Preferencje help
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 26

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
2
100%
Public feelings concerning radiation are still controversy. The main sources of trouble seems to be the failure nuclear power plant and danger of terroristic attack, which may cause temporally enhanced level of radiation leading to harmful health effects. Since radiation induced cellular damage is attributed primarily to harmful effect of free radicals, molecules with direct free radical scavenging properties are particularly promising as radiation modifiers/protectors, i.e. agents which present prior to or shortly after radiation exposure alter to response of tissues to radiation. Unfortunately, some of known radioprotectors are toxic at doses required for radioprotection. Resveratrol (RSV), an natural polyphenol is produced in several plants in response to injury, stress, bacteria or fungi infection, UV-irradiation and exposure to ozone. It is present in human diet i.e. in fruits and in wine. RSV is known for its antioxidant, anti-inflammatory, analgesic, antiviral, cardioprotective, neuroprotective and antiageing action and it has been shown to have chemopreventive effects with respect to several human disease such as cardiovascular disease, osteoporosis and gastric ulcers. Depending on the dose, RSV may act as antioxidant or as pro-oxidant. RSV improves sperm count and motility in rodents and prevent DNA damage caused by cryptopreservation of human sperm. Moreover, RSV acting with other agents, inhibits the toxic action of them. There are evidences that RSV is able to modulate the behavior of cells in response to radiation induced damage. Minimalization of radiation induced damage to somatic and germ cells by RSV might be useful in cancer therapy to prevent the damage to normal cells as well as in case of radiological accidents.
The NATO Science Programme joining in the celebration of 50th Anniversary of Founding of the NATO by organisation of NATO Advanced Study Institute „Human Monitoring after Environmental and Occupational Exposure to Chemical and Physical Agents", which was held in Tekirova-Antalya (Turkey), September 23-October 3,1999. The director of ASI was dr Diana Anderson from TNO-BIBRA (UK). The members of Scientific Organizing Committee were also dr R. Sram (Czech Republik), dr A. Karakaya (Turkey), Dr P. O'Neill (USA), dr R. Bos (Netherlands), dr M. Lotti (Italy). It was a high-level tutorial course for scientists at the post-doctoral level from NATO countries and from NATO Cooperation Partner countries. NATO-ASI attended about 100 scientists from about 30 countries. There were 40 lectures, 20 oral presentations and 43 posters presented, 19 authors of posters were invited to additional short oral presentations. Subject of course concerned undesirable effects of chemical and physical agents on human health. The aim of NATO-Advanced Study Institute was the meeting of scientists working in different fields of science to present and discuss the knowledge and recent developments in the field of human monitoring. The majority of lectures concerned about biomonitoring of people exposed to genotoxic agents at work place and environment. Dr A. Autio (Switzerland) presented definitions of different kinds of bimarkers proposed by The Committee on Biological Markers in Environmental Healths of USA Academy of Science/National Research Council. Dr D. Anderson (UK) introduced history of biomonitoring. The main lecturers on this topic were dr W. Au (USA), dr R. Sram (Czech Republik), dr M. Lotti (Italy), dr J. Timbell (USA), Dr E. Moustacchi (France). The following group of lectures presented by dr D. Anderson (UK), dr A. Wyrobek (USA), dr J. Bonde (Dennmark), dr H. Norppa (Finland) was regarded to male-mediated mutagenic effect in offspring induced by genotoxic physical and chemical agents. This part of course was the most interesting to the author of this report. She has presented the poster „Male-mediated F1 effects in mice subchronic exposed to low doses of X-rays". The author of this report found NATO-ASI as very fruitful initiative for scientific view-exchange between scientists from NATO countries and for NATO Cooperation Partner countries.
Wprowadzenie. Nonylofenol (NF) występuje w produktach codziennego użytku zawierających polichlorek winylu (PCV). Narażenie ludzi na nonylofenol związane jest z jego obecnością w wodzie wodociągowej i żywności. Promieniowanie jonizujące pochodzi ze źródeł naturalnych oraz sztucznych, stosowanych szczególnie w medycynie oraz w nauce i przemyśle. Oba czynniki występują powszechnie w środowisku człowieka, dlatego ekspozycja na ich skojarzone działanie wydaje się wielce prawdopodobne. Cel badań. Celem badań było określenie wpływu subchronicznego podawania samcom myszy nonylofenolu oraz poddawania ich skojarzonemu działaniu promieniowania jonizującego i nonylofenolu na indukcję pęknięć nici DNA w komórkach somatycznych różnych narządów. Materiał i metoda. Materiał stanowiły myszy Pzh:SFIS, którym przez 8 tygodni, 5 razy w tygodniu podawano dootrzewnowo zawiesinę nonylofenolu w oleju słonecznikowym (25 mg/kg mc lub 50 mg/kg mc NF) lub poddawano je skojarzonemu działaniu promieniowania X i nonylofenolu (0,05 Gy + 25 mg/kg mc NF). Grupy zwierząt zabijano po 24 h oraz po 1, 4 i 8 tygodniach od zakończenia narażania. Z myszy izolowano szpik kostny, wątroby, nerki, płuca i śledziony. Oceny uszkodzeń DNA dokonano za pomocą testu kometowego. Wyniki. Na działanie nonylofenolu najbardziej wrażliwe okazały się limfocyty szpiku kostnego, mniej komórki śledziony i płuc. Nonylofenol nie indukował występowanie pęknięć nici DNA w komórkach wątroby i nerek. Ośmiotygodniowe skojarzone działanie promieniowania jonizującego i nonylofenolu w komórkach większości badanych narządów powodowało zwiększenie częstości występowania pęknięć nici DNA w porównaniu do skutków działania samego nonylofenolu. Spośród badanych komórek najbardziej wrażliwe na skojarzone działanie promieniowania jonizującego i nonylofenolu (0.05 Gy + 25 mg/kg mc NF dziennie) okazały się limfocyty szpiku kostnego i komórki śledziony, a najmniej komórki nerek i płuc. Wnioski. Nonylofenol indukuje uszkodzenia materiału genetycznego limfocytów szpiku kostnego oraz komórek śledziony i płuc. Skojarzone działanie promieniowania jonizującego i nonylofenolu powoduje występowanie pęknięć nici DNA limfocytów szpiku kostnego, komórek wątroby, płuc, śledziony i nerek, ze znacznie większą częstością niż sam nonylofenol. Uszkodzenia te mogą być więc stymulowane przez promieniowanie.
Phthalates are widely present in human environment. Widespead exposure to those agents, which are compounds of numerous daily use products, is unavoidable. In the current paper following phthalates benzylbutyl phthalate (BBP), din- butyl phthalate (DBP), di(2-ethylhexyl)phthalate (DEHP), diethyl phthalate (DEP), di-isononyl phthalate (DINP) are described. Phthalates mainly enter to the composition of plastic goods, like boxes and containers for storage of foods, toys, medical devices, and also cosmetics, personal care products, as well as paints, vanishes, printing inks. This paper describes the occurence of individual phthalates in the environment (water, air) and in different products. During production, transportation, manufacturing of goods and improper disposal, phthalates released into soil, water and air. For example indoor air included 13 mg/m3 phthalates, where 72 % of all constitutes DEP (2.29 mg/m3), BBP (3.97 mg/m3) and DEHP (2.43 mg/m3). Exposure to phthalates take place mainly by ingestion or inhalation air or through the skin. Presence of phthalates were observed in numerous food products and is connected with migration of those compounds from food storage containers to preserved food. They could mirgate to salivia during sucking and chewing of toys and this way increased exposure to of children. The results of studies regarding to concentration of phthalates in human tissues and excretions are also described. The level of phthalates were measured in numerous of human biological samples. For example, DEHP, DEP and DBP were detected at levels of 5.71 mg/L in blood serum, of 0.30 mg/L in semen and of 0.72 mg/kg in fat samples.
The general exposure to endocrine disruptors, including phthalates, is considered as one of the reason diminished sperm count and deteriorated sperm quality, which may lead to infertility and higher incidence of congenital malformations of the genital tract. This article describes the effects of selected phthalates di(2-ethylhexyl)phthalate (DEHP), dibutyl phthalate (DBP); butylbenzyl phthalate (BBP), diethyl phthalate (DEP), di-isononyl phthalate (DINP) on the male gametes, reproduction and the offspring of exposed animals. Results of several papers in vitro showed that above mentioned phthalates are weakly estrogenic, whereas in vivo studies showed that they have rather antiandrogenic abilities. Review of papers regarding to laboratory animals confirmed that phthalates cause diminished sperm count, increased frequency of abnormal spermatozoa and DNA damage in germ cells, especially after chronic exposure and in case exposure of immature animals. Phthalates may induce in male gametes mutations leading to increased pre- and postnatal mortality of the offspring and to incidence of congenital malformations, growth retardation, delay in sexual development, shortening of anogenital distance in males, disturbances in sex ratio and diminished quality of semen in F1 generation. The sensitivity on mammalian life stages on phthalates seems to be as follows: fetal>peripubertal>adult. The human studies provided limited evidence of an association between phthalate exposure and semen quality. Concentration of phthalates in semen of men at the level from 0.08 to 1.32 mg/kg was related to declined semen quality and infertility. Majority of human data showed the connection of increased level of phthalates in urine and sperm quality, however on the basis results of other studies, the impact of environmental exposure on sperm parameters seems to be rather small.
Celem pracy było określenie indukcji mikrojąder w retikulocytach i erytrocytach polichromatycznych myszy pod wpływem subchronicznej ekspozycji na promieniowanie X, nonylofenol (NF) lub na skojarzone działanie obu czynników. Myszy Pzh: SFIS narażane były przez 8 tygodni, 5 razy w tygodniu. Dawki wynosiły 0.05 Gy lub 0,10 Gy promieniowania X, 25 mg/kg mc lub 50 mg/kg mc nonylofenolu, a w przypadku skojarzonego działania 0,05 Gy + 25 mg/kg mc NF lub 0,10 Gy + 50 mg/kg mc NF. Zarówno promieniowania X, jak i NF działając oddzielnie indukowały powstawanie mikrojąder w retikulocytach i erytrocytach polichromatycznych myszy. Skojarzone działanie obu czynników w retikulocytach krwi obwodowej oraz w erytrocytach polichromatycznych szpiku kostnego indukowało zwiększoną częstość występowania mikrojąder w porównaniu do efektów działania każdego z czynników oddzielnie. W retikulocytach szpiku kostnego skojarzone działanie obu czynników w małych dawkach (0,05 Gy + 50 mg/kg mc NF) powodowało zwiększenie efektu mutagennego. Natomiast, w przypadku skojarzenia obu czynników w większych dawkach (0,10 Gy + 50 mg/kg mc NF), nonylofenol może wywierać efekt ochronny w stosunku do DNA retikulocytów powodując zmniejszenie uszkodzeń indukowanych przez promieniowanie X.
Maria Skłodowska was born on November 7, 1867 in Warsaw (Poland). Her parents were teachers. Maria’s mother has died in 1878 of tuberculosis. In 1893 and 1894, respectively, Maria was awarded master’s degrees in physics and in mathematics from the Sorbonne University. In 1895 Maria married Pierre Curie. In 1897 their daughter Irene was born. Maria investigated rays emitted by uranium salts. She hypothesized that the radiation come from atom and called this phenomenon “radioactivity”. In 1898, Maria and Pierre discovered new radioactive elements polonium and radium. In 1902 she isolated pure radium chloride and defined radium atomic mass. In June 1903, Maria supervised by Professor Lippmann was awarded her doctorate in physics from the Sorbonne University of Paris after presentation of the thesis “Investigation of radioactive bodies”. In December 1903, Maria was awarded the Nobel Prize in Physics, along with her husband Pierre and Henri Becquerel, for their work on radioactivity. In 1904, the daughter Eve was born. On 19 April 1906, Pierre was killed in a road accident in Paris. In 1910 Maria isolated radium as a pure metal. She also defined an international standard for radioactive emissions (curie), published her fundamental results on radioactivity and textbook of radiology. She also defined the international pattern of radium. In 1911, she won her second Nobel Prize, this time in Chemistry, for her discovery of radium and polonium. In 1914 she was appointed director in the Radium Institute in Paris. During World War I, Maria became the director of the Red Cross Radiology Service and set up France’s first military radiology centre. In May 1932 she has attended the official opening ceremony of the Radium Institute in Warsaw. On 4 July 1934, Maria Skłodowska-Curie has died aged 66 years in Sancellemoz sanatorium (France) of aplastic anemia.
Przedstawiono wyniki dotyczące zmian morfologicznych plemników myszy po ekspozycji spermatogonii na promieniowanie X lub cyklofosfamid oraz na skojarzone działanie obu czynników.
Ionizing radiation may cause damage to living tissue by producing free radicals like reactive oxygen species (ROS). ROS can randomly react with lipids, proteins and nucleic acids of cell causing oxidative stress and damage in these macromolecules, leading to pathogenesis of chronic diseases and age related and also cancer. The first line of defense from the damaging effects of ROS is antioxidants, which convert the oxidants to less reactive species. Lycopene (LYC) is an acyclic isomer of beta-carotene. It synthesized by plants or autotrophic bacteria but not by animals. Red fruits and vegetables, including tomatoes, watermelons, pink grapefruits, apricots, pink guavas and papaya contain LYC. This carotenoid has very strong antioxidant properties. The many studies confirm that dietary supplementation with LYC reduces risk of cancers of many organs, but also retard the growth of the tumors. LYC has also chemopreventive effects against other diseases such as cardiovascular disease, osteoporosis, male infertility and inhibits the toxic action of other agents. Numerous in vitro and animal studies showed that LYC may provide protection against damages induced by ionizing radiation. It suggests that supplementation of LYC might be useful in diminishing of negative effect of cancer radiotherapy or in mitigating the effects of possible radiation accidents on human health.
Dokonano oceny wpływu promieniowania X, nonylfenolu oraz skojarzonego działania obu czynników na indukcją mikrojąder w retikulocytach krwi obwodowej i szpiku kostnego oraz w erytrocytach polichromatycznych szpiku kostnego myszy
Celem pracy było zbadanie wpływu bisfenolu A oraz skojarzonego działania promieniowania X i bisfenolu A na indukcję mikrojąder w retikulocytach krwi obwodowej i szpiku kostnego samców myszy. Myszy Pzh:Sfis przez 2 tygodnie napromieniano promieniowaniem X (0,05 Gy i 0,10 Gy) lub podawano im bisfenol A (5 mg/kg mc, 10 mg/kg mc, 15 mg/kg mc, 20 mg/ kg mc, 40 mg/kg mc) lub poddawano skojarzonemu działaniu obu czynników (0,05 Gy + 5 mg/kg mc BPA lub 0,10 Gy + 10 mg/kg mc BPA). Bisfenol A i promieniowanie X zastosowane osobno stymulowały powstawanie mikrojąder w retikulocytach szpiku kostnego i krwi obwodowej. Skojarzone działanie promieniowania X i bisfenolu A zwiększało częstość występowania mikrojąder w porównaniu do efektów notowanych w następstwie działania samego bisfenolu A. Niekiedy, szczególnie po zastosowaniu skojarzenia obu czynników w małych dawkach, efekty skojarzonego działania przewyższały również rezultaty uzyskane po działaniu samego promieniowania jonizującego. Promieniowanie jonizujące jest prawdopodobnie czynnikiem decydującym o pękaniu lub nierównomiernej dystrybucji chromosomów w wyniku skojarzonego działania z bisfenolem A, który jest słabszym mutagenem.
Niniejsza praca jest przeglądem piśmiennictwa dotyczącego toksycznego, mutagennego i kancerogennego działania butadienu i jego metabolitów.
Lutein and zeaxanthin are naturally occurring xanthophylls, mainly present in green, leafy vegetables and egg’s yolk. Their presence is connected with blue spectrum light absorbance, including UV. This property, and fact, that these xanthophylls are accumulated by human eye’s macula, leads to eye’s protective functions of them including protection from age-related macular degeneration (AMD). Also, antioxidative features of lutein and zeaxanthin are boosting overall health of human body. Numerous studies proves anti-inflammatory and protective attributes of these compounds, based on many, different mechanisms. One of them is regulating redox potential in cells, and impact on expression of linked genes. In preventing of eye diseases, an important gene that is regulated by lutein and zeaxanthin is the Nrf2 gene, whose increased activity leads to optimizing the cellular response to reactive oxygen species (ROS) and preventing related diseases. Other research confirms antiproliferative properties of mentioned compounds in case of certain human cancer cell lines. There are e.g.: HepG2 (hepatitis cancer), MCF-7 (breast cancer), which treated in vitro with lutein solution showed reduction of cell growth. Lutein alone, during in vivo studies conducted on mice, exhibited also radioprotective properties, positively affecting the vitality of animals. Lutein provides also increasing of tolerance to UV radiation, reducing inflammatory processes in the skin and preventing oncogenesis. Low intake of lutein and zeaxanthin, associated with “western diet”, rich in simple carbohydrates and processed food, common in developed countries, including Poland, is linked with diabetes and obesity incidence. Assuming, lutein and zeaxanthin significantly affect the well-being of the human body, and their appropriate amount in diet can help reduce risk of many diseases. For supplementation, the optimized dosage of these xanthophylls includes doses of 10 mg for lutein and 2 mg for zeaxanthin, and it is recommended to consume along with fats or meals rich in fats.
Background. Ionizing radiation (IR) carry adequate energy to ionize or remove electrons from an atom. Particles interact with water to produce reactive oxygen species (ROS). Genistein (GEN) is a naturally occurring phytoestrogen and the basic isoflavonoid in soybeans and soybean-enriched products and is believed to have the strongest antioxidant activity. Objective. The study aimed at the investigation if application of GEN at different time prior or past irradiation may ameliorate or reduce injury of DNA in human lymphocytes. Material and Methods. The isolated lymphocytes were exposed to X-irradiation (0.5; 1 Gy). GEN (1 μM/ml; 10 μM/ ml) was appended to attempts at various times prior or past irradiation (1 h prior, immediately prior, immediately past, 1 h past). We joined each X-rays dose with each GEN dose. After 1h of incubation DNA damages were examined using Comet assay. Results. Combination of 1 μM/ml of GEN given 1 h before irradiation with low or high dose markedly decreased induced by irradiation DNA injury. Higher dose of GEN applied immediately before or after irradiation markedly extended the frequency of DNA injury generated by irradiation. The result of application 1 μM/ml GEN 1 h after irradiation was not significantly different compared to control. The effect of 1 Gy + 10 μM/ml GEN was not significantly lower compared to each agent alone. Conclusions. Only a very low concentration of GEN applied before irradiation, may be considered as a potential radiomitigator/radioprotector. High doses of GEN work as a radiosentitizer and may potent the effects of radiotherapy.
Zbadano wpływ narażenia samców myszy na różne dawki winblastyny oraz na skojarzone dawki promieniowania X i winblastyny na ilość i jakość ich gamet oraz na płodność, występowanie zgonów wewnątrzmacicznych oraz wad wrodzonych u potomstwa.
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 2 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.