nanomaterials and their toxicity.

  11. Inherent aerobic capacity-dependent differences in breast carcinogenesis.

    Science.gov (United States)

    Thompson, Henry J; Jones, Lee W; Koch, Lauren G; Britton, Steven L; Neil, Elizabeth S; McGinley, John N

    2017-09-01

    Although regular physical activity is associated with improvement in aerobic capacity and lower breast cancer risk, there are heritable sets of traits that affect improvement in aerobic capacity in response to physical activity. Although aerobic capacity segregates risk for a number of chronic diseases, the effect of the heritable component on cancer risk has not been evaluated. Therefore, we investigated breast carcinogenesis in rodent models of heritable fitness in the absence of induced physical activity. Female offspring of N:NIH rats selectively bred for low (LIAC) or high (HIAC) inherent aerobic capacity were injected intraperitoneally with 1-methyl-1-nitrosurea (70 mg/kg body wt). At study termination 33 weeks post-carcinogen, cancer incidence (14.0 versus 47.3%; P < 0.001) and multiplicity (0.18 versus 0.85 cancers per rat; P < 0.0001) were significantly decreased in HIAC versus LIAC rats, respectively. HIAC had smaller visceral and subcutaneous body fat depots than LIAC and activity of two proteins that regulated the mammalian target of rapamycin, protein kinase B (Akt), and adenosine monophosphate-activated protein kinase were suppressed and activated, respectively, in HIAC. Although many factors distinguish between HIAC and LIAC, it appears that the protective effect of HIAC against breast carcinogenesis is mediated, at least in part, via alterations in core metabolic signaling pathways deregulated in the majority of human breast cancers. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Mismatch repair pathway: molecules, functions, and role in colorectal carcinogenesis.

    Science.gov (United States)

    Sameer, Aga Syed; Nissar, Saniya; Fatima, Kaneez

    2014-07-01

    The microsatellite instability (MSI) pathway is one of the important mutational pathways that play a critical role in colorectal carcinogenesis. About 15% of colorectal cancers (CRCs) are characterized by MSI. MSI tumors usually arise because of a genetic defect in mismatch repair (MMR) genes, one of the main DNA-repairing systems. MMR is a highly conserved biological pathway that plays a key role in maintaining genomic stability by correcting the base-base mismatches and insertion/deletion mispairs generated during DNA replication and recombination. Escherichia coli MutS and MutL and their eukaryotic homologs, MutSα and MutLα, respectively, are key players in MMR-associated genome maintenance. Mutations in at least five pivotal genes of MMR, namely, in those encoding mutS homolog 2 (MSH2), mutL homolog 1 (MLH1), mutS homolog 6 (MSH6), postmeiotic segregation increased 1 (PMS1), and postmeiotic segregation, increased 2 (PMS2) have been found in CRC, highlighting the importance of understanding the basic structure and functions of the essential molecules that make up the MMR system. In this review, we have attempted to focus on this aspect, that is, the role that MMR molecules play in CRC carcinogenesis.

  13. Experimental photoimmunology: immunologic ramifications of UV-induced carcinogenesis

    International Nuclear Information System (INIS)

    Daynes, R.A.; Bernhard, E.J.; Gurish, M.F.; Lynch, D.H.

    1981-01-01

    The use of animal model systems to investigate the sequence of events which lead to the induction and progression of skin tumors following chronic ultraviolet light (UVL) exposure has clearly shown that the direct mutagenic effects of UVL is only one of the components involved in this process. In spite of the fact that overt carcinogenesis is only one of the many effects produced by UV light, most hypotheses as to the mechanism by which UVL can cause the mutations necessary to achieve the transformed phenotype have focused on the direct effects of UVL on DNA and the generation of carcinogenic compounds. Investigations during the last 5 yr, however, have clearly demonstrated that immunologic factors are also critically important in the pathogenesis of UV-induced skin cancers. A complete understanding of UV-carcinogenesis must therefore consider the mechanisms which allow the transformed cell to evade immunologic rejection by the host in addition to those aspects which deal with conversion of a normal cell to a cancer cell. It is the object of this review to provide both a historical account of the work which established the immunologic consequences of chronic UVL exposure and the results of recent experiments designed to investigate the kinetics and mechanisms by which UVL affects the immunologic apparatus. In addition, a hypothetical model is presented to explain the sequence of events which ultimately lead to the emergence of the suppressor T-cells which regulate antitumor immune responses

  14. Radiation carcinogenesis in context: how do irradiated tissues become tumors?

    Science.gov (United States)

    Barcellos-Hoff, Mary Helen; Nguyen, David H

    2009-11-01

    It is clear from experimental studies that genotype is an important determinant of cancer susceptibility in general, and for radiation carcinogenesis specifically. It has become increasingly clear that genotype influences not only the ability to cope with DNA damage but also influences the cooperation of other tissues, like the vasculature and immune system, necessary for the establishment of cancer. Our experimental data and that of others suggest that the carcinogenic action of ionizing radiation (IR) can also be considered a two-compartment problem: while IR can alter genomic sequence as a result of DNA damage, it can also induce signals that alter multicellular interactions and phenotypes that underpin carcinogenesis. Rather than being accessory or secondary to genetic damage, we propose that such non-targeted radiation effects create the critical context that promotes cancer development. This review focuses on experimental studies that clearly define molecular mechanisms by which cell interactions contribute to cancer in different organs, and addresses how non-targeted radiation effects may similarly act though the microenvironment. The definition of non-targeted radiation effects and their dose dependence could modify the current paradigms for radiation risk assessment since radiation non-targeted effects, unlike DNA damage, are amenable to intervention. The implications of this perspective in terms of reducing cancer risk after exposure are discussed.

  15. Sewage sludge does not induce genotoxicity and carcinogenesis

    Science.gov (United States)

    Silva, Paula Regina Pereira; Barbisan, Luis Fernando; Dagli, Maria Lúcia Zaidan; Saldiva, Paulo Hilário Nascimento

    2012-01-01

    Through a series of experiments, the genotoxic/mutagenic and carcinogenic potential of sewage sludge was assessed. Male Wistar rats were randomly assigned to four groups: Group 1 - negative control; Group 2 - liver carcinogenesis initiated by diethylnitrosamine (DEN; 200 mg/kg i.p.); Group 3 and G4-liver carcinogenesis initiated by DEN and fed 10,000 ppm or 50,000 ppm of sewage sludge. The animals were submitted to a 70% partial hepatectomy at the 3rd week. Livers were processed for routine histological analysis and immunohistochemistry, in order to detect glutathione S-transferase positive altered hepatocyte foci (GST-P+ AHF). Peripheral blood samples for the comet assay were obtained from the periorbital plexus immediately prior to sacrificing. Polychromatic erythrocytes (PCEs) were analyzed in femoral bone-marrow smears, and the frequencies of those micronucleated (MNPCEs) registered. There was no sewage-sludge-induced increase in frequency of either DNA damage in peripheral blood leucocytes, or MNPCEs in the femoral bone marrow. Also, there was no increase in the levels of DNA damage, in the frequency of MNPCEs, and in the development of GST-P AHF when compared with the respective control group. PMID:23055806

  16. Considerations for skin carcinogenesis experiments using inducible transgenic mouse models.

    Science.gov (United States)

    Popis, Martyna C; Wagner, Rebecca E; Constantino-Casas, Fernando; Blanco, Sandra; Frye, Michaela

    2018-01-24

    This study was designed to estimate the percentage of non-malignant skin tumours (papillomas) progressing to malignant squamous cell carcinomas (SCCs) in a carcinogenesis study using established transgenic mouse models. In our skin cancer model, we conditionally induced oncogenic point mutant alleles of p53 and k-ras in undifferentiated, basal cells of the epidermis. Upon activation of the transgenes through administration of tamoxifen, the vast majority of mice (> 80%) developed skin papillomas, yet primarily around the mouth. Since these tumours hindered the mice eating, they rapidly lost weight and needed to be culled before the papillomas progressed to SCCs. The mouth papillomas formed regardless of the route of application, including intraperitoneal injections, local application to the back skin, or subcutaneous insertion of a tamoxifen pellet. Implantation of a slow releasing tamoxifen pellet into 18 mice consistently led to papilloma formation, of which only one progressed to a malignant SCC. Thus, the challenges for skin carcinogenesis studies using this particular cancer mouse model are low conversion rates of papillomas to SCCs and high frequencies of mouth papilloma formation.

  17. Mitochondrial DNA variants in colorectal carcinogenesis: Drivers or passengers?

    Science.gov (United States)

    Errichiello, Edoardo; Venesio, Tiziana

    2017-10-01

    Mitochondrial DNA alterations have widely been reported in many age-related degenerative diseases and tumors, including colorectal cancer. In the past few years, the discovery of inter-genomic crosstalk between nucleus and mitochondria has reinforced the role of mitochondrial DNA variants in perturbing this essential signaling pathway and thus indirectly targeting nuclear genes involved in tumorigenic and invasive phenotype. Mitochondrial dysfunction is currently considered a crucial hallmark of carcinogenesis as well as a promising target for anticancer therapy. Mitochondrial DNA alterations include point mutations, deletions, inversions, and copy number variations, but numerous studies investigating their pathogenic role in cancer have provided inconsistent evidence. Furthermore, the biological impact of mitochondrial DNA variants may vary tremendously, depending on the proportion of mutant DNA molecules carried by the neoplastic cells (heteroplasmy). In this review, we discuss the role of different type of mitochondrial DNA alterations in colorectal carcinogenesis and, in particular, we revisit the issue of whether they may be considered as causative driver or simply genuine passenger events. The advent of high-throughput techniques as well as the development of genetic and pharmaceutical interventions for the treatment of mitochondrial dysfunction in colorectal cancer are also explored.

  18. Role of the chronic bacterial infection in urinary bladder carcinogenesis

    International Nuclear Information System (INIS)

    Higgy, N.A.

    1985-01-01

    The purpose of this thesis was to determine whether or not bacterial infection of the urinary bladder had a role in urinary bladder carcinogenesis. To investigate this proposition, four separate studies were conducted. The first study developed an experimental animal model where bacterial infection of the urinary bladder could be introduced and maintained for a period in excess of one year. The method of infection, inoculation of bacteria (Escherichia coli type 04) subserosally into the vesical wall, successfully caused persistent infection in the majority of animals. In the second study the temporal effects of bacterial infection on the induction of urothelial ornithine decarboxylase (ODC) and 3 H-thymidine uptake and DNA synthesis were examined. Bacterial infection of the urinary bladder induced urothelial ODC with a peak in enzyme activity 6 hr after infection. 3 H-Thymidine uptake and DNA synthesis peaked 48 hr after infection and coincided with the urothelial hyperplasia that occurred in response to the infection. In the third study the specific bladder carcinogen N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN) was given to rats concurrent with the urinary bacterial infection. In the fourth study rats were administered sodium nitrate and either dibutylamine or piperazine in the drinking water. The infected group developed bladder tumors while none were detected in the non-infected rats. From these studies it may be concluded that bacterial infection may have a significant role in the process of urinary bladder carcinogenesis

  19. [THE ROLE OF ESTROGENS IN THE CARCINOGENESIS OF LUNG CANCER].

    Science.gov (United States)

    Uchikova, E; Uchikov, A; Dimitrakova, E; Uchikov, P

    2016-01-01

    Morbidity and mortality from lung cancer has dramatically increased in women as compared to men over the past few years. Historically, smoking has been considered the major risk factor for lung cancer regardless of gender. Several recent lines of evidence implicate gender differences in the observed differences in prevalence and histologic type which cannot be explained based on the carcinogenic action of nicotine. Several recent studies underscore the importance of reproductive and hormonal factors in the carcinogenesis of lung cancer Lung cancer morbidity and mortality in Bulgaria was 16.2/100000 women and 14.6/ 100000 women, resp. Lung cancer morbidity in Europe was 39/100000 women. Lung cancer is extremely sensitive to estrogens. The latter act directly or as effect modifiers for the relationship between smoking and lung cancer. Further research examining the relationship between serum estrogen levels and the estrogen receptor expression in normal and tumor lung tissue samples can help elucidate the importance of reproductive and hormonal (exogenous and endogenous) factors in the carcinogenesis of lung cancer.

  20. E-cadherin: Its dysregulation in carcinogenesis and clinical implications.

    Science.gov (United States)

    Wong, Sonia How Ming; Fang, Chee Mun; Chuah, Lay-Hong; Leong, Chee Onn; Ngai, Siew Ching

    2018-01-01

    E-cadherin is a transmembrane glycoprotein which connects epithelial cells together at adherens junctions. In normal cells, E-cadherin exerts its tumour suppressing role mainly by sequestering β-catenin from its binding to LEF (Lymphoid enhancer factor)/TCF (T cell factor) which serves the function of transcribing genes of the proliferative Wnt signaling pathway. Despite the ongoing debate on whether the loss of E-cadherin is the cause or effect of epithelial-mesenchymal transition (EMT), E-cadherin functional loss has frequently been associated with poor prognosis and survival in patients of various cancers. The dysregulation of E-cadherin expression that leads to carcinogenesis happens mostly at the epigenetic level but there are cases of genetic alterations as well. E-cadherin expression has been linked to the cellular functions of invasiveness reduction, growth inhibition, apoptosis, cell cycle arrest and differentiation. Studies on various cancers have shown that these different cellular functions are also interdependent. Recent studies have reported a rapid expansion of E-cadherin clinical relevance in various cancers. This review article summarises the multifaceted effect E-cadherin expression has on cellular functions in the context of carcinogenesis as well as its clinical implications in diagnosis, prognosis and therapeutics. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. PHYSICO-CHEMICAL ASSESSMENT OF POMACE EXHAUSTED ...

    African Journals Online (AJOL)

    M’Sadak Y, Makhlouf M and El Amrouni S

    2016-05-01

    May 1, 2016 ... 2851. 6093. 3.1.2. Physico-chemical characterization. The physicochemical characteristics vary across different pomace oil extraction systems. (classic, press and continuous). Classical system. Table 2. Qualitative Characterization of pomace exhausted by the classical system. Parameters. Abbreviation.

  2. Physico-chemical Properties of Serendipity Berry ...

    African Journals Online (AJOL)

    This study evaluates the physico-chemical properties of serendipity berry. Physico-chemical properties of the serendipity berries were analyzed. The total number of berries in a bunch of fruit ranged from 45 to 98. This depends on the size of the bunch. The results revealed the dry matter, moisture, soluble solids and vitamin ...

  3. Physicochemical characteristics of Malaysian honeys influenced by ...

    African Journals Online (AJOL)

    Honey is a natural product that produced by honeybees or stingless bees. Consumers always found the best quality of honey by observing the physicochemical properties. However, storage time and temperature can affect the quality of honey. This study aimed to determine the physicochemical properties (moisture content, ...

  4. Phytochemical content, antioxidant capacity and physicochemical ...

    African Journals Online (AJOL)

    We investigated the antioxidant and physicochemical properties of pomegranate (Punica granatum cv. Bhagwa) fruit grown in three microclimates in South Africa. The physicochemical properties of fruit peel and arils differed among the growing locations, including weight and redness color of both peel and arils. Contents of ...

  5. Microbiological And Physicochemical Analyses Of Oil Contaminated ...

    African Journals Online (AJOL)

    Michael Horsfall

    The physicochemical properties of the soil samples analysed shows the pH ... Keywords: Oil contaminated soil, microbial isolates, mechanical workshops and physicochemical parameters. Pollution of the environment by petroleum ... strains capable of degrading Poly aromatic hydrocarbons have been isolated from soil and.

  6. Physico-chemical characterization and the in vitro genotoxicity of medical implants metal alloy (TiAlV and CoCrMo) and polyethylene particles in human lymphocytes.

    Science.gov (United States)

    Gajski, Goran; Jelčić, Zelimir; Oreščanin, Višnja; Gerić, Marko; Kollar, Robert; Garaj-Vrhovac, Vera

    2014-01-01

    The main objective of the present study was to investigate chemical composition and possible cyto/genotoxic potential of several medical implant materials commonly used in total hip joint replacement. Medical implant metal alloy (Ti6Al4V and CoCrMo) and high density polyethylene particles were analyzed by energy dispersive X-ray spectrometry while toxicological characterization was done on human lymphocytes using multi-biomarker approach. Energy dispersive X-ray spectrometry showed that none of the elements identified deviate from the chemical composition defined by appropriate ISO standard. Toxicological characterization showed that the tested materials were non-cyto/genotoxic as determined by the comet and cytokinesis-block micronucleus (CBMN) assay. Particle morphology was found (by using scanning electron and optical microscope) as flat, sharp-edged, irregularly shaped fiber-like grains with the mean particle size less than 10µm; this corresponds to the so-called "submicron wear". The very large surface area per wear volume enables high reactivity with surrounding media and cellular elements. Although orthopedic implants proved to be non-cyto/genotoxic, in tested concentration (10μg/ml) there is a constant need for monitoring of patients that have implanted artificial hips or other joints, to minimize the risks of any unwanted health effects. The fractal and multifractal analyses, performed in order to evaluate the degree of particle shape effect, showed that the fractal and multifractal terms are related to the "remnant" level of the particles' toxicity especially with the cell viability (trypan blue method) and total number of nucleoplasmic bridges and nuclear buds as CBMN assay parameters. © 2013.

  7. Comparative evaluation of physicochemical properties of jatropha curcas seed oil for coolant-lubricant application

    Science.gov (United States)

    Murad, Muhamad Nasir; Sharif, Safian; Rahim, Erween Abd.; Abdullah, Rozaini

    2017-09-01

    Increased attention to environmental issues due to industrial activities has forced the authorities raise awareness and implement regulations to reduce the use of mineral oil. Some vegetable oils unexplored or less explored, particularly the non-edible oils such as Jatropha curcas oil (JCO) and others. Physicochemical properties of JCO is compared with others edible oils, synthetic ester and fatty alcohol to obtain a viable alternative in metal cutting fluids. The oil was found to show the suitability of properties for coolant-lubricant applications in term of its physicochemical properties and better in flash point and viscosity value.

  8. Physico-chemical characterisation of particulate heavy metals from municipal solid waste incinerator emissions and their contributions to ambient air quality. Case of Toulon MSWI (South of France); Caracterisation physico-chimique et tracage des emissions particulaires metalliques d'une usine d'incineration d'ordures menageres dans l'air ambiant. Exemple de l'UIOM de Toulon (Var, France)

    Energy Technology Data Exchange (ETDEWEB)

    Le Floch, M

    2004-07-15

    The aims of this study are the physico-chemical characterisation, the apportionment and the following of particulate heavy metals from MSWI emissions. Various methods (in situ data treatment, unmixing models and codes, UNMIX or CMB, sequential extractions and extended X-ray absorption fine structure (EXAFS) agree in the following: - identification of the MSWI source in two profiles (Zn - Ca and Ba - Cu - Fe - Zn - Pb - Ca); - estimation of its contribution of up to 25% of the total sources contribution; - showing the seasonal variability in term of profile and contribution of this source; - suggest the potential of emitted elements to enter the food chain; This EXAFS first approach on atmospheric particulate matter shows that zinc and lead are in an atomic environment with calcium, silicon and aluminum. In spite of disputable conclusions, isotopic lead ratios define a 'MSWI' end-member and confirm that the town-center of Toulon is outside the MSWI plume influence. (author)

  9. Silver nanoparticles protect human keratinocytes against UVB radiation-induced DNA damage and apoptosis: potential for prevention of skin carcinogenesis

    Science.gov (United States)

    Arora, Sumit; Tyagi, Nikhil; Bhardwaj, Arun; Rusu, Lilia; Palanki, Rohan; Vig, Komal; Singh, Shree R.; Singh, Ajay P.; Palanki, Srinivas; Miller, Michael E.; Carter, James E.; Singh, Seema

    2015-01-01

    Ultraviolet (UV)-B radiation from the sun is an established etiological cause of skin cancer, which afflicts more than a million lives each year in the United States alone. Here, we tested the chemopreventive efficacy of silver-nanoparticles (AgNPs) against UVB-irradiation-induced DNA damage and apoptosis in human immortalized keratinocytes (HaCaT). AgNPs were synthesized by reduction-chemistry and characterized for their physicochemical properties. AgNPs were well tolerated by HaCaT cells and their pretreatment protected them from UVB-irradiation-induced apoptosis along with significant reduction in cyclobutane-pyrimidine-dimer formation. Moreover, AgNPs pre-treatment led to G1-phase cell-cycle arrest in UVB-irradiated HaCaT cells. AgNPs were efficiently internalized in UVB-irradiated cells and localized into cytoplasmic and nuclear compartments. Furthermore, we observed an altered expression of various genes involved in cell-cycle, apoptosis and nucleotide-excision repair in HaCaT cells treated with AgNPs prior to UVB-irradiation. Together, these findings provide support for potential utility of AgNPs as novel chemopreventive agents against UVB-irradiation-induced skin carcinogenesis. PMID:25804413

  10. Human AP Endonuclease 1: A Potential Marker for the Prediction of Environmental Carcinogenesis Risk

    Directory of Open Access Journals (Sweden)

    Jae Sung Park

    2014-01-01

    Full Text Available Human apurinic/apyrimidinic endonuclease 1 (APE1 functions mainly in DNA repair as an enzyme removing AP sites and in redox signaling as a coactivator of various transcription factors. Based on these multifunctions of APE1 within cells, numerous studies have reported that the alteration of APE1 could be a crucial factor in development of human diseases such as cancer and neurodegeneration. In fact, the study on the combination of an individual’s genetic make-up with environmental factors (gene-environment interaction is of great importance to understand the development of diseases, especially lethal diseases including cancer. Recent reports have suggested that the human carcinogenic risk following exposure to environmental toxicants is affected by APE1 alterations in terms of gene-environment interactions. In this review, we initially outline the critical APE1 functions in the various intracellular mechanisms including DNA repair and redox regulation and its roles in human diseases. Several findings demonstrate that the change in expression and activity as well as genetic variability of APE1 caused by environmental chemical (e.g., heavy metals and cigarette smoke and physical carcinogens (ultraviolet and ionizing radiation is likely associated with various cancers. These enable us to ultimately suggest APE1 as a vital marker for the prediction of environmental carcinogenesis risk.

  11. [The role of sonic hedgehog pathway in skin carcinogenesis].

    Science.gov (United States)

    Lesiak, Aleksandra; Sysa-Jedrzejowska, Anna; Narbutt, Joanna

    2010-08-01

    Non melanoma skin cancers (NMSC) involving basal (BCC)--and squamosus cell carcinomas (SCC) and are the most frequent skin cancers in Caucasians. Ultraviolet radiation is the main environmental risk factor for NMSC development. The aim of this paper is to review the latest opinions concerning the role of sonic hedgehog pathway in non-melanoma skin cancers development. Experimental data indicate that sonic hedgehog pathway might be involved in skin carcinogenesis. Under physiological conditions sonic hedgehog pathway is responsible for normal embryogenesis, regeneration of damaged tissues and for regulation of cell proliferation. It was revealed that UVR caused inactivated mutation in PATCHED gene encoding Ptch1 protein. These events lead to deregulation of sonic hedgehog pathway trough activation of Smo protein and Gli transcriptional factors what stimulates cell proliferation and in consequence NMSC development. Literature data indicate that understanding of molecular background of skin cancers might be a reason for introduction of new therapeutic approaches including sonic hedgehog pathway inhibitors.

  12. Chemical and radiation carcinogenesis in man and experimental animals

    International Nuclear Information System (INIS)

    Miller, J.A.; Miller, E.C.

    1975-01-01

    It is now well established that some cancer in man results from exposures to certain chemicals and radiations, both ultraviolet and ionizing radiations. These chemical and physical agents are also carcinogenic in experimental animals and, where adequately tested, in mammalian cell cultures. However, only very limited data are available on the relative roles of and the interrelationships, if any, between these various environmental agents in the causation of the majority of the cancers in man. Nothing is known of the relationship between these agents and possible carcinogenic viral information in the etiology of cancer in man. Furthermore, little is known about the molecular mechanisms by which chemicals and radiations induce cancers in either man or experimental animals. The objective of this brief review is to present certain aspects of chemical and radiation carcinogenesis in man and experimental animals and some of the problems in the elucidation of their roles in carinogenesis in the human

  13. Thymus in experimental carcinogenesis of the prostate gland.

    Science.gov (United States)

    Borodin, Yu I; Lomshakov, A A; Astashov, V V; Kazakov, O V; Mayorov, A P; Larionov, P M

    2014-10-01

    We studied structural changes in the prostate gland, thymus, and lymph nodes in CBA mice after transplantation of Ehrlich ascites tumor cells into the prostate gland. On experimental day 5, the number of blood and lymph vessels decreased in the gland; the percentage of connective tissue elements and glandular tissue and the number of immunoblasts in the thymus increased. On day 18, the number of blood vessels in the tumor decreased; the width of the cortex and glandular tissue increased in the thymus, while the number of immunoblasts was reduced. On day 28, tumor infiltration and increased number of lymphatic vessels in its stroma were observed; parenchyma was reduced, and the area of the connective tissue increased in the thymus. These structural changes indicated the development of accidental involution of the thymus during carcinogenesis of the prostate.

  14. Ovarian serous carcinoma: recent concepts on its origin and carcinogenesis

    Directory of Open Access Journals (Sweden)

    Li Jie

    2012-03-01

    Full Text Available Abstract Recent morphologic and molecular genetic studies have led to a paradigm shift in our conceptualization of the carcinogenesis and histogenesis of pelvic (non-uterine serous carcinomas. It appears that both low-grade and high-grade pelvic serous carcinomas that have traditionally been classified as ovarian in origin, actually originate, at least in a significant subset, from the distal fallopian tube. Clonal expansions of the tubal secretory cell probably give rise to serous carcinomas, and the degree of ciliated conversion is a function of the degree to which the genetic hits deregulate normal differentiation. In this article, the authors review the evidentiary basis for aforementioned paradigm shift, as well as its potential clinical implications.

  15. Pathogenesis and biomarkers of carcinogenesis in ulcerative colitis

    DEFF Research Database (Denmark)

    Thorsteinsdottir, Sigrun; Gudjonsson, Thorkell; Nielsen, Ole Haagen

    2011-01-01

    One of the most serious complications of ulcerative colitis is the development of colorectal cancer. Screening patients with ulcerative colitis by standard histological examination of random intestinal biopsy samples might be inefficient as a method of cancer surveillance. This Review focuses...... on the current understanding of the pathogenesis of ulcerative colitis-associated colorectal cancer and how this knowledge can be transferred into patient management to assist clinicians and pathologists in identifying patients with ulcerative colitis who have an increased risk of colorectal cancer. Inflammation....... Although progress has been made in the understanding of inflammation-driven carcinogenesis, markers based on these findings possess insufficient sensitivity or specificity to be usable as reliable biomarkers for risk of colorectal cancer development in patients with ulcerative colitis. However, screening...

  16. Studies on the multistage nature of radiation carcinogenesis

    International Nuclear Information System (INIS)

    Fry, R.J.M.; Ley, R.D.; Grube, D.; Staffeldt, E.

    1980-01-01

    With low dose levels of ionizing or ultraviolet radiation, the number of initiation events exceeds the number of tumors that grow to a detectable size. Ionizing radiation, which is a complete carcinogen, appears to be a more effective initiator than an enhancer or promoter. However, the initiation and promotion aspects of ionizing radiation have been studied in very few organ systems. In the case of UVR, with or without photosensitizers such as psoralens, the requirement of a relatively large number of exposures for carcinogenesis suggests that the expression of the initiated cells as frank tumors requires a number of events spread out over the time of the development of the tumor. Both ionizing and ultraviolet radiation are, perhaps, underutilized as tools for probing the mechanism of both initiation and promotion

  17. Collagen mRNA levels changes during colorectal cancer carcinogenesis

    DEFF Research Database (Denmark)

    Skovbjerg, Hanne; Anthonsen, Dorit; Lothe, Inger M B

    2009-01-01

    BACKGROUND: Invasive growth of epithelial cancers is a complex multi-step process which involves dissolution of the basement membrane. Type IV collagen is a major component in most basement membranes. Type VII collagen is related to anchoring fibrils and is found primarily in the basement membrane...... zone of stratified epithelia. Immunohistochemical studies have previously reported changes in steady-state levels of different alpha(IV) chains in several epithelial cancer types. In the present study we aimed to quantitatively determine the mRNA levels of type IV collagen (alpha1/alpha 4/alpha 6......) and type VII collagen (alpha1) during colorectal cancer carcinogenesis. METHODS: Using quantitative RT-PCR, we have determined the mRNA levels for alpha1(IV), alpha 4(IV), alpha 6(IV), and alpha1(VII) in colorectal cancer tissue (n = 33), adenomas (n = 29) and in normal tissue from the same individuals...

  18. Mechanistic modelling of genetic and epigenetic events in radiation carcinogenesis

    International Nuclear Information System (INIS)

    Andreev, S. G.; Eidelman, Y. A.; Salnikov, I. V.; Khvostunov, I. K.

    2006-01-01

    Methodological problems arise on the way of radiation carcinogenesis modelling with the incorporation of radiobiological and cancer biology mechanistic data. The results of biophysical modelling of different endpoints [DNA DSB induction, repair, chromosome aberrations (CA) and cell proliferation] are presented and applied to the analysis of RBE-LET relationships for radiation-induced neoplastic transformation (RINT) of C3H/10T1/2 cells in culture. Predicted values for some endpoints correlate well with the data. It is concluded that slowly repaired DSB clusters, as well as some kind of CA, may be initiating events for RINT. As an alternative interpretation, it is possible that DNA damage can induce RINT indirectly via epigenetic process. A hypothetical epigenetic pathway for RINT is discussed. (authors)

  19. Carcinogenesis related to intense pulsed light and UV exposure

    DEFF Research Database (Denmark)

    Hedelund, L; Lerche, C; Wulf, H C

    2006-01-01

    This study examines whether intense pulsed light (IPL) treatment has a carcinogenic potential itself or may influence ultraviolet (UV)-induced carcinogenesis. Secondly, it evaluates whether UV exposure may influence IPL-induced side effects. Hairless, lightly pigmented mice (n=144) received three...... IPL treatments at 2-week intervals. Simulated solar radiation was administered preoperatively [six standard erythema doses (SED) four times weekly for 11 weeks] as well as pre- and postoperatively (six SED four times weekly up to 26 weeks). Skin tumors were assessed weekly during a 12-month...... observation period. Side effects were evaluated clinically. No tumors appeared in untreated control mice or in just IPL-treated mice. Skin tumors developed in UV-exposed mice independently of IPL treatments. The time it took for 50% of the mice to first develop skin tumor ranged from 47 to 49 weeks...

  20. Human papillomaviruses and carcinogenesis: well-established and novel models.

    Science.gov (United States)

    Viarisio, Daniele; Gissmann, Lutz; Tommasino, Massimo

    2017-10-01

    Human papillomaviruses (HPVs) infect the cutaneous or mucosal epithelia and are classified phylogenetically as genera and species. Persistent infections by the mucosal high-risk (HR) HPV types from genus alpha are associated with cancer development of the genital and upper respiratory tracts. The products of two early genes, E6 and E7, are the major HR HPV oncoproteins, being essential in all steps of the carcinogenic process. Cutaneous beta HPV types are proposed, together with ultraviolet (UV) radiation, to promote non-melanoma skin cancer development. However, in contrast to the HR HPV types, beta HPV types appear to be required only at an early stage of carcinogenesis, facilitating the accumulation of UV-induced DNA mutations. Although findings in experimental models also suggest that beta HPV types and other carcinogens may synergize in the induction of malignancies, these possibilities need to be confirmed in human studies. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Protein expression analysis of inflammation-related colon carcinogenesis

    Directory of Open Access Journals (Sweden)

    Yasui Yumiko

    2009-01-01

    Full Text Available Background: Chronic inflammation is a risk factor for colorectal cancer (CRC development. The aim of this study was to determine the differences in protein expression between CRC and the surrounding nontumorous colonic tissues in the mice that received azoxymethane (AOM and dextran sodium sulfate (DSS using a proteomic analysis. Materials and Methods: Male ICR mice were given a single intraperitoneal injection of AOM (10 mg/kg body weight, followed by 2% (w/v DSS in their drinking water for seven days, starting one week after the AOM injection. Colonic adenocarcinoma developed after 20 weeks and a proteomics analysis based on two-dimensional gel electrophoresis and ultraflex TOF/TOF mass spectrometry was conducted in the cancerous and nontumorous tissue specimens. Results: The proteomic analysis revealed 21 differentially expressed proteins in the cancerous tissues in comparison to the nontumorous tissues. There were five markedly increased proteins (beta-tropomyosin, tropomyosin 1 alpha isoform b, S100 calcium binding protein A9, and an unknown protein and 16 markedly decreased proteins (Car1 proteins, selenium-binding protein 1, HMG-CoA synthase, thioredoxin 1, 1 Cys peroxiredoxin protein 2, Fcgbp protein, Cytochrome c oxidase, subunit Va, ETHE1 protein, and 7 unknown proteins. Conclusions: There were 21 differentially expressed proteins in the cancerous tissues of the mice that received AOM and DSS. Their functions include metabolism, the antioxidant system, oxidative stress, mucin production, and inflammation. These findings may provide new insights into the mechanisms of inflammation-related colon carcinogenesis and the establishment of novel therapies and preventative strategies to treat carcinogenesis in the inflamed colon.

  2. NADPH Oxidases and Their Roles in Skin Homeostasis and Carcinogenesis.

    Science.gov (United States)

    Rudolf, Jana; Raad, Houssam; Taieb, Alain; Rezvani, Hamid Reza

    2017-11-17

    Skin protects the body from dehydration, pathogens, and external mutagens. NADPH oxidases are central components for regulating the cellular redox balance. There is increasing evidence indicating that reactive oxygen species (ROS) generated by members of this enzyme family play important roles in the physiology and pathophysiology of the skin. Recent Advances: NADPH oxidases are active producers of ROS such as superoxide and hydrogen peroxide. Different isoforms are found in virtually all tissues. They play pivotal roles in normal cell homeostasis and in the cellular responses to various stressors. In particular, these enzymes are integral parts of redox-sensitive prosurvival and proapoptotic signaling pathways, in which they act both as effectors and as modulators. However, continuous (re)activation of NADPH oxidases can disturb the redox balance of cells, in the worst-case scenario in a permanent manner. Abnormal NADPH oxidase activity has been associated with a wide spectrum of diseases, as well as with aging and carcinogenesis. Sunlight with its beneficial and deleterious effects induces the activation of NADPH oxidases in the skin. Evidence for the important roles of this enzyme family in skin cancer and skin aging, as well as in many chronic skin diseases, is now emerging. Understanding the precise roles of NADPH oxidases in normal skin homeostasis, in the cellular responses to solar radiation, and during carcinogenesis will pave the way for their validation as therapeutic targets not only for the prevention and treatment of skin cancers but also for many other skin-related disorders. Antioxid. Redox Signal. 00, 000-000.

  3. Mushroom Ganoderma lucidum prevents colitis-associated carcinogenesis in mice.

    Directory of Open Access Journals (Sweden)

    Daniel Sliva

    Full Text Available Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT. The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice.Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP] and inflammation (dextran sodium sulfate [DSS] in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue.Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer.

  4. Paradoxes in carcinogenesis: New opportunities for research directions

    Directory of Open Access Journals (Sweden)

    Kramer Barnett S

    2007-08-01

    Full Text Available Abstract Background The prevailing paradigm in cancer research is the somatic mutation theory that posits that cancer begins with a single mutation in a somatic cell followed by successive mutations. Much cancer research involves refining the somatic mutation theory with an ever increasing catalog of genetic changes. The problem is that such research may miss paradoxical aspects of carcinogenesis for which there is no likely explanation under the somatic mutation theory. These paradoxical aspects offer opportunities for new research directions that should not be ignored. Discussion Various paradoxes related to the somatic mutation theory of carcinogenesis are discussed: (1 the presence of large numbers of spatially distinct precancerous lesions at the onset of promotion, (2 the large number of genetic instabilities found in hyperplastic polyps not considered cancer, (3 spontaneous regression, (4 higher incidence of cancer in patients with xeroderma pigmentosa but not in patients with other comparable defects in DNA repair, (5 lower incidence of many cancers except leukemia and testicular cancer in patients with Down's syndrome, (6 cancer developing after normal tissue is transplanted to other parts of the body or next to stroma previously exposed to carcinogens, (7 the lack of tumors when epithelial cells exposed to a carcinogen were transplanted next to normal stroma, (8 the development of cancers when Millipore filters of various pore sizes were was inserted under the skin of rats, but only if the holes were sufficiently small. For the latter paradox, a microarray experiment is proposed to try to better understand the phenomena. Summary The famous physicist Niels Bohr said "How wonderful that we have met with a paradox. Now we have some hope of making progress." The same viewpoint should apply to cancer research. It is easy to ignore this piece of wisdom about the means to advance knowledge, but we do so at our peril.

  5. Mechanisms of caffeine-induced inhibition of UVB carcinogenesis

    Directory of Open Access Journals (Sweden)

    Allan H Conney

    2013-06-01

    Full Text Available Sunlight-induced nonmelanoma skin cancer is the most prevalent cancer in the United States with more than 2 million cases per year. Several studies have shown an inhibitory effect of caffeine administration on UVB-induced skin cancer in mice, and these studies are paralleled by epidemiology studies that indicate an inhibitory effect of coffee drinking on nonmelanoma skin cancer in humans. Strikingly, decaffeinated coffee consumption had no such inhibitory effect.Mechanism studies indicate that caffeine has a sunscreen effect that inhibits UVB-induced formation of thymine dimers and sunburn lesions in the epidermis of mice. In addition, caffeine administration has a biological effect that enhances UVB-induced apoptosis thereby enhancing the elimination of damaged precancerous cells, and caffeine administration also enhances apoptosis in tumors. Caffeine administration enhances UVB-induced apoptosis by p53-dependent and p53-independent mechanisms. Exploration of the p53-independent effect indicated that caffeine administration enhanced UVB-induced apoptosis by inhibiting the UVB-induced increase in ATR-mediated formation of phospho-Chk1 (Ser345 and abolishing the UVB-induced decrease in cyclin B1 which resulted in caffeine-induced premature and lethal mitosis in mouse skin. In studies with cultured primary human keratinocytes, inhibition of ATR with siRNA against ATR inhibited Chk1 phosphorylation and enhanced UVB-induced apoptosis. Transgenic mice with decreased epidermal ATR function that were irradiated chronically with UVB had 69% fewer tumors at the end of the study compared with irradiated littermate controls with normal ATR function. These results, which indicate that genetic inhibition of ATR (like pharmacologic inhibition of ATR via caffeine inhibits UVB-induced carcinogenesis and supports the concept that ATR-mediated phosphorylation of Chk1 is an important target for caffeine’s inhibitory effect on UVB-induced carcinogenesis.

  6. Mushroom Ganoderma lucidum Prevents Colitis-Associated Carcinogenesis in Mice

    Science.gov (United States)

    Sliva, Daniel; Loganathan, Jagadish; Jiang, Jiahua; Jedinak, Andrej; Lamb, John G.; Terry, Colin; Baldridge, Lee Ann; Adamec, Jiri; Sandusky, George E.; Dudhgaonkar, Shailesh

    2012-01-01

    Background Epidemiological studies suggest that mushroom intake is inversely correlated with gastric, gastrointestinal and breast cancers. We have recently demonstrated anticancer and anti-inflammatory activity of triterpene extract isolated from mushroom Ganoderma lucidum (GLT). The aim of the present study was to evaluate whether GLT prevents colitis-associated carcinogenesis in mice. Methods/Principal Findings Colon carcinogenesis was induced by the food-borne carcinogen (2-Amino-1-methyl-6-phenylimidazol[4,5-b]pyridine [PhIP]) and inflammation (dextran sodium sulfate [DSS]) in mice. Mice were treated with 0, 100, 300 and 500 mg GLT/kg of body weight 3 times per week for 4 months. Cell proliferation, expression of cyclin D1 and COX-2 and macrophage infiltration was assessed by immunohistochemistry. The effect of GLT on XRE/AhR, PXR and rPXR was evaluated by the reporter gene assays. Expression of metabolizing enzymes CYP1A2, CYP3A1 and CYP3A4 in colon tissue was determined by immunohistochemistry. GLT treatment significantly suppressed focal hyperplasia, aberrant crypt foci (ACF) formation and tumor formation in mice exposed to PhIP/DSS. The anti-proliferative effects of GLT were further confirmed by the decreased staining with Ki-67 in colon tissues. PhIP/DSS-induced colon inflammation was demonstrated by the significant shortening of the large intestine and macrophage infiltrations, whereas GLT treatment prevented the shortening of colon lengths, and reduced infiltration of macrophages in colon tissue. GLT treatment also significantly down-regulated PhIP/DSS-dependent expression of cyclin D1, COX-2, CYP1A2 and CYP3A4 in colon tissue. Conclusions Our data suggest that GLT could be considered as an alternative dietary approach for the prevention of colitis-associated cancer. PMID:23118901

  7. Relevance of CCL3/CCR5 axis in oral carcinogenesis.

    Science.gov (United States)

    da Silva, Janine Mayra; Moreira Dos Santos, Tálita Pollyanna; Sobral, Lays Martin; Queiroz-Junior, Celso Martins; Rachid, Milene Alvarenga; Proudfoot, Amanda E I; Garlet, Gustavo Pompermaier; Batista, Aline Carvalho; Teixeira, Mauro Martins; Leopoldino, Andréia Machado; Russo, Remo Castro; Silva, Tarcília Aparecida

    2017-08-01

    The chemokine CCL3 is a chemotactic cytokine crucial for inflammatory cell recruitment in homeostatic and pathological conditions. CCL3 might stimulate cancer progression by promoting leukocyte accumulation, angiogenesis and tumour growth. The expression of CCL3 and its receptors CCR1 and CCR5 was demonstrated in oral squamous cell carcinoma (OSCC), but their role was not defined. Here, the functions of CCL3 were assessed using a model of chemically induced tongue carcinogenesis with 4-nitroquinoline-1-oxide (4NQO). Lineages of OSCC were used to analyse the effects of CCL3 in vitro . The 4NQO-induced lesions exhibited increased expression of CCL3, CCR1 and CCR5. CCL3 -/- and CCR5 -/- mice presented reduced incidence of tongue tumours compared to wild-type (WT) and CCR1 -/- mice. Consistently, attenuated cytomorphological atypia and reduced cell proliferation were observed in lesions of CCL3 -/- and CCR5 -/- mice. OSCC from CCL3 -/- mice exhibited lower infiltration of eosinophils and reduced expression of Egf, Fgf1, Tgf-β1, Vegfa, Vegfb, Itga-4, Vtn, Mmp-1a, Mmp-2 and Mmp-9 than WT mice. In vitro , CCL3 induced invasion and production of CCL5, IL-6, MMP -2, -8, -9. Blockage of CCL3 in vitro using α-CCL3 or Evasin-1 (a CCL3-binding protein) impaired tumour cell invasion. In conclusion, CCL3/CCR5 axis has pro-tumourigenic effects in oral carcinogenesis. The induction of inflammatory and angiogenic pathways and eosinophils recruitment appear to be the underlying mechanism explaining these effects. These data reveal potential protective effects of CCL3 blockade in oral cancer.

  8. Present status of theories and data analyses of mathematical models for carcinogenesis

    International Nuclear Information System (INIS)

    Kai, Michiaki; Kawaguchi, Isao

    2007-01-01

    Reviewed are the basic mathematical models (hazard functions), present trend of the model studies and that for radiation carcinogenesis. Hazard functions of carcinogenesis are described for multi-stage model and 2-event model related with cell dynamics. At present, the age distribution of cancer mortality is analyzed, relationship between mutation and carcinogenesis is discussed, and models for colorectal carcinogenesis are presented. As for radiation carcinogenesis, models of Armitage-Doll and of generalized MVK (Moolgavkar, Venson, Knudson, 1971-1990) by 2-stage clonal expansion have been applied to analysis of carcinogenesis in A-bomb survivors, workers in uranium mine (Rn exposure) and smoking doctors in UK and other cases, of which characteristics are discussed. In analyses of A-bomb survivors, models above are applied to solid tumors and leukemia to see the effect, if any, of stage, age of exposure, time progression etc. In miners and smokers, stages of the initiation, promotion and progression in carcinogenesis are discussed on the analyses. Others contain the analyses of workers in Canadian atomic power plant, and of patients who underwent the radiation therapy. Model analysis can help to understand the carcinogenic process in a quantitative aspect rather than to describe the process. (R.T.)

  9. Physico-chemical composition and radicalscavenging activity ...

    African Journals Online (AJOL)

    Physico-chemical composition and radicalscavenging activity evaluation of the extracts of Aristolochia albida Duch. (Aristolochiaceae) of Benin. Félix F.D. Guinnin, Isabelle T. Sacramento, Jean-Marc Ategbo, Cocou Dossa Pascal Agbangnan ...

  10. Physicochemically functional ultrathin films by interfacial polymerization

    Science.gov (United States)

    Lonsdale, Harold K.; Babcock, Walter C.; Friensen, Dwayne T.; Smith, Kelly L.; Johnson, Bruce M.; Wamser, Carl C.

    1990-01-01

    Interfacially-polymerized ultrathin films containing physicochemically functional groups are disclosed, both with and without supports. Various applications are disclsoed, including membrane electrodes, selective membranes and sorbents, biocompatible materials, targeted drug delivery, and narrow band optical absorbers.

  11. Evaluation of some physicochemical parameters and benthic ...

    African Journals Online (AJOL)

    Evaluation of some physicochemical parameters and benthic macroinvertebrates of Ikere Gorge Reservoir in Oyo State, Nigeria. ... Reservoir is relatively under stress due to dominance of indicators of pollution. Keywords: Anthropogenic activities, Bioindicator, Ikere Gorge Reservoir, Melanoides tuberculata, Water quality.

  12. 3d-METAL COMPLEXES WITH BARBITURIC ACID DERIVATIVES

    Directory of Open Access Journals (Sweden)

    T. V. Koksharova

    2015-04-01

    Full Text Available The various aspects of the 3d-metal complexes with barbiturates and uric acid chemistry such as composition, structure, physicochemical properties, possible fields of application – have been illustrated in this review

  13. Physicochemical, heavy metal and mineral elements assessment of ...

    African Journals Online (AJOL)

    The Benin-Agbor road is a major road linking Edo State and the Eastern states of Nigeria, characterized by daily vehicular movements. The inhabitants of the area depend on the river waters mainly for their domestic purposes. It was against the above background that this research was conducted in order to assess the ...

  14. Physico-chemical properties and heavy metal content of water ...

    African Journals Online (AJOL)

    user

    The water quality examination in Ife–North Local Government of Osun State Nigeria was conducted by determining the physico–chemical parameters of 40 samples. Surface water, bore holes, wells and pipe borne water samples were collected from major towns in the Local Government Area and analyzed. Results showed ...

  15. Heavy Metals and Physicochemical Properties of Soils in Kano ...

    African Journals Online (AJOL)

    12o 08' N; and longitude 8o34' to 8o 42' E. Three irrigation sites each (Yansama, Sharada and Rafin .... use in batteries, alloys, pigments, plastics and their discharge through domestic and industrial sewages ... showed relatively low mobility to the exchange complex in comparison to the total amount in the soil across all ...

  16. Effects of environmental stressors on histone modifications and their relevance to carcinogenesis: a systematic review.

    NARCIS (Netherlands)

    Dik, S.; Scheepers, P.T.J.; Godderis, L.

    2012-01-01

    Carcinogenesis is a complex process involving both genetic and epigenetic mechanisms. The cellular molecular epigenetic machinery, including histone modifications, is associated with changes in gene expression induced by exposure to environmental agents. In this paper, we systematically reviewed

  17. Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Tanaka, Takuji [Cytopatholgy Division, Tohkai Cytopathology Institute, Cancer Research and Prevention (TCI-CaRP), 5-1-2 Minami-uzura, Gifu 500-8285 (Japan); Department of Tumor Pathology, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194 (Japan)

    2012-07-16

    Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described.

  18. Modulation of Estrogen Chemical Carcinogenesis by Botanical Supplements used for Postmenopausal Women’s Health

    Science.gov (United States)

    Snelten, Courtney S.; Dietz, Birgit; Bolton, Judy L.

    2012-01-01

    Breast cancer risk has been associated with long-term estrogen exposure including traditional hormone therapy (HT, formally hormone replacement therapy). To avoid traditional HT and associated risks, women have been turning to botanical supplements such as black cohosh, red clover, licorice, hops, dong gui, and ginger to relieve menopausal symptoms despite a lack of efficacy evidence. The mechanisms of estrogen carcinogenesis involve both hormonal and chemical pathways. Botanical supplements could protect women from estrogen carcinogenesis by modulating key enzymatic steps [aromatase, P4501B1, P4501A1, catechol-O-methyltransferase (COMT), NAD(P)H quinone oxidoreductase 1 (NQO1), and reactive oxygen species (ROS) scavenging] in estradiol metabolism leading to estrogen carcinogenesis as outlined in Figure 1. This review summarizes the influence of popular botanical supplements used for women’s health on these key steps in the estrogen chemical carcinogenesis pathway, and suggests that botanical supplements may have added chemopreventive benefits by modulating estrogen metabolism. PMID:24223609

  19. Preclinical Cancer Chemoprevention Studies Using Animal Model of Inflammation-Associated Colorectal Carcinogenesis

    International Nuclear Information System (INIS)

    Tanaka, Takuji

    2012-01-01

    Inflammation is involved in all stages of carcinogenesis. Inflammatory bowel disease, such as ulcerative colitis and Crohn’s disease is a longstanding inflammatory disease of intestine with increased risk for colorectal cancer (CRC). Several molecular events involved in chronic inflammatory process are reported to contribute to multi-step carcinogenesis of CRC in the inflamed colon. They include over-production of free radicals, reactive oxygen and nitrogen species, up-regulation of inflammatory enzymes in arachidonic acid biosynthesis pathway, up-regulation of certain cytokines, and intestinal immune system dysfunction. In this article, firstly I briefly introduce our experimental animal models where colorectal neoplasms rapidly develop in the inflamed colorectum. Secondary, data on preclinical cancer chemoprevention studies of inflammation-associated colon carcinogenesis by morin, bezafibrate, and valproic acid, using this novel inflammation-related colorectal carcinogenesis model is described

  20. Age and Space Irradiation Modulate Tumor Progression: Implications for Carcinogenesis Risk

    Data.gov (United States)

    National Aeronautics and Space Administration — Age plays a major role in tumor incidence and is an important consideration when modeling the carcinogenesis process or estimating cancer risks. Epidemiological data...

  1. Investigating the Role of FIP200 in Mammary Carcinogenesis Using a Transgenic Mouse Model

    National Research Council Canada - National Science Library

    Nagy, Tamas

    2007-01-01

    ...) deletion in mammary-specific polyoma middle-T transgenic mice. We monitored mammary carcinogenesis in positive control (FAKFlox/Flox; MMTV-PyVT) and target (FAKFlox/Flox; MMTV-Cre; MMTV-PyVT) females...

  2. Chronic Inflammation in Colorectal Carcinogenesis: Role of Inflammatory Mediators, Intestinal Microbes, and Chemoprevention Potency

    OpenAIRE

    Tedja, Irwin; Abdullah, Murdani

    2013-01-01

    Colorectal carcinogenesis is a multi-factorial process which involves accumulation of genetic defect, protein modification, and cell interaction with matrix in colonic epithelial cells. Chronic inflammation is suspected to play role in carcinogenesis by inhibiting apoptosis, impairing DNA, and chronically stimulating mucosal proliferation. Alteration in intestinal microbes' population, either in one particular species or in overall composition, may also cause chronic inflammation which increa...

  3. The level of claudin-7 is reduced as an early event in colorectal carcinogenesis

    DEFF Research Database (Denmark)

    Lange, Jette Bornholdt; Friis, Stine; Godiksen, Sine

    2011-01-01

    -regulation of the oncogenic serine protease, matriptase, induces leakiness in epithelial barriers both in vivo and in vitro. We found in an in-silico search tight co-regulation between matriptase and claudin-7 expression. We have previously shown that the matriptase expression level decreases during colorectal carcinogenesis....... In the present study we investigated whether claudin-7 expression is likewise decreased during colorectal carcinogenesis, thereby causing or contributing to the compromised epithelial leakiness of dysplastic tissue....

  4. Chemoprevention of glandular stomach carcinogenesis through duodenogastric reflux in rats by a COX-2 inhibitor.

    OpenAIRE

    Oba, Masaru; Miwa, Koichi; Fujimura, Takashi; Harada, Shin-ichi; Sasaki, Shozo; Hattori, Takanori

    2008-01-01

    Duodenogastric reflux (DGR) causes glandular stomach carcinogenesis in rats without carcinogens. We aimed to investigate how this carcinogenesis might be prevented by a selective COX-2 inhibitor, meloxicam. A series of 188 Fisher 344 rats underwent a surgical DGR procedure and were divided into 2 groups. One group was given commercial chow (control group), and the other an experimental chow containing meloxicam [0.3 mg/kg bw/day] (meloxicam group). The animals were sequentially sacrificed at ...

  5. Pulmonary Oxidative Stress, Inflammation and Cancer: Respirable Particulate Matter, Fibrous Dusts and Ozone as Major Causes of Lung Carcinogenesis through Reactive Oxygen Species Mechanisms

    Directory of Open Access Journals (Sweden)

    Spyridon Loridas

    2013-08-01

    Full Text Available Reactive oxygen or nitrogen species (ROS, RNS and oxidative stress in the respiratory system increase the production of mediators of pulmonary inflammation and initiate or promote mechanisms of carcinogenesis. The lungs are exposed daily to oxidants generated either endogenously or exogenously (air pollutants, cigarette smoke, etc.. Cells in aerobic organisms are protected against oxidative damage by enzymatic and non-enzymatic antioxidant systems. Recent epidemiologic investigations have shown associations between increased incidence of respiratory diseases and lung cancer from exposure to low levels of various forms of respirable fibers and particulate matter (PM, at occupational or urban air polluting environments. Lung cancer increases substantially for tobacco smokers due to the synergistic effects in the generation of ROS, leading to oxidative stress and inflammation with high DNA damage potential. Physical and chemical characteristics of particles (size, transition metal content, speciation, stable free radicals, etc. play an important role in oxidative stress. In turn, oxidative stress initiates the synthesis of mediators of pulmonary inflammation in lung epithelial cells and initiation of carcinogenic mechanisms. Inhalable quartz, metal powders, mineral asbestos fibers, ozone, soot from gasoline and diesel engines, tobacco smoke and PM from ambient air pollution (PM10 and PM2.5 are involved in various oxidative stress mechanisms. Pulmonary cancer initiation and promotion has been linked to a series of biochemical pathways of oxidative stress, DNA oxidative damage, macrophage stimulation, telomere shortening, modulation of gene expression and activation of transcription factors with important role in carcinogenesis. In this review we are presenting the role of ROS and oxidative stress in the production of mediators of pulmonary inflammation and mechanisms of carcinogenesis.

  6. Short-term carcinogenesis evaluation of Casearia sylvestris

    Directory of Open Access Journals (Sweden)

    Cleide A.S. Tirloni

    Full Text Available Abstract Casearia sylvestris Sw., Salicaceae, is an important medicinal plant widely used in Brazil for the treatment of various cardiovascular disorders. This species was included as of interest by Brazilian Unified Health System. Although preclinical studies described cardiovascular protective effects and apparent absence of toxicity, no studies have evaluated its carcinogenic potential. In this study, we proposed a short-term carcinogenesis evaluation of C. sylvestris in Wistar rats, aiming to check the safety of this species to use it as proposed by Brazilian Unified Health System. C. sylvestris leaves were obtained and the crude extract was prepared by maceration from methanol/water. Wistar rats were orally treated for 12 weeks with 50, 250 or 500 mg kg−1 of crude extract or vehicle. Body weight, daily morbidity and mortality were monitored. Blood and bone marrow samples were collect for micronucleus test, comet assay and tumor markers evaluation. Vital organs were removed to macro and histopathological analyses. The crude extract did not induce mutagenic and genotoxic effects and no alterations were observed in important tumor markers. Finally, no detectable signs of injury through gross pathology or histopathological examinations were observed. Our results certify the absence of the crude extract toxicity, indicating its safety, even at prolonged exposure as proposed by Brazilian Unified Health System.

  7. Effects of retinoids on ultraviolet-induced carcinogenesis

    International Nuclear Information System (INIS)

    Epstein, J.H.

    1981-01-01

    The evidence for effects of the retinoids on UV-induced carcinogenesis is sparse. Clinical observations indicate that topical RA can cause significant regression of premalignant actinic keratoses. Also there is some evidence that this agent can cause dissolution of some basal cell epitheliomas. However this latter effect does not appear to be of therapeutic value. Systemic retinoids are of little value in the treatment of premalignant and malignant cutaneous lesions though 13-cis-retinoic acid might be of use in the basal cell nevus syndrome. Examination of the influence of the retinoids on photocarcinogenesis essentially has been confined to RA and animal experimentation. RA in nontoxic concentrations can both stimulate and inhibit photocarcinogenesis depending upon the circumstances of the study. The mechanisms of these responses are not clear. Influences on DNA synthesis directly and/or indirectly or on immune responses may be involved in both effects. Preliminary studies with oral 13-cis-retinoic acid have not demonstrated any effects to date on UV-induced skin cancer formation

  8. Recent Concepts of Ovarian Carcinogenesis: Type I and Type II

    Directory of Open Access Journals (Sweden)

    Masafumi Koshiyama

    2014-01-01

    Full Text Available Type I ovarian tumors, where precursor lesions in the ovary have clearly been described, include endometrioid, clear cell, mucinous, low grade serous, and transitional cell carcinomas, while type II tumors, where such lesions have not been described clearly and tumors may develop de novo from the tubal and/or ovarian surface epithelium, comprise high grade serous carcinomas, undifferentiated carcinomas, and carcinosarcomas. The carcinogenesis of endometrioid and clear cell carcinoma (CCC arising from endometriotic cysts is significantly influenced by the free iron concentration, which is associated with cancer development through the induction of persistent oxidative stress. A subset of mucinous carcinomas develop in association with ovarian teratomas; however, the majority of these tumors do not harbor any teratomatous component. Other theories of their origin include mucinous metaplasia of surface epithelial inclusions, endometriosis, and Brenner tumors. Low grade serous carcinomas are thought to evolve in a stepwise fashion from benign serous cystadenoma to a serous borderline tumor (SBT. With regard to high grade serous carcinoma, the serous tubal intraepithelial carcinomas (STICs of the junction of the fallopian tube epithelium with the mesothelium of the tubal serosa, termed the “tubal peritoneal junction” (TPJ, undergo malignant transformation due to their location, and metastasize to the nearby ovary and surrounding pelvic peritoneum. Other theories of their origin include the ovarian hilum cells.

  9. BRAFV600E: implications for carcinogenesis and molecular therapy.

    LENUS (Irish Health Repository)

    Cantwell-Dorris, Emma R

    2012-02-01

    The mitogen-activated protein kinase (MAPK)\\/extracellular signal-regulated kinase (ERK) pathway is frequently mutated in human cancer. This pathway consists of a small GTP protein of the RAS family that is activated in response to extracellular signaling to recruit a member of the RAF kinase family to the cell membrane. Active RAF signals through MAP\\/ERK kinase to activate ERK and its downstream effectors to regulate a wide range of biological activities including cell differentiation, proliferation, senescence, and survival. Mutations in the v-raf murine sarcoma viral oncogenes homolog B1 (BRAF) isoform of the RAF kinase or KRAS isoform of the RAS protein are found as activating mutations in approximately 30% of all human cancers. The BRAF pathway has become a target of interest for molecular therapy, with promising results emerging from clinical trials. Here, the role of the most common BRAF mutation BRAF(V600E) in human carcinogenesis is investigated through a review of the literature, with specific focus on its role in melanoma, colorectal, and thyroid cancers and its potential as a therapeutic target.

  10. [Gut microbiota: What impact on colorectal carcinogenesis and treatment?

    Science.gov (United States)

    Bruneau, Antoine; Baylatry, Minh-Tam; Joly, Anne Christine; Sokol, Harry

    2018-01-01

    The gut microbiota, composed of 10 14 microorganisms, is now considered as a "hidden organ", regarding to its digestive, metabolic and immune functions, which are helpful to its host. For the last 15 years, advances in molecular biology have highlighted the association of gut microbiota dysbiosis with several diseases, including colorectal cancer. An increased abundance of some bacteria (including Fusobacterium nucleatum, Bacteroides fragilis, Escherichia coli) is associated with cancer, whereas others seem to be protective (Faecalibacterium prausnitzii). Several mechanisms, which are species-specific, are involved in colorectal carcinogenesis. Most of the time, bacterial toxins are involved in pro-inflammatory processes and in activation of angiogenesis and cellular proliferation pathways. The identification of these bacteria leads to envisage the gut microbiota as potential screening tool for colorectal cancer. Recent studies showed a relation between the gut microbiota and the efficacy and toxicity of chemotherapies (oxaliplatin, irinotecan) and immunotherapies (including ipilimumab). Therapeutic approaches targeting the gut microbiota are now available (probiotics, fecal microbiota transplantation…). New therapeutic strategy combining both chemotherapy and/or immunotherapy with an adjuvant treatment targeting the gut microbiota can now be developed in order to improve treatment response and tolerance. Copyright © 2017 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  11. HPV16 E7 Genetic Conservation Is Critical to Carcinogenesis.

    Science.gov (United States)

    Mirabello, Lisa; Yeager, Meredith; Yu, Kai; Clifford, Gary M; Xiao, Yanzi; Zhu, Bin; Cullen, Michael; Boland, Joseph F; Wentzensen, Nicolas; Nelson, Chase W; Raine-Bennett, Tina; Chen, Zigui; Bass, Sara; Song, Lei; Yang, Qi; Steinberg, Mia; Burdett, Laurie; Dean, Michael; Roberson, David; Mitchell, Jason; Lorey, Thomas; Franceschi, Silvia; Castle, Philip E; Walker, Joan; Zuna, Rosemary; Kreimer, Aimée R; Beachler, Daniel C; Hildesheim, Allan; Gonzalez, Paula; Porras, Carolina; Burk, Robert D; Schiffman, Mark

    2017-09-07

    Although most cervical human papillomavirus type 16 (HPV16) infections become undetectable within 1-2 years, persistent HPV16 causes half of all cervical cancers. We used a novel HPV whole-genome sequencing technique to evaluate an exceptionally large collection of 5,570 HPV16-infected case-control samples to determine whether viral genetic variation influences risk of cervical precancer and cancer. We observed thousands of unique HPV16 genomes; very few women shared the identical HPV16 sequence, which should stimulate a careful re-evaluation of the clinical implications of HPV mutation rates, transmission, clearance, and persistence. In case-control analyses, HPV16 in the controls had significantly more amino acid changing variants throughout the genome. Strikingly, E7 was devoid of variants in precancers/cancers compared to higher levels in the controls; we confirmed this in cancers from around the world. Strict conservation of the 98 amino acids of E7, which disrupts Rb function, is critical for HPV16 carcinogenesis, presenting a highly specific target for etiologic and therapeutic research. Published by Elsevier Inc.

  12. LTA4H regulates cell cycle and skin carcinogenesis.

    Science.gov (United States)

    Oi, Naomi; Yamamoto, Hiroyuki; Langfald, Alyssa; Bai, Ruihua; Lee, Mee-Hyun; Bode, Ann M; Dong, Zigang

    2017-07-01

    Leukotriene A4 hydrolase (LTA4H), a bifunctional zinc metallo-enzyme, is reportedly overexpressed in several human cancers. Our group has focused on LTA4H as a potential target for cancer prevention and/or therapy. In the present study, we report that LTA4H is a key regulator of cell cycle at the G0/G1 phase acting by negatively regulating p27 expression in skin cancer. We found that LTA4H is overexpressed in human skin cancer tissue. Knocking out LTA4H significantly reduced skin cancer development in the 7,12-dimethylbenz(a)anthracene (DMBA)-initiated/12-O-tetradecanoylphorbol-13-acetate (TPA)-promoted two-stage skin cancer mouse model. LTA4H depletion dramatically decreased anchorage-dependent and -independent skin cancer cell growth by inducing cell cycle arrest at the G0/G1 phase. Moreover, our findings showed that depletion of LTA4H enhanced p27 protein stability, which was associated with decreased phosphorylation of CDK2 at Thr160 and inhibition of the CDK2/cyclin E complex, resulting in down-regulated p27 ubiquitination. These findings indicate that LTA4H is critical for skin carcinogenesis and is an important mediator of cell cycle and the data begin to clarify the mechanisms of LTA4H's role in cancer development. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Influence of the physicochemical characteristics of pollutants on their uptake in moss

    Science.gov (United States)

    Varela, Z.; Fernández, J. A.; Real, C.; Carballeira, A.; Aboal, J. R.

    2015-02-01

    Bryophytes are commonly used as biomonitors to estimate the atmospheric deposition of heavy metals and metalloids. However, the tissue concentrations of these elements in moss do not always accurately reflect atmospheric levels. The aim of the present study was to investigate whether element uptake in moss is affected by the physicochemical characteristics of the elements. Factor analysis was used to identify any patterns of covariance in the accumulation of elements in samples of the moss Pseudoscleropodium purum collected from the surroundings of different factories and from control sites. The variation in the concentrations of elements was similar in moss from both types of sites and was related to the binding properties of the elements. This suggests that the physicochemical characteristics of the elements determine the uptake of metals and metalloids from the atmosphere. Therefore, in studies that use multiple correlations among elements as indicators of a common origin of contaminants, erroneous conclusions may be reached by overlooking the adsorption properties of the moss.

  14. Physicochemical characterization and antibacterial activity of Rajata Bhasma and silver nanoparticle

    OpenAIRE

    Sharma, Revati; Bhatt, Ahsan; Thakur, Mansee

    2016-01-01

    Introduction: Bhasma, an Ayurvedic metallo-mineral preparation, is claimed to be biologically produced nanoparticles. Rajata (silver) is a noble metal known for its antimicrobial activity. Rajata Bhasma (RB) is expected to be composed of nanoparticles. With all these facts in place, this study was conducted to evaluate RB for the presence of silver nanoparticle (SNP) and its antimicrobial effect. Aim: The aim of this study is to analyze the physicochemical characterization, antibacterial acti...

  15. Physico-chemical parameters of soil in some selected dumpsites in ...

    African Journals Online (AJOL)

    Physico-chemical parameters of soil were found to have influence on the availability of heavy metals in plants. pH values recorded in the control site ranges from 7.8 to 9.2 indicating that all the soils studied were alkaline. The control site has a value of 7.16. The conductivity values range from 4.2 x 10-2 to 4.0x105μScm-1 .

  16. Trace metal speciation in the Baltic sea

    OpenAIRE

    Gelting, Johan

    2006-01-01

    Physicochemical speciation of metals in natural waters is very important for understanding their distribution, mobility, bioavailability and toxicity. To be able to understand the behaviour of an aqueous element and the transformation between chemical and physical species, there is a need for reliable methods that enable measurements of specific fractions of metals. Many different techniques are used for metal speciation, of which many suffer from problems. Ultrafiltration has frequently been...

  17. The Physicochemical Quality of Traditional Burduf Cheese

    Directory of Open Access Journals (Sweden)

    Carmen Pop

    2013-11-01

    Full Text Available The aim of this study is the assessmentof the quality control of raw milk and traditional burduf cheese obtained fromcow milk mixed with 10% sheep milk. Appreciation of the integrity and freshness assessmentof milk (cow and sheep was tested by physico-chemical analysis.On theshelf-live were determined the physico-chemical parameters in cheese samples. Theantibiotics residues were tested of the milk samples with portable analyser,model Rosa Charm Reader. Theresults of physico-chemical determinations for the milk and cheese samples werewithin the maximum permissible by data legislation. Regardingthe content of antibiotics, the results were negative both for cow milk and forsheep milk. The sensorycharacteristics of burduf cheese are influenced by the different types of milk.

  18. Modeling the accumulation of As, Cd, Cu, Pb and Zn in grasses (Agrotis sp. and Poa sp. and stinging nettle (Urtica dioica on selected sites taking into account soil physico-chemical properties

    Directory of Open Access Journals (Sweden)

    Boshoff M. C.

    2013-04-01

    Full Text Available The effect of soil properties on the accumulation of metals in two vegetation types was evaluated at 10 sites with a wide variation in soil physicochemical properties pH, organic carbon, clay percentage , total soil metal concentration and exchangeable soil metal content. Accumulation modeling was conducted for grasses (Agrostis sp. and Poa sp. and stinging nettle (Urtica dioica.

  19. Actinide physicochemical data assessment and selection

    International Nuclear Information System (INIS)

    Navratil, J.D.

    1984-01-01

    There is a continuing need to have reliable physicochemical data of actinide compounds and actinide elements in aqueous solution available for nuclear engineers and scientists. These data are needed for all aspects of the nuclear fuel cycle - from the behavior of actinides in reactor fuels at high temperature and pressure to actinide behavior in geologic depository environments. This paper summarizes the status of actinide physicochemical data assessment and selection. The topics to be covered include data assessment of chemical thermodynamic properties and solubilities of actinide compounds and solution equilibria of the actinides

  20. Immunophenotypic Analysis in Early Müllerian Serous Carcinogenesis.

    Science.gov (United States)

    Nafisi, Houman; Ghorab, Zeina; Ismill, Nadia; Dubé, Valerie; Plotkin, Anna; Han, Guangming; Cesari, Matthew; Lu, Fang-I; Saad, Reda; Khalifa, Mahmoud; Nofech-Mozes, Sharon

    2015-09-01

    Studies on the immunophenotypes of early forms of serous carcinoma arising from female genital tract are limited. We aimed to examine p53, p16(Ink4a), estrogen receptor (ER), progesterone receptor (PR), ERBB2, WT1, and Ki-67 protein expression in endometrial intraepithelial carcinoma (n=29), serous tubal intraepithelial lesion (n=4) and carcinoma (STIC, n=10), and the putative precursor p53 signature (n=11). Among endometrial intraepithelial carcinoma, 80% demonstrated p53 overexpression and 10% were consistent with a null phenotype. p16(Ink4a) immunostaining were observed in all endometrial intraepithelial carcinoma cases. ER, PR, ERBB2, and WT1 were positive in 54%, 25%, 11%, and 18% of cases, respectively. STIC cases demonstrated p53 overexpression and null phenotype in 90% and 10%, respectively. All STIC cases were p16(Ink4a) and WT1 positive, whereas ER and PR were positive in 70% and 20%, respectively. All STICs were negative for ERBB2. Among serous tubal intraepithelial lesion cases, 75% demonstrated p53 overexpression and 25% a null phenotype. p53 was positive in all 11 p53 signature cases, whereas p16(Ink4a) was universally negative. Finally, ER and PR were positive in 100% and 73% of p53 signature cases, respectively. These results suggest that p16(Ink4a) has a role in early Müllerian serous carcinogenesis but is absent in the earliest noncommitted lesion. p16(Ink4a) immunohistochemistry can be used as an adjunct confirmatory tool in p53-null cases with limited surface area.

  1. Thymoquinone Attenuates Diethylnitrosamine Induction of Hepatic Carcinogenesis Through Antioxidant Signaling

    Directory of Open Access Journals (Sweden)

    Mohamed M. Sayed-Ahmed

    2010-01-01

    Full Text Available Hepatocellular carcinoma accounts for about 80–90% of all liver cancer and is the fourth most common cause of cancer mortality. Although there are many strategies for the treatment of liver cancer, chemoprevention seems to be the best strategy for lowering the incidence of this disease. Therefore, this study has been initiated to investigate whether thymoquinone (TQ, Nigella sativa derived-compound with strong antioxidant properties, supplementation could prevent initiation of hepatocarcinogenesis-induced by diethylnitrosamine (DENA, a potent initiator and hepatocarcinogen, in rats. Male Wistar albino rats were divided into four groups. Rats of Group 1 received a single intraperitoneal (I.P. injection of normal saline. Animals in Group 2 were given TQ (4 mg/kg/day in drinking water for 7 consecutive days. Rats of Group 3 were injected with a single dose of DENA (200 mg/kg, I.P.. Animals in Group 4 were received TQ and DENA. DENA significantly increased alanine transaminase (ALT, alkaline phosphatase (ALP, total bilirubin, thiobarbituric acid reactive substances (TBARS and total nitrate/nitrite (NOx and decreased reduced glutathione (GSH, glutathione peroxidase (GSHPx, glutathione-s-transferase (GST and catalase (CAT activity in liver tissues. Moreover, DENA decreased gene expression of GSHPx, GST and CAT and caused severe histopathological lesions in liver tissue. Interestingly, TQ supplementation completely reversed the biochemical and histopathological changes induced by DENA to the control values. In conclusion, data from this study suggest that: (1 decreased mRNA expression of GSHPx, CAT and GST during DENA-induced initiation of hepatic carcinogenesis, (2 TQ supplementation prevents the development of DENA-induced initiation of liver cancer by decreasing oxidative stress and preserving both the activity and mRNA expression of antioxidant enzymes.

  2. Chemical composition, physicochemical and functional properties of ...

    African Journals Online (AJOL)

    The results of chemical composition, physicochemical and functional properties for both lupin samples indicated that lupins can be used as a raw material for various food products manufacturing and provide consistency in food processing, analogous to other food legumes. Therefore, the research findings can be used by ...

  3. A comparative study of microbiological and physicochemical ...

    African Journals Online (AJOL)

    A comparative study of microbiological and physicochemical characteristics of water distributed from two water treatment plants in Rwanda. ... Thus, as recommendation to WASAC authority, there is a need for improvement in the water management strategy for better water quality especially along the distribution network.

  4. Physicochemical, antioxidant, and sensorial properties of peach ...

    African Journals Online (AJOL)

    Preparation of varieties of processed peach products could be a good option to supply in lean season. Objective of the study was to assess the quality characteristics of peach snacks prepared from 11 different cultivars. We investigated the physicochemical (soluble solid, titratable acidity, hardness and dry yield), antioxidant ...

  5. Physicochemical and Bacteriological Characteristics of Rainwater ...

    African Journals Online (AJOL)

    ADOWIE PERE

    This study investigated the physicochemical and bacteriological characteristics of rainwater harvested from three different rooftop sheets in Esan West Local Government Area, Edo State. Parameters investigated include pH, TSS, TDS, Turbidity, Acidity, Ca2+, Fe, Pb, Cr, TBC, TCC and E-coli. The results showed that mean ...

  6. Soil physicochemical properties and their significance for ...

    African Journals Online (AJOL)

    Soil physicochemical properties and their significance for sustainable sugarcane production in Kesem Allaideghe plains irrigation project area, Eastern Ethiopia. ... In order to improve soil structure and water availability, addition of gypsum, plant residues and organic matter are recommended. Keywords: Soil survey ...

  7. Physicochemical Characteristics of groundwater quality from Yola ...

    African Journals Online (AJOL)

    MICHAEL

    ABSTRACT: Some physicochemical parameters related to groundwater quality obtained from Yola Area of. Northeastern Nigeria was investigated for the purpose of drinking and irrigation. An attempt was also made to develop linear regression equations to predict the concentration of water quality having significant ...

  8. Distinct physicochemical characteristics of different beef from ...

    African Journals Online (AJOL)

    Jane

    2011-04-11

    Apr 11, 2011 ... A total of 30 Qinchuan cattle were used to investigate the physicochemical characteristics of beef from three different parts of cattle carcass, namely longissimus dorsi (LD), serratus ventralis (SV) and semitendinosus (ST). Multiple parameters were ranked in the descending order of ST > SV > LD, and.

  9. Physicochemical characteristics of communal rangeland soils along ...

    African Journals Online (AJOL)

    This study investigated the relative association of surface (0–20 cm) soil physicochemical properties, viz. electrical conductivity, cation exchange capacity (CEC), soil organic carbon, available phosphorus, particle size composition, soil aggregate stability and microbial respiration, along a toposequence in two vegetation ...

  10. Determination of the chemical composition, the physicochemical ...

    African Journals Online (AJOL)

    The chemical composition of the seed of Telfairia occidentalis (fluted pumpkin), the physicochemical properties of the seed oil and the amino acids profiles of the seed protein have been determined. In proximate composition, the crude fat content of 58.41% indicates that the plant seed is an oil seed. Its protein content of ...

  11. Physicochemical, Nutritional, and Functional Characteristics of ...

    African Journals Online (AJOL)

    ... a good source of nutritional components and essential nutrients, including minerals and amino acids, and have functional properties, which, if properly utilized, can improve human nutrition and health. Keywords: Grewia tenax, Physicochemical, Amino acids, Nutrition, Functional properties, Minerals, Volatile compounds ...

  12. Physicochemical characteristics of geophagic clayey soils from ...

    African Journals Online (AJOL)

    ONOS

    2010-09-06

    Sep 6, 2010 ... Physicochemical properties of geophagic clayey soils from South Africa and Swaziland were determined in order to appreciate their capability to perform the functions for which they are consumed and possible consequences of the practice in humans. Tests conducted included colour, texture, pH, electrical ...

  13. Physicochemical and textural properties of kombucha fermented ...

    African Journals Online (AJOL)

    The possibility of kombucha application cultivated on two different tea types in combination with probiotics for milk fermentation at different temperatures, as well as the physicochemical and textural properties of manufactured fermented milk products were investigated. Combination of probiotic starter culture and kombucha ...

  14. Comparative Studies on Some Physicochemical Properties of ...

    African Journals Online (AJOL)

    Industrial and nutritional processes have increased the demands for oil and this in turn has led to the search for oils from different types of seeds. It is in this vein that baobab seed oil was extracted, analyzed and some of it physicochemical properties compared with those of vegetable, peanut and palm oils. The percentage ...

  15. Physicochemical characterization of traditional Ghanaian cooking ...

    African Journals Online (AJOL)

    Traditional vegetable oils derived from Egusi (Citrullus colocynthis) and Werewere (Cucumeropsis manni) could prove to be an important commodity for Ghanaians, serving as a potential alternative source of common cooking oils. This study measured several physicochemical properties of Egusi and Werewere oils to ...

  16. Physicochemical Characterization of Inclusion Complex of Catechin ...

    African Journals Online (AJOL)

    Its physicochemical properties were investigated by ultravioletvisible spectrometry (UV), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffractometry (XRD) and differential scanning calorimetry (DSC). Results: The characteristic UV absorption peaks for catechin, the physical ...

  17. Preparation and physicochemical evaluation of transdermal ...

    African Journals Online (AJOL)

    Purpose: To prepare transdermal ketoprofen metered-dose aerosol formulations containing menthol and isopropyl myristate (IPM) as penetration enhancers and to evaluate their physicochemical and permeation properties. Methods: Selected ratios of ketoprofen, ethanol, polyvinylpyrrolidone K30 (PVP K30, anti-nucleant),.

  18. Comparison of Effects of Oligosaccharides on Physicochemical ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of different oligosaccharides on the physicochemical properties of corn starch. Methods: The blue value and retrogradation of corn starch were evaluated following the addition of different oligosaccharides and compared with control. Pasting properties, melting enthalpy and melting.

  19. Physicochemical and microbiological characteristics of Italian salami ...

    African Journals Online (AJOL)

    The purpose of this study was to evaluate and compare the inclusion of different levels of pequi (Caryocar Brasiliense, Cambess) pulp in the processing of Italian salami made of lamb for the evaluation of their physicochemical and microbiological characteristics. Six formulations of Italian salamis were processed: no pequi ...

  20. Physico-Chemical Characterization and Pollution Index ...

    African Journals Online (AJOL)

    Physico-Chemical Characterization and Pollution Index Determination of Leachates from Warri Waste Dumpsite, Southern Nigeria. ... This study characterizes the leachates quality of an active dumpsite in Warri, Delta State and also analyses its contamination or pollution potential. Leachate Pollution Index (LPI) - a tool for ...

  1. Examination of rheological and physicochemical characteristics in ...

    African Journals Online (AJOL)

    The aim of the study was to determine the effect of the biological origin and temperature on rheological and physicochemical characteristics of honey. The honey of the selected varieties differed in color, scent, microstructure, total acidity, moisture, and pH. The level of moisture statistically significantly correlated with the ...

  2. Physicochemical properties of nanostructured lipid carriers as ...

    African Journals Online (AJOL)

    The melting point depression of NLC80 was 5.71°C below bulk lipid's melting point (61.56°C), while NLC20 exhibited two melting points at 54.80 and 59.10°C. ... Key words: Nanostructured lipid carriers, colloidal delivery system, polysorbate 80, polysorbate 20, highpressure homogenization, physicochemical properties.

  3. Isolation and Physicochemical Characterization of Lignin from ...

    African Journals Online (AJOL)

    The isolated lignins were characterized by some physico-chemical parameters and spectroscopy methods like Futran Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscopy (SEM). Lignin from Chromolaena odorata was found to be more pure than the one from Tithonia diversifolia as evident from the ...

  4. Physicochemical Characteristics of Water Available for Livestock ...

    African Journals Online (AJOL)

    The study was carried out to determine physicochemical properties of water available for livestock and human use in Lala District, Gombi Local Government Area of Adamawa State, North eastern Nigeria. Questionnaire,oral interview and visual observations were employed to evaluate the physical quality of the water ...

  5. Physicochemical composition and antioxidant properties of a ...

    African Journals Online (AJOL)

    Physicochemical composition and antioxidant properties of a sweetpotato variety ( Ipomoea batatas L) commercially sold in South Eastern Nigeria. ... Results show that this sweet potato variety has potentials of biological properties and could have wide utility in food, alcohol and sugar industries. In addition, it could serve as ...

  6. Microbiological, physicochemical properties and biogenic amine ...

    African Journals Online (AJOL)

    Thirty three strained yoghurt samples were collected from local open markets in different provinces of Turkey (Afyon [AF], Aydın [AY], Burdur [B], Isparta [I] and Muğla [M]). Physicochemical and microbiological properties, as well as biogenic amine content, were examined in each of the samples. The dry matter (17.90 to ...

  7. Physicochemical characteristics of osmotically dehydrated tomato ...

    African Journals Online (AJOL)

    Physicochemical characteristics of osmotically dehydrated tomato (Lycopersicon esculentum) under different common drying methods. JAV Famurewa, AO Raji. Abstract. This study investigated the effect of different common drying methods on the chemical composition of osmotically dehydrated tomato. The quality of ...

  8. Correlations between soil microbial and physicochemical variations ...

    Indian Academy of Sciences (India)

    Prakash

    Soil management practices alter the physicochemical properties of soil, and the soil microbial community may respond to these changes in ways that affect the ability of the soil to resist soil-borne diseases. Soil microbial diversity drops when the soil is subjected to intensive exploitation during agricultural production.

  9. Assessment of microbiological and physicochemical parameters of ...

    African Journals Online (AJOL)

    The main objective of our study was to determine the physicochemical and microbiological characteristics of two water samples: river and ground water, in Gikondo industrial park, compared to the tap water. Samples were collected from the main three sources: industrial park effluent water (river water), industrial spring ...

  10. Physicochemical evolution and positive selection of the ...

    Indian Academy of Sciences (India)

    2010-04-08

    Apr 8, 2010 ... It is not clear whether matK evolves under Darwinian selection. In this study, the gymnosperm Taxaceae, Cephalotaxaceae and Pinaceae were used to illustrate the physicochemical evolution, molecular adaptation and evolutionary dynamics of gene divergence in matKs. matK sequences were amplified ...

  11. Physicochemical, toxicological and ecological analysis of ...

    African Journals Online (AJOL)

    Dams built to supply electricity, irrigation and fresh water, change the characteristics of the region they are located. The ecological, limnological characteristics and the quality of water in the dam reservoir deteriorate with time. In this study, the physicochemical, toxicological and ecological parameters of Gökçekaya Dam ...

  12. Comparative physicochemical and genotoxicity assessments of ...

    African Journals Online (AJOL)

    The textile industry has become indispensable in view of its basic and social importance to human life, but its environmental impact has continued to be a subject of concern. The objectives of the present study were to assess and compare the physico-chemical and genotoxicity properties of a corporate textile mill effluent ...

  13. Evaluation of Physicochemical, Functional and Sensory Properties ...

    African Journals Online (AJOL)

    Evaluation of Physicochemical, Functional and Sensory Properties of Fermented Fura Powder Supplemented with Soy. ... Nigerian Food Journal ... and sensory properties while another sample was stored at room temperature; samples were withdrawn at intervals of 4 and 6 weeks for some functional properties evaluation.

  14. TEMPORAL AND SPATIAL PHYSICOCHEMICAL WATER QUALITY ...

    African Journals Online (AJOL)

    TEMPORAL AND SPATIAL PHYSICOCHEMICAL WATER QUALITY. IN BLANTYRE URBAN STREAMS. S.M. Kuyeli1, W.R.L Masamba. ∗2. , E. Fabiano3, S.M. Sajidu3, E.M.T. Henry4. 1Blantyre City Assembly Pollution Control Office, Private Bag 67, Blantyre, Malawi. 2Harry Oppenheimer Okavango Research Centre, ...

  15. Physicochemical changes of raffia sap ( Raphia mambillensis ...

    African Journals Online (AJOL)

    The chemical content of a substance can influence its shelf life. Fermentation causes changes in freshly tapped sap and therefore makes its large scale use difficult. In order to study the effect of time on fermentation on the raffia sap property, its physico-chemical and microbiological characteristics were determined during ...

  16. Physicochemical properties of nanoparticles titania from alcohol ...

    African Journals Online (AJOL)

    The physicochemical properties of synthesized TiO2 nanoparticles from integrating sol-gel with flame-based techniques were studied. The synthesized nanoparticles properties were compared after using methanol, ethanol, and propanol fuel sources. The synthesized TiO2 were characterized by X-ray diffraction (XRD), ...

  17. Seasonal variation in fish abundance and physicochemical ...

    African Journals Online (AJOL)

    There is a positive correlation between fish abundance and biomass for wet and dry seasons (r = 0.60 and 0.76 respectively). There was no significant difference between fish abundance in the two seasons. Variations occurred between physico-chemical parameters of water samples. Analysis of the lagoon waters showed ...

  18. Bacteriological and physicochemical evaluation of syrups produced ...

    African Journals Online (AJOL)

    Bacteriological and physicochemical evaluation of syrups produced from local starch sources. ... The syrups were produced, using acid hydrolysis, from starches obtained from Colocasia esculenta, Zea mays and Manihot palmata. The viable bacterial count gave low counts of Leuconostoc mesenteroides, Bacillus subtills ...

  19. Bacteriological, physicochemical and mineral studies on Awedele ...

    African Journals Online (AJOL)

    EJIRO

    physicochemical quality of the water samples was also assessed. The mineral content of the adjacent soil samples was also determined. Antibiotic resistance among isolated Enterococcus species was highest to penicillin as all isolates demonstrated complete resistance to the antibiotics. Prevalence of gentamycin-.

  20. Using of phytoplankton and physicochemical parameters as ...

    African Journals Online (AJOL)

    Samples were collected from six sites covering the lake Timsah during the period summer 2005-spring 2006, representing the four seasons, including water and phytoplankton samples, in order to evaluating phytoplankton algal community and physicochemical parameters. A total of One-hundard and two taxa have been ...

  1. Comparative evaluation of the physicochemical composition and ...

    African Journals Online (AJOL)

    Eleazu Chinedum

    2012-09-24

    Sep 24, 2012 ... The physicochemical composition and microbial quality of 7 different water sources (Umudike ukwu bore hole (B5) ... bore hole (B4), Umudike school borehole A (B7), Umudike school bore hole B (B6) and Ahiaeke bore hole (B9) used for root and ..... water sample. Polluted and waste water has higher BOD.

  2. Comparison of Effects of Oligosaccharides on Physicochemical ...

    African Journals Online (AJOL)

    Purpose: To investigate the effect of different oligosaccharides on the physicochemical properties of corn starch. Methods: The blue value and retrogradation of corn starch were evaluated following the addition of different oligosaccharides and compared with control. Pasting properties, melting enthalpy and melting ...

  3. Physicochemical and antimicrobial properties of Trichosanthes ...

    African Journals Online (AJOL)

    The core objective of this research was to determine the characteristics of oils, nutritional composition and antimicrobial activities of T. anguina and S. mahagoni seeds. Physicochemical characteristics of oils implied higher degree of unsaturation in T. anguina whereas, S. mahagoni oil contained appreciable level of ...

  4. Physicochemical and sensory characteristics of yoghurt produce ...

    African Journals Online (AJOL)

    Objective: To evaluate the physicochemical and sensory acceptability of yoghurt produced from ewe, goat and a mixture of ewe milk and goat milk in Nigeria in order for the populace to harness the nutritional and therapeutic benefits of the milks. Methods: Samples of whole cow milk (WCM) as standard, goat milk (GM), ewe ...

  5. Physicochemical parameters and antibiotics residuals in Algerian ...

    African Journals Online (AJOL)

    The physicochemical analyses of the Algerian honeys show that 56% of samples correspond to Codex standards and 44% not in conformity with the standards required by the Codex Alimentarius and EU, because part of the samples had one or more defects. The percentage not in conformity was due to the high rates of ...

  6. ASSESSMENT OF PHYSICO-CHEMICAL PARAMETERS OF ...

    African Journals Online (AJOL)

    B. S. Chandravanshi

    analyzed for various physico-chemical parameters. The study indicated that the mean value of studied parameters, except electrical conductivity, total dissolved solids, turbidity, total alkalinity, calcium ion, sulphate ion, and total phosphorus of the river water samples were within the permissible limit of WHO for drinking water ...

  7. Physicochemical and powder properties of alpha- and ...

    African Journals Online (AJOL)

    Cob alpha-celluloses (CAC) was extracted from maize cobs by defibering, delignification and bleaching; then subjected to acid hydrolysis to obtain Cob- microcrystalline-cellulose (CMCC). Their physicochemical properties were evaluated and compared with those of Avicel®, a commercial variety of microcrystalline ...

  8. Physicochemical Flux and Phytoplankton diversity in Shagari ...

    African Journals Online (AJOL)

    USER

    2007-03-20

    Mar 20, 2007 ... Physicochemical Flux and Phytoplankton diversity in Shagari Reservoir,Sokoto, Nigeria. *1I.M. Magami, 1T. Adamu and 2A.A. Aliero. 1Zoology Unit, Department of Biological Sciences, Usmanu Danfodiyo University, Sokoto, Nigeria. 2Botany Unit, Department of Biological Sciences, Usmanu Danfodiyo ...

  9. Physico-chemical water characteristics and aquatic ...

    African Journals Online (AJOL)

    Physico-chemical water characteristics and aquatic macroinvertebrates of Lake Tsimanampesotse, south-western Madagascar. ... Water quality and aquatic invertebrates were investigated in April and August 2013 to provide baseline data in order to measure possible changes of the area in the future. Changes in water ...

  10. Comparative Studies on Some Physicochemical Properties of ...

    African Journals Online (AJOL)

    ABSTRACT: Industrial and nutritional processes have increased the demands for oil and this in turn has led to the search for oils from different types of seeds. It is in this vein that baobab seed oil was extracted, analyzed and some of it physicochemical properties compared with those of vegetable, peanut and palm oils.

  11. SOME PHYSICOCHEMICAL PROPERTIES AND APPLICATION OF ...

    African Journals Online (AJOL)

    The α-cellulose was also employed as disintegrant in some tablet formulations. Some of the physicochemical and flow properties evaluated were, moisture content, bulk density, packed density, Carrs compressibility, angle of repose and Hausner quotient. The tablet properties studied were, disintegration time, hardness, ...

  12. Changing concepts of dietary fiber: implications for carcinogenesis.

    Science.gov (United States)

    Ferguson, L R; Chavan, R R; Harris, P J

    2001-01-01

    The dietary fiber (DF) hypothesis suggested that DF, as plant cell walls, protected against colorectal cancer. The implicit assumption in much historic literature was that the readily analyzed and quantified nonstarch polysaccharide (NSP) component was critical in cancer protection. However, the presence of polymeric phenolic components such as lignin or suberin has profound effects on the physicochemical properties of the cell walls and largely determines their physiological properties in humans. In certain groups of food plants, degradation of cell walls that contain neither lignin nor suberin releases ferulic acid and other hydroxycinnamic acids. These acids have antioxidant, antimutagenic, and other anticancer effects, including modulation of gene expression and immune response. Reexamination of literature on cancer protection suggests that plant cell walls containing significant amounts of phenolic components may be the most likely to protect against cancer. In the last 30 years, the definition of DF has been incrementally expanded to incorporate NSP extracted from plant cell walls and from sources other than plant cell walls, then resistant starch, and most recently nondigestible oligosaccharides. On the early definitions, increased consumption of DF could only be achieved by increasing the intake of whole grains, brans, or other food plant material that would increase the intake of plant cell walls containing significant amounts of phenolic components. However, the new definitions make it possible to increase "dietary fiber" without consuming any such materials. We suggest that this could have negative connotations for cancer risk in human populations.

  13. Chemopreventive Strategies for Inflammation-Related Carcinogenesis: Current Status and Future Direction

    Science.gov (United States)

    Kanda, Yusuke; Osaki, Mitsuhiko; Okada, Futoshi

    2017-01-01

    A sustained and chronically-inflamed environment is characterized by the presence of heterogeneous inflammatory cellular components, including neutrophils, macrophages, lymphocytes and fibroblasts. These infiltrated cells produce growth stimulating mediators (inflammatory cytokines and growth factors), chemotactic factors (chemokines) and genotoxic substances (reactive oxygen species and nitrogen oxide) and induce DNA damage and methylation. Therefore, chronic inflammation serves as an intrinsic niche for carcinogenesis and tumor progression. In this article, we summarize the up-to-date findings regarding definitive/possible causes and mechanisms of inflammation-related carcinogenesis derived from experimental and clinical studies. We also propose 10 strategies, as well as candidate agents for the prevention of inflammation-related carcinogenesis. PMID:28422073

  14. Chronic inflammation-associated genomic instability paves the way for human esophageal carcinogenesis

    Science.gov (United States)

    Tian, Dongping; Lei, Zhijin; Chen, Donglin; Xu, Zexin; Su, Min

    2016-01-01

    Chronic inflammation is associated with increased risk of cancer development, whereas the link between chronic inflammation and esophageal carcinogenesis is still obscure heretofore. This study aimed to investigate the relationship between chronic inflammation and DNA damage, as well as the possible role of DNA damage in esophageal carcinogenic process. Endoscopic esophageal biopsies from 109 individuals from Chaoshan littoral, a high-risk region for esophageal squamous cell carcinoma (ESCC), were examined to evaluate the association between chronic inflammation and histological severity, while additional 204 esophageal non-tumor samples from patients with ESCC were collected. Immunohistochemistry was performed to detect the oxidative DNA damage and DNA double-strand breaks (DSBs). Significantly positive correlation was observed between degree of chronic inflammation and esophageal precursor lesions (rs = 0.37, P inflammation (rs = 0.21, P inflammation degree (P inflammation-associated genomic instability with esophageal carcinogenesis and suggest possibilities for early detection and intervention of esophageal carcinogenesis. PMID:27028857

  15. The Combination of Three Natural Compounds Effectively Prevented Lung Carcinogenesis by Optimal Wound Healing.

    Directory of Open Access Journals (Sweden)

    Linxin Liu

    Full Text Available The tumor stroma has been described as "normal wound healing gone awry". We explored whether the restoration of a wound healing-like microenvironment may facilitate tumor healing. Firstly, we screened three natural compounds (shikonin, notoginsenoside R1 and aconitine from wound healing agents and evaluated the efficacies of wound healing microenvironment for limiting single agent-elicited carcinogenesis and two-stage carcinogenesis. The results showed that three compounds used alone could promote wound healing but had unfavorable efficacy to exert wound healing, and that the combination of three compounds made up treatment disadvantage of a single compound in wound healing and led to optimal wound healing. Although individual treatment with these agents may prevent cancer, they were not effective for the treatment of established tumors. However, combination treatment with these three compounds almost completely prevented urethane-induced lung carcinogenesis and reduced tumor burden. Different from previous studies, we found that urethane-induced lung carcinogenesis was associated with lung injury independent of pulmonary inflammation. LPS-induced pulmonary inflammation did not increase lung carcinogenesis, whereas decreased pulmonary inflammation by macrophage depletion promoted lung carcinogenesis. In addition, urethane damaged wound healing in skin excision wound model, reversed lung carcinogenic efficacy by the combination of three compounds was consistent with skin wound healing. Further, the combination of these three agents reduced the number of lung cancer stem cells (CSCs by inducing cell differentiation, restoration of gap junction intercellular communication (GJIC and blockade of the epithelial-to-mesenchymal transition (EMT. Our results suggest that restoration of a wound healing microenvironment represents an effective strategy for cancer prevention.

  16. Biological Complexities in Radiation Carcinogenesis and Cancer Radiotherapy: Impact of New Biological Paradigms

    Directory of Open Access Journals (Sweden)

    Hossein Mozdarani

    2012-01-01

    Full Text Available Although radiation carcinogenesis has been shown both experimentally and epidemiologically, the use of ionizing radiation is also one of the major modalities in cancer treatment. Various known cellular and molecular events are involved in carcinogenesis. Apart from the known phenomena, there could be implications for carcinogenesis and cancer prevention due to other biological processes such as the bystander effect, the abscopal effect, intrinsic radiosensitivity and radioadaptation. Bystander effects have consequences for mutation initiated cancer paradigms of radiation carcinogenesis, which provide the mechanistic justification for low-dose risk estimates. The abscopal effect is potentially important for tumor control and is mediated through cytokines and/or the immune system (mainly cell-mediated immunity. It results from loss of growth and stimulatory and/or immunosuppressive factors from the tumor. Intrinsic radiosensitivity is a feature of some cancer prone chromosomal breakage syndromes such as ataxia telangectiasia. Radiosensitivity is manifested as higher chromosomal aberrations and DNA repair impairment is now known as a good biomarker for breast cancer screening and prediction of prognosis. However, it is not yet known whether this effect is good or bad for those receiving radiation or radiomimetic agents for treatment. Radiation hormesis is another major concern for carcinogenesis. This process which protects cells from higher doses of radiation or radio mimic chemicals, may lead to the escape of cells from mitotic death or apoptosis and put cells with a lower amount of damage into the process of cancer induction. Therefore, any of these biological phenomena could have impact on another process giving rise to genome instability of cells which are not in the field of radiation but still receiving a lower amount of radiation. For prevention of radiation induced carcinogenesis or risk assessment as well as for successful radiation

  17. Estimating radiation-induced cancer risk using MVK two-stage model for carcinogenesis

    International Nuclear Information System (INIS)

    Kai, M.; Kusama, T.; Aoki, Y.

    1993-01-01

    Based on the carcinogenesis model as proposed by Moolgavkar et al., time-dependent relative risk models were derived for projecting the time variation in excess relative risk. If it is assumed that each process is described by time-independent linear dose-response relationship, the time variation in excess relative risk is influenced by the parameter related with the promotion process. The risk model based carcinogenesis theory would play a marked role in estimating radiation-induced cancer risk in constructing a projection model or transfer model

  18. Zinc Oxide Nanoparticles Enhance Physicochemical Characteristics of Grossman Sealer.

    Science.gov (United States)

    Versiani, Marco Aurélio; Abi Rached-Junior, Fuad Jacob; Kishen, Anil; Pécora, Jesus Djalma; Silva-Sousa, Yara Terezinha; de Sousa-Neto, Manoel Damião

    2016-12-01

    Metallic antibacterial nanoparticles have been shown to provide distinct antibacterial advantage and antibiofilm efficacy when applied in infected root canals. The purpose of this study was to evaluate the influence of incorporating zinc oxide nanoparticles (ZnO-Np) on the physicochemical properties of Grossman sealer. Grossman sealer was prepared according to its original formula. Additionally, 4 experimental sealers were prepared by replacing the zinc oxide component of the powder with ZnO-Np (average size of 20 nm) in different amounts (25%, 50%, 75%, and 100%). Characterization of the setting time, flow, solubility, dimensional changes, and radiopacity were performed according to American National Standards Institute (ANSI)/American Dental Association (ADA) Specification 57. Scanning electron microscopic and energy-dispersive X-ray spectroscopic analyses were conducted to assess the ultrastructural and chemical characteristics of experimental sealers subjected to the solubility test. Statistical analyses were performed with analysis of variance and post hoc Tukey-Kramer tests with a significance level of 5%. A statistically significant difference in the setting time was observed among groups (P < .05), but only 25% ZnO-Np sealer complied with ANSI/ADA requirements. There was a significant difference in the flow characteristics between the control and 25% and 75% ZnO-Np experimental sealers (P < .05), but all sealers conformed to ANSI/ADA standardization; 25% ZnO-Np sealer showed significantly less solubility (1.81% ± 0.31%) and dimensional change (-0.34% ± 0.12%) than other sealers (P < .05). All sealers showed ultrastructural changes with increasing solubility. ZnO-Np decreased the setting time and dimensional changes characteristic of Grossman sealer; 25% ZnO-Np improved the physicochemical properties of Grossman sealer in accordance with ANSI/ADA requirements. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All

  19. Microbiological and physico-chemical studies on irradiated dewatered sludge

    International Nuclear Information System (INIS)

    Hilmy, N.; Suwirma, S.; Harsoyo; Suhadi, F.

    1987-01-01

    Microbiological and physico-chemical studies on irradiated dewatered sludge. Microbiological and physico-chemical dewatered have been carried out and non-irradiated dewatered sludge of Jakarta city, collected during the rainy and dry season. Total bacterial counts of non-irradiated dewatered sludge with water content of around 20%, were found to be about 7x10 8 per g during the rainy season and 7x10 6 up to 1.3x10 8 per g during the dry season, while coliform fecal Streptococcus and Pseudomonas were found to be 1.6x10 4 to 1.0x10 7 , 3x10 5 , and 5x10 3 per g, respectively. No Salmonella, Shigella and Vibrio were detected in all of the samples observed. About 10% of the total number of coliforms were found to be Escherichia coli. A dose of 6 kGy could eliminate the coliform, E. Coli, fecal Streptococcus and Pseudomonas from all of the dewatered sludge observed. The nutrient value of the sludge was sufficient, i.e. total nitrogen content ranged between 1 and 4,42%, phosphorus between 1.55 and 2.36%, and potassium between 0,1 and 0,2% of dry matter. Heavy metal contents were found a little bit high to be applied as animal feed, but it is still acceptable for soil conditioner. Combining 3 months storage at ambient environment and irradiation dose of 2.5 kGy were found to work synergistically to eliminate coliforms and E. Coli from sludge. (author). 8 figs, 17 refs

  20. SIX1 Oncoprotein as a Biomarker in a Model of Hormonal Carcinogenesis and in Human Endometrial Cancer.

    Science.gov (United States)

    The oncofetal protein sine oculis-related homeobox 1 (SIX1) is a developmental transcription factor associated with carcinogenesis in animal models and humans. In a model of hormonal carcinogenesis, mice neonatally exposed to the soy phytoestrogen, genistein (GEN), or the synthet...

  1. A comprehensive physico-chemical, mineralogical and morphological characterization of Indian mineral wastes.

    Science.gov (United States)

    Gedam, Vidyadhar V; Jha, Rajesh; Labhasetwar, Pawan; Engelsen, Christian J

    2013-08-01

    This paper provides a comprehensive characterization of mineral waste such as fly ash, bottom ash, slag and construction demolition (C&D) collected from four different thermal power plants, three steel plants and three C&D waste generation sites in India. To determine utilisation potential and environmental concerns, as received fly ash, bottom ash, slag and C&D waste were analysed for physico-chemical, mineralogical and morphological properties. The physico-chemical properties analysed include pH, moisture content, acid insoluble residue, loss on ignition(LOI), carbon content, fineness, chloride content, sulphate content, reactive silica content, XRF and heavy metal analysis. Morphological and mineralogical characteristics were investigated using scanning electron microscopy-energy dispersive X-ray. Particle size distribution was obtained using particle size analyser. The material analysed has different compositions and were selected with a view to determine their suitability for different applications in cement and concrete industry and for further research studies.

  2. [Histologic study on impeding leukoplakia carcinogenesis of golden hamster cheek pouch about Erigeron breviscapus (Vant) Hand-Mazz].

    Science.gov (United States)

    Zhou, C T; Zhong, W J; Hua, L; Hu, H F; Jin, Z G

    2000-06-01

    To observe the effect of Erigeron breviscapus (Vant) Hand Mazz (HEr) in impeding oral leukoplakia carcinogenesis, and to seek effective Chinese herb medicine that can impede precarcinoma of oral mucosas. 132 golden hamsters were randomly divided into model group (60 animals), HEr group (60 animals), and control group 12 animals. Salley's leukoplakia carcinogenesis model of golden hamster cheek pouch was used in this study. HEr was injected into the stomach to impede evolution of carcinogenesis. Pathological specimens were observed via naked eye and light microscope between model group and HEr group. Results were compared. Observation via naked-eye showed that leukoplakia rate of HEr group (18.2%) was lower than that of model group (27.3%). Observation via light microscope showed that carcinogenesis rate descended one fold and displasia rate descended 0.4 fold in HEr group. HEr has exact effect in impeding leukoplakia carcinogenesis.

  3. Physicochemical and Sensorial Characterization of Honey Spirits.

    Science.gov (United States)

    Anjos, Ofélia; Frazão, David; Caldeira, Ilda

    2017-07-27

    Distilled spirits are usually made from fermented sugar-based materials, such as wines or fermented fruits, but other products can be used, namely berries or honey. In this work, an evaluation of honey spirits is done based on its physicochemical and sensory characteristics. Fourteen honey spirit samples of different brands of honey spirit were purchased at the market and from artisan Portuguese producers. Several analytical determinations, namely alcoholic strength, dry matter, density, total acidity, chromatic characteristics, methanol, acetaldehyde, ethyl acetate and higher alcohols were done to characterize all samples. The results pointed out several differences in physicochemical composition of samples. In general, these drinks are characterized by an alcohol strength between 37.4% and 53.0% and a low methanol content, quite null for most samples. Samples with higher ethanol content corresponded to the artisanal samples. Significant differences ( p drink, which has gained market value.

  4. Physicochemical properties of mixed phosphorus halides

    International Nuclear Information System (INIS)

    Sladkov, I.B.; Tugarinova, N.S.

    1996-01-01

    Certain physicochemical properties (thermodynamic characteristics at boiling point, critical constants, density of liquid on the saturation line) of mixed phosphorus halides (PI 3 , PI 2 F, PIF 2 , PI 2 Cl, PICl 2 , PI 1 Br, PIBr 2 , PIClF, PIBrCl, etc.) are determined by means of approximate methods. Reliability of the results obtained is confirmed by comparison of calculated and experimental data for phosphorus compounds of the same type. 7 refs., 3 figs., 4 tabs

  5. Characterization of physicochemical properties of ivy nanoparticles for cosmetic application.

    Science.gov (United States)

    Huang, Yujian; Lenaghan, Scott C; Xia, Lijin; Burris, Jason N; Stewart, C Neal; Zhang, Mingjun

    2013-02-01

    Naturally occurring nanoparticles isolated from English ivy (Hedera helix) have previously been proposed as an alternative to metallic nanoparticles as sunscreen fillers due to their effective UV extinction property, low toxicity and potential biodegradability. This study focused on analyzing the physicochemical properties of the ivy nanoparticles, specifically, those parameters which are crucial for use as sunscreen fillers, such as pH, temperature, and UV irradiation. The visual transparency and cytotoxicity of ivy nanoparticles were also investigated comparing them with other metal oxide nanoparticles. Results from this study demonstrated that, after treatment at 100°C, there was a clear increase in the UV extinction spectra of the ivy nanoparticles caused by the partial decomposition. In addition, the UVA extinction spectra of the ivy nanoparticles gradually reduced slightly with the decrease of pH values in solvents. Prolonged UV irradiation indicated that the influence of UV light on the stability of the ivy nanoparticle was limited and time-independent. Compared to TiO2 and ZnO nanoparticles, ivy nanoparticles showed better visual transparency. Methylthiazol tetrazolium assay demonstrated that ivy nanoparticles exhibited lower cytotoxicity than the other two types of nanoparticles. Results also suggested that protein played an important role in modulating the three-dimensional structure of the ivy nanoparticles. Based on the results from this study it can be concluded that the ivy nanoparticles are able to maintain their UV protective capability at wide range of temperature and pH values, further demonstrating their potential as an alternative to replace currently available metal oxide nanoparticles in sunscreen applications.

  6. Physico-chemical standardization of Sitopaladi churna

    Science.gov (United States)

    Makhija, Inder Kumar; Shreedhara, Chandrashekara Shastry; Ram, Holavana Hally Nanjundaiah Setty Aswatha

    2012-01-01

    Background: Standardization of a compound Ayurvedic formulation is a critical and essential issue to be considered in assuring the therapeutic efficacy and safety and to rationalize their use in the health care. Sitopaladi churna is a reputed polyherbal formulation of Ayurveda. It is prescribed for the treatment of pleurodynia, intercostal neuralgia, cold, cough associated with bronchitis, pneumonia, tuberculosis, viral respiratory infection, and in pharyngeal and chest congestion. Objective: The present study aimed at physico-chemical standardization of in-house and two marketed brands of Sitopaladi churna. Materials and Methods: In our investigation, in-house churna and two commercial brands of Sitopaladi churna were standardized based on powder microscopy, physico-chemical evaluations, thin layer chromatography (TLC) and high performance thin layer chromatography (HPTLC) finger printing as per standard procedures. Results: The set parameters were sufficient to evaluate the churna based on various physico-chemical parameters. Conclusion: The data evolved can be adopted for laying down the standards for the manufacturing units of Sitopaladi churna. PMID:23284216

  7. The properties of red seaweed (Kappaphycus alvarezii) and its effect on mammary carcinogenesis.

    Science.gov (United States)

    Chang, Vi-Sion; Okechukwu, Patrick N; Teo, Swee-Sen

    2017-03-01

    The edible red seaweed (Kappaphycus alvarezii) is one of the algae species which was found to be rich in nutrients and nutraceutical. Hence, K. alvarezii may have the ability to suppress cancer through its antiproliferative properties. The aim of this study was to investigate the potential compounds of K. alvarezii, cytotoxicity properties of K. alvarezii extract on breast cancer cell line (MCF-7), investigated toxicity effect of high dosage K. alvarezii extract in rats and determined the effect of K. alvarezii on 7, 12-dimethylbenz[a]anthracene (DMBA) mammary carcinogenesis in rats. The method of LCMS/MS and MTT assay were used. For animal study, sub-chronic toxicity method was used, the rats were supplemented with 2000mg/kg body weight daily of K. alvarezii crude extracts by oral gavage. For the anticancer effect of K. alvarezii crude extracts, this study consisted of three groups of the experimental, untreated and normal group of rats. The experimental and untreated groups of rats were induced with mammary tumour with DMBA. The experimental group of rats was given with K. alvarezii crude extracts orally. The results were being used to compare with the untreated group of rats and normal group of rats. All the rats were fed with standard diet and water ad libitum. Mortality, behavior changes and tumour sizes were observed specifically. The differences between the three groups of rats were evaluated by using the ANOVA test. By using LCMS/MS method, six unknown compounds were analysed. K. alvarezii crude extract reduced the cell viability of MCF-7 from 84.91% to 0.81% and the IC 50 value is 4.1±0.69mg/mL. For sub-chronic and heavy metal toxicity studies, no significant difference was found in haematological and biochemical values of the control group and experimental group. The growth rate of tumours in the untreated group of rats was found significantly higher than the experimental group of rats. Besides that, the white blood cells level in untreated group was

  8. Diet, lifestyle, heritable factors and colorectal carcinogenesis: associations with histopathological and molecular endpoints

    NARCIS (Netherlands)

    Wark, P.A.

    2007-01-01

    Background: Diet, lifestyle and heritable factors have been related to colorectal cancer risk; to date, their relevance to the overall scope of colorectal carcinogenesis, has not been clearly established.Aim and Methods: To evaluate whether distinguishing colorectal tissue by its histopathological

  9. Effects of dietary fat on virus-induced pancreatic carcinogenesis in guinea fowl

    NARCIS (Netherlands)

    Kirev, T.; Woutersen, R.A.; Kril, A.

    2002-01-01

    The present study was performed to assess the effects of diets supplemented with low (5%) and high (20%) corn oil on a Pts 56 retrovirus-induced model of pancreatic carcinogenesis in guinea fowl. The early microscopic lesions appear after 3 mo after virus treatment and progress over time. Eight to

  10. Molecular and cellular pathways associated with chromosome 1p deletions during colon carcinogenesis

    Directory of Open Access Journals (Sweden)

    Payne CM

    2011-05-01

    Full Text Available Claire M Payne, Cheray Crowley-Skillicorn, Carol Bernstein, Hana Holubec, Harris BernsteinDepartment of Cell Biology and Anatomy, College of Medicine, University of Arizona Tucson, AZ, USAAbstract: Chromosomal instability is a major pathway of sporadic colon carcinogenesis. Chromosome arm 1p appears to be one of the “hot spots” in the non-neoplastic mucosa that, when deleted, is associated with the initiation of carcinogenesis. Chromosome arm 1p contains genes associated with DNA repair, spindle checkpoint function, apoptosis, multiple microRNAs, the Wnt signaling pathway, tumor suppression, antioxidant activities, and defense against environmental toxins. Loss of 1p is dangerous since it would likely contribute to genomic instability leading to tumorigenesis. The 1p deletion-associated colon carcinogenesis pathways are reviewed at the molecular and cellular levels. Sporadic colon cancer is strongly linked to a high-fat/low-vegetable/low-micronutrient, Western-style diet. We also consider how selected dietary-related compounds (eg, excess hydrophobic bile acids, and low levels of folic acid, niacin, plant-derived antioxidants, and other modulatory compounds might affect processes leading to chromosomal deletions, and to the molecular and cellular pathways specifically altered by chromosome 1p loss.Keywords: chromosome 1p, colon carcinogenesis, molecular pathways, cellular pathways

  11. Palytoxin: exploiting a novel skin tumor promoter to explore signal transduction and carcinogenesis.

    Science.gov (United States)

    Wattenberg, Elizabeth V

    2007-01-01

    Palytoxin is a novel skin tumor promoter, which has been used to help probe the role of different types of signaling mechanisms in carcinogenesis. The multistage mouse skin model indicates that tumor promotion is an early, prolonged, and reversible phase of carcinogenesis. Understanding the molecular mechanisms underlying tumor promotion is therefore important for developing strategies to prevent and treat cancer. Naturally occurring tumor promoters that bind to specific cellular receptors have proven to be useful tools for investigating important biochemical events in multistage carcinogenesis. For example, the identification of protein kinase C as the receptor for the prototypical skin tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) (also called phorbol 12-myristate 13-acetate, PMA) provided key evidence that tumor promotion involves the aberrant modulation of signaling cascades that govern cell fate and function. The subsequent discovery that palytoxin, a marine toxin isolated from zoanthids (genus Palythoa), is a potent skin tumor promoter yet does not activate protein kinase C indicated that investigating palytoxin action could help reveal new aspects of tumor promotion. Interestingly, the putative receptor for palytoxin is the Na(+),K(+)-ATPase. This review focuses on palytoxin-stimulated signaling and how palytoxin has been used to investigate alternate biochemical mechanisms by which important targets in carcinogenesis can be modulated.

  12. Mammary carcinogenesis in rats: basic facts and recent results in Brookhaven

    International Nuclear Information System (INIS)

    Shellabarger, C.J.; Stone, J.P.; Holtzman, s.

    1982-01-01

    Some research results from experiments investigating neutron-induced mammary carcinogenesis in rats are presented. The additive effects of neutrons and 3-methylcholanthrene on mammary adenocarcinoma were determined. Synergism between diethylstilbestrol and neutrons was likewise studied. Differences in mammary neoplastic response between strains of laboratory rats was also investigated

  13. Dietary fish oil (MaxEPA) enhances pancreatic carcinogenesis in azaserine-treated rats

    NARCIS (Netherlands)

    Appel, M.J.; Woutersen, R.A.

    1996-01-01

    In the present study the putative chemopreventive effect of dietary fish oil (MaxEPA) on azaserine-induced pancreatic carcinogenesis in rats was investigated. Groups of rats were maintained on a semipurified low-fat (LF; 5 wt%) diet or on semipurified high-fat (HF; 25 wt%) diets containing 5 wt%

  14. Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

    International Nuclear Information System (INIS)

    Fabrikant, J.I.

    1981-05-01

    The current knowledge of the carcinogenic effect of radiation in man is considered. The discussion is restricted to dose-incidence data in humans, particularly to certain of those epidemiological studies of human populations that are used most frequently for risk estimation for low-dose radiation carcinogenesis in man. Emphasis is placed solely on those surveys concerned with nuclear explosions and medical exposures

  15. Radiation carcinogenesis. Comprehensive three-year progress report, 1 May 1972--15 March 1976

    International Nuclear Information System (INIS)

    Warren, S.; Gates, O.

    1976-03-01

    Progress is reported on studies on the pathological effects of various doses of x radiation on rats and mice, with emphasis on radioinduced carcinogenesis in parabiont rats with one of the pair exposed to 1000 R of whole body x radiation and the other shielded. Results are included from studies on alterations in metabolic parameters and life span induced by irradiation

  16. p21 Ablation in Liver Enhances DNA Damage, Cholestasis, and Carcinogenesis

    NARCIS (Netherlands)

    Ehedego, H.; Boekschoten, M.V.; Hu, W.; Doler, C.; Haybaeck, J.; Gassler, N.; Muller, M.R.; Liedtke, C.; Trautwein, C.

    2015-01-01

    Genetic mouse studies suggest that the NF-¿B pathway regulator NEMO (also known as IKK¿) controls chronic inflammation and carcinogenesis in the liver. However, the molecular mechanisms explaining the function of NEMO are not well defined. Here, we report that overexpression of the cell-cycle

  17. Induction of human breast cell carcinogenesis by triclocarban and intervention by curcumin

    Energy Technology Data Exchange (ETDEWEB)

    Sood, Shilpa; Choudhary, Shambhunath; Wang, Hwa-Chain Robert, E-mail: hcrwang@utk.edu

    2013-09-06

    Highlights: •Triclocarban exposure induces breast epithelial cell carcinogenesis. •Triclocarban induces the Erk–Nox pathway, ROS elevation, and DNA damage. •Physiological doses of triclocarban induce cellular carcinogenesis. •Non-cytotoxic curcumin blocks triclocarban-induced carcinogenesis and pathways. -- Abstract: More than 85% of breast cancers are sporadic and attributable to long-term exposure to environmental carcinogens and co-carcinogens. To identify co-carcinogens with abilities to induce cellular pre-malignancy, we studied the activity of triclocarban (TCC), an antimicrobial agent commonly used in household and personal care products. Here, we demonstrated, for the first time, that chronic exposure to TCC at physiologically-achievable nanomolar concentrations resulted in progressive carcinogenesis of human breast cells from non-cancerous to pre-malignant. Pre-malignant carcinogenesis was measured by increasingly-acquired cancer-associated properties of reduced dependence on growth factors, anchorage-independent growth and increased cell proliferation, without acquisition of cellular tumorigenicity. Long-term TCC exposure also induced constitutive activation of the Erk–Nox pathway and increases of reactive oxygen species (ROS) in cells. A single TCC exposure induced transient induction of the Erk–Nox pathway, ROS elevation, increased cell proliferation, and DNA damage in not only non-cancerous breast cells but also breast cancer cells. Using these constitutively- and transiently-induced changes as endpoints, we revealed that non-cytotoxic curcumin was effective in intervention of TCC-induced cellular pre-malignancy. Our results lead us to suggest that the co-carcinogenic potential of TCC should be seriously considered in epidemiological studies to reveal the significance of TCC in the development of sporadic breast cancer. Using TCC-induced transient and constitutive endpoints as targets will likely help identify non-cytotoxic preventive

  18. Physicochemical and toxicological characteristics of welding fume derived particles generated from real time welding processes.

    Science.gov (United States)

    Chang, Cali; Demokritou, Philip; Shafer, Martin; Christiani, David

    2013-01-01

    Welding fume particles have been well studied in the past; however, most studies have examined welding fumes generated from machine models rather than actual exposures. Furthermore, the link between physicochemical and toxicological properties of welding fume particles has not been well understood. This study aims to investigate the physicochemical properties of particles derived during real time welding processes generated during actual welding processes and to assess the particle size specific toxicological properties. A compact cascade impactor (Harvard CCI) was stationed within the welding booth to sample particles by size. Size fractionated particles were extracted and used for both off-line physicochemical analysis and in vitro cellular toxicological characterization. Each size fraction was analyzed for ions, elemental compositions, and mass concentration. Furthermore, real time optical particle monitors (DustTrak™, TSI Inc., Shoreview, Minn.) were used in the same welding booth to collect real time PM2.5 particle number concentration data. The sampled particles were extracted from the polyurethane foam (PUF) impaction substrates using a previously developed and validated protocol, and used in a cellular assay to assess oxidative stress. By mass, welding aerosols were found to be in coarse (PM 2.5–10), and fine (PM 0.1–2.5) size ranges. Most of the water soluble (WS) metals presented higher concentrations in the coarse size range with some exceptions such as sodium, which presented elevated concentration in the PM 0.1 size range. In vitro data showed size specific dependency, with the fine and ultrafine size ranges having the highest reactive oxygen species (ROS) activity. Additionally, this study suggests a possible correlation between welders' experience, the welding procedure and equipment used and particles generated from welding fumes. Mass concentrations and total metal and water soluble metal concentrations of welding fume particles may be

  19. Heavy Metal-Induced Oxidative DNA Damage in Earthworms: A Review

    Directory of Open Access Journals (Sweden)

    Takeshi Hirano

    2010-01-01

    Full Text Available Earthworms can be used as a bio-indicator of metal contamination in soil, Earlier reports claimed the bioaccumulation of heavy metals in earthworm tissues, while the metal-induced mutagenicity reared in contaminated soils for long duration. But we examined the metal-induced mutagenicity in earthworms reared in metal containing culture beddings. In this experiment we observed the generation of 8-oxoguanine (8-oxo-Gua in earthworms exposed to cadmium and nickel in soil. 8-oxo-Gua is a major premutagenic form of oxidative DNA damage that induces GC-to-TA point mutations, leading to carcinogenesis.

  20. Physicochemical and microbiological characterization of linolenic ...

    African Journals Online (AJOL)

    Physicochemical parameters of the extracted oils were respectively as follow: refractive index (1.46 and 1.45), acid value (3.74 ± 1.62 and 2.80 mg KOH/g), peroxide value (6.67 ± 0.58 and 5.33 ± 0.60 meq O2/kg), iodine value (132.54 ± 1.22 and 118.57 ± 1.22 g I2/100 g), saponification value (183.63 ± 3.24 and 189.23 ...

  1. Physicochemical model for reactive sputtering of hot target

    Energy Technology Data Exchange (ETDEWEB)

    Shapovalov, Viktor I., E-mail: vishapovalov@mail.ru; Karzin, Vitaliy V.; Bondarenko, Anastasia S.

    2017-02-05

    A physicochemical model for reactive magnetron sputtering of a metal target is described in this paper. The target temperature in the model is defined as a function of the ion current density. Synthesis of the coating occurs due to the surface chemical reaction. The law of mass action, the Langmuir isotherm and the Arrhenius equation for non-isothermal conditions were used for mathematical description of the reaction. The model takes into consideration thermal electron emission and evaporation of the target surface. The system of eight algebraic equations, describing the model, was solved for the tantalum target sputtered in the oxygen environment. It was established that the hysteresis effect disappears with the increase of the ion current density. - Highlights: • When model is applied for a cold target, hysteresis width is proportional to the ion current density. • Two types of processes of hot target sputtering are possible, depending on the current density: with and without the hysteresis. • Sputtering process is dominant at current densities less than 50 A/m{sup 2} and evaporation can be neglected. • For current densities over 50 A/m{sup 2} the hysteresis width reaches its maximum and the role of evaporation increases.

  2. Biological responses to diesel exhaust particles (DEPs depend on the physicochemical properties of the DEPs.

    Directory of Open Access Journals (Sweden)

    Eun-Jung Park

    Full Text Available Diesel exhaust particles (DEPs are the main components of ambient particulate materials, including polyaromatic hydrocarbons (PAHs, n-PAHs, heavy metals, and gaseous materials. Many epidemiological, clinical, and toxicological studies have shown that ambient particles, including DEPs, are associated with respiratory disorders, such as asthma, allergic rhinitis, and lung cancer. However, the relationship between the biological response to DEPs and their chemical composition remains unclear. In this study, we investigated the physicochemical properties of DEPs before toxicological studies, and then administered a single intratracheal instillation of DEPs to mice. The mice were then killed 1, 7, 14 and 28 days after DEP exposure to observe the biological responses induced by DEPs over time. Our findings suggest that DEPs engulfed into cells induced a Th2-type inflammatory response followed by DNA damage, whereas DEPs not engulfed into cells induced a Th1-type inflammatory response. Further, the physicochemical properties, including surface charge, particle size, and chemical composition, of DEPs play a crucial role in determining the biological responses to DEPs. Consequently, we suggest that the biological response to DEPs depend on cell-particle interaction and the physicochemical properties of the particles.

  3. Gold nanoparticles physicochemically bonded onto tungsten disulfide nanosheet edges exhibit augmented plasmon damping

    Directory of Open Access Journals (Sweden)

    Gregory T. Forcherio

    2017-07-01

    Full Text Available Augmented plasmonic damping of dipole-resonant gold (Au nanoparticles (NP physicochemically bonded onto edges of tungsten disulfide (WS2 nanosheets, ostensibly due to hot electron injection, is quantified using electron energy loss spectroscopy (EELS. EELS allows single-particle spatial resolution. A measured 0.23 eV bandwidth expansion of the localized surface plasmon resonance upon covalent bonding of 20 nm AuNP to WS2 edges was deemed significant by Welch’s t-test. Approximately 0.19 eV of the measured 0.23 eV expansion went beyond conventional radiative and nonradiative damping mechanisms according to discrete dipole models, ostensibly indicating emergence of hot electron transport from AuNP into the WS2. A quantum efficiency of up to 11±5% spanning a 7 fs transfer process across the optimized AuNP-TMD ohmic junction is conservatively calculated. Putative hot electron transport for AuNP physicochemically bonded to TMD edges exceeded that for AuNP physically deposited onto the TMD basal plane. This arose from contributions due to (i direct physicochemical bond between AuNP and WS2; (ii AuNP deposition at TMD edge sites; and (iii lower intrinsic Schottky barrier. This improves understanding of photo-induced doping of TMD by metal NP which could benefit emerging catalytic and optoelectronic applications.

  4. Physicochemical conditions and properties of particles in urban runoff and rivers: Implications for runoff pollution.

    Science.gov (United States)

    Wang, Qian; Zhang, Qionghua; Wu, Yaketon; Wang, Xiaochang C

    2017-04-01

    In this study, to gain an improved understanding of the fate and fractionation of particle-bound pollutants, we evaluated the physicochemical conditions and the properties of particles in rainwater, urban runoff, and rivers of Yixing, a city with a large drainage density in the Taihu Lake Basin, China. Road runoff and river samples were collected during the wet and dry seasons in 2015 and 2016. There were significant differences between the physicochemical conditions (pH, oxidation-reduction potential (ORP), and electroconductivity (EC)) of rainwater, runoff, and rivers. The lowest pH and highest ORP values of rainwater provide the optimal conditions for leaching of particle-bound pollutants such as heavy metals. The differences in the physicochemical conditions of the runoff and rivers may contribute to the redistribution of pollutants between particulate and dissolved phases after runoff is discharged into waterways. Runoff and river particles were mainly composed of silt and clay (rivers. The ratio of turbidity to TSS increased with the proportion of fine particles and was associated with the accumulation of pollutants and settling ability of particles, which shows that it can be used as an index when monitoring runoff pollution. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Gold nanoparticles physicochemically bonded onto tungsten disulfide nanosheet edges exhibit augmented plasmon damping

    Science.gov (United States)

    Forcherio, Gregory T.; Dunklin, Jeremy R.; Backes, Claudia; Vaynzof, Yana; Benamara, Mourad; Roper, D. Keith

    2017-07-01

    Augmented plasmonic damping of dipole-resonant gold (Au) nanoparticles (NP) physicochemically bonded onto edges of tungsten disulfide (WS2) nanosheets, ostensibly due to hot electron injection, is quantified using electron energy loss spectroscopy (EELS). EELS allows single-particle spatial resolution. A measured 0.23 eV bandwidth expansion of the localized surface plasmon resonance upon covalent bonding of 20 nm AuNP to WS2 edges was deemed significant by Welch's t-test. Approximately 0.19 eV of the measured 0.23 eV expansion went beyond conventional radiative and nonradiative damping mechanisms according to discrete dipole models, ostensibly indicating emergence of hot electron transport from AuNP into the WS2. A quantum efficiency of up to 11±5% spanning a 7 fs transfer process across the optimized AuNP-TMD ohmic junction is conservatively calculated. Putative hot electron transport for AuNP physicochemically bonded to TMD edges exceeded that for AuNP physically deposited onto the TMD basal plane. This arose from contributions due to (i) direct physicochemical bond between AuNP and WS2; (ii) AuNP deposition at TMD edge sites; and (iii) lower intrinsic Schottky barrier. This improves understanding of photo-induced doping of TMD by metal NP which could benefit emerging catalytic and optoelectronic applications.

  6. Physicochemical and sensorial quality of banana genotypes

    Directory of Open Access Journals (Sweden)

    Ronielli Cardoso Reis

    2016-03-01

    Full Text Available Despite the diversity of banana varieties in Brazil, only a few cultivars have the proper agronomic traits and fruit quality for commercial exploitation. This study aimed at evaluating the physicochemical traits and sensorial acceptance of banana genotypes, in order to identify those with potential for commercial growing. Six improved banana genotypes were assessed (BRS Maravilha, PC 0101, FHIA 18, TM 2803, YB 4203 and BRS Caipira, as well as three commercial cultivars (Grand Naine, Pacovan and Prata Anã. Analyses of peel and pulp color, peel thickness, pulp yield, moisture, pH, soluble solids, titratable acidity, total carotenoids and sensorial acceptance were performed. The BRS Maravilha, FHIA 18, YB 4203 and BRS Caipira genotypes presented physicochemical traits similar to the Grand Naine, Pacovan and Prata Anã commercial cultivars. The BRS Maravilha and TM 2803 genotypes had sensorial acceptance similar to the Prata Anã and Grand Naine cultivars, and are therefore promising for commercial growing, with the advantage of being resistant to the black Sigatoka and Panama disease.

  7. Physicochemical parameters of Amazon Melipona honey

    Directory of Open Access Journals (Sweden)

    Ligia Bicudo de Almeida-Muradian

    2007-06-01

    Full Text Available Stingless bees produce a honey that is different from the Apis honey in terms of composition. There aren't enough data to establish quality control parameters for this product, mainly due to lack of research results. The aim of this work is to evaluate some physicochemical parameters that can be used for the characterization and for the quality control of the Meliponinae honey. Four different samples were collected in the Amazon region of Brazil in 2004 (Melipona compressipes manaoense bee and Melipona seminigra merribae bee. Honey analyses were performed as described by the official methods. The mean results were: moisture (30.13%, pH (3.65, acidity (24.57 mEq/kg, water activity (0.75, fructose (31.91%, glucose (29.30% and sucrose (0.19%. These results reinforce the need for a specific regulation for stingless bee honey. This will only be feasible when enough data is available to establish upper and lower limits for the physicochemical parameters used for quality control.

  8. Physicochemical, structural and induced ferromagnetic properties of ...

    Indian Academy of Sciences (India)

    methods by which we can control their structural defects is doping with foreign metallic ions. It was found experimen- tally that doping of TCOs with some metallic ions could increase the concentration of carriers and/or improve the con- ductivity [2]. Besides, the doping process could generate extra exotic properties in TCOs, ...

  9. Advances in Understanding of Penile Carcinogenesis: The Search for Actionable Targets.

    Science.gov (United States)

    Chipollini, Juan; Chaing, Sharon; Azizi, Mounsif; Kidd, Laura C; Kim, Patricia; Spiess, Philippe E

    2017-08-16

    Penile cancer (PeCa) is a rare malignancy with potentially devastating effects. Squamous cell carcinoma is the most common variant with distinct precancerous lesions before development into invasive disease. Involvement of the inguinal lymph nodes is the most important prognostic factor in PeCa, and once disease is present outside the groin, prognosis is poor. Metastatic PeCa is challenging to treat and often requires multidisciplinary approaches in management. Due to its rarity, molecular understanding of the disease continues to be limited with most studies based on small, single center series. Thus far, it appears PeCa has diverse mechanisms of carcinogenesis affecting similar molecular pathways. In this review, we evaluate the current landscape of the molecular carcinogenesis of PeCa and explore ongoing research on potential actionable targets of therapy. The emergence of anti-epidermal growth factor receptor (EGFR) and other immunotherapeutic strategies may improve outcomes for PeCa patients.

  10. The pleiotropic roles of transforming growth factor beta inhomeostasis and carcinogenesis of endocrine organs.

    Energy Technology Data Exchange (ETDEWEB)

    Fleisch, Markus C.; Maxwell, Christopher A.; Barcellos-Hoff,Mary-Helen

    2006-01-13

    Transforming growth factor beta (TGF-beta) is a ubiquitous cytokine that plays a critical role in numerous pathways regulating cellular and tissue homeostasis. TGF-beta is regulated by hormones and is a primary mediator of hormone response in uterus, prostate and mammary gland. This review will address the role of TGF-beta in regulating hormone dependent proliferation and morphogenesis. The subversion of TGF-beta regulation during the processes of carcinogenesis, with particular emphasis on its effects on genetic stability and epithelial to mesenchymal transition (EMT), will also be examined. An understanding of the multiple and complex mechanisms of TGF-beta regulation of epithelial function, and the ultimate loss of TGF-beta function during carcinogenesis, will be critical in the design of novel therapeutic interventions for endocrine-related cancers.

  11. Defining the role of polyamines in colon carcinogenesis using mouse models

    Directory of Open Access Journals (Sweden)

    Natalia A Ignatenko

    2011-01-01

    Full Text Available Genetics and diet are both considered important risk determinants for colorectal cancer, a leading cause of death in the US and worldwide. Genetically engineered mouse (GEM models have made a significant contribution to the characterization of colorectal cancer risk factors. Reliable, reproducible, and clinically relevant animal models help in the identification of the molecular events associated with disease progression and in the development of effictive treatment strategies. This review is focused on the use of mouse models for studying the role of polyamines in colon carcinogenesis. We describe how the available mouse models of colon cancer such as the multiple intestinal neoplasia (Min mice and knockout genetic models facilitate understanding of the role of polyamines in colon carcinogenesis and help in the development of a rational strategy for colon cancer chemoprevention.

  12. Use of medaka as a tool in studies of radiation effects and chemical carcinogenesis

    International Nuclear Information System (INIS)

    Hyodo-Taguchi, Y.; Aoki, K.; Matsudaira, H.

    1982-01-01

    The medaka, Oryzias latipes, a small freshwater oviparous fish, is common in Japan and found in some parts of Asia. Adult fish are 3.0-3.5 cm long and weigh 0.5-0.7 g. The small fish have been used extensively in this laboratory for analysis of radiation effects and for study of chemical carcinogenesis. These fish are relatively easy to rear and their reproductive biology is well known. Recently, inbred strains of the fish have been established by full sister-brother mating. In this report, we will review experimental results using medaka in studies of : 1) radiation effects on spermatogenesis, and 2) induction of hepatic tumors by MAM acetate, we will also review use of medaka in related studies of radiation effects and chemical carcinogenesis. (author)

  13. Cervical carcinogenesis: the role of co-factors and generation of reactive oxygen species

    Directory of Open Access Journals (Sweden)

    Giuliano Anna

    2003-01-01

    Full Text Available Several HPV co-factors have been proposed, some more or less consistently associated with cervical dysplasia and cancer risk. More research, using prospective cohort designs, is needed to further describe where in carcinogenesis these factors are working and to assess the biological mechanism of these factors. In addition, further research is needed to define the role of various hormonal contraceptive formulations in promoting cervical carcinogenesis. While many interesting scientific questions remain to be answered, results from the numerous epidemiological studies conducted to date indicate that cervical dysplasia and cancer may be reduced if the oxidant antioxidant ratio is shifted to more of and antioxidant profile. In addition to cervical cancer screening, a reduction in cervical cancer incidence may be accomplished by reducing tobacco use, increasing nutritional status, and utilizing barrier contraception to prevent infection with other sexually acquired infections.

  14. Activation-Induced Cytidine Deaminase Links Ovulation-Induced Inflammation and Serous Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Stav Sapoznik

    2016-02-01

    Full Text Available In recent years, the notion that ovarian carcinoma results from ovulation-induced inflammation of the fallopian tube epithelial cells (FTECs has gained evidence. However, the mechanistic pathway for this process has not been revealed yet. In the current study, we propose the mutator protein activation-induced cytidine deaminase (AID as a link between ovulation-induced inflammation in FTECs and genotoxic damage leading to ovarian carcinogenesis. We show that AID, previously shown to be functional only in B lymphocytes, is expressed in FTECs under physiological conditions, and is induced in vitro upon ovulatory-like stimulation and in vivo in carcinoma-associated FTECs. We also report that AID activity results in epigenetic, genetic and genomic damage in FTECs. Overall, our data provides new insights into the etiology of ovarian carcinogenesis and may set the ground for innovative approaches aimed at prevention and early detection.

  15. Physico-chemical Analysis of an Ultisol Polluted with Different ...

    African Journals Online (AJOL)

    Physicochemical analyses were carried out on an ultisol previously polluted with different petroleum products and later treated with poultry droppings than planted with poultry droppings then planted with maize in the. Teaching and research Farm of Benson Idahosa University, Benin City Nigeria. Physicochemical analysis ...

  16. Physico-chemical and bacteriological quality of rainwater in Egbema ...

    African Journals Online (AJOL)

    Physico-chemical and bacteriological quality of rainwater in Egbema was determined with samples harvested directly, from zinc roof, thatched roof and asbestos roof, at different periods of the rainy season namely, Early, peak and late rains. The values of the physico-chemical parameters were on the higher side at the early ...

  17. Bacteriological and Physicochemical Qualities of Ebutte River in ...

    African Journals Online (AJOL)

    Michael Horsfall

    ABSTRACT: The bacteriological and physicochemical qualities of Ebutte River in Ebutte Community were carried out to ascertain the variation in the quality of the river between August, 2010 and January, 2011.The bacteriological and physicochemical assessments were studied using the basic microbiological techniques.

  18. Physico-chemical properties and sensory evaluation of jam made ...

    African Journals Online (AJOL)

    This study was carried out to investigate the possibility of producing jam from black-plum and to evaluate the physico-chemical properties, nutritional properties and consumer acceptability of the product. Black-plum jam was produced using traditional openkettle method. The physico-chemical analyses of black-plum fruit ...

  19. Physico-chemical evaluation of wastewater in Katsina metropolis ...

    African Journals Online (AJOL)

    Physico-chemical evaluation of wastewater in Katsina metropolis, Katsina Nigeria. A Abba, S Ibrahim, A.Y. Ugya. Abstract. The study was designed to assess the physico-chemical parameters of wastewater at Katsina metropolis from June-August, 2015. Water samples were collected twice in a month at three (3) sampling ...

  20. Investigation into the physico-chemical properties and ...

    African Journals Online (AJOL)

    user

    The physico-chemical and hydrochemical study of commercial borehole waters in Yenagoa, Bayelsa. State have been carried out. Eight commercial borehole water samples were analyze for various physico-chemical parameters using standard methods. The results obtained shows that the water samples quality examined ...

  1. Physico-chemical, sensory and microbiological qualities of yoghurt ...

    African Journals Online (AJOL)

    This study was conducted to evaluate the physico-chemical, sensory and microbiological qualities of some yoghurt brands sold in Kano Metropolis using standard procedures. The physico-chemical characteristics (viscosity, specific gravity, pH, titratable acidity, fat content) and Sensory properties (color, flavor, smell) were ...

  2. Physico-chemical and biotic factors influencing microalgal seed ...

    African Journals Online (AJOL)

    The growth of Chlorella vulgaris in open pond aquatic conditions poses serious challenges due to the interplay of both physico-chemical and biotic factors. We report here the monitoring of physico-chemical and biotic parameters affecting the propagation of C. vulgaris seed culture for inoculation of a large scale raceway ...

  3. Seasonal variations of physico-chemical properties of the Great ...

    African Journals Online (AJOL)

    The present study was attempted on the physico-chemical variability of the Great Vedaranyam Swamp of the Point Calimere Wildlife Sanctuary, South-east coast of India. Seasonal variation study was carried out to examine level of varying physico-chemical parameters such as temperature, salinity, pH, dissolved oxygen, ...

  4. Assessment Of Some Physicochemical Parameters Levels In Sachet

    African Journals Online (AJOL)

    some physicochemical parameters in sachet drinking water in Katsina Urban Area, Nigeria. In specific terms, the research seeks to realize the following objectives: Determine the level of some physicochemical parameters in the sachet water; Compare these levels with. International Standard of World Health Organization.

  5. Physicochemical properties and transport of steroids across Caco-2 cells

    NARCIS (Netherlands)

    Faassen, F.; Kelder, J.; Lenders, J.; Onderwater, R.; Vromans, H.

    2003-01-01

    Purpose. The purpose of this work was to study the relevant physicochemical properties for the absorption of steroids. Methods. Various physicochemical properties of steroids were calculated (molecular weight, ClogP, static polar surface area [PSA], etc.). Within this series of steroids, different

  6. Assessment of Physico-chemical and Microbiological qualities of ...

    African Journals Online (AJOL)

    Assessment of Physico-chemical and Microbiological qualities of Abattoir Wastewater in Sokoto, Nigeria. AB Rabah, UJJ Ijah, SB Manga, ML Ibrahim. Abstract. Wastewater samples were collected from three different points in Sokoto (Nigeria) abattoir and the physico-chemical and the microbiological qualities were ...

  7. Bacteriological and physicochemical analysis of waste water from ...

    African Journals Online (AJOL)

    Assessment of the bacteriological and physicochemical characteristics of ten freshwater fish ponds stocked with African catfish (Clarias gariepinus) was conducted within Ilorin metropolis. The results of physicochemical properties of the water samples showed that the pH, total hardness, salinity, and suspended solid ranged ...

  8. Evaluation of bisphenol A, physicochemical properties and microbial ...

    African Journals Online (AJOL)

    The aim of this study was to evaluate the bisphenol A (BPA), physicochemical properties and microbial characterization of borehole water stored in plastic containers. Three brands of plastic containers filled with borehole water were collected from homes in Ugbowo, Benin city. Physicochemical parameters were determined ...

  9. Comparative assessment of physico-chemical quality of bottled and ...

    African Journals Online (AJOL)

    Samples of various brands of bottled water sold in Dar es Salaam, Tanzania were analyzed for physicochemical water quality parameters. For comparison purposes, tap water was similarly examined. The results showed great variations in physico-chemical quality of bottled water, with some samples exceeding the ...

  10. Microbiological and physico-chemical analysis of soymilk and ...

    African Journals Online (AJOL)

    Microbiological and physico-chemical analysis of soymilk and soyflour sold in Uyo metropolis, Nigeria. A. A. Brooks, N. U. Asamudo, F. C Udoukpo. Abstract. Ten samples each of unbranded soymilk and soyflour sold in Uyo metropolis were subjected to microbiological and physico-chemical studies. The microorganisms ...

  11. Physicochemical stability and sensory acceptance of a carbonated ...

    African Journals Online (AJOL)

    Physicochemical stability and sensory acceptance of a carbonated cashew beverage with fructooligosaccharide added. ... Physicochemical analyzes (pH, titratable acidity, soluble solids (°Brix), vitamin C, reducing sugars) and sensory evaluation (triangular test and acceptance test) were performed throughout 60 days of ...

  12. Physicochemical properties of water quality of Imeh, Edegelem and ...

    African Journals Online (AJOL)

    KC

    laboratory to investigate some selected physico-chemical characteristics. Also, bacteriological study was ... the selected physico-chemical parameters were within the world health organization (WHO) permissible in both rainy and dry ..... Also, Ammonia is toxic to fish and that the toxicity increases with increasing pH and ...

  13. Changes in physico-chemical properties and flavour compounds ...

    African Journals Online (AJOL)

    Four types of Obushera, a fermented millet or sorghum beverage:Ekitiribita Obuteire, Obutoko and Enturire were analyzed for their physico-chemical properties, sugars, organic acids and volatile compounds during fermentation. Standard chemical methods were used to determine the physico-chemical properties of ...

  14. Physico-Chemical and Bacteriological Characteristics of Noyyal ...

    African Journals Online (AJOL)

    The study was conducted to findout the physico-chemical and bacteriological characteristics of Noyyal River and ground water quality of Perur, India. The river water and ground water (bore well and open well) samples were collected in and around Perur and analyzed for various physico-chemical and bacteriological ...

  15. Biologically-based mechanistic models of radiation-related carcinogenesis applied to epidemiological data.

    Science.gov (United States)

    Rühm, Werner; Eidemüller, Markus; Kaiser, Jan Christian

    2017-10-01

    Biologically-based mechanistic models that are used in combining current understanding of human carcinogenesis with epidemiological studies were reviewed. Assessment was made of how well they fit the data, whether they account for non-linear radiobiological low-dose effects, and whether they suggest any implications for the dose response at low doses and dose rates. However, the present paper does not make an attempt to provide a complete review of the existing literature on biologically-based models and their application to epidemiological data. In most studies the two-stage clonal expansion (TSCE) model of carcinogenesis was used. The model provided robust estimates of identifiable parameters and radiation risk. While relatively simple, it is flexible, so that more stages can easily be added, and tests made of various types of radiation action. In general, the model performed similarly or better than descriptive excess absolute and excess relative risk models, in terms of quality of fit and number of parameters. Only very rarely the shape of dose-response predicted by the models was investigated. For some tumors, when more detailed biological information was known, additional pathways were included in the model. The future development of these models will benefit from growing knowledge on carcinogenesis processes, and in particular from use of biobank tissue samples and advances in omics technologies. Their use appears a promising approach to investigate the radiation risk at low doses and low dose rates. However, the uncertainties involved are still considerable, and the models provide only a simplified description of the underlying complexity of carcinogenesis. Current assumptions in radiation protection including the linear-non-threshold (LNT) model are not in contradiction to what is presently known on the process of cancer development.

  16. Gastric microbiota and carcinogenesis: the role of non-Helicobacter pylori bacteria: a systematic review

    Directory of Open Access Journals (Sweden)

    Emanuel Dias-Jácome

    Full Text Available Background and aim: Helicobacter pylori is the strongest risk factor for gastric cancer. However, recent advances in DNA sequencing technology have revealed a complex microbial community in the stomach that could also contribute to the development of gastric cancer. The aim of this study was to present recent scientific evidence regarding the role of non-Helicobacter pylori bacteria in gastric carcinogenesis. Methods: A systematic review of original articles published in PubMed in the last ten years related to gastric microbiota and gastric cancer in humans was performed. Results: Thirteen original articles were included. The constitution of gastric microbiota appears to be significantly affected by gastric cancer and premalignant lesions. In fact, differences in gastric microbiota have been documented, depending on Helicobacter pylori status and gastric conditions, such as non-atrophic gastritis, intestinal metaplasia and cancer. Gastric carcinogenesis can be associated with an increase in many bacteria (such as Lactobacillus coleohominis, Klebsiella pneumoniae or Acinetobacter baumannii as well as decrease in others (such as Porphyromonas spp, Neisseria spp, Prevotella pallens or Streptococcus sinensis. However, there is no conclusive data that confirms if these changes in microbiota are a cause or consequence of the process of carcinogenesis. Conclusions: Even though there is limited evidence in humans, microbiota differences between normal individuals, pre-malignant lesions and gastric cancer could suggest a progressive shift in the constitution of gastric microbiota in carcinogenesis, possibly resulting from a complex cross-talk between gastric microbiota and Helicobacter pylori. However, further studies are needed to elucidate the specific role (if any of different microorganisms.

  17. The substrate of the biopsychosocial influences in the carcinogenesis of the digestive tract

    OpenAIRE

    Georgică C. Târtea; Cristina Florescu; Daniel Pirici; Daniel Caragea; Elena A. Târtea; Cristin C. Vere

    2016-01-01

    Digestive cancer represents a severe public health problem, being one of the main causes of death. It is considered a multifactorial disease, with hereditary predisposition, environmental factors, and other factors involved in carcinogenesis. Both the evolution and the pathogenesis of digestive neoplasms remain incompletely elucidated. As a multifactorial disease, it can be approached by taking into account the biopsychosocial influences via enteric nervous system. Many peptides and non-pepti...

  18. Dynamic landscape of pancreatic carcinogenesis reveals early molecular networks of malignancy.

    Science.gov (United States)

    Kong, Bo; Bruns, Philipp; Behler, Nora A; Chang, Ligong; Schlitter, Anna Melissa; Cao, Jing; Gewies, Andreas; Ruland, Jürgen; Fritzsche, Sina; Valkovskaya, Nataliya; Jian, Ziying; Regel, Ivonne; Raulefs, Susanne; Irmler, Martin; Beckers, Johannes; Friess, Helmut; Erkan, Mert; Mueller, Nikola S; Roth, Susanne; Hackert, Thilo; Esposito, Irene; Theis, Fabian J; Kleeff, Jörg; Michalski, Christoph W

    2018-01-01

    The initial steps of pancreatic regeneration versus carcinogenesis are insufficiently understood. Although a combination of oncogenic Kras and inflammation has been shown to induce malignancy, molecular networks of early carcinogenesis remain poorly defined. We compared early events during inflammation, regeneration and carcinogenesis on histological and transcriptional levels with a high temporal resolution using a well-established mouse model of pancreatitis and of inflammation-accelerated Kras G12D -driven pancreatic ductal adenocarcinoma. Quantitative expression data were analysed and extensively modelled in silico. We defined three distinctive phases-termed inflammation, regeneration and refinement-following induction of moderate acute pancreatitis in wild-type mice. These corresponded to different waves of proliferation of mesenchymal, progenitor-like and acinar cells. Pancreas regeneration required a coordinated transition of proliferation between progenitor-like and acinar cells. In mice harbouring an oncogenic Kras mutation and challenged with pancreatitis, there was an extended inflammatory phase and a parallel, continuous proliferation of mesenchymal, progenitor-like and acinar cells. Analysis of high-resolution transcriptional data from wild-type animals revealed that organ regeneration relied on a complex interaction of a gene network that normally governs acinar cell homeostasis, exocrine specification and intercellular signalling. In mice with oncogenic Kras, a specific carcinogenic signature was found, which was preserved in full-blown mouse pancreas cancer. These data define a transcriptional signature of early pancreatic carcinogenesis and a molecular network driving formation of preneoplastic lesions, which allows for more targeted biomarker development in order to detect cancer earlier in patients with pancreatitis. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

  19. Allergic inflammation does not impact chemical-induced carcinogenesis in the lungs of mice

    Directory of Open Access Journals (Sweden)

    Doris Konstantinos

    2010-08-01

    Full Text Available Abstract Background Although the relationship between allergic inflammation and lung carcinogenesis is not clearly defined, several reports suggest an increased incidence of lung cancer in patients with asthma. We aimed at determining the functional impact of allergic inflammation on chemical carcinogenesis in the lungs of mice. Methods Balb/c mice received single-dose urethane (1 g/kg at day 0 and two-stage ovalbumin during tumor initiation (sensitization: days -14 and 0; challenge: daily at days 6-12, tumor progression (sensitization: days 70 and 84; challenge: daily at days 90-96, or chronically (sensitization: days -14 and 0; challenge: daily at days 6-12 and thrice weekly thereafter. In addition, interleukin (IL-5 deficient and wild-type C57BL/6 mice received ten weekly urethane injections. All mice were sacrificed after four months. Primary end-points were number, size, and histology of lung tumors. Secondary end-points were inflammatory cells and mediators in the airspace compartment. Results Ovalbumin provoked acute allergic inflammation and chronic remodeling of murine airways, evident by airspace eosinophilia, IL-5 up-regulation, and airspace enlargement. Urethane resulted in formation of atypical alveolar hyperplasias, adenomas, and adenocarcinomas in mouse lungs. Ovalbumin-induced allergic inflammation during tumor initiation, progression, or continuously did not impact the number, size, or histologic distribution of urethane-induced pulmonary neoplastic lesions. In addition, genetic deficiency in IL-5 had no effect on urethane-induced lung tumorigenesis. Conclusions Allergic inflammation does not impact chemical-induced carcinogenesis of the airways. These findings suggest that not all types of airway inflammation influence lung carcinogenesis and cast doubt on the idea of a mechanistic link between asthma and lung cancer.

  20. Disease Heterogeneity and Immune Biomarkers in Preclinical Mouse Models of Ovarian Carcinogenesis

    Science.gov (United States)

    2014-08-01

    the cancer risk, including the cervical epithelial transformation zone with HPV [41], the esophageal-gastric junction and Barrett’s esophagus [42], and...Sweetwood JP, Cheng Y, Pace JL, et al. (2000) Development of a syngeneic mouse model for events related to ovarian cancer . Carcinogenesis 21: 585–591...endometriosis-associated ovarian cancer (EAOC, endometrial and clear cell). Of these genes, complement pathway genes were consistently present, suggesting

  1. In Vivo Testing of Chemopreventive Agents Using the Dog Model of Spontaneous Prostate Carcinogenesis

    Science.gov (United States)

    2001-03-01

    that there would be tional health survey of 211 Irish setter dogs (L.T. Glick- no advantage for members of a highly domesticated man, unpublished results...understand the mechanisms of prostate cancer development. This research will benefit the health and welfare of both dogs and humans. ACKNOWLEDGMENT This...AD Award Number: DAMD17-98-1-8550 TITLE: In Vivo Testing of Chemopreventive Agents Using the Dog Model of Spontaneous Prostate Carcinogenesis

  2. Digestive forms of Chagas disease and carcinogenesis: a study of association

    OpenAIRE

    Gullo, Caio Eduardo; Estofolete, Cássia Fernanda; Gil, Cristiane Damas; Christiano, Adriana Borgonovi; Netinho, João Gomes

    2012-01-01

    The authors analyze the relation between gastrointestinal carcinogenesis and Chagas disease, based on detailed review of the literature. To this end, epidemiological, experimental and human material pathology description studies have been selected. The article discusses the possibility of protection being afforded by not fully known morphokinetic cellular, immune and neuroendocrine factors that would be secondary to plexus degeneration. Also aspects related to the parasite-host interaction fr...

  3. Differentiation and carcinogenesis: an integrated multilevel study of mechanisms from molecules to man. Progress report

    International Nuclear Information System (INIS)

    1985-01-01

    This study sought to identify and characterize mesenchymal progenitor cells (MPCs) in vitro, to identify the in vivo equivalent of the in vitro MPCs, and to determine the relationship between the presence or response of these cells both in vitro and eventually in vivo to altered proliferative capacity (in vitro cellular senescence, in vivo organismal aging) and altered susceptibility to carcinogenesis (frequency of in vitro neoplastic transformation and age-related frequency of in vivo cancer incidence). 16 refs

  4. Colonic protein fermentation and promotion of colon carcinogenesis by thermolyzed casein

    Science.gov (United States)

    Corpet, Denis E.; Yin, Y.; Zhang, X. M.; Rémésy, C.; Stamp, D.; Medline, A.; Thompson, L.U.; Bruce, W. R.; Archer, M. C.

    1995-01-01

    Thermolyzed casein is known to promote the growth of aberrant crypt foci (ACF) and colon cancer when it is fed to rats that have been initiated with azoxymethane. We speculated that the promotion was a consequence of increased colonic protein fermentation (i.e., that the thermolysis of the casein decreases its digestibility, increases the amount of protein reaching the colon, and increases colonic protein fermentation and that the potentially toxic products of this fermentation promote colon carcinogenesis). We found that the thermolysis of casein reduces its digestibility and increases colonic protein fermentation, as assessed by fecal ammonium and urinary phenol, cresol, and indol-3-ol. Thermolysis of two other proteins, soy and egg white protein, also increases colonic protein fermentation with increased fecal ammonia and urinary phenols, and thermolysis of all three proteins increases the levels of ammonia and butyric, valeric, and i-valeric acids in the cecal contents. We found, however, that the increased protein fermentation observed with thermolysis is not associated with promotion of colon carcinogenesis. With casein, the kinetics of protein fermentation with increasing thermolysis time are clearly different from the kinetics of promotion of ACF growth. The formation of the fermentation products was highest when the protein was thermolyzed for one hour, whereas promotion was highest for protein that had been thermolyzed for two or more hours. With soy and egg white, thermolysis increased colonic protein fermentation but did not promote colon carcinogenesis. Thus, although thermolysis of dietary casein increases colonic protein fermentation, products of this fermentation do not appear to be responsible for the promotion of colon carcinogenesis. Indeed, the results suggest that protein fermentation products do not play an important role in colon cancer promotion. PMID:7603887

  5. A selective cyclooxygenase-2 inhibitor prevents inflammation-related squamous cell carcinogenesis of the forestomach via duodenogastric reflux in rats

    OpenAIRE

    Oba, Masaru; Miwa, Koichi; Fujimura, Takeshi; Harada, Shin-ichi; Sasaki, Shozo; Oyama, Katsunobu; Ohta, Tetsuo; Hattori, Takanori

    2009-01-01

    Background: Duodenal reflux causes inflammation-related squamous cell carcinogenesis in the forestomach of rats without any carcinogens. The aim of this study was to investigate the efficacy of a selective cyclooxygenase (COX)-2 inhibitor, meloxicam, in preventing this carcinogenesis. Methods: A series of 188 rats underwent a surgical duodenogastric reflux procedure and were divided into 2 groups. One group was given commercial chow (control group), and the other was given experimental chow c...

  6. Modification of N-Methyl-N-Nitrosourea initiated bladder carcinogenesis in Wistar rats by terephthalic acid

    International Nuclear Information System (INIS)

    Cui Lunbiao; Shi Yuan; Dai Guidong; Pan Hongxin; Chen Jianfeng; Song Ling; Wang Shouling; Chang, Hebron C.; Sheng Hongbing; Wang Xinru

    2006-01-01

    The effect of terephthalic acid (TPA) on urinary bladder carcinogenesis was examined. Male Wistar rats were initiated by injection of N-Methyl-N-Nitrosourea (MNU) (20 mg/kg b.w. ip) twice a week for 4 weeks, then given basal diet containing 5% TPA, 5% TPA plus 4% Sodium bicarbonate (NaHCO 3 ) or 1% TPA for the next 22 weeks, and then euthanized. 5% TPA treatment induced a high incidence of urinary bladder calculi and a large amount of precipitate. Though 5% TPA plus 4% Sodium bicarbonate (NaHCO 3 ) and 1% TPA treatment did not induce urinary bladder calculi formation, they resulted in a moderate increase in urinary precipitate. Histological examination of urinary bladder revealed that MNU-5% TPA treatment resulted in a higher incidence of simple hyperplasia, papillary or nodular hyperplasia (PN hyperplasia), papilloma and cancer than MNU control. MNU-5% TPA plus 4% Sodium bicarbonate (NaHCO 3 ) and 1% TPA treatment increased slightly the incidence of simple hyperplasia and PN hyperplasia (not statistically significant). The major elements of the precipitate are phosphorus, potassium, sulfur, chloride, calcium and TPA. The present study indicated that the calculi induced by TPA had a strong promoting activity on urinary bladder carcinogenesis and the precipitate containing calcium terephthalate (CaTPA) may also have weak promoting activity on urinary bladder carcinogenesis

  7. Detouring the Undesired Route of Helicobacter pylori-Induced Gastric Carcinogenesis

    International Nuclear Information System (INIS)

    Kim, Eun-Hee; Hong, Kyung-Sook; Hong, Hua; Hahm, Ki Baik

    2011-01-01

    Epidemiological and experimental evidence has emerged that a dysregulated inflammation is associated with most of the tumors, and many studies have begun to unravel the molecular pathways linking inflammation and cancer. As a typical example linking these associations, Helicobacter pylori (H. pylori) infection-associated atrophic gastritis has been recognized as precursor lesion of gastric cancer. The identification of transcription factors such as NF-κB and STAT3, and their gene products such as IL-8, COX-2, iNOS, cytokines, chemokines and their receptors, etc have laid the molecular foundation for our understanding of the decisive role of inflammation in carcinogenesis. In addition to the role as the initiator of cancer, inflammation contributes to survival and proliferation of malignant cells, tumor angiogenesis, and even metastasis. In this review, the fundamental mechanisms of H. pylori-induced carcinogenesis as well as the possibility of cancer prevention through suppressing H. pylori-induced inflammation are introduced. We infer that targeting inflammatory pathways have a potential role to detour the unpleasant journey to H. pylori-associated gastric carcinogenesis

  8. Chronic Inflammation-Related HPV: A Driving Force Speeds Oropharyngeal Carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Xin Liu

    Full Text Available Oropharyngeal squamous cell carcinoma (OPSCC has been known to be a highly aggressive disease associated with human papilloma virus (HPV infection. To investigate the relationship between HPV and chronic inflammation in oropharyngeal carcinogenesis, we collected 140 oral mucous fresh specimens including 50 OPSCC patients, 50 cancer in situ, 30 precancerous lesions, and 10 normal oral mucous. Our data demonstrated that there was a significantly higher proportion of severe chronic inflammation in dysplastic epithelia in comparison with that in normal tissues (P<0.001. The positive rate of HPV 16 was parallel with the chronic inflammation degrees from mild to severe inflammation (P<0.05. The positive rate of HPV 16 was progressively improved with the malignant progression of oral mucous (P<0.05. In addition, CD11b+ LIN- HLA-DR-CD33+ MDSCs were a critical cell population that mediates inflammation response and immune suppression in HPV-positive OPSCC. These indicated that persistent chronic inflammation-related HPV infection might drive oropharyngeal carcinogenesis and MDSCs might pay an important role during this process. Thus, a combination of HPV infection and inflammation expression might become a helpful biomedical marker to predict oropharyngeal carcinogenesis.

  9. 65Zn kinetics as a biomarker of DMH induced colon carcinogenesis

    International Nuclear Information System (INIS)

    Chadha, Vijayta Dani

    2012-01-01

    Dietary factors are considered crucial for the prevention of initiating events in the multistep progression of colon carcinoma. There is substantial evidence that zinc may play a pivotal role in host defense against several malignancies, including colon cancer. The present study was conducted to evaluate the kinetics of zinc utilization following experimental colon carcinogenesis in rat model. The rats were segregated into two groups viz., untreated control and DMH treated. Colon carcinogenesis was established through weekly subcutaneous injections of DMH (30mg/Kg body weight) for 16 weeks. Whole body 65 Zn kinetics followed two compartment kinetics, with Tb1 representing the initial fast component of the biological half-life and Tb2, the slower component. The present study revealed a significant depression in the Tb1 and Tb2 components of 65 Zn in DMH treated rats. Further, DMH treatment caused a significant increase in the percent uptake values of 65 Zn in the colon, small intestine, kidney and blood, whereas a significant decrease was observed in the liver. Subcellular distribution revealed a significant increase in 65 Zn uptake in the mitochondrial and microsomal fractions following 16 weeks of DMH supplementation. The present study demonstrated a slow mobilization of zinc during promotion of experimentally induced colon carcinogenesis and provides a physiological basis for the role of zinc in colon tumorigenesis, a paradigm which may have clinical implications in the management of colon cancer. (author)

  10. The scientific basis for the establishment of threshold levels and dose response relationships of carcinogenesis

    International Nuclear Information System (INIS)

    1975-01-01

    The International Atomic Energy Agency hosted a two day Symposium from 2-3 December 1974 at its Headquarters, organized by the 'International Academy for Environmental Safety and the Forum fur Wissenschaft, Wirtschaft und Politik' on the subject 'Scientific Basis for the Establishment of Threshold. Levels and Dose Response Relationships of Carcinogenesis'. Following an introductory paper by the Radiation Biology Section of the Agency on 'Radiation Carcinogenesis - Dose Response Relationship, Threshold and Risk Estimates', a series of papers dealt with this problem in chemical carcinogenesis.It was suggested that more experiments should be done using non-human primates for tests of carcinogens, especially chemicals. Preliminary experiments using monkeys with a potent carcinogen - nitrosoamine - indicate that there could possibly be a dose where no effect can be observed during the 5 year period of study. It was also pointed out that the overall cost/benefit and risk/ benefit relationships should be taken into consideration in determining limits for chemicals which are potentially carcinogenic but are used routinely by the public and industries; these considerations have been weighed in setting exposure limits for radiation

  11. Recent progress in nickel carcinogenesis. [Cornybacterium; E. coli; S. typhimurium; B. subtillis

    Energy Technology Data Exchange (ETDEWEB)

    Sunderman, F.W. Jr.

    1984-01-01

    Research on nickel carcinogenesis from 1979 to 1983 is reviewed. Epidemiological studies have strengthened the evidence that workers in nickel refineries have increased risks of lung and sinonasal cancers, but have not substantiated increased risks of respiratory cancers in other nickel-exposed workers. Carcinogenesis bioassays have demonstrated carcinogenicity of certain nickel sulfide, hydroxide, selenide, arsenide, antimonide, and telluride compounds following parenteral administration to rodents. Positive bacterial mutagenesis tests have been obtained with Ni(II) in Cornybacterium, but not in E. coli, S. typhimurium, or B. subtilis. Transformation assays of several soluble and crystalline Ni compounds have been positive in Syrian hamster embryo cells. Ni(II) binds to DNA, RNA, and nucleoproteins, and becomes localized in nucleoli. Genotoxic effects of Ni include: (a) chromosomal aberrations, including sister-chromatid exchanges, (b) DNA strandbreaks and DNA-protein cross-links, (c) inhibition of DNA and RNA synthesis, (d) infidelity of DNA transcription, and (e) mutations at the HGPRTase locus in Chinese hamster cells and the TK locus in mouse lymphoma cells. These findings are consistent with somatic mutation as the mechanism for initiation of nickel carcinogenesis. Ni compounds cause reversible transition of double-stranded poly(dG-dC) DNA from the right-handed B-helix to the left-handed Z-helix, suggesting a mechanism whereby nickel might modulate oncogene expression. 99 references, 6 tables.

  12. Detouring the Undesired Route of Helicobacter pylori-Induced Gastric Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Ki Baik Hahm

    2011-07-01

    Full Text Available Epidemiological and experimental evidence has emerged that a dysregulated inflammation is associated with most of the tumors, and many studies have begun to unravel the molecular pathways linking inflammation and cancer. As a typical example linking these associations, Helicobacter pylori (H. pylori infection-associated atrophic gastritis has been recognized as precursor lesion of gastric cancer. The identification of transcription factors such as NF-κB and STAT3, and their gene products such as IL-8, COX-2, iNOS, cytokines, chemokines and their receptors, etc have laid the molecular foundation for our understanding of the decisive role of inflammation in carcinogenesis. In addition to the role as the initiator of cancer, inflammation contributes to survival and proliferation of malignant cells, tumor angiogenesis, and even metastasis. In this review, the fundamental mechanisms of H. pylori-induced carcinogenesis as well as the possibility of cancer prevention through suppressing H. pylori-induced inflammation are introduced. We infer that targeting inflammatory pathways have a potential role to detour the unpleasant journey to H. pylori-associated gastric carcinogenesis.

  13. Deficiency of the Erc/mesothelin gene ameliorates renal carcinogenesis in Tsc2 knockout mice.

    Science.gov (United States)

    Zhang, Danqing; Kobayashi, Toshiyuki; Kojima, Tetsuo; Kanenishi, Kenji; Hagiwara, Yoshiaki; Abe, Masaaki; Okura, Hidehiro; Hamano, Yoshitomo; Sun, Guodong; Maeda, Masahiro; Jishage, Kou-ichi; Noda, Tetsuo; Hino, Okio

    2011-04-01

    Genetic crossing experiments were performed between tuberous sclerosis-2 (Tsc2) KO and expressed in renal carcinoma (Erc) KO mice to analyze the function of the Erc/mesothelin gene in renal carcinogenesis. We found the number and size of renal tumors were significantly less in Tsc2+/-;Erc-/- mice than in Tsc2+/-;Erc+/+ and Tsc2+/-;Erc+/- mice. Tumors from Tsc2+/-;Erc-/- mice exhibited reduced cell proliferation and increased apoptosis, as determined by proliferating cell nuclear antigen (Ki67) and TUNEL analysis, respectively. Adhesion to collagen-coated plates in vitro was enhanced in Erc-restored cells and decreased in Erc-suppressed cells with siRNA. Tumor formation by Tsc2-deficient cells in nude mice was remarkably suppressed by stable knockdown of Erc with shRNA. Western blot analysis showed that the phosphorylation of focal adhesion kinase, Akt and signal transducer and activator of transcription protein 3 were weaker in Erc-deficient/suppressed cells compared with Erc-expressed cells. These results indicate that deficiency of the Erc/mesothelin gene ameliorates renal carcinogenesis in Tsc2 KO mice and inhibits the phosphorylation of several kinases of cell adhesion mechanism. This suggests that Erc/mesothelin may have an important role in the promotion and/or maintenance of carcinogenesis by influencing cell-substrate adhesion via the integrin-related signal pathway. © 2011 Japanese Cancer Association.

  14. Detouring the Undesired Route of Helicobacter pylori-Induced Gastric Carcinogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Eun-Hee; Hong, Kyung-Sook; Hong, Hua [Lab of Translational Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, 7-45 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Hahm, Ki Baik, E-mail: hahmkb@gachon.ac.kr [Lab of Translational Medicine, Lee Gil Ya Cancer and Diabetes Institute, Gachon University of Medicine and Science, 7-45 Songdo-dong, Yeonsu-gu, Incheon 406-840 (Korea, Republic of); Department of Gastroenterology, Gachon Graduate School of Medicine, Gil Hospital, Incheon 406-840 (Korea, Republic of)

    2011-07-25

    Epidemiological and experimental evidence has emerged that a dysregulated inflammation is associated with most of the tumors, and many studies have begun to unravel the molecular pathways linking inflammation and cancer. As a typical example linking these associations, Helicobacter pylori (H. pylori) infection-associated atrophic gastritis has been recognized as precursor lesion of gastric cancer. The identification of transcription factors such as NF-κB and STAT3, and their gene products such as IL-8, COX-2, iNOS, cytokines, chemokines and their receptors, etc have laid the molecular foundation for our understanding of the decisive role of inflammation in carcinogenesis. In addition to the role as the initiator of cancer, inflammation contributes to survival and proliferation of malignant cells, tumor angiogenesis, and even metastasis. In this review, the fundamental mechanisms of H. pylori-induced carcinogenesis as well as the possibility of cancer prevention through suppressing H. pylori-induced inflammation are introduced. We infer that targeting inflammatory pathways have a potential role to detour the unpleasant journey to H. pylori-associated gastric carcinogenesis.

  15. Antibiotic suppression of intestinal microbiota reduces heme-induced lipoperoxidation associated with colon carcinogenesis in rats.

    Science.gov (United States)

    Martin, O C B; Lin, C; Naud, N; Tache, S; Raymond-Letron, I; Corpet, D E; Pierre, F H

    2015-01-01

    Epidemiological studies show that heme iron from red meat is associated with increased colorectal cancer risk. In carcinogen-induced-rats, a heme iron-rich diet increases the number of precancerous lesions and raises associated fecal biomarkers. Heme-induced lipoperoxidation measured by fecal thiobarbituric acid reagents (TBARs) could explain the promotion of colon carcinogenesis by heme. Using a factorial design we studied if microbiota could be involved in heme-induced carcinogenesis, by modulating peroxidation. Rats treated or not with an antibiotic cocktail were given a control or a hemoglobin-diet. Fecal bacteria were counted on agar and TBARs concentration assayed in fecal water. The suppression of microbiota by antibiotics was associated with a reduction of crypt height and proliferation and with a cecum enlargement, which are characteristics of germ-free rats. Rats given hemoglobin diets had increased fecal TBARs, which were suppressed by the antibiotic treatment. A duplicate experiment in rats given dietary hemin yielded similar results. These data show that the intestinal microbiota is involved in enhancement of lipoperoxidation by heme iron. We thus suggest that microbiota could play a role in the heme-induced promotion of colorectal carcinogenesis.

  16. DNA Damage in Inflammation-Related Carcinogenesis and Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Shiho Ohnishi

    2013-01-01

    Full Text Available Infection and chronic inflammation have been recognized as important factors for carcinogenesis. Under inflammatory conditions, reactive oxygen species (ROS and reactive nitrogen species (RNS are generated from inflammatory and epithelial cells and result in oxidative and nitrative DNA damage, such as 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG and 8-nitroguanine. The DNA damage can cause mutations and has been implicated in the initiation and/or promotion of inflammation-mediated carcinogenesis. It has been estimated that various infectious agents are carcinogenic to humans (IARC group 1, including parasites (Schistosoma haematobium (SH and Opisthorchis viverrini (OV, viruses (hepatitis C virus (HCV, human papillomavirus (HPV, and Epstein-Barr virus (EBV, and bacterium Helicobacter pylori (HP. SH, OV, HCV, HPV, EBV, and HP are important risk factors for bladder cancer, cholangiocarcinoma, hepatocellular carcinoma, cervical cancer, nasopharyngeal carcinoma, and gastric cancer, respectively. We demonstrated that 8-nitroguanine was strongly formed via inducible nitric oxide synthase (iNOS expression at these cancer sites of patients. Moreover, 8-nitroguanine was formed in Oct3/4-positive stem cells in SH-associated bladder cancer tissues and in Oct3/4- and CD133-positive stem cells in OV-associated cholangiocarcinoma tissues. Therefore, it is considered that oxidative and nitrative DNA damage in stem cells may play a key role in inflammation-related carcinogenesis.

  17. Unravelling metal mobility under complex contaminant signatures.

    Science.gov (United States)

    de Souza Machado, Anderson Abel; Spencer, Kate L; Zarfl, Christiane; O'Shea, Francis T

    2018-05-01

    Metals are concerning pollutants in estuaries, where contamination can undergo significant remobilisation driven by physico-chemical forcing. Environmental concentrations of metals in estuarine sediments are often higher than natural backgrounds, but show no contiguity to potential sources. Thus, better understanding the metal mobility in estuaries is essential to improve identification of pollution sources and their accountability for environmental effects. This study aims to identify the key biogeochemical drivers of metal mobilisation on contaminated estuarine sediments through (1) evaluation of the potential mobilisation under controlled conditions, and (2) investigation of the relevance of metal mobilisation for in situ pollution levels in an area with multiple contaminant sources. Sediments from a saltmarsh adjacent to a coastal landfill, a marina, and a shipyard on the Thames Estuary (Essex, UK) were exposed in the laboratory (24h, N=96, 20°C) to water under various salinity, pH, and redox potential. Major cations, Fe(II), and trace metal concentrations were analysed in the leachate and sediment. Salinity, pH and redox had a significant effect on metal mobilisation (pmetal spatial distribution. However, physicochemical parameters explained up to 97% of geochemically normalized metal concentrations in sediments. Organic matter and pH were dominant factors for most of the metal concentrations at the sediment surface. At subsurface, major cations (Ca, Na, Mg and K) were determinant predictors of metal concentrations. Applying the empirical model obtained in the laboratory to geochemical conditions of the studied saltmarsh it was possible to demonstrate that Fe mobilisation regulates the fate of this (and other) metal in that area. Thus, present results highlight the importance of metal mobility to control sediment pollution and estuarine fate of metals. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Metal-metal-hofteproteser

    DEFF Research Database (Denmark)

    Ulrich, Michael; Overgaard, Søren; Penny, Jeannette

    2014-01-01

    In Denmark 4,456 metal-on-metal (MoM) hip prostheses have been implanted. Evidence demonstrates that some patients develope adverse biological reactions causing failures of MoM hip arthroplasty. Some reactions might be systemic. Failure rates are associated with the type and the design of the Mo...

  19. Techniques for physicochemical characterization of nanomaterials

    Science.gov (United States)

    Lin, Ping-Chang; Lin, Stephen; Wang, Paul C.; Sridhar, Rajagopalan

    2014-01-01

    Advances in nanotechnology have opened up a new era of diagnosis, prevention and treatment of diseases and traumatic injuries. Nanomaterials, including those with potential for clinical applications, possess novel physicochemical properties that have an impact on their physiological interactions, from the molecular level to the systemic level. There is a lack of standardized methodologies or regulatory protocols for detection or characterization of nanomaterials. This review summarizes the techniques that are commonly used to study the size, shape, surface properties, composition, purity and stability of nanomaterials, along with their advantages and disadvantages. At present there are no FDA guidelines that have been developed specifically for nanomaterial based formulations for diagnostic or therapeutic use. There is an urgent need for standardized protocols and procedures for the characterization of nanoparticles, especially those that are intended for use as theranostics. PMID:24252561

  20. Physicochemical characterization of purple banana fiber

    International Nuclear Information System (INIS)

    Goncalves, A.P.B.; Guimaraes, D.H.; Miranda, C.S.; Oliveira, J.C.; Cruz, A.M.F.; Luporini, S.; Jose, N.M.

    2014-01-01

    Due to the environmental appeal that has grown in recent years, researches involving the use of renewable sources raw materials reaffirm this need. The vegetable fibers has excelled as promising materials with possibilities in different applications. The objective of this work is the evaluation of the physicochemical properties of banana fiber. These fibers were extracted from the banana pseudostem of a species not yet reported in the literature, Musa velutina, known as purple banana. For this experiment were used in natura fibers and processed fibers with NaOH 5% which were characterized by TGA, DSC, DRX and FTIR analysis. In the thermal analysis, both tested fibers showed good thermal properties. In DRX analysis, the processed fibers showed higher crystallinity. The use of these materials implies adding value to an agricultural waste in addition to being a more ecologically correct proposal. (author)

  1. Physicochemical and morphological characterisation of nanoparticles from photocopiers: implications for environmental health.

    Science.gov (United States)

    Bello, Dhimiter; Martin, John; Santeufemio, Christopher; Sun, Qingwei; Lee Bunker, Kristin; Shafer, Martin; Demokritou, Philip

    2013-08-01

    Several reports link printing and photocopying with genotoxicity, immunologic and respiratory diseases. Photocopiers and printers emit nanoparticles, which may be involved in these diseases. The physicochemical and morphological composition of these emitted nanoparticles, which is poorly understood and is critical for toxicological evaluations, was assessed in this study using both real-time instrumentation and analytical methods. Tests included elemental composition (40 metals), semi-volatile organics (100 compounds) and single particle analysis, using multiple high-sensitivity/resolution techniques. Identical analyses were performed on the toners and dust collected from copier's exhaust filter. Engineered nanoparticles, including titanium dioxide, iron oxide and fumed silica, and several metals were found in toners and airborne nanoscale fraction. Chemical composition of airborne nanoscale fraction was complex and reflected toner chemistry. These findings are important in understanding the origin and toxicology of such nanoparticles. Further investigation of their chemistry, larger scale exposure studies and thorough toxicological characterisation of emitted nanoparticles is needed.

  2. Natural Minerals Coated by Biopolymer Chitosan: Synthesis, Physicochemical, and Adsorption Properties

    Science.gov (United States)

    Budnyak, T. M.; Yanovska, E. S.; Kichkiruk, O. Yu.; Sternik, D.; Tertykh, V. A.

    2016-11-01

    Natural minerals are widely used in treatment technologies as mineral fertilizer, food additive in animal husbandry, and cosmetics because they combine valuable ion-exchanging and adsorption properties together with unique physicochemical and medical properties. Saponite (saponite clay) of the Ukrainian Podillya refers to the class of bentonites, a subclass of layered magnesium silicate montmorillonite. Clinoptilolits are aluminosilicates with carcase structure. In our work, we have coated biopolymer chitosan on the surfaces of natural minerals of Ukrainian origin — Podilsky saponite and Sokyrnitsky clinoptilolite. Chitosan mineral composites have been obtained by crosslinking of adsorbed biopolymer on saponite and clinoptilolite surface with glutaraldehyde. The obtained composites have been characterized by the physicochemical methods such as thermogravimetric/differential thermal analyses (DTA, DTG, TG), differential scanning calorimetry, mass analysis, nitrogen adsorption/desorption isotherms, scanning electron microscopy (SEM), and Fourier transform infrared (FTIR) spectroscopy to determine possible interactions between the silica and chitosan molecule. The adsorption of microquantities of cations Cu(II), Zn(II), Fe(III), Cd(II), and Pb(II) by the obtained composites and the initial natural minerals has been studied from aqueous solutions. The sorption capacities and kinetic adsorption characteristics of the adsorbents were estimated. It was found that the obtained results have shown that the ability of chitosan to coordinate heavy metal ions Zn(II), Cu(II), Cd(II), and Fe(III) is less or equal to the ability to retain ions of these metals in the pores of minerals without forming chemical bonds.

  3. Physicochemical and phytochemical standardization with HPTLC fingerprinting of Nigella sativa L. seeds.

    Science.gov (United States)

    Ahmad, Aftab; Husain, Asif; Mujeeb, Mohd; Siddiqui, Nasir Ali; Damanhouri, Zoheir A A; Bhandari, Anil

    2014-09-01

    This study was designed to perform the physicochemical and phytochemical standardization with HPTLC fingerprinting of Nigella sativa seeds in order to establish the standard pharmacognostical parameters of this miracle herb. Different parameters like extractive values; total ash value, acid insoluble ash value and water soluble ash value, moisture content, loss on drying, pH values of Nigella sativa seeds were performed. Preliminary phytochemical screening was done to detect different phytoconstituents by using the Harborne's phytochemical methods. Quantification of phenolic and flavonoid contents, determination of pesticides residues, aflatoxin and heavy metals were also carried out. HPTLC fingerprinting of methanolic extract was performed using CAMAG-HPTLC system connected with win CAT software. Preliminary phytochemical screening of the extracts in different solvent revealed the presence of carbohydrates, phenolic compounds, flavonoids, alkaloids, proteins, saponins, lipids, sterols and tannins. Total flavonoid and phenolic contents in methanolic extract was found to be 1.4 mg/gm and 9.8 mg/gm extract respectively. Concentrations of heavy metals were found within acceptable limits. Pesticides residues and aflatoxins were not detected. The physicochemical and phytochemical standards along with HPTLC fingerprint profile established as an outcome of this research may be utilized as substantial data for identification, purification and standardization of Nigella sativa seeds.

  4. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-02-07

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  5. Metallated metal-organic frameworks

    Energy Technology Data Exchange (ETDEWEB)

    Bury, Wojciech; Farha, Omar K.; Hupp, Joseph T.; Mondloch, Joseph E.

    2017-08-22

    Porous metal-organic frameworks (MOFs) and metallated porous MOFs are provided. Also provided are methods of metallating porous MOFs using atomic layer deposition and methods of using the metallated MOFs as catalysts and in remediation applications.

  6. Roles of metal ion complexation and membrane permeability in the metal flux through lipophilic membranes. Labile complexes at permeation liquid membranes

    NARCIS (Netherlands)

    Zhang, Z.; Buffle, J.; Leeuwen, van H.P.; Wojciechowski, K.

    2006-01-01

    The various physicochemical factors that influence the flux of carrier-transported metal ions through permeation liquid membranes (PLM) are studied systematically. Understanding PLM behavior is important (i) to optimize the application of PLM as metal speciation sensors in environmental media and

  7. Toxicity of heavy metals to fish: an important consideration for sucessful aquaculture

    OpenAIRE

    Nnaji, J.C.; Okoye, F.C.

    2007-01-01

    Heavy metals are toxic to man, animals and plants once safe limits are exceeded. Then ability to bio accumulate in plant and animal tissues makes them particularly hazardous. Heavy metals are toxic to all aquatic biota and cause high mortality of fish larva, fry, fingerling and adult fish. They accumulate in the gills, heart, liver, kidneys, brain, bones and muscles of fish. The physico-chemical forms of heavy metals determine their mobility, availability and toxicity to fish. These metals en...

  8. Unique battery with an active membrane separator having uniform physico-chemically functionalized ion channels and a method making the same

    Science.gov (United States)

    Gerald, II, Rex E.; Ruscic, Katarina J [Chicago, IL; Sears, Devin N [Spruce Grove, CA; Smith, Luis J [Natick, MA; Klingler, Robert J [Glenview, IL; Rathke, Jerome W [Homer Glen, IL

    2012-02-21

    The invention relates to a unique battery having an active, porous membrane and method of making the same. More specifically the invention relates to a sealed battery system having a porous, metal oxide membrane with uniform, physicochemically functionalized ion channels capable of adjustable ionic interaction. The physicochemically-active porous membrane purports dual functions: an electronic insulator (separator) and a unidirectional ion-transporter (electrolyte). The electrochemical cell membrane is activated for the transport of ions by contiguous ion coordination sites on the interior two-dimensional surfaces of the trans-membrane unidirectional pores. The membrane material is designed to have physicochemical interaction with ions. Control of the extent of the interactions between the ions and the interior pore walls of the membrane and other materials, chemicals, or structures contained within the pores provides adjustability of the ionic conductivity of the membrane.

  9. Metal-metal-hofteproteser

    DEFF Research Database (Denmark)

    Ulrich, Michael; Overgaard, Søren; Penny, Jeannette

    2014-01-01

    In Denmark 4,456 metal-on-metal (MoM) hip prostheses have been implanted. Evidence demonstrates that some patients develope adverse biological reactions causing failures of MoM hip arthroplasty. Some reactions might be systemic. Failure rates are associated with the type and the design of the Mo......M hip implant. A Danish surveillance programme has been initiated addressing these problems....

  10. Chronic ultraviolet exposure-induced p53 gene alterations in sencar mouse skin carcinogenesis model

    International Nuclear Information System (INIS)

    Tong, Ying; Smith, M.A.; Tucker, S.B.

    1997-01-01

    Alterations of the tumor suppressor gene p53 have been found in ultraviolet radiation (UVR) related human skin cancers and in UVR-induced murine skin tumors. However, links between p53 gene alterations and the stages of carcinogenesis induced by UVR have not been clearly defined. We established a chronic UVR exposure-induced Sencar mouse skin carcinogenesis model to determine the frequency of p53 gene alterations in different stages of carcinogenesis, including UV-exposed skin, papillomas, squamous-cell carcinomas (SCCs), and malignant spindle-cell tumors (SCTs). A high incidence of SCCs and SCTs were found in this model. Positive p53 nuclear staining was found in 10137 (27%) of SCCs and 12124 (50%) of SCTs, but was not detected in normal skin or papillomas. DNA was isolated from 40 paraffin-embedded normal skin, UV-exposed skin, and tumor sections. The p53 gene (exons 5 and 6) was amplified from the sections by using nested polymerase chain reaction (PCR). Subsequent single-strand conformation polymorphism (SSCP) assay and sequencing analysis revealed one point mutation in exon 6 (coden 193, C → A transition) from a UV-exposed skin sample, and seven point mutations in exon 5 (codens 146, 158, 150, 165, and 161, three C → T, two C → A, one C → G, and one A → T transition, respectively) from four SCTs, two SCCs and one UV-exposed skin sample. These experimental results demonstrate that alterations in the p53 gene are frequent events in chronic UV exposure-induced SCCs and later stage SCTs in Sencar mouse skin. 40 refs., 5 figs., 1 tab

  11. Kimchi protects against azoxymethane/dextran sulfate sodium-induced colorectal carcinogenesis in mice.

    Science.gov (United States)

    Kim, Hee-Young; Song, Jia-Le; Chang, Hee-Kyung; Kang, Soon-Ah; Park, Kun-Young

    2014-08-01

    The chemopreventive effects of different types and quantities of kimchi prepared with different subingredients, including commercial kimchi (CK), standardized kimchi (SK), cancer-preventive kimchi (CPK), and anticancer kimchi (ACK), on colorectal carcinogenesis in mice were evaluated. The development of colon cancer was induced in male BALB/c mice with a single intraperitoneal injection of azoxymethane (AOM, 10 mg/kg body weight) and subsequent treatment with 2% dextran sulfate sodium (DSS) in drinking water for 7 days for two cycles. After exposure to AOM and DSS, treatment with the methanolic extracts from different kimchis, particularly 1.89 g/kg of ACK, significantly increased colon length, decreased the ratio of colon weight/length, and resulted in the lowest number of tumors compared with the other kimchi-treated groups. Histological observation revealed that ACK was able to suppress AOM- and DSS-induced colonic mucosal damage and neoplasia. ACK also significantly decreased the mRNA levels of proinflammatory cytokines (TNF-α, IL-6, and IFN-γ) as well as the mRNA and protein expression of inducible nitric oxide synthase and cyclooxygenase-2 (COX-2). In addition, the mRNA and protein expression of p53 and p21 was elevated in colon tissues from the ACK-treated mice compared with the other kimchi-treated groups. Our results suggest that kimchi exerted a suppressive effect on AOM- and DSS-induced colorectal carcinogenesis in the BALB/c mice. The anticancer effects of ACK were particularly potent. Thus, it is possible that the health-promoting subingredients added to ACK might be used to prevent colon carcinogenesis in humans.

  12. Kimchi Protects Against Azoxymethane/Dextran Sulfate Sodium–Induced Colorectal Carcinogenesis in Mice

    Science.gov (United States)

    Kim, Hee-Young; Song, Jia-Le; Chang, Hee-Kyung; Kang, Soon-Ah

    2014-01-01

    Abstract The chemopreventive effects of different types and quantities of kimchi prepared with different subingredients, including commercial kimchi (CK), standardized kimchi (SK), cancer-preventive kimchi (CPK), and anticancer kimchi (ACK), on colorectal carcinogenesis in mice were evaluated. The development of colon cancer was induced in male BALB/c mice with a single intraperitoneal injection of azoxymethane (AOM, 10 mg/kg body weight) and subsequent treatment with 2% dextran sulfate sodium (DSS) in drinking water for 7 days for two cycles. After exposure to AOM and DSS, treatment with the methanolic extracts from different kimchis, particularly 1.89 g/kg of ACK, significantly increased colon length, decreased the ratio of colon weight/length, and resulted in the lowest number of tumors compared with the other kimchi-treated groups. Histological observation revealed that ACK was able to suppress AOM- and DSS-induced colonic mucosal damage and neoplasia. ACK also significantly decreased the mRNA levels of proinflammatory cytokines (TNF-α, IL-6, and IFN-γ) as well as the mRNA and protein expression of inducible nitric oxide synthase and cyclooxygenase-2 (COX-2). In addition, the mRNA and protein expression of p53 and p21 was elevated in colon tissues from the ACK-treated mice compared with the other kimchi-treated groups. Our results suggest that kimchi exerted a suppressive effect on AOM- and DSS-induced colorectal carcinogenesis in the BALB/c mice. The anticancer effects of ACK were particularly potent. Thus, it is possible that the health-promoting subingredients added to ACK might be used to prevent colon carcinogenesis in humans. PMID:25029638

  13. Dysregulation of microRNAs in colonic field carcinogenesis: implications for screening.

    Directory of Open Access Journals (Sweden)

    Dhananjay P Kunte

    Full Text Available Colorectal cancer (CRC screening tests often have a trade-off between efficacy and patient acceptability/cost. Fecal tests (occult blood, methylation engender excellent patient compliance but lack requisite performance underscoring the need for better population screening tests. We assessed the utility of microRNAs (miRNAs as markers of field carcinogenesis and their potential role for CRC screening using the azoxymethane (AOM-treated rat model. We found that 63 miRNAs were upregulated and miR-122, miR-296-5p and miR-503# were downregulated in the uninvolved colonic mucosa of AOM rats. We monitored the expression of selected miRNAs in colonic biopsies of AOM rats at 16 weeks and correlated it with tumor development. We noted that the tumor bearing rats had significantly greater miRNA modulation compared to those without tumors. The miRNAs showed good diagnostic performance with an area under the receiver operator curve (AUROC of >0.7. We also noted that the miRNA induction in the colonic mucosa was mirrorred in the mucus layer fecal colonocytes isolated from AOM rat stool and the degree of miRNA induction was greater in the tumor bearing rats compared to those without tumors. Lastly, we also noted significant miRNA modulation in the Pirc rats- the genetic model of colon carcinogenesis, both in the uninvolved colonic mucosa and the fecal colonocytes. We thus demonstrate that miRNAs are excellent markers of field carcinogenesis and could accurately predict future neoplasia. Based on our results, we propose an accurate, inexpensive, non-invasive miRNA test for CRC risk stratification based on rectal brushings or from abraded fecal colonocytes.

  14. Protective Effect of Lactobacillus casei on DMH-Induced Colon Carcinogenesis in Mice.

    Science.gov (United States)

    Irecta-Nájera, Cesar Antonio; Del Rosario Huizar-López, María; Casas-Solís, Josefina; Castro-Félix, Patricia; Santerre, Anne

    2017-06-01

    The administration of probiotics is a promising approach to reduce the prevalence of colon cancer, a multifactorial disease, with hereditary factors, as well as environmental lifestyle-related risk factors. Biogenic polyamines, putrescine, spermidine, and spermine are small cationic molecules with great roles in cell proliferation and differentiation as well as regulation of gene expression. Ornithine decarboxylase is the first rate-limiting enzyme for polyamine synthesis, and upregulation of ornithine decarboxylase activity and polyamine metabolism has been associated with abnormal cell proliferation. This paper is focused on studying the protective role of Lactobacillus casei ATCC 393 in a chemically induced mouse model of colon carcinogenesis, directing our attention on aberrant crypt foci as preneoplastic markers, and on polyamine metabolism as a possible key player in carcinogenesis. BALB/c mice were administered 1,2-dimethylhydrazine dihydrochloride (DMH) to induce colon cancer (20 mg/kg body weight, subcutaneous, twice a week for 24 weeks). L. casei ATCC 393 was given orally (10 6  CFU, twice a week), 2 weeks before DMH administration. Hematoxylin and eosin staining, high-performance liquid chromatography, and Western blotting were used to evaluate aberrant crypt foci, urinary polyamines, and ornithine decarboxylase expression in the colon. The experimental data showed that the preventive administration of L. casei ATCC 393 may delay the onset of cancer as it significantly reduced the number of DMH-induced aberrant crypt foci, the levels of putrescine, and the expression of ornithine decarboxylase. Hence, this probiotic strain has a prospective role in protection against colon carcinogenesis, and its antimutagenic activity may be associated with the maintenance of polyamine metabolism.

  15. Effects of selenium on Pteridium aquilinum and urethane-induced lung carcinogenesis.

    Science.gov (United States)

    Nakahara, Sheila B R; Sanches, Daniel S; Caniceiro, Beatriz D; Wysochi, Harry L; da Silva, Graziela B; Latorre, Andreia O

    2013-10-01

    The results of our previous study demonstrated that ptaquiloside, the main toxic agent found in Pteridium aquilinum, suppresses natural killer (NK) cell-mediated cytotoxicity. However, the ability of ptaquiloside to suppress the cytotoxicity of NK cells was prevented by selenium supplementation. NK cells play an important role in the innate immune response and have the ability to kill tumor cells. Therefore, we hypothesized that selenium may prevent the higher susceptibility to urethane-induced lung carcinogenesis that has been observed in mice treated with P. aquilinum. The immunosuppressive effects of ptaquiloside have been associated with a higher number of urethane-induced lung nodules in mice. Hence, we assessed the effects of P. aquilinum-induced immunosuppression on urethane-induced lung carcinogenesis in C57BL/6 mice that had been supplemented with selenium. For these experiments, mice were treated with both an aqueous extract of P. aquilinum (20 g/kg/day) and selenium (1.3 mg/kg) by gavage once daily for 14 days followed by a once-weekly intraperitoneal injection of urethane (1 g/kg) for 10 weeks that was accompanied by gavage 5 days a week. Lung adenomas in mice that had been treated with P. aquilinum plus urethane occurred with a frequency that was 44% higher than that in mice that had been treated with only urethane. In mice that had been supplemented with selenium and treated with P. aquilinum plus urethane, the occurrence of lung adenomas was reduced to 26%. These results suggest that selenium prevents the immunosuppressive effects of P. aquilinum on urethane-induced lung carcinogenesis.

  16. Chemoprevention by Probiotics During 1,2-Dimethylhydrazine-Induced Colon Carcinogenesis in Rats.

    Science.gov (United States)

    Walia, Sohini; Kamal, Rozy; Dhawan, D K; Kanwar, S S

    2018-04-01

    Probiotics are believed to have properties that lower the risk of colon cancer. However, the mechanisms by which they exert their beneficial effects are relatively unknown. To assess the impact of probiotics in preventing induction of colon carcinogenesis in rats. The rats were divided into six groups viz., normal control, Lactobacillus plantarum (AdF10)-treated, Lactobacillus rhamnosus GG (LGG)-treated, 1,2-dimethylhydrazine (DMH)-treated, L. plantarum (AdF10) + DMH-treated and L. rhamnosus GG (LGG) + DMH-treated. Both the probiotics were supplemented daily at a dose of 2 × 10 10 cells per day. DMH at a dose of 30 mg/kg body weight was administered subcutaneously twice a week for the first 4 weeks and then once every week for a duration of 16 weeks. Glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and catalase as protein expression of genes involved in apoptosis were assessed during DMH-induced colon carcinogenesis in rats. DMH treatment decreased the activity of GSH, GPx, GST, SOD and catalase. However, AdF10 and LGG supplementation to DMH-treated rats significantly increased the activity of these enzymes. Further, DMH treatment revealed alterations in the protein expressions of various genes involved in the p53-mediated apoptotic pathway such as p53, p21, Bcl-2, Bax, caspase-9 and caspase-3, which, however, were shifted towards normal control levels upon simultaneous supplementation with probiotics. The present study suggests that probiotics can provide protection against oxidative stress and apoptotic-related protein disregulation during experimentally induced colon carcinogenesis.

  17. Role of atypical chemokine receptor ACKR2 in experimental oral squamous cell carcinogenesis.

    Science.gov (United States)

    da Silva, Janine Mayra; Dos Santos, Tálita Pollyanna Moreira; Saraiva, Adriana Machado; Fernandes de Oliveira, Ana Laura; Garlet, Gustavo Pompermaier; Batista, Aline Carvalho; de Mesquita, Ricardo Alves; Russo, Remo Castro; da Silva, Tarcília Aparecida

    2018-03-14

    Chemokines and chemokine receptors are critical in oral tumourigenesis. The atypical chemokine receptor ACKR2 is a scavenger of CC chemokines controlling the availability of these molecules at tumour sites, but the role of ACKR2 in the context of oral carcinogenesis is unexplored. In this study, wild-type (WT) and ACKR2 deficient mice (ACKR2 -/- ) were treated with chemical carcinogen 4-nitroquinoline-1-oxide (4NQO) for induction of oral carcinogenesis. Tongues were collected for macro and microscopic analysis and to evaluate the expression of ACKRs, CC chemokines and its receptors, inflammatory cytokines, angiogenic factors, adhesion molecules and extracellular matrix components. An increased expression of ACKR2 in squamous cell carcinoma (SCC) lesions of 4NQO-treated WT mice was observed. No significant differences were seen in the ACKR1, ACKR3 and ACKR4 mRNA expression comparing SCC lesions from WT and ACKR2 -/- treated mice. Significantly higher expression of CCL2, IL-6 and IL-17 was detected in ACKR2 -/- treated mice. In contrast, the expression of other CC-chemokines, and receptors, angiogenic factors, adhesion molecules and extracellular matrix components were similarly increased in SCC lesions of both groups. Clinical and histopathological analysis revealed no differences in inflammatory cell recruitment and in the SCC incidence comparing WT and ACKR2 -/- treated mice. The results suggest that ACKR2 expression regulates inflammation in tumour-microenvironment but the absence of ACKR2 does not impact chemically-induced oral carcinogenesis. Copyright © 2018 Elsevier Ltd. All rights reserved.

  18. 1,8-cineole prevents UVB-induced skin carcinogenesis by targeting the aryl hydrocarbon receptor

    Science.gov (United States)

    Park, Joon; Kim, Yong Ho; Lee, Nam Hyouck; Kim, Young Eon; Kim, Yoonsook; Song, Kyung-Mo; Jung, Sung Keun

    2017-01-01

    1,8-cineole is a natural monoterpene cyclic ether present in Eucalyptus, and has been reported to exhibit anti-inflammatory and antioxidant effects. However, the preventive effect of 1,8-cineole on skin carcinogenesis and the molecular mechanism of action responsible remains unknown. In the present study, we investigated the effect of 1,8-cineole on UVB-induced skin carcinogenesis. 1,8-cineole inhibited UVB-induced cyclooxygenase-2 (COX-2) protein and mRNA expression and prostaglandin E2 (PGE2) generation in HaCaT cells. 1,8-cineole also inhibited phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, and phosphorylation of its upstream kinases, c-Src and epidermal growth factor receptor (EGFR). Quantitative real-time RT-PCR (qRT-PCR) and drug affinity responsive target stability (DARTS) assay results showed that 1,8-cineole suppressed UVB-induced expression of a target gene of the aryl hydrocarbon receptor (AhR), cyp1a1, and directly binds to AhR. Knockdown of AhR suppressed COX-2 expression as well as phosphorylation of ERK1/2 in HaCaT cells. Furthermore, topical treatment of 1,8-cineole on mouse skin delayed tumor incidence and reduced tumor numbers, while inhibiting COX-2 expression in vivo. Taken together, these results suggest that 1,8-cineole is a potent chemopreventive agent that inhibits UVB-induced COX-2 expression by targeting AhR to suppress UVB-induced skin carcinogenesis. PMID:29285309

  19. Long non-coding RNA HOTAIR promotes carcinogenesis and invasion of gastric adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Na Keum; Lee, Jung Hwa; Park, Chan Hyuk; Yu, Dayeon; Lee, Yong Chan [Division of Gastroenterology, Department of Internal Medicine, Yonsei Institute of Gastroenterology, Yonsei University College of Medicine, Seoul (Korea, Republic of); Cheong, Jae-Ho; Noh, Sung Hoon [Department of Surgery, Yonsei University College of Medicine (Korea, Republic of); Lee, Sang Kil, E-mail: sklee@yuhs.ac [Division of Gastroenterology, Department of Internal Medicine, Yonsei Institute of Gastroenterology, Yonsei University College of Medicine, Seoul (Korea, Republic of)

    2014-08-22

    Highlights: • HOTAIR expression was tested in fifty patients with gastric cancer. • Cell proliferation was measured after HOTAIR silencing in gastric cancer cell line. • siRNA–HOTAIR suppresses cell invasiveness and capacity of migration. • Knock down of HOTAR leads to decreased expression of EMT markers. • Inhibition of HOTAIR induces apoptosis and cell cycle arrest. - Abstract: Gastric cancer is one of the major causes of cancer death worldwide; however, the mechanism of carcinogenesis is complex and poorly understood. Long non-coding RNA HOTAIR (HOX transcript antisense RNA) recently emerged as a promoter of metastasis in various cancers including gastric cancer. Here we investigated the impact of HOTAIR on apoptosis, cell proliferation and cell cycle to dissect the carcinogenesis of gastric cancer. We examined the mechanism of invasion and metastasis and analyzed the clinical significance of HOTAIR. Downregulation of HOTAIR was confirmed by two different siRNAs. The expression of HOTAIR was significantly elevated in various gastric cancer cell lines and tissues compared to normal control. si-HOTAIR significantly reduced viability in MKN 28, MKN 74, and KATO III cells but not in AGS cells. si-HOTAIR induced apoptosis in KATO III cells. Lymphovascular invasion and lymph node metastasis were more common in the high level of HOTAIR group. si-HOTAIR significantly decreased invasiveness and migration. si-HOTAIR led to differential expression of epithelial to mesenchymal transition markers. We found that HOTAIR was involved in inhibition of apoptosis and promoted invasiveness, supporting a role for HOTAIR in carcinogenesis and progression of gastric cancer.

  20. Impact of physico-chemical parameters on the physiological growth ...

    African Journals Online (AJOL)

    Impact of physico-chemical parameters on the physiological growth of Arthrospira (Spirulina platensis) exogenous strain UTEXLB2340. Yahia Mustafa A Fagiri, Aisha Salleh, Saifeldin Ahmed F El-Nagerabi ...

  1. Nanoparticles for intravascular applications: physicochemical characterization and cytotoxicity testing

    NARCIS (Netherlands)

    Matuszak, J.; Baumgartner, J.; Zaloga, J.; Juenet, M.; Da Silva, A.E.; Franke, D.; Almer, G.; Texier, I.; Faivre, D.; Metselaar, Josbert Maarten; Navarro, F.P.; Chauvierre, C.; Prassl, R.; Dézsi, L.; Urbanics, R.; Alexiou, C.; Mangge, H.; Szebeni, J.; Letourneur, D.; Cicha, I.

    2016-01-01

    Aim: We report the physicochemical analysis of nanosystems intended for cardiovascular applications and their toxicological characterization in static and dynamic cell culture conditions. Methods: Size, polydispersity and ζ-potential were determined in 10 nanoparticle systems including liposomes,

  2. Evaluation of physico-chemical parameters of agricultural soils ...

    African Journals Online (AJOL)

    Evaluation of physico-chemical parameters of agricultural soils irrigated by the waters of the hydrolic basin of Sebou River and their influences on the transfer of trace elements into sugar crops (the case of sugar cane)

  3. Changes in the physicochemical and microbial quality of wastewater ...

    African Journals Online (AJOL)

    Bauer disk diffusion method from which the Multiple Antibiotic Resistance (MAR) Index was calculated. There was improvement in the physicochemical parameters analyzed. The biological oxygen demand, dissolved oxygen, pH, temperature, ...

  4. Studies on some Physicochemical Properties of the Plant Gum ...

    African Journals Online (AJOL)

    A. senegal, A. sieberiana and A. nilotica) in Batagarawa, Katsina State, were determined and compared. Data generated from the study confirm that there are a number of physicochemical differences between the gum exudates.

  5. Evaluation of physicochemical, functional and textural properties of ...

    African Journals Online (AJOL)

    20°C for nine days and six months, respectively, were investigated. The combined effect of proteolytic activity and physicochemical changes in the muscle (pH, solubility and proteolytic activity) altered the molecular structure of the proteins.

  6. Clay facial masks: physicochemical stability at different storage temperatures.

    Science.gov (United States)

    Zague, Vivian; de Almeida Silva, Diego; Baby, André Rolim; Kaneko, Telma Mary; Velasco, Maria Valéria Robles

    2007-01-01

    Clay facial masks--formulations that contain a high percentage of solids dispersed in a liquid vehicle--have become of special interest due to specific properties presented by clays, such as particle size, cooling index, high adsorption capacity, and plasticity. Although most of the physicochemical properties of clay dispersions have been studied, specific aspects concerning the physicochemical stability of clay mask products remain unclear. This work aimed at investigating the accelerated physicochemical stability of clay mask formulations stored at different temperatures. Formulations were subjected to centrifuge testing and to thermal treatment for 15 days, during which temperature was varied from -5.0 degrees to 45.0 degrees C. The apparent viscosity and visual aspect (homogeneity) of all formulations were affected by temperature variation, whereas color, odor, and pH value remained unaltered. These results, besides the estimation of physicochemical stability under aging, can be useful in determining the best storage conditions for clay-based formulations.

  7. physico-chemical properties of well water samples from some

    African Journals Online (AJOL)

    Administrator

    chemical causes changes to the quality of the receiving water body. (Aremu et ... Sample collection, treatment and preservation: Water samples ... DEVIATION VALUES OF PHYSICO-CHEMICAL PARAMETERS OF. THE WELL WATER SAMPLES COMPARED WITH WHO STANDARD FOR DRINKING WATER. PARAMETER.

  8. On the physico-chemical characteristics of brines

    Digital Repository Service at National Institute of Oceanography (India)

    Shirodkar, P.V.; Rao, P.V.S.S.D.P.; Singbal, S.Y.S.

    Analyses of the natural brines form the salt lakes, salt pans and the artificial brines obtained after the solar desalination of seawater respectively, showed wide differences in their physico-chemical characteristics. The natural brines are markEd...

  9. Thrombospondin-2 overexpression in the skin of transgenic mice reduces the susceptibility to chemically induced multistep skin carcinogenesis.

    Science.gov (United States)

    Kunstfeld, Rainer; Hawighorst, Thomas; Streit, Michael; Hong, Young-Kwon; Nguyen, Lynh; Brown, Lawrence F; Detmar, Michael

    2014-05-01

    We have previously reported stromal upregulation of the endogenous angiogenesis inhibitor thrombospondin-2 (TSP-2) during multistep carcinogenesis, and we found accelerated and enhanced skin angiogenesis and carcinogenesis in TSP-2 deficient mice. To investigate whether enhanced levels of TSP-2 might protect from skin cancer development. We established transgenic mice with targeted overexpression of TSP-2 in the skin and subjected hemizygous TSP-2 transgenic mice and their wild-type littermates to a chemical skin carcinogenesis regimen. TSP-2 transgenic mice showed a significantly delayed onset of tumor formation compared to wild-type mice, whereas the ratio of malignant conversion to squamous cell carcinomas was comparable in both genotypes. Computer-assisted morphometric analysis of blood vessels revealed pronounced tumor angiogenesis already in the early stages of carcinogenesis in wild type mice. TSP-2 overexpression significantly reduced tumor blood vessel density in transgenic mice but had no overt effect on LYVE-1 positive lymphatic vessels. The percentage of desmin surrounded, mature tumor-associated blood vessels and the degree of epithelial differentiation remained unaffected. The antiangiogenic effect of transgenic TSP-2 was accompanied by a significantly increased number of apoptotic tumor cells in transgenic mice. Our results demonstrate that enhanced levels of TSP-2 in the skin result in reduced susceptibility to chemically-induced skin carcinogenesis and identify TSP-2 as a new target for the prevention of skin cancer. Copyright © 2014 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Environmental pollution and DNA methylation: carcinogenesis, clinical significance, and practical applications.

    Science.gov (United States)

    Cao, Yi

    2015-09-01

    Environmental pollution is one of the main causes of human cancer. Exposures to environmental carcinogens result in genetic and epigenetic alterations which induce cell transformation. Epigenetic changes caused by environmental pollution play important roles in the development and progression of environmental pollution-related cancers. Studies on DNA methylation are among the earliest and most conducted epigenetic research linked to cancer. In this review, the roles of DNA methylation in carcinogenesis and their significance in clinical medicine were summarized, and the effects of environmental pollutants, particularly air pollutants, on DNA methylation were introduced. Furthermore, prospective applications of DNA methylation to environmental pollution detection and cancer prevention were discussed.

  11. Alterations in keratins and associated proteins during 4- Nitroquinoline-1-oxide induced rat oral carcinogenesis

    Directory of Open Access Journals (Sweden)

    Deepak Kanojia

    2012-01-01

    Full Text Available Background: Oral squamous cell carcinoma (OSCC is the sixth largest group of malignancies globally and the single largest group of malignancies in the Indian subcontinent. Despite the advances in treatment and therapeutic modalities the five year survival rate of OSCC has not changed in the last few decades, and remains less than 40%. Several studies have focused on defining molecular markers that can either detect cancer at an early stage or can predict patient′s outcome. However, such markers are still undefined. Keratins (K are epithelia predominant intermediate filament proteins which are expressed in a differentiation dependent and site specific manner. Keratins are being used as biomarkers in different epithelial disorders including cancer. They are associated with desmoplakin and α6β4 integrin which are components of desmosomes and hemidesmosomes respectively. Materials and Methods: 4-Nitroquinoline 1-Oxide (4NQO was used as a carcinogen for the development of various stages of oral carcinogenesis in rat lingual mucosa. Two-Dimentional gel electrophoresis was performed for the separation of Keratins followed by western blotting for their specific identification. Western blotting and RT PCR was carried out for desmoplakin and α6β4 integrin respectively to understand their levels. Immunohistochemical analysis was carried out to further study the localization of desmoplakin and α6 integrin. Results: In this study we have analysed the alterations in Keratins and associated proteins during sequential stages of 4NQO induced rat oral carcinogenesis. Our results showed that the alterations primarily begin after the dysplastic changes in the lingual epithelium like the elevation of Keratins 5/6a, ectopic expression of Keratin 8, increase in suprabasal expression of α6 integrin and increase in desmoplakin levels. Most of these alterations persisted till the development of SCC except desmoplakin, the levels of which were downregulated in

  12. Thyroid cancer. Reevaluation of an experimental model for radiogenic endocrine carcinogenesis

    International Nuclear Information System (INIS)

    Clifton, K.H.

    1984-11-01

    The status of experimental studies of radiogenic thyroid cancer is appraised, and some older data are reinterpreted in the light of more recent findings. Problems of thyroid dosimetry, particularly the dosimetry of internal radioiodides, are discussed. The steps in radiation carcinogenesis during the acute phase, the latent phase, and the phase of tumor growth are discussed in terms of thyroid epithelial cell population changes. The roles of three cell populations (undamaged or completely repaired epithelial cells, oncogenically initiated cells, and terminally damaged but functionally competent cells) in neoplasia are described. Finally, the implications for man of these experimental results and conclusions are discussed. 89 refs., 4 figs

  13. Thermodynamic considerations on the role of heat and mass transfer in biochemical causes of carcinogenesis

    Science.gov (United States)

    Lucia, Umberto; Grisolia, Giulia; Ponzetto, Antonio; Deisboeck, Thomas S.

    2018-01-01

    Cellular homoeostasis involves a continuous interaction between the cell and its microenvironment. As such, active and passive transport of ions, nutrients, molecules and water are the basis for biochemical-physical cell life. These transport phenomena change the internal and external ionic concentrations, and, as a consequence, the cell membrane's electric potential and the pH. In this paper we focus on the relationship between these ion transport-induced pH and membrane voltage changes to highlight their impact on carcinogenesis. The preliminary results suggest a critical role for Cl- in driving tumour transformation towards a more malignant phenotype.

  14. Predicting cancer rates in astronauts from animal carcinogenesis studies and cellular markers

    Science.gov (United States)

    Williams, J. R.; Zhang, Y.; Zhou, H.; Osman, M.; Cha, D.; Kavet, R.; Cuccinotta, F.; Dicello, J. F.; Dillehay, L. E.

    1999-01-01

    The radiation space environment includes particles such as protons and multiple species of heavy ions, with much of the exposure to these radiations occurring at extremely low average dose-rates. Limitations in databases needed to predict cancer hazards in human beings from such radiations are significant and currently do not provide confidence that such predictions are acceptably precise or accurate. In this article, we outline the need for animal carcinogenesis data based on a more sophisticated understanding of the dose-response relationship for induction of cancer and correlative cellular endpoints by representative space radiations. We stress the need for a model that can interrelate human and animal carcinogenesis data with cellular mechanisms. Using a broad model for dose-response patterns which we term the "subalpha-alpha-omega (SAO) model", we explore examples in the literature for radiation-induced cancer and for radiation-induced cellular events to illustrate the need for data that define the dose-response patterns more precisely over specific dose ranges, with special attention to low dose, low dose-rate exposure. We present data for multiple endpoints in cells, which vary in their radiosensitivity, that also support the proposed model. We have measured induction of complex chromosome aberrations in multiple cell types by two space radiations, Fe-ions and protons, and compared these to photons delivered at high dose-rate or low dose-rate. Our data demonstrate that at least three factors modulate the relative efficacy of Fe-ions compared to photons: (i) intrinsic radiosensitivity of irradiated cells; (ii) dose-rate; and (iii) another unspecified effect perhaps related to reparability of DNA lesions. These factors can produce respectively up to at least 7-, 6- and 3-fold variability. These data demonstrate the need to understand better the role of intrinsic radiosensitivity and dose-rate effects in mammalian cell response to ionizing radiation. Such

  15. Development of Carcinogenesis Bioassay Models: Response of Small Fish Species to Various Classes of Carcinogens

    Science.gov (United States)

    1991-12-20

    453-465. I Hawkins, W.E., R.M. Overstreet, and W.W. Walker. 1988. Carcinogenicity tests with small fish species. Aquatic Toxicology 11:113-128. I...Journal of Aquatic Animal Health 3: 213-220. I Hendricks, J.D. 1982. Chemical carcinogenesis in fish. In: Aquatic Toxicology , LJ. Weber (Editor...Regulatory Toxicology and Pharmacology 9: I 5-22. Malins, D.C. and G.K. Ostrander. 1991. Perspectives in aquatic toxicology . Annual Review I of

  16. Physicochemical properties of concentrated Martian surface waters

    Science.gov (United States)

    Tosca, Nicholas J.; McLennan, Scott M.; Lamb, Michael P.; Grotzinger, John P.

    2011-05-01

    Understanding the processes controlling chemical sedimentation is an important step in deciphering paleoclimatic conditions from the rock records preserved on both Earth and Mars. Clear evidence for subaqueous sedimentation at Meridiani Planum, widespread saline mineral deposits in the Valles Marineris region, and the possible role of saline waters in forming recent geomorphologic features all underscore the need to understand the physical properties of highly concentrated solutions on Mars in addition to, and as a function of, their distinct chemistry. Using thermodynamic models predicting saline mineral solubility, we generate likely brine compositions ranging from bicarbonate-dominated to sulfate-dominated and predict their saline mineralogy. For each brine composition, we then estimate a number of thermal, transport, and colligative properties using established models that have been developed for highly concentrated multicomponent electrolyte solutions. The available experimental data and theoretical models that allow estimation of these physicochemical properties encompass, for the most part, much of the anticipated variation in chemistry for likely Martian brines. These estimates allow significant progress in building a detailed analysis of physical sedimentation at the ancient Martian surface and allow more accurate predictions of thermal behavior and the diffusive transport of matter through chemically distinct solutions under comparatively nonstandard conditions.

  17. Physicochemical properties of cookies enriched with xylooligosaccharides.

    Science.gov (United States)

    Ayyappan, P; Abirami, A; Anbuvahini, N A; Tamil Kumaran, P S; Naresh, M; Malathi, D; Antony, Usha

    2016-07-01

    The growing commercial importance of xylooligosaccharides is based on their beneficial health properties, particularly their ability to stimulate the growth and activity of intestinal bacteria such as Bifidobacterium and Lactobacillus species. Xylooligosaccharides are less sweet, acid, and heat stable, with low recommended levels of intake compared to other oligosaccharides. In view of the consumer demand for foods with low sugar, low fat, and high fiber contents, they are suitable for incorporation into bakery products. In this study, we have developed wheat-based cookies incorporated with xylooligosaccharides at 5%, 10%, and 15% levels. The nutritive value and physicochemical properties of the cookies changed with xylooligosaccharides incorporation; both crude fiber and dietary fiber contents increased by 14% and 35%, respectively, in the enriched cookies. The moisture levels increased with increase in the percentage of xylooligosaccharides incorporated. Cookies with 5% xylooligosaccharides were found most acceptable, although the color was slightly darker compared to the control, while cookies with 10% and 15% xylooligosaccharides were softer and darker and therefore less acceptable. Enrichment with xylooligosaccharides at 5% provided a product stable for 21 days at room temperature (25 ± 2℃). The storage stability of cookies with higher levels of xylooligosaccharides was less than the 5% xylooligosaccharides cookies and control. The retention of the prebiotic xylooligosaccharides in the products was relatively high (74%). © The Author(s) 2015.

  18. Daptomycin: Physicochemical, Analytical, and Pharmacological Properties.

    Science.gov (United States)

    Tótoli, Eliane Gandolpho; Garg, Sanjay; Salgado, Hérida Regina Nunes

    2015-12-01

    Daptomycin is the first approved member of a new class of antimicrobials, the cyclic lipopeptides, and presents selective action against gram-positive bacteria, including methicillin- and vancomycin-resistant strains. Considering that resistance to daptomycin is rare, the drug has become very important for current clinical practice. This review covers daptomycin's physicochemical characteristics, antibacterial spectrum, mechanism of action, pharmacokinetics, clinical applications, side effects, drug interactions, and the analytical methods used to measure daptomycin in pharmaceutical products and biologic samples. Special attention has been given to therapeutic drug monitoring reports, as studies have shown its highly variable pharmacokinetics in specific circumstances, such as in patients suffering from critical illness, morbid obesity, severe sepsis, and kidney injury. For the same reason, methods described for therapeutic drug monitoring of daptomycin in the special patient population have been reviewed. In addition, the review presents a discussion of environmentally friendly analytical methods for daptomycin, which are necessary to reduce the impact of our activities on the environment. However, it was observed that there is a gap in the literature in this regard and further research involving the development of "green" methodologies for the analysis of daptomycin is necessary. The review will be useful to the clinical community in assisting with the responsible use of daptomycin, which is critical to prevent the emergence of resistant strains.

  19. Microbiological and physicochemical quality of drinking water

    International Nuclear Information System (INIS)

    Chan, Chee Ling; Zalifah, M.K.; Norrakiah, A.S.

    2007-01-01

    This study was conducted on the water samples collected before and after filtration treatment was given. Five types of filtered drinking water (A1, B1, C1, D1 and E2) were chosen randomly from houses in Klang Valley for analyses. The purpose of this study was to determine the quality of filtered drinking water by looking into microbiological aspect and several physicochemical analyses such as turbidity, pH and total suspended solid (TSS). The microbiological analyses were performed to trace the presence of indicator organisms and pathogens such as Escherichia coli, Streptococcus faecalis and Pseudomonas aeruginosa. All of the water did not comply with the regulations of Food Act as consisted of more than 10 3 -10 4 cfu/ mL for total plate count. However, the total coliforms and E. coli were detected lower than 4 cfu/ mL and not exceeding the maximum limit of Food Act. While the presence of S. faecalis and P. aeruginosa were negative in all samples. The pH value was slightly acidic (pH -4 - 2.2 x 10 -3 mg/ L) and the turbidity for all the samples were recorded below 1 Nephelometric Turbidity units (NTU) thus, complying with the regulations. All the water samples that undergo the filtration system were fit to be consumed. (author)

  20. Pharmaceutical wastewater treatment: a physicochemical study

    International Nuclear Information System (INIS)

    Saleem, M.

    2007-01-01

    A physicochemical study for the treatment of pharmaceutical wastewater was performed. Objective of the laboratory investigation was to study the removal of color, Total Dissolved Solids (TDS), Biochemical Oxygen Demand (BOD), Chemical Oxygen Demand (COD), turbidity and phenol and bring them up to the allowable limits for reuse purposes. Efficiency of coagulation, flocculation, sedimentation, sand filtration followed by activated carbon adsorption was determined. It was found that tested coagulants (alum, ferric chloride, and ferrous sulphate) are not much effective and required high dosage for the removal; of TSS, BOD, COD and turbidity. Alum was found to be more effective among tested coagulants and reduce TSS, BOD, COD and turbidity 79.6%, 34.8, 48.6% and 69.2% respectively. Sand filtration further reduced the studied parameters 97.7%, 95.7%, 93.9% and 76.9% respectively. As the concentration of phenol in the studied pharmaceutical wastewater was 100 mg/l, granular activated carbon was used to remove phenol up to the allowable limit for reuse purpose. Activated carbon adsorption further reduces phenol, TDS, TSS, BOD, and COD up to 99.9%, 99.1%, 21.4%, 81.3% and 71.1% respectively. High removal of color observed after activated carbon adsorption. It was concluded that the suggested treatment scheme is suitable to bring the effluent quality up to the water quality standards. (author)

  1. Physicochemical characterization of two deproteinized bovine xenografts

    Directory of Open Access Journals (Sweden)

    Thais Accorsi-Mendonça

    2008-03-01

    Full Text Available Calcium phosphate salts, or more specifically hydroxyapatite, are products of great interest in the fields of medical and dental science due to their biocompatibility and osteoconduction property. Deproteinized xenografts are primarily constituted of natural apatites, sintered or not. Variations in the industrial process may affect physicochemical properties and, therefore, the biological outcome. The purpose of this work was to characterize the physical and chemical properties of deproteinized xenogenic biomaterials, Bio-Oss (Geistlich Biomaterials, Wolhuser, Switzerland and Gen-Ox (Baumer S.A., Brazil, widely used as bone grafts. Scanning electron microscopy, infrared region spectroscopy, X-ray diffraction, thermogravimetry and degradation analysis were conducted. The results show that both materials presented porous granules, composed of crystalline hydroxyapatite without apparent presence of other phases. Bio-Oss presented greater dissolution in Tris-HCl than Gen-Ox in the degradation test, possibly due to the low crystallinity and the presence of organic residues. In conclusion, both commercial materials are hydroxyapatite compounds, Bio-Oss being less crystalline than Gen-Ox and, therefore, more prone to degradation.

  2. PHYSICOCHEMICAL AND RHEOLOGICAL CHARACTERIZATION OF AVOCADO OILS

    Directory of Open Access Journals (Sweden)

    Tamara de Souza Jorge

    2015-08-01

    Full Text Available Avocado oil is rich in bioactive compounds, which can improve human health by acting as an antioxidant. It may be extracted from different varieties of avocado, such as Margarida and Hass varieties, each of them with particular characteristics. Aiming to evaluate the differences between them, avocado fruits and pulps from these were analyzed according to their physicochemical characteristics. After extracted, the oils had their bioactive characteristics studied and rheological behavior determined through a rotational rheometer. They were then compared to commercial avocado oil. The fruits of Margarida variety had greater size, higher weight (664.51 g, and higher pulp yield (72.19% than Hass variety, which showed higher lipid content (65.29 g/100 g dry basis. The commercial oil showed less primary oxidative degradation, whereas Margarida variety had a lower level of secondary degradation products as well as a higher content of bioactive compounds, such as phytosterols (999.60 mg/kg and tocopherols (36.73 mg/kg. The rheological behaviors of both oils were appropriately described through Newton model, with R2 > 0.999 for all temperatures. By an Arrhenius type equation, it was verified that Hass's rheological parameters are more influenced by temperature than Margarida and commercial oil, presenting activation energy of 33.6 kJ/mol.

  3. Comparison of physicochemical properties of suppositories containing starch hydrolysates

    OpenAIRE

    Piotr Belniak; Katarzyna Świąder; Michał Szumiło; Aleksandra Hyla; Ewa Poleszak

    2017-01-01

    The purpose of this work was to determine the effect of starch hydrolysates (SH) on the physicochemical properties of suppositories. The study was conducted with suppositories with acetaminophen (AAP) a typical antipyretic analgesic, as model drug on lipophilic (cocoa butter) and hydrophilic base (polyethylene glycol 1500?+?400). The suppositories with and without the addition of SH were examined for physicochemical tests according to European Pharmacopoeia 8th edition (Ph. Eur.): the uniform...

  4. Physicochemical properties and biological activities of Thai plant mucilages for artificial saliva preparation.

    Science.gov (United States)

    Manosroi, Aranya; Pattamapun, Kassara; Khositsuntiwong, Narinthorn; Kietthanakorn, Bang-on; Issarangporn, Witchapong; Chankhampan, Charinya; Manosroi, Worapaka; Manosroi, Jiradej

    2015-01-01

    Plant mucilages can be found in various parts of several Thai plants, which can be used as thickening, moisturizing, and lubricating agents in artificial saliva formulations. The objective of this study was to evaluate the physicochemical properties, biological activity, and cytotoxicity of Thai plant mucilages. The mucilages from Thai plants were extracted by various processes (temperature and pH variation, microwave oven, steam, and Tris-HCl buffer extraction). The viscosity and the rheology were evaluated using viscometer. Antioxidative activities including DPPH radical scavenging and metal chelating activities were investigated. The mucilages were determined for cytotoxicity on normal human gingival fibroblasts and anti-adherent activity of Streptococcus mutans. Mucilages from Ocimum citriodorum Vis. (Lamiaceae), Artocarpus heterophyllus Lam. (Moraceae), Abelmoschus esculentus (Linn.) Moench. (Malvaceae), and Basella alba Linn. (Basellaceae) exhibited pseudoplastic non-Newtonian rheology. The highest DPPH radical-scavenging and metal-chelating activities were observed in the mucilages from B. alba (microwave, 3 min) and A. esculentus (microwave, 1 min) with the SC50 and MC50 values (50% of scavenging activity and 50% of metal chelating activity, respectively) of 0.71 ± 0.32 and 1.11 ± 0.52 mg/ml, respectively. Most mucilages exhibited no cytotoxicity to normal human gingival fibroblasts. The mucilage from A. esculentus (microwave, 5 min) gave the shortest wetting time of 2.75 ± 0.51 min. The highest S. mutans adhesion inhibition was observed in A. esculentus (pH 11) of 5.39 ± 9.70%. This study has indicated the suitable physicochemical and biological properties and the potential application of mucilages from Thai plants for artificial saliva preparation.

  5. SHORT COMMUNICATION PHYSICO-CHEMICAL QUALITY OF ...

    African Journals Online (AJOL)

    Preferred Customer

    found in four wells situated in densely populated and in the vicinity of metal workshops, heavy motor traffic/commercial/motor station areas, and are indicative of localized anthropogenic contamination. Apart from these limitations, all the other chemical evidences show that the water is good and potable. The determined data.

  6. Thermodynamic data-base for metal fluorides

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Jae Hyung; Lee, Byung Gik; Kang, Young Ho and others

    2001-05-01

    This study is aimed at collecting useful data of thermodynamic properties of various metal fluorides. Many thermodynamic data for metal fluorides are needed for the effective development, but no report of data-base was published. Accordingly, the objective of this report is to rearrange systematically the existing thermodynamic data based on metal fluorides and is to use it as basic data for the development of pyrochemical process. The physicochemical properties of various metal fluorides and metals were collected from literature and such existing data base as HSC code, TAPP code, FACT code, JANAF table, NEA data-base, CRC handbook. As major contents of the thermodynamic data-base, the physicochemical properties such as formation energy, viscosity, density, vapor pressure, etc. were collected. Especially, some phase diagrams of eutectic molten fluorides are plotted and thermodynamic data of liquid metals are also compiled. In the future, the technical report is to be used as basic data for the development of the pyrochemical process which is being carried out as a long-term nuclear R and D project.

  7. Thermodynamic data-base for metal fluorides

    International Nuclear Information System (INIS)

    Yoo, Jae Hyung; Lee, Byung Gik; Kang, Young Ho and others

    2001-05-01

    This study is aimed at collecting useful data of thermodynamic properties of various metal fluorides. Many thermodynamic data for metal fluorides are needed for the effective development, but no report of data-base was published. Accordingly, the objective of this report is to rearrange systematically the existing thermodynamic data based on metal fluorides and is to use it as basic data for the development of pyrochemical process. The physicochemical properties of various metal fluorides and metals were collected from literature and such existing data base as HSC code, TAPP code, FACT code, JANAF table, NEA data-base, CRC handbook. As major contents of the thermodynamic data-base, the physicochemical properties such as formation energy, viscosity, density, vapor pressure, etc. were collected. Especially, some phase diagrams of eutectic molten fluorides are plotted and thermodynamic data of liquid metals are also compiled. In the future, the technical report is to be used as basic data for the development of the pyrochemical process which is being carried out as a long-term nuclear R and D project

  8. Biosorption of Zinc (Zn) and lead (Pb) by metal resistant bacterial isolate from mining tail

    Energy Technology Data Exchange (ETDEWEB)

    Bautista Hernandez, D. A.; Carranza Alvarado, M.; Fernandez Linares, L.; Ramirez Landy, I.

    2009-07-01

    The use of microbial biomass in the removal of metals in solution, mainly of low concentrations (100 mg L{sup -}1), present advantages in relation to the physicochemical methods. The resistant microorganisms are potential bio sorbents. The objective of the present study was the isolation, starting from mining tail, of strains with capacity of metal bio sorption (Zn and Pb). (Author)

  9. Biosorption of Zinc (Zn) and lead (Pb) by metal resistant bacterial isolate from mining tail

    International Nuclear Information System (INIS)

    Bautista Hernandez, D. A.; Carranza Alvarado, M.; Fernandez Linares, L.; Ramirez Landy, I.

    2009-01-01

    The use of microbial biomass in the removal of metals in solution, mainly of low concentrations (100 mg L - 1), present advantages in relation to the physicochemical methods. The resistant microorganisms are potential bio sorbents. The objective of the present study was the isolation, starting from mining tail, of strains with capacity of metal bio sorption (Zn and Pb). (Author)

  10. Synthesis of borohydrides of rare earth metals by mechanic-chemical methods

    International Nuclear Information System (INIS)

    Gafurov, B.A.; Nasrulloeva, D.Kh.; Khakyorov, I.Z.; Saidov, V.Ya.

    2010-01-01

    Present article is devoted to synthesis of borohydrides of rare earth metals by mechanic-chemical methods. The borohydrides of rare earth metals were obtained by means of mechanic-chemical methods. Physicochemical properties of obtained lanthanoid borohydrides were studied by means of X-ray phase analysis.

  11. Radiation carcinogenesis

    International Nuclear Information System (INIS)

    Fry, R.J.M.

    1976-01-01

    The risk of iatrogenic tumors with radiation therapy is so outweighed by the benefit of cure that estimates of risk have not been considered necessary. However, with the introduction of chemotherapy, combined therapy, and particle radiation therapy, the comparative risks should be examined. In the case of radiation, total dose, fractionation, dose rate, dose distribution, and radiation quality should be considered in the estimation of risk. The biological factors that must be considered include incidence of tumors, latent period, degree of malignancy, and multiplicity of tumors. The risk of radiation induction of tumors is influenced by the genotype, sex, and age of the patient, the tissues that will be exposed, and previous therapy. With chemotherapy the number of cells at risk is usually markedly higher than with radiation therapy. Clearly the problem of the estimation of comparative risks is complex. This paper presents the current views on the comparative risks and the importance of the various factors that influence the estimation of risk

  12. Electrochemical metal speciation in natural and model polyelectrolyte systems

    NARCIS (Netherlands)

    Hoop, van den M.A.G.T.

    1994-01-01

    The purpose of the research described in this thesis was to examine the applicability of electro-analytical techniques in obtaining information on the speciation of metals, i.e. their distribution over different physico-chemical forms, in aquatic systems containing charged macromolecules.

  13. Heavy metals concentrations in water bodies around aquamarine ...

    African Journals Online (AJOL)

    Water samples from three streams in the mining area of Eggon Hill were analysed. The Physicochemical values obtained were compared with WHO permissible standards in drinking water. Except for Cu and Zn with levels within permissible limits, other heavy metals determined were found to have levels above the WHO ...

  14. Pollution assessment and heavy metal determination by AAS in ...

    African Journals Online (AJOL)

    Foisal

    below detective level. This study points out the health risk status of waste water for residents and aquatic living being, an ultimate concern for their survival in the region. Key words: Waste water, pollution assessment, physico-chemical parameters, atomic absorption spectrophotometer (AAS), heavy metal contamination.

  15. Coordinated Increased Expression of Cyclooxygenase2 and Nuclear Factor B Is a Steady Feature of Urinary Bladder Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Stylianos Kontos

    2010-01-01

    Full Text Available Objectives. The inescapable relationship between chronic inflammation and carcinogenesis has long been established. Our objective was to investigate COX-2 and NF-B immunohistochemical expression in a large series of normal epithelium and bladder carcinomas. Methods. Immunohistochemical methodology was performed on formalin-fixed, paraffin-embedded sections from urinary bladder carcinomas of 140 patients (94 males and 46 females with bladder carcinomas. Results. COX-2 expression is increased in the cytoplasm of bladder cells, during loss of cell differentiation (s=0.61, -value<.001 and in muscle invasive carcinomas (-value<.001. A strong positive association between tumor grade and nuclear expression of NFB has been established. A positive correlation between COX-2 and nuclear NFB immunoreactivity was observed. Conclusions. The possible coordinated upregulation of NFB and COX-2, during bladder carcinogenesis, indicates that agents inhibitors of these two molecules may represent a possible new treatment strategy, by virtue of their role in bladder carcinogenesis.

  16. End-Binding Protein 1 (EB1) Up-regulation is an Early Event in Colorectal Carcinogenesis

    Science.gov (United States)

    Stypula-Cyrus, Yolanda; Mutyal, Nikhil N.; Cruz, Mart Angelo Dela; Kunte, Dhananjay P.; Radosevich, Andrew J.; Wali, Ramesh; Roy, Hemant K.; Backman, Vadim

    2014-01-01

    End-binding protein (EB1) is a microtubule protein that binds to the tumor suppressor adenomatous polyposis coli (APC). While EB1 is implicated as a potential oncogene, its role in cancer progression is unknown. Therefore, we analyzed EB1/APC expression at the earliest stages of colorectal carcinogenesis and in the uninvolved mucosa ("field effect") of human and animal tissue. We also performed siRNA-knockdown in colon cancer cell lines. EB1 is up-regulated in early and field carcinogenesis in the colon, and the cellular/nano-architectural effect of EB1 knockdown depended on the genetic context. Thus, dysregulation of EB1 is an important early event in colon carcinogenesis. PMID:24492008

  17. Dynamic changes in the gene expression profile during rat oral carcinogenesis induced by 4-nitroquinoline 1-oxide.

    Science.gov (United States)

    Ge, Shuyun; Zhang, Ji; Du, Yanzhi; Hu, Bin; Zhou, Zengtong; Lou, Jianing

    2016-03-01

    The typical progression of oral cancer is from hyperplastic epithelial lesions through dysplasia to invasive carcinoma. It is important to investigate malignant oral cancer progression and development in order to determine useful approaches of prevention of dysplastic lesions. The present study aimed to gain insights into the underlying molecular mechanism of oral carcinogenesis by establishing a rat model of oral carcinogenesis using 4‑nitroquinoline 1‑oxide. Subsequently, transcription profile analysis using an integrating microarray was performed. The dynamic gene expression changes of the six stages of rat oral carcinogenesis (normal, mild epithelial dysplasia, moderate dysplasia, severe dysplasia, carcinoma in situ and oral squamous cell carcinomas) were analyzed using component plane presentations (CPP)‑self‑organizing map (SOM). Six genes were verified by quantitative polymerase chain reaction, immunohistochemistry and succinate dehydrogenase (SDH) activity assay kit. Numerous differentially expressed genes (DEGs) were identified during rat oral carcinogenesis. CPP‑SOM determined that these DEGs were primarily enriched during cell cycle, apoptosis, inflammatory response and tricarboxylic acid cycle, indicating the coordinated regulation of molecular networks. In addition, the expression of specific DEGs, such as janus kinase 3, cyclin‑dependent kinase A‑1, B‑cell chronic lymphocytic leukaemia/lymphoma 2‑like 2, nuclear factor‑κB, tumor necrosis factor receptor superfamily member 1A, cyclin D1 and SDH were identified to have high concordance with the results from microarray data. The current study demonstrated that oral carcinogenesis is a multi‑step and multi‑gene process, with a distinct pattern alteration along a continuum of malignant transformation. In addition, this comprehensive investigation provided a theoretical basis for the understanding of the molecular alterations associated with oral carcinogenesis.

  18. Borides of the group 1 metals of the periodic system

    International Nuclear Information System (INIS)

    Samsonov, G.V.; Serebryakova, T.I.; Neronov, V.A.

    1975-01-01

    The borides of alkali metals (lithium, sodium, potassium) and the metals of a copper subgroup (copper, silver, gold) are described. Consideration is given to the crystalline structure and state diagrams of the metal systems within the first group of the Periodic Table with boron. Existence, formation conditions and physico-chemical properties of binary boride phases are characterized. Conclusion is made as to the absence of interaction between boron and silver. Information on the interaction between gold and boron is scanty and conflicting. Methods are described suitable for the production of the borides of the metals within the first group of the Periodic Table [ru

  19. Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

    International Nuclear Information System (INIS)

    Takahashi, Mami; Hori, Mika; Mutoh, Michihiro; Wakabayashi, Keiji; Nakagama, Hitoshi

    2011-01-01

    Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropyl)amine (BOP) into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5′ CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention

  20. STICS, SCOUTs and p53 signatures; a new language for pelvic serous carcinogenesis.

    Science.gov (United States)

    Mehra, Karishma; Mehrad, Mitra; Ning, Geng; Drapkin, Ronny; McKeon, Frank D; Xian, Wa; Crum, Christopher P

    2011-01-01

    The events leading to the most common and most lethal ovarian carcinoma - high grade serous carcinoma - have been poorly understood. However, the detailed pathologic study of asymptomatic women with germ-line BRCA 1 or BRCA2 (BCRA+) mutations has unearthed an early malignancy, serous tubal intraepithelial carcinomas (STIC), which has linked many peritoneal and ovarian serous carcinomas to the fimbria. The distinction between high-grade serous and endometrioid carcinomas continues to narrow, with shared alterations in expression of pTEN, PAX2 and p53. Moreover, the discovery of clonal alterations in p53 in benign tubal epithelium, - p53 signatures - has established a foundation for a serous cancer precursor in the fimbria. We have expanded this concept to include a generic secretory cell outgrowth (SCOUT) in the fallopian tube that is associated with altered PAX2 expression. As the repertoire of gene alterations is expanded and its link to serous carcinogenesis clarified, a cogent pathway to high-grade Mullerian carcinomas will emerge. This will challenge conventional thinking about ovarian carcinogenesis but will provide a new template for studies of ovarian cancer prevention.

  1. Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

    Energy Technology Data Exchange (ETDEWEB)

    Takahashi, Mami, E-mail: mtakahas@ncc.go.jp; Hori, Mika; Mutoh, Michihiro [Division of Cancer Development System, Carcinogenesis Research Group, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-ku, Tokyo 104-0045 (Japan); Wakabayashi, Keiji [Graduate School of Nutritional and Environmental Sciences, University of Shizuoka, Yada 52-1, Suruga-ku, Shizuoka 422-8526 (Japan); Nakagama, Hitoshi [Division of Cancer Development System, Carcinogenesis Research Group, National Cancer Center Research Institute, 1-1, Tsukiji 5-chome, Chuo-ku, Tokyo 104-0045 (Japan)

    2011-02-09

    Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropyl)amine (BOP) into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5′ CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention.

  2. Gut Microbe-Mediated Suppression of Inflammation-Associated Colon Carcinogenesis by Luminal Histamine Production.

    Science.gov (United States)

    Gao, Chunxu; Ganesh, Bhanu Priya; Shi, Zhongcheng; Shah, Rajesh Rasik; Fultz, Robert; Major, Angela; Venable, Susan; Lugo, Monica; Hoch, Kathleen; Chen, Xiaowei; Haag, Anthony; Wang, Timothy C; Versalovic, James

    2017-10-01

    Microbiome-mediated suppression of carcinogenesis may open new avenues for identification of therapeutic targets and prevention strategies in oncology. Histidine decarboxylase (HDC) deficiency has been shown to promote inflammation-associated colorectal cancer by accumulation of CD11b + Gr-1 + immature myeloid cells, indicating a potential antitumorigenic effect of histamine. Here, we demonstrate that administration of hdc + Lactobacillus reuteri in the gut resulted in luminal hdc gene expression and histamine production in the intestines of Hdc -/- mice. This histamine-producing probiotic decreased the number and size of colon tumors and colonic uptake of [ 18 F]-fluorodeoxyglucose by positron emission tomography in Hdc -/- mice. Administration of L. reuteri suppressed keratinocyte chemoattractant (KC), Il22, Il6, Tnf, and IL1α gene expression in the colonic mucosa and reduced the amounts of proinflammatory, cancer-associated cytokines, keratinocyte chemoattractant, IL-22, and IL-6, in plasma. Histamine-generating L. reuteri also decreased the relative numbers of splenic CD11b + Gr-1 + immature myeloid cells. Furthermore, an isogenic HDC-deficient L. reuteri mutant that was unable to generate histamine did not suppress carcinogenesis, indicating a significant role of the cometabolite, histamine, in suppression of chronic intestinal inflammation and colorectal tumorigenesis. These findings link luminal conversion of amino acids to biogenic amines by gut microbes and probiotic-mediated suppression of colorectal neoplasia. Copyright © 2017 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  3. Tumor suppressive role of sestrin2 during colitis and colon carcinogenesis

    Science.gov (United States)

    Ro, Seung-Hyun; Xue, Xiang; Ramakrishnan, Sadeesh K; Cho, Chun-Seok; Namkoong, Sim; Jang, Insook; Semple, Ian A; Ho, Allison; Park, Hwan-Woo; Shah, Yatrik M; Lee, Jun Hee

    2016-01-01

    The mTOR complex 1 (mTORC1) and endoplasmic reticulum (ER) stress pathways are critical regulators of intestinal inflammation and colon cancer growth. Sestrins are stress-inducible proteins, which suppress both mTORC1 and ER stress; however, the role of Sestrins in colon physiology and tumorigenesis has been elusive due to the lack of studies in human tissues or in appropriate animal models. In this study, we show that human SESN2 expression is elevated in the colon of ulcerative colitis patients but is lost upon p53 inactivation during colon carcinogenesis. In mouse colon, Sestrin2 was critical for limiting ER stress and promoting the recovery of epithelial cells after inflammatory injury. During colitis-promoted tumorigenesis, Sestrin2 was shown to be an important mediator of p53’s control over mTORC1 signaling and tumor cell growth. These results highlight Sestrin2 as a novel tumor suppressor, whose downregulation can accelerate both colitis and colon carcinogenesis. DOI: http://dx.doi.org/10.7554/eLife.12204.001 PMID:26913956

  4. Molecular Mechanism of Gastric Carcinogenesis in Helicobacter pylori-Infected Rodent Models

    Directory of Open Access Journals (Sweden)

    Takeshi Toyoda

    2014-06-01

    Full Text Available Since the discovery of Helicobacter pylori (H. pylori, many efforts have been made to establish animal models for the investigation of the pathological features and molecular mechanisms of gastric carcinogenesis. Among the animal models, Mongolian gerbils and mice are particularly useful for the analysis of H. pylori-associated inflammatory reactions and gastric cancer development. Inhibitors of oxidative stress, cyclooxygenase-2 (COX-2 and nuclear factor-κB, exert preventive effects on chronic gastritis and the development of adenocarcinomas in H. pylori-infected gerbils. Genetically-modified mouse models, including transgenic and knockout mice, have also revealed the importance of p53, COX-2/prostaglandin, Wnt/β-catenin, proinflammatory cytokines, gastrin and type III mucin in the molecular mechanisms of gastric carcinogenesis. Microarray technology is available for comprehensive gene analysis in the gastric mucosa of mouse models, and epigenetics, such as DNA methylation, could be an alternative approach to correlate the observations in animal models with the etiology in humans.

  5. Environment and breast cancer - the role of xenooestrogens in breast cancer carcinogenesis

    International Nuclear Information System (INIS)

    Plesnicar, A.; Kralj, B.; Druzina, B.; Kovac, V.

    2002-01-01

    Background. The survival rate of breast cancer patients has not changed much in the last few decades in developed countries. In order to improve the efficacy of breast cancer prevention and treatment, the role of xenooestrogens in the mechanisms of its development has been evaluated. These industrial chemicals bear little structural resemblance to each other and bind to the oestrogen receptors of exposed cells and/or trigger oestrogenic responses in laboratory test systems. Exposure to xenooestrogens has been regarded as a risk factor for carcinogenesis and a preventable cause of breast carcinoma. Several epidemiological and experimental studies in in vivo and in in vitro conditions of the influence of xenooestrogens on the occurrence of breast cancer have been conducted in the last decades and have shown ambiguous results. Conclusions. No increase in breast carcinoma incidence could be found in women who were exposed to relatively high concentrations of xenooestrogens for extended periods and small quantities of these compounds that are present in the environment probably cannot act as etiological agents for the occurrence of this disease. A multi step approach is suggested regarding the sequence of studies and measures that should be taken to further assess the importance of xenooestrogens on breast cancer carcinogenesis. (author)

  6. Evaluation of carcinogenic potential of diuron in a rat mammary two-stage carcinogenesis model.

    Science.gov (United States)

    Grassi, Tony Fernando; Rodrigues, Maria Aparecida Marchesan; de Camargo, João Lauro Viana; Barbisan, Luís Fernando

    2011-04-01

    This study aimed to evaluate the carcinogenic potential of the herbicide Diuron in a two-stage rat medium-term mammary carcinogenesis model initiated by 7,12-dimethylbenz(a)anthracene (DMBA). Female seven-week-old Sprague-Dawley (SD) rats were allocated to six groups: groups G1 to G4 received intragastrically (i.g.) a single 50 mg/kg dose of DMBA; groups G5 and G6 received single administration of canola oil (vehicle of DMBA). Groups G1 and G5 received a basal diet, and groups G2, G3, G4, and G6 were fed the basal diet with the addition of Diuron at 250, 1250, 2500, and 2500 ppm, respectively. After twenty-five weeks, the animals were euthanized and mammary tumors were histologically confirmed and quantified. Tumor samples were also processed for immunohistochemical evaluation of the expressions of proliferating cell nuclear antigen (PCNA), cleaved caspase-3, estrogen receptor-α (ER-α), p63, bcl-2, and bak. Diuron treatment did not increase the incidence or multiplicity of mammary tumors (groups G2 to G4 versus Group G1). Also, exposure to Diuron did not alter tumor growth (cell proliferation and apoptosis indexes) or immunoreactivity to ER-α, p63 (myoephitelial marker), or bcl-2 and bak (apoptosis regulatory proteins). These findings indicate that Diuron does not have a promoting potential on mammary carcinogenesis in female SD rats initiated with DMBA.

  7. Gene Systems Network Inferred from Expression Profiles in Hepatocellular Carcinogenesis by Graphical Gaussian Model

    Directory of Open Access Journals (Sweden)

    Saito Shigeru

    2007-01-01

    Full Text Available Hepatocellular carcinoma (HCC in a liver with advanced-stage chronic hepatitis C (CHC is induced by hepatitis C virus, which chronically infects about 170 million people worldwide. To elucidate the associations between gene groups in hepatocellular carcinogenesis, we analyzed the profiles of the genes characteristically expressed in the CHC and HCC cell stages by a statistical method for inferring the network between gene systems based on the graphical Gaussian model. A systematic evaluation of the inferred network in terms of the biological knowledge revealed that the inferred network was strongly involved in the known gene-gene interactions with high significance , and that the clusters characterized by different cancer-related responses were associated with those of the gene groups related to metabolic pathways and morphological events. Although some relationships in the network remain to be interpreted, the analyses revealed a snapshot of the orchestrated expression of cancer-related groups and some pathways related with metabolisms and morphological events in hepatocellular carcinogenesis, and thus provide possible clues on the disease mechanism and insights that address the gap between molecular and clinical assessments.

  8. [In vitro and in vivo effects of mango pulp (Mangifera indica cv. Azucar) in colon carcinogenesis].

    Science.gov (United States)

    Corrales-Bernal, Andrea; Amparo Urango, Luz; Rojano, Benjamín; Maldonado, Maria Elena

    2014-03-01

    Mango pulp contains ascorbic acid, carotenoids, polyphenols, terpenoids and fiber which are healthy and could protect against colon cancer. The aim of this study was to evaluate the antiproliferative and preventive capacity of an aqueous extract of Mangifera indica cv. Azúcar on a human colon adenocarcinoma cell line (SW480) and in a rodent model of colorectal cancer, respectively. The content of total phenolics, flavonoids and carotenoids were also analyzed in the extract. SW480 cell growth was inhibited in a dose and time dependent manner by 22.3% after a 72h exposure to the extract (200 µg/ mL). Colon carcinogenesis was initiated in Balb/c mice by two intra-peritoneal injections of azoxymethane (AOM) at the third and fourth week of giving mango in drinking water (0.3%, 0.6%, 1.25%). After 10 weeks of treatment, in the colon of mice receiving 0.3% mango, aberrant crypt foci formation was inhibited more than 60% (p=0,05) and the inhibition was dose-dependent when compared with controls receiving water. These results show that mango pulp, a natural food, non toxic, part of human being diet, contains bioactive compounds able to reduce growth of tumor cells and to prevent the appearance of precancerous lesions in colon during carcinogenesis initiation.

  9. Influence of Chronic Moderate Sleep Restriction and Exercise on Inflammation and Carcinogenesis in Mice

    Science.gov (United States)

    Zielinski, Mark R.; Davis, J. Mark; Fadel, James R.; Youngstedt, Shawn D.

    2013-01-01

    The effects of chronic moderate sleep restriction and exercise training on carcinogenesis were examined in adenomatous polyposis coli multiple intestinal neoplasma (APC Min+/-) mice, a genetic strain which is predisposed to developing adenomatous polyposis. The mice were randomized to one of four 11 week treatments in a 2×2 design involving sleep restriction (by 4 h/day) vs. normal sleep and exercise training (1 h/day) vs. sedentary control. Wild-type control mice underwent identical experimental treatments. Compared with the wild-type mice, APC Min+/- mice had disrupted hematology and enhanced pro-inflammatory cytokine production from peritoneal exudate cells. Among the APC Min+/- mice, consistent interactions of sleep loss and exercise were found for measures of polyp formation, inflammation, and hematology. Sleep loss had little effect on these variables under sedentary conditions, but sleep loss had clear detrimental effects under exercise conditions. Exercise training resulted in improvements in these measures under normal sleep conditions, but exercise tended to elicit no effect or to exacerbate the effects of sleep restriction. Significant correlations of inflammation with polyp burden were observed. Among wild-type mice, similar, but less consistent interactions of sleep restriction and exercise were found. These data suggest that the benefits of exercise on carcinogenesis and immune function were impaired by chronic moderate sleep restriction, and that harmful effects of sleep restriction were generally realized only in the presence of exercise. PMID:22433899

  10. Enhancement of broccoli indole glucosinolates by methyl jasmonate treatment and effects on prostate carcinogenesis.

    Science.gov (United States)

    Liu, Ann G; Juvik, John A; Jeffery, Elizabeth H; Berman-Booty, Lisa D; Clinton, Steven K; Erdman, John W

    2014-11-01

    Broccoli is rich in bioactive components, such as sulforaphane and indole-3-carbinol, which may impact cancer risk. The glucosinolate profile of broccoli can be manipulated through treatment with the plant stress hormone methyl jasmonate (MeJA). Our objective was to produce broccoli with enhanced levels of indole glucosinolates and determine its impact on prostate carcinogenesis. Brassica oleracea var. Green Magic was treated with a 250 μM MeJA solution 4 days prior to harvest. MeJA-treated broccoli had significantly increased levels of glucobrassicin, neoglucobrassicin, and gluconasturtiin (P broccoli powder, or 10% MeJA broccoli powder. Diets were fed throughout the study until termination at 20 weeks of age. Hepatic CYP1A was induced with MeJA broccoli powder feeding, indicating biological activity of the indole glucosinolates. Following ∼ 15 weeks on diets, neither of the broccoli treatments significantly altered genitourinary tract weight, pathologic score, or metastasis incidence, indicating that broccoli powder at 10% of the diet was ineffective at reducing prostate carcinogenesis in the TRAMP model. Whereas broccoli powder feeding had no effect in this model of prostate cancer, our work demonstrates the feasibility of employing plant stress hormones exogenously to stimulate changes in phytochemical profiles, an approach that may be useful for optimizing bioactive component patterns in foods for chronic-disease-prevention studies.

  11. Vital-dye-enhanced multimodal imaging of neoplastic progression in a mouse model of oral carcinogenesis

    Science.gov (United States)

    Hellebust, Anne; Rosbach, Kelsey; Wu, Jessica Keren; Nguyen, Jennifer; Gillenwater, Ann; Vigneswaran, Nadarajah; Richards-Kortum, Rebecca

    2013-12-01

    In this longitudinal study, a mouse model of 4-nitroquinoline 1-oxide chemically induced tongue carcinogenesis was used to assess the ability of optical imaging with exogenous and endogenous contrast to detect neoplastic lesions in a heterogeneous mucosal surface. Widefield autofluorescence and fluorescence images of intact 2-NBDG-stained and proflavine-stained tissues were acquired at multiple time points in the carcinogenesis process. Confocal fluorescence images of transverse fresh tissue slices from the same specimens were acquired to investigate how changes in tissue microarchitecture affect widefield fluorescence images of intact tissue. Widefield images were analyzed to develop and evaluate an algorithm to delineate areas of dysplasia and cancer. A classification algorithm for the presence of neoplasia based on the mean fluorescence intensity of 2-NBDG staining and the standard deviation of the fluorescence intensity of proflavine staining was found to separate moderate dysplasia, severe dysplasia, and cancer from non-neoplastic regions of interest with 91% sensitivity and specificity. Results suggest this combination of noninvasive optical imaging modalities can be used in vivo to discriminate non-neoplastic from neoplastic tissue in this model with the potential to translate this technology to the clinic.

  12. Preventive Effects of Fermented Brown Rice and Rice Bran against Prostate Carcinogenesis in TRAP Rats

    Directory of Open Access Journals (Sweden)

    Toshiya Kuno

    2016-07-01

    Full Text Available Fermented brown rice and rice bran with Aspergillus oryzae (FBRA is considered to have the potential to prevent chemically-induced carcinogenesis in multiple organs of rodents. In the present study, we evaluated the possible chemopreventive effects of FBRA against prostate tumorigenesis. Six-week-old male rats of the transgenic rat for adenocarcinoma of prostate (TRAP strain were fed diets containing 5% or 10% FBRA for 15 weeks. Animals were sacrificed at 21 weeks of age, and the ventral and lateral prostate were removed for histopathological evaluation and immunoblot analyses. FBRA decreased the incidence of adenocarcinoma in the lateral prostate and suppressed the progression of prostate carcinogenesis. Treatment with FBRA induced apoptosis and inhibited cell proliferation in histologically high-grade prostatic intraepithelial neoplasias. Phospho-AMP-activated kinase α (Thr172 was up-regulated in the prostate of rats fed the diet supplemented with FBRA. These results indicate that FBRA controls tumor growth by activating pathways responsive to energy deprivation and suggest that FBRA has translational potential for the prevention of human prostate cancer.

  13. Nutraceutical Approach for Preventing Obesity-Related Colorectal and Liver Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Hisataka Moriwaki

    2012-01-01

    Full Text Available Obesity and its related metabolic abnormalities, including insulin resistance, alterations in the insulin-like growth factor-1 (IGF-1/IGF-1 receptor (IGF-1R axis, and the state of chronic inflammation, increase the risk of colorectal cancer (CRC and hepatocellular carcinoma (HCC. However, these findings also indicate that the metabolic disorders caused by obesity might be effective targets to prevent the development of CRC and HCC in obese individuals. Green tea catechins (GTCs possess anticancer and chemopreventive properties against cancer in various organs, including the colorectum and liver. GTCs have also been known to exert anti-obesity, antidiabetic, and anti-inflammatory effects, indicating that GTCs might be useful for the prevention of obesity-associated colorectal and liver carcinogenesis. Further, branched-chain amino acids (BCAA, which improve protein malnutrition and prevent progressive hepatic failure in patients with chronic liver diseases, might be also effective for the suppression of obesity-related carcinogenesis because oral supplementation with BCAA reduces the risk of HCC in obese cirrhotic patients. BCAA shows these beneficial effects because they can improve insulin resistance. Here, we review the detailed relationship between metabolic abnormalities and the development of CRC and HCC. We also review evidence, especially that based on our basic and clinical research using GTCs and BCAA, which indicates that targeting metabolic abnormalities by either pharmaceutical or nutritional intervention may be an effective strategy to prevent the development of CRC and HCC in obese individuals.

  14. Role of Helicobacter pylori infection in gastric carcinogenesis: Current knowledge and future directions

    Science.gov (United States)

    Sokic-Milutinovic, Aleksandra; Alempijevic, Tamara; Milosavljevic, Tomica

    2015-01-01

    Helicobacter pylori (H. pylori) plays a role in the pathogenesis of gastric cancer. The outcome of the infection depends on environmental factors and bacterial and host characteristics. Gastric carcinogenesis is a multistep process that is reversible in the early phase of mucosal damage, but the exact point of no return has not been identified. Therefore, two main therapeutic strategies could reduce gastric cancer incidence: (1) eradication of the already present infection; and (2) immunization (prior to or during the course of the infection). The success of a gastric cancer prevention strategy depends on timing because the prevention strategy must be introduced before the point of no return in gastric carcinogenesis. Although the exact point of no return has not been identified, infection should be eradicated before severe atrophy of the gastric mucosa develops. Eradication therapy rates remain suboptimal due to increasing H. pylori resistance to antibiotics and patient noncompliance. Vaccination against H. pylori would reduce the cost of eradication therapies and lower gastric cancer incidence. A vaccine against H. pylori is still a research challenge. An effective vaccine should have an adequate route of delivery, appropriate bacterial antigens and effective and safe adjuvants. Future research should focus on the development of rescue eradication therapy protocols until an efficacious vaccine against the bacterium becomes available. PMID:26556993

  15. Multistage models of carcinogenesis and their implications for dose-response models and risk projections

    International Nuclear Information System (INIS)

    Hoel, D.G.

    1992-01-01

    Multistage models are used to both describe the biological steps in developing a cancer and as a mathematical description of the relationship of exposure to tumor incidence. With the rapid development of molecular biology the stages of tumor development are becoming understood. Specifically, the effect and role of proto-oncogenes and suppressor genes are exciting developments in the field of carcinogenesis. Mathematically the field has moved from the original Armitage-Doll multistage model to the more current cell kinetic models. These latter models attempt to describe both the rate of cell mutation and the birth-death process involved in clonal expansion. This then allows modeling of both initiation and promotion or cellular proliferation. The field of radiation carcinogenesis has a considerable body of data and knowledge. Unfortunately, relatively little work has been done with the cell kinetic models as to estimation of tumor incidence. This may be due to the newness of kinetic models in general. The field holds promise and it is essential if we are to develop better human risk estimates from exposure to ionizing radiation. (author)

  16. Folate and cancer: how DNA damage, repair and methylation impact on colon carcinogenesis.

    Science.gov (United States)

    Duthie, Susan J

    2011-02-01

    Inappropriate diet may contribute to one third of cancer deaths. Folates, a group of water-soluble B vitamins present in high concentrations in green, leafy vegetables, maintain DNA stability through their ability to donate one-carbon units for cellular metabolism. Folate deficiency has been implicated in the development of several cancers, including cancer of the colorectum, breast, ovary, pancreas, brain, lung and cervix. Generally, data from the majority of human studies suggest that people who habitually consume the highest level of folate, or with the highest blood folate concentrations, have a significantly reduced risk of developing colon polyps or cancer. However, an entirely protective role for folate against carcinogenesis has been questioned, and recent data indicate that an excessive intake of synthetic folic acid (from high-dose supplements or fortified foods) may increase human cancers by accelerating growth of precancerous lesions. Nonetheless, on balance, evidence from the majority of human studies indicates that dietary folate is genoprotective against colon cancer. Suboptimal folate status in humans is widespread. Folate maintains genomic stability by regulating DNA biosynthesis, repair and methylation. Folate deficiency induces and accelerates carcinogenesis by perturbing each of these processes. This review presents recent evidence describing how these mechanisms act, and interact, to modify colon cancer risk.

  17. Aggravation of serum Hepatocyte Growth Factor levels during hepato carcinogenesis in Rats

    International Nuclear Information System (INIS)

    Abdelgawad, M.R.; Ghareeb, N.A.

    2010-01-01

    Hepatocyte growth factor (HGF) has an essential role during liver development and it plays an important role in the regeneration and repair of injured tissues and acting as a mitogen, motogen and morphogens for a variety of epithelial cells. The role of HGF in carcinogenesis is in straggle and so, the present study aimed to through light through the level of HGF during different steps of carcinogenesis. Forty male rats were given diethylnitrosamine (DEN) in drinking water (100 mg/l) for up to 16 weeks. Eight rats were sacrificed at 8, 12 and 16 weeks. Besides, 8 hepatoma bearing rats were exposed to a single dose gamma irradiation (3 Gy) were sacrificed after 2 weeks from exposure (2 rats died, 36 hrs post irradiation) and 8 hepatoma bearing rats were sacrificed after 4 weeks from receiving a combined antioxidant (N-acetylcysteine and Lmethionine). Serum HGF was assayed by enzyme linked immunosorbent assay (ELISA). Serum HGF level in DEN treated rats and in exposed hepatoma bearing rats was significantly higher than in control rats whereas, serum HGF level after treatment with N acetylcysteine and L-methionine for 4 weeks was significantly decreased than DEN treated rats and concluded that serum HGF may play a role during promotion and progression of hepatocellular carcinoma (HCC) and during treatment

  18. Cell Cycle Phase Abnormalities Do Not Account for Disordered Proliferation in Barrett's Carcinogenesis

    Directory of Open Access Journals (Sweden)

    Pierre Lao-Sirieix

    2004-11-01

    Full Text Available Barrett's esophagus (BE epithelium is the precursor lesion for esophageal adenocarcinoma. Cell cycle proteins have been advocated as biomarkers to predict the malignant potential in BE. However, whether disruption of the cell cycle plays a causal role in Barrett's carcinogenesis is not clear. Specimens from the Barrett's dysplasia—carcinoma sequence were immunostained for cell cycle phase markers (cyclin D1 for G1; cyclin A for S, G2, and M; cytoplasmic cyclin B1 for G2; and phosphorylated histone 3 for M phase and expressed as a proportion of proliferating cells. Flow cytometric analysis of the cell cycle phase of prospective biopsies was also performed. The proliferation status of nondysplastic BE was similar to gastric antrum and D2, but the proliferative compartment extended to the luminal surface. In dysplastic samples, the number of proliferating cells correlated with the degree of dysplasia (P < .001. The overall levels of cyclins A and B1 correlated with the degree of dysplasia (P < .001. However, the cell cycle phase distribution measured with both immunostaining and flow cytometry was conserved during all stages of BE, dysplasia, and cancer. Hence, the increased proliferation seen in Barrett's carcinogenesis is due to abnormal cell cycle entry or exit, rather than a primary abnormality within the cell cycle.

  19. A20 restricts wnt signaling in intestinal epithelial cells and suppresses colon carcinogenesis.

    Directory of Open Access Journals (Sweden)

    Ling Shao

    Full Text Available Colon carcinogenesis consists of a multistep process during which a series of genetic and epigenetic adaptations occur that lead to malignant transformation. Here, we have studied the role of A20 (also known as TNFAIP3, a ubiquitin-editing enzyme that restricts NFκB and cell death signaling, in intestinal homeostasis and tumorigenesis. We have found that A20 expression is consistently reduced in human colonic adenomas than in normal colonic tissues. To further investigate A20's potential roles in regulating colon carcinogenesis, we have generated mice lacking A20 specifically in intestinal epithelial cells and interbred these with mice harboring a mutation in the adenomatous polyposis coli gene (APC(min. While A20(FL/FL villin-Cre mice exhibit uninflamed intestines without polyps, A20(FL/FL villin-Cre APC(min/+ mice contain far greater numbers and larger colonic polyps than control APC(min mice. We find that A20 binds to the β-catenin destruction complex and restricts canonical wnt signaling by supporting ubiquitination and degradation of β-catenin in intestinal epithelial cells. Moreover, acute deletion of A20 from intestinal epithelial cells in vivo leads to enhanced expression of the β-catenin dependent genes cyclinD1 and c-myc, known promoters of colon cancer. Taken together, these findings demonstrate new roles for A20 in restricting β-catenin signaling and preventing colon tumorigenesis.

  20. Chemopreventive effects of nobiletin and its colonic metabolites on colon carcinogenesis.

    Science.gov (United States)

    Wu, Xian; Song, Mingyue; Wang, Minqi; Zheng, Jinkai; Gao, Zili; Xu, Fei; Zhang, Guodong; Xiao, Hang

    2015-12-01

    Nobiletin (NBT) is a major citrus flavonoid with various health benefits. Herein, we investigated the colon cancer chemopreventive effects of NBT and its colonic metabolites in a colitis-associated colon carcinogenesis mouse model as well as in human colon cancer cell models. In azoxymethane/dextran sulfate sodium treated mice, oral administration of NBT effectively decreased both incidence and multiplicity of colonic tumors. NBT showed significant antiproliferative, proapoptotic, and anti-inflammatory effects in the mouse colon. HPLC analysis revealed that oral administration of NBT resulted in high levels of metabolites, i.e. 3'-demethylnobiletin (M1), 4'-demethylnobiletin (M2), and 3',4'-didemethylnobiletin (M3) in the colonic mucosa. In contrast, the colonic level of NBT was about 20-fold lower than the total colonic level of three metabolites. Cell culture studies demonstrated that the colonic metabolites of NBT significantly inhibited the growth of human colon cancer cells, caused cell-cycle arrest, induced apoptosis, and profoundly modulated signaling proteins related with cell proliferation and cell death. All of these effects were much stronger than those produced by NBT alone. Our results demonstrated that oral administration of NBT significantly inhibited colitis-associated colon carcinogenesis in mice, and this chemopreventive effect was strongly associated with its colonic metabolites. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  1. Experimental Animal Models of Pancreatic Carcinogenesis for Prevention Studies and Their Relevance to Human Disease

    Directory of Open Access Journals (Sweden)

    Hitoshi Nakagama

    2011-02-01

    Full Text Available Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropylamine (BOP into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5’ CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention.

  2. Experimental animal models of pancreatic carcinogenesis for prevention studies and their relevance to human disease.

    Science.gov (United States)

    Takahashi, Mami; Hori, Mika; Mutoh, Michihiro; Wakabayashi, Keiji; Nakagama, Hitoshi

    2011-02-09

    Pancreatic cancer is difficult to cure, so its prevention is very important. For this purpose, animal model studies are necessary to develop effective methods. Injection of N-nitrosobis(2-oxopropyl)amine (BOP) into Syrian golden hamsters is known to induce pancreatic ductal adenocarcinomas, the histology of which is similar to human tumors. Moreover, K-ras activation by point mutations and p16 inactivation by aberrant methylation of 5' CpG islands or by homozygous deletions have been frequently observed in common in both the hamster and humans. Thus, this chemical carcinogenesis model has an advantage of histopathological and genetic similarity to human pancreatic cancer, and it is useful to study promotive and suppressive factors. Syrian golden hamsters are in a hyperlipidemic state even under normal dietary conditions, and a ligand of peroxizome proliferator-activated receptor gamma was found to improve the hyperlipidemia and suppress pancreatic carcinogenesis. Chronic inflammation is a known important risk factor, and selective inhibitors of inducible nitric oxide synthase and cyclooxygenase-2 also have protective effects against pancreatic cancer development. Anti-inflammatory and anti-hyperlipidemic agents can thus be considered candidate chemopreventive agents deserving more attention.

  3. Temoporfin-loaded liposomes: physicochemical characterization.

    Science.gov (United States)

    Kuntsche, Judith; Freisleben, Ines; Steiniger, Frank; Fahr, Alfred

    2010-07-11

    Temoporfin (mTHPC) is a potent but highly hydrophobic second-generation photosensitizer and has been approved for the palliative treatment of patients with advanced head and neck cancer by photodynamic therapy. Liposome formulations have been evaluated as carrier system for this drug to overcome some problems associated with the commercial formulation Foscan where the drug is dissolved in a mixture of water-free ethanol and propylene glycol. The present study focuses on the physicochemical characterization of different liposome formulations with special emphasis on the influence of drug incorporation on the thermal phase behavior of the liposomes. In addition to conventional liposomes, pegylated lipids were used for the preparation of "stealth" liposomes. The dispersions as well as freeze-dried formulations were characterized by photon correlation spectroscopy, differential scanning calorimetry and cryo-electron microscopy. Incorporation of temoporfin resulted in a distinct concentration dependent decrease of the main phase transition of the liposomes. In case of liposomes based on dipalmitoylphosphatidylcholine/-glycerol, phase transition was close or even below body temperature. In contrast, if phospholipids with longer fatty acid chains (distearoylphosphatidylcholine/-glycerol) were used, phase transitions were well above body temperature even at high drug load. Size and thermal behavior were not distinctly influenced by the addition of pegylated lipids but cryo-electron microscopic investigations indicate the presence of micellar structures in addition to vesicles. Lyophilization and reconstitution led to an alteration in the morphology but had overall no distinct influence on the colloidal stability. 2010 Elsevier B.V. All rights reserved.

  4. Modelling carcinogenesis after radiotherapy using Poisson statistics: implications for IMRT, protons and ions.

    Science.gov (United States)

    Jones, Bleddyn

    2009-06-01

    Current technical radiotherapy advances aim to (a) better conform the dose contours to cancers and (b) reduce the integral dose exposure and thereby minimise unnecessary dose exposure to normal tissues unaffected by the cancer. Various types of conformal and intensity modulated radiotherapy (IMRT) using x-rays can achieve (a) while charged particle therapy (CPT)-using proton and ion beams-can achieve both (a) and (b), but at greater financial cost. Not only is the long term risk of radiation related normal tissue complications important, but so is the risk of carcinogenesis. Physical dose distribution plans can be generated to show the differences between the above techniques. IMRT is associated with a dose bath of low to medium dose due to fluence transfer: dose is effectively transferred from designated organs at risk to other areas; thus dose and risk are transferred. Many clinicians are concerned that there may be additional carcinogenesis many years after IMRT. CPT reduces the total energy deposition in the body and offers many potential advantages in terms of the prospects for better quality of life along with cancer cure. With C ions there is a tail of dose beyond the Bragg peaks, due to nuclear fragmentation; this is not found with protons. CPT generally uses higher linear energy transfer (which varies with particle and energy), which carries a higher relative risk of malignant induction, but also of cell death quantified by the relative biological effect concept, so at higher dose levels the frank development of malignancy should be reduced. Standard linear radioprotection models have been used to show a reduction in carcinogenesis risk of between two- and 15-fold depending on the CPT location. But the standard risk models make no allowance for fractionation and some have a dose limit at 4 Gy. Alternatively, tentative application of the linear quadratic model and Poissonian statistics to chromosome breakage and cell kill simultaneously allows estimation of

  5. Physicochemical processes and wastes in the ocean

    International Nuclear Information System (INIS)

    O'Connor, T.P.

    1987-01-01

    This is volume two of the Oceanic Processes in Marine Pollution series. This volume emphasizes physical and chemical processes associated with wastes disposed of into the ocean. Physical processes include dilution, dispersion, and mixing wastes. Chemical processes include adsorption kinetics, binding of metals, and bioavailability of radioactive materials. This book also examines vertical transport of wastes and the role of marine organisms in the transport of waste materials

  6. Physico-chemical quality of boreholes in Densu Basin of Ghana

    Science.gov (United States)

    Amoako, J.; Karikari, A. Y.; Ansa-Asare, O. D.

    2011-09-01

    Physico-chemical characteristics of 74 boreholes from communities within Densu Basin were assessed following procedures outlined in Standard Methods for the Examination of Water and Wastewater. The aim was to assess the status of the boreholes water quality for any contamination for management action to ensure the quality of health of the people in the area. The water quality parameters analyzed included conductivity, pH, turbidity, color, major ions, nutrients, and metals. The study showed that most of the physico-chemical constituents were within the WHO guideline limits. pH values ranged from 6.0 to 8.21, while conductivity varied between 117 and 3,500 μS/cm and turbidity from 0.6 to 19.0 NTU. However, a few of the parameters fell outside the limits prescribed by the World Health Organization (WHO 2004). Fourteen, 9, and 7% of the boreholes exceeded the WHO guideline values for nitrate (NO3), fluoride (F-) and iron (Fe), respectively. Locations where high concentration of Fe and Mn occurred, efforts must be made to remove them to discourage the use of surface waters which may be contaminated by harmful bacteria.

  7. Prediction of ecotoxicity of hydrocarbon-contaminated soils using physicochemical parameters

    Energy Technology Data Exchange (ETDEWEB)

    Wong, D.C.L.; Chai, E.Y.; Chu, K.K.; Dorn, P.B.

    1999-11-01

    The physicochemical properties of eight hydrocarbon-contaminated soils were used to predict toxicity to earthworms (Eisenia fetida) and plants. The toxicity of these preremediated soils was assessed using earthworm avoidance, survival, and reproduction and seed germination and root growth in four plant species. No-observed-effect and 25% inhibitory concentrations were determined from the earthworm and plant assays. Physical property measurements and metals analyses of the soils were conducted. Hydrocarbon contamination was characterized by total petroleum hydrocarbons, oil and grease, and GC boiling-point distribution. Univariate and multivariate statistical methods were used to examine relationships between physical and chemical properties and biological endpoints. Soil groupings based on physicochemical properties and toxicity from cluster and principal component analyses were generally similar. Correlation analysis identified a number of significant relationships between soil parameters and toxicity that were used in univariate model development. Total petroleum hydrocarbons by gas chromatography and polars were identified as predictors of earthworm avoidance and survival and seed germination, explaining 65 to 75% of the variation in the data. Asphaltenes also explained 83% of the variation in seed germination. Gravimetric total petroleum hydrocarbons explained 40% of the variation in earthworm reproduction, whereas 43% of the variation in plant root growth was explained by asphaltenes. Multivariate one-component partial least squares models, which identified predictors similar to those identified by the univariate models, were also developed for worm avoidance and survival and seed germination and had predictive powers of 42 and 29%, respectively.

  8. Effects of wet torrefaction on the physicochemical properties and pyrolysis product properties of rice husk

    International Nuclear Information System (INIS)

    Zhang, Shuping; Chen, Tao; Xiong, Yuanquan; Dong, Qing

    2017-01-01

    Highlights: • Wet torrefaction of rice husk prior to pyrolysis was applied. • Wet torrefaction has the dual advantages of dry torrefaction and demineralisation. • Wet torrefaction at the mild reaction condition promoted the production of bio-oil. • Biochar produced can be used as the feedstock for preparation of nanosilica. - Abstract: Wet torrefaction in the temperature range from 150 to 240 °C for 60 min was applied on rice husk sample prior to pyrolysis process in this work. Its effects on the physicochemical properties and pyrolysis product properties were evaluated. The analysis results of physicochemical properties of raw and pretreated samples indicated that wet torrefaction not only improved the fuel characteristics but also removed a large amount of alkali and alkaline earth metal species with the dual advantages of dry torrefaction and demineralisation. On the basis of pyrolysis experiment results, it was found that wet torrefaction at the mild reaction condition had a positive impact on bio-oil production, but more severe wet torrefaction condition was not reasonable. The highest relative content of levoglucosan (57.2%) was obtained from pyrolysis of rice husk sample after wet torrefaction at 210 °C, which was about 6.2 times higher than that of raw rice husk. The results of biochar analysis suggested that biochar produced from sample after wet torrefaction and pyrolysis seems not a desirable solid fuel, it can be used as the feedstock for preparation of nanosilica.

  9. Daily physicochemical, microbiological and ecotoxicological fluctuations of a hospital effluent according to technical and care activities.

    Science.gov (United States)

    Boillot, C; Bazin, C; Tissot-Guerraz, F; Droguet, J; Perraud, M; Cetre, J C; Trepo, D; Perrodin, Y

    2008-09-15

    The problem of hospital effluents falls into the framework of hazardous substances due to the specific substances used and discharged for the most part into urban drainage networks without prior treatment. This in-depth study has led to greater understanding of the effluents discharged by hospitals. The experimental program implemented consisted in carrying out parallel sampling of the effluents of one hospital: a 24 h-average sample and 5 periodic samples corresponding to fractions of times and hospital activities. The samples were characterized by physicochemical, microbiological and ecotoxicological analyses. The results highlight that the effluents contained very little bacterial flora and a moderate organic pollution. However, a numerous of specific pollutants were detected: AOX, glutaraldehyde, free chlorine, detergents, Freon 113 as well as alcohols, acetone, formaldehyde, acetaldehyde, ammonium, phenols and several metals. The battery of bioassays showed that the effluents had a high level of ecotoxicity partly linked to particles in suspension and, that pollution fluctuated greatly during the day in connection with hospital activities. Finally, the PNEC values compared to the concentrations of pollutants dosed in the effluents highlighted that their toxicity was mainly due to several major pollutants, in particular free chlorine. Some hypotheses require additional experiments to be carried out. They concern: reactions of fermentations likely to occur in the drainage network and to form secondary toxic compounds, retention of chlorine by particles and physicochemical characterization of suspended solids.

  10. Trophically available metal - A variable feast

    International Nuclear Information System (INIS)

    Rainbow, Philip S.; Luoma, Samuel N.; Wang Wenxiong

    2011-01-01

    Assimilation of trace metals by predators from prey is affected by the physicochemical form of the accumulated metal in the prey, leading to the concept of a Trophically Available Metal (TAM) component in the food item definable in terms of particular subcellular fractions of accumulated metal. As originally defined TAM consists of soluble metal forms and metal associated with cell organelles, the combination of separated fractions which best explained particular results involving a decapod crustacean predator feeding on bivalve mollusc tissues. Unfortunately TAM as originally defined has subsequently frequently been used in the literature as an absolute description of that component of accumulated metal that is trophically available in all prey to all consumers. It is now clear that what is trophically available varies between food items, consumers and metals. TAM as originally defined should be seen as a useful starting hypothesis, not as a statement of fact. - Trophically Available Metal (TAM), the component of accumulated metal in food that is taken up by a feeding animal, varies with food type and consumer.

  11. Trophically available metal - A variable feast

    Energy Technology Data Exchange (ETDEWEB)

    Rainbow, Philip S., E-mail: p.rainbow@nhm.ac.uk [Department of Zoology, Natural History Museum, Cromwell Rd, London SW7 5BD (United Kingdom); Luoma, Samuel N. [Department of Zoology, Natural History Museum, Cromwell Rd, London SW7 5BD (United Kingdom); John Muir Institute of the Environment, University of California, Davis, CA 95616 (United States); Wang Wenxiong [College of Marine and Environmental Sciences, State Key Laboratory for Marine Environmental Sciences, Xiamen University, Fujian (China)

    2011-10-15

    Assimilation of trace metals by predators from prey is affected by the physicochemical form of the accumulated metal in the prey, leading to the concept of a Trophically Available Metal (TAM) component in the food item definable in terms of particular subcellular fractions of accumulated metal. As originally defined TAM consists of soluble metal forms and metal associated with cell organelles, the combination of separated fractions which best explained particular results involving a decapod crustacean predator feeding on bivalve mollusc tissues. Unfortunately TAM as originally defined has subsequently frequently been used in the literature as an absolute description of that component of accumulated metal that is trophically available in all prey to all consumers. It is now clear that what is trophically available varies between food items, consumers and metals. TAM as originally defined should be seen as a useful starting hypothesis, not as a statement of fact. - Trophically Available Metal (TAM), the component of accumulated metal in food that is taken up by a feeding animal, varies with food type and consumer.

  12. Head and neck cancer due to heavy metal exposure via tobacco smoking and professional exposure: A review

    International Nuclear Information System (INIS)

    Khlifi, Rim; Hamza-Chaffai, Amel

    2010-01-01

    Chronic exposures to heavy metals via tobacco smoking and professional exposure may increase the risk of head and neck cancer, although the epidemiologic evidence is limited by problems of low study power and inadequate adjustment for tobacco and professional exposure use. Numerous scientific reviews have examined the association of various heavy metals exposure with respiratory cancer as well as other cancer types, but few have been published on head and neck cancer. The purpose of this paper, therefore, is to review the head and neck tract cancer-related data on exposure to heavy metals via smoking and working exposure and to study the major mechanisms underlying some toxic metals carcinogenesis.

  13. Advances in Understanding How Heavy Metal Pollution Triggers Gastric Cancer

    Directory of Open Access Journals (Sweden)

    Wenzhen Yuan

    2016-01-01

    Full Text Available With the development of industrialization and urbanization, heavy metals contamination has become a major environmental problem. Numerous investigations have revealed an association between heavy metal exposure and the incidence and mortality of gastric cancer. The mechanisms of heavy metals (lead, cadmium, mercury, chromium, and arsenic contamination leading to gastric cancer are concluded in this review. There are four main potential mechanisms: (1 Heavy metals disrupt the gastric mucosal barrier by decreasing mucosal thickness, mucus content, and basal acid output, thereby affecting the function of E-cadherin and inducing reactive oxygen species (ROS damage. (2 Heavy metals directly or indirectly induce ROS generation and cause gastric mucosal and DNA lesions, which subsequently alter gene regulation, signal transduction, and cell growth, ultimately leading to carcinogenesis. Exposure to heavy metals also enhances gastric cancer cell invasion and metastasis. (3 Heavy metals inhibit DNA damage repair or cause inefficient lesion repair. (4 Heavy metals may induce other gene abnormalities. In addition, heavy metals can induce the expression of proinflammatory chemokine interleukin-8 (IL-8 and microRNAs, which promotes tumorigenesis. The present review is an effort to underline the human health problem caused by heavy metal with recent development in order to garner a broader perspective.

  14. Advances in Understanding How Heavy Metal Pollution Triggers Gastric Cancer.

    Science.gov (United States)

    Yuan, Wenzhen; Yang, Ning; Li, Xiangkai

    2016-01-01

    With the development of industrialization and urbanization, heavy metals contamination has become a major environmental problem. Numerous investigations have revealed an association between heavy metal exposure and the incidence and mortality of gastric cancer. The mechanisms of heavy metals (lead, cadmium, mercury, chromium, and arsenic) contamination leading to gastric cancer are concluded in this review. There are four main potential mechanisms: (1) Heavy metals disrupt the gastric mucosal barrier by decreasing mucosal thickness, mucus content, and basal acid output, thereby affecting the function of E-cadherin and inducing reactive oxygen species (ROS) damage. (2) Heavy metals directly or indirectly induce ROS generation and cause gastric mucosal and DNA lesions, which subsequently alter gene regulation, signal transduction, and cell growth, ultimately leading to carcinogenesis. Exposure to heavy metals also enhances gastric cancer cell invasion and metastasis. (3) Heavy metals inhibit DNA damage repair or cause inefficient lesion repair. (4) Heavy metals may induce other gene abnormalities. In addition, heavy metals can induce the expression of proinflammatory chemokine interleukin-8 (IL-8) and microRNAs, which promotes tumorigenesis. The present review is an effort to underline the human health problem caused by heavy metal with recent development in order to garner a broader perspective.

  15. Desempenho físico-químico de metais e estruturas de concreto de redes de distribuição de energia: estudo de caso na região de Manaus Physicochemical performance of metals and concrete structures used in electricity distribution networks: case study in Manaus region

    Directory of Open Access Journals (Sweden)

    Kleber Franke Portella

    2006-07-01

    Full Text Available The influence of natural aging furthered by atmospheric corrosion of parts of electric transformers and materials, as well as of concrete poles and cross arms containing corrosion inhibitors was evaluated in Manaus. Results for painted materials, it could showed that loss of specular gloss was more intensive in aliphatic polyurethane points than in acrylic polyurethane ones. No corrosion was observed for metal and concrete samples until 400 days of natural aging. Corrosion in steel reinforcement was noticed in some poles, arising from manufacturing faults, such as low cement content, water/cement ratio, thin concrete cover thickness, etc. The performance of corrosion inhibitors was assessed by many techniques after natural and accelerated aging in a 3.5% saline aqueous solution. The results show the need for better chemical component selection and its concentration in the concrete mixture.

  16. The Power Generation from Coal in Pakistan: Assessment of Physicochemical Pollutant Indicators in Indigenous Reserves in Comparison to the Foreign Coal

    OpenAIRE

    Ghazia Anjum; M. Nasiruddin Khan

    2017-01-01

    Electricity production through coal combustion is the only viable solution in minimum timing. As environmental chemists, our primary goal is to assess environmental hazards and suggest cost-effective technologies for reducing combustion pollutants. In the present study, indigenous coal samples from different mines were analyzed for their physicochemical properties and toxic metals. Five samples from foreign coal mines were also studied for comparison purposes and already in use for power gen...

  17. Relationship between physico-chemical characteristics and potential toxicity of PM10.

    Science.gov (United States)

    Megido, Laura; Suárez-Peña, Beatriz; Negral, Luis; Castrillón, Leonor; Suárez, Susana; Fernández-Nava, Yolanda; Marañón, Elena

    2016-11-01

    PM10 was sampled at a suburban location affected by traffic and industry in the north of Spain. The samples were analysed to determine the chemical components of PM10 (organic and elemental carbon, soluble chemical species and metals). The aim of this study was to assess the toxicity of PM10 in terms of the bulk analysis and the physico-chemical properties of the particles. Total carbon, sulphates, ammonium, chlorides and nitrates were found to be the major constituents of PM10. The contribution of the last of these was found to increase significantly with PM10 concentration (Pearson coefficient correlation of 0.7, p-value major risk to human health. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Synthesis and physicochemical properties of uranyl molybdate complexes of ammonium, potassium, rubidium, and cesium ions

    International Nuclear Information System (INIS)

    Fedoseev, A.M.; Budantseva, N.A.; Shirokova, I.B.; Yurik, T.K.; Andreev, G.B.; Krupa, Zh-K.

    2001-01-01

    Effect of experimental conditions on composition and intimacy of yield of crystal phases in the UO 2 MoO 4 -M 2 MoO 4 -H 2 O system, where M is cation of alkali metal or ammonium, is studied. The compounds of morphotropic raw with overall formula M 2 UO 2 (MoO 4 ) 2 ·H 2 O, where M=K, Ru, Cs, NH 4 , are synthesized by hydrothermal method from aqueous solutions at 160-180 Deg C. The dependence of composition and certain physico-chemical properties of the binary uranyl molybdates is investigated from the nature of out-spherical cation as well as IR-spectra and thermal behavior of synthesized compounds are inspected [ru

  19. Physico-chemical characteristics of sulfated mixed oxides of Sn with some rare earth elements

    International Nuclear Information System (INIS)

    Jyothi, T.M.; Mirakar, S.P.; Sreekumar, K.; Sugunan, S.; Talawar, M.B.

    2000-01-01

    A series of binary mixed oxides of tin with three rare earth elements viz. La, Ce and Sm were prepared by coprecipitation method and sulfate treatment was performed by treating the mixed hydroxides with sulfuric acid or ammonium sulfate. The physico-chemical characterization has been done by XRD, BET-SA, SEM, EDX, TG-DTA and IR spectroscopy. Adsorption of n-butylamine was used to probe the acidic properties of the catalysts. The strength and distribution of acid sites depend on the mixed metal oxide composition, as well as on the preparation method. The rare earth modified sulfated tin oxide catalysis are more active in the oxidative dehydrogenation of cyclohexanol and cyclohexane, compared to the corresponding mixed oxide systems and sulfated tin oxide. Among the different sulfated oxide systems investigated, cerium promoted catalysts displayed a better selectivity towards dehydrogenation products. (author)

  20. Understanding Alterations in Cell Nano-architecture during Early Carcinogenesis using Optical Microscopy

    Science.gov (United States)

    Damania, Dhwanil

    Carcinogenesis is a complex multi-step process which eventually results in a malignant phenotype that often progresses into a fatal metastatic stage. There are several molecular changes (e.g. DNA methylation, activation of proto-oncogenes, loss of tumor-suppressor genes, histone acetylation) that occur in cells prior to the microscopically detectable morphological alterations. Hence, it is intuitive that these molecular changes should impact various biochemical, biophysical and transport processes within the cell and therefore its nanoscale morphology. Furthermore, recent studies have established that apparently `normal' cells (i.e., away from the actual tumor location) undergo similar genetic/epigenetic changes as the actual cancer cells, giving rise to the phenomenon of field carcinogenesis. Unfortunately, traditional microscopy or histopathology cannot resolve structures below 300 nm due to diffraction-limited resolution. Hence, we developed a novel optical imaging technique, partial wave spectroscopic (PWS) microscopy or optical nanocytology which quantifies the nanoscale refractive-index fluctuations (i.e. mass-density variations such as chromatin compaction) in an optically measured biomarker, disorder strength (Ld). This dissertation proves the nanoscale sensitivity of PWS nanocytology and shows that increase in Ld parallels neoplastic potential of a cell by using standardized cell-lines and animal-models. Based on concept of field carcinogenesis, we employ PWS nanocytology in a multi-center clinical study on approximately 450 patients in four different cancer-types (colon, ovarian, thyroid and lung) and we illustrate that nanoscale disorder increase is a ubiquitous phenomenon across different organs. We further demonstrate the potential of PWS nanocytology in predicting risk for developing future neoplasia. Biologically, we prove that cytoskeletal organization in both nucleus and cytoplasm plays a crucial role in governing L d-differences. Moreover, we