Дисертації з теми "Fluorides Physiological effect"

This study aimed to (1) review the reported levels of fluoride in drinking waters, food stuffs and other environmental media around the world, and the current magnitude of prevalence of fluorosis observed in human being and animals, with special reference to India and (2) critically evaluate the strategy adopted for prevention and control of the fluorosis problem in India by conducting questionnaire surveys with professionals from 11 endemic districts, and high school students of two schools located at an endemic area with high fluorosis incidences. Through a comprehensive literature review, it was able to identify 18 endemic states in India with high fluoride levels in their drinking waters while having various degrees of fluorosis problems. These states were further classified into three categories, namely high (>10 mg/L fluoride in drinking waters), moderate (5-9.9 mg/L) and low (1-4.9 mg/L) endemic regions. There were five, nine and four states falling into the high, moderate and low endemic categories, respectively. High fluoride concentrations were observed in the soil near industrial sites, foodstuffs and beverages, and tea leaves. Also, adverse effects of fluoride on terrestrial and aquatic plants, terrestrial vertebrates and invertebrates, and aquatic vertebrates and invertebrates, were observed and demonstrated in laboratory conditions. The questionnaire survey with Indian professionals in 11 fluoride endemic districts found that although all districts had received funds for combating fluorosis problems, there had been delays in executing the associated health promotion, monitoring and treatment programmes in some districts and the utilisation of the fund for the programmes was quite slow. Staff appointment, staff training, medical treatment provision, education and awareness activities, referral hospital facility provision, vehicle facility, monthly reporting, clinical survey and water and urine samples testing, timely monitoring and supervision, and involvement of various medical staff, were found to be inadequate in most districts. In the questionnaire survey conducted at the two high schools, one of the schools (school A) was supplied with alternate source of filtered water (i.e., with normal fluoride concentration) and the second school (school B) was one, which had non-defluoridated ground water supply for drinking (i.e., with high fluoride concentration). This survey found that the awareness about signs of fluorosis, field visit of health worker, cause and preventability of fluorosis, and perception of spread of fluorosis, was comparatively better amongst students of school A than that of school B. Both the schools’ students had positive attitude towards cooperation, prevention and control efforts being made for fluorosis.
published_or_final_version
Environmental Management
Master
Master of Science in Environmental Management

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
A opacidade de cápsula posterior (OCP) é a complicação tardia mais comum após a remoção da catarata. Caracteriza-se pelo desenvolvimento de uma nova barreira à passagem da luz, principalmente quando localizada no eixo óptico, promovendo perda gradativa da visão. Várias técnicas foram desenvolvidas com o intuito de se evitar a OCP. O objetivo deste trabalho foi avaliar o efeito do tratamento da superfície de LIOs acrílicas utilizando-se plasma de Flúor ou polietilenoglicol (PEG) na prevenção da OCP. Foram utilizados 40 olhos de coelhos, submetidos à cirurgia de facoemulsificação, e distribuídos em quatro grupos experimentais (n=10), sendo, grupo Controle (CG), coelhos sem implante de LIO; grupo com LIO tratada com plasma de polietilenoglicol (GPEG), grupo com LIO tratada com plasma de Flúor (GF), e grupo com LIO comercial (GL). As cápsulas posteriores das lentes dos grupos foram avaliadas por meio de análise histopatológica, incluindo morfometria e imunohistoquímica. Os grupos GPEG e GL apresentaram menor espessura da cápsula posterior na avaliação inicial (12 semanas) em relação ao controle. No período final de avaliação (seis meses), os tratamentos da superfície da LIO à base deplasma de flúor e polietilenoglicol não reduziram o desenvolvimento das alterações histológicas associadas à opacidade de cápsula posterior. O tratamento das superfícies das lentes intraoculares com plasma de flúor e polietilenoglicol pode ser realizado como adjuvante na prevenção da opacidade de cápsula posterior, pois não causa alterações na morfologia da lente após facoemulsificação
The posterior capsule opacification (PCO) is the most common late complication after cataract removal. It is characterized by the development of a new barrier to the passage of light, especially when located on the optical axis, promoting gradual loss of vision. Various techniques have been developed with the aim of preventing PCO. The objective of this study was to evaluate the effect of surface treatment of acrylic IOLs using Fluorine plasma or polyethylene glycol (PEG) in prevent for PCO. Forty rabbit eyes that underwent phacoemulsification were used and distributed into four experimental groups (n = 10): Control group (CG), rabbits without IOL implantation; IOL group treated with polyethylene glycol plasma (GPEG), IOL group treated with fluoride plasma (GF), and commercial IOL group (GL). The posterior capsule of the lens were evaluated by histopathological analysis, including morphometric and immunohistochemical studies. The GPEG and GL groups presented thinner posterior capsule at initial assessment (12 weeks) compared to control group. At the end of evaluation (six months), the treatment of IOL surface with fluorine and polyethylene glycol plasma did not reduce the development of histological changes associated with posterior capsule opacification. The surface treatment of IOLs with Fluoride and polyethylene glycol can be performed as an adjuvant in prevention PCO, because it does not cause changes in the morphology of lens after phacoemulsification surgery

Orientador: Cláudia Valéria Seullner Brandão
Banca: José Joaquim Titton Ranzani
Banca: Cláudia Helena Pellizon
Resumo: A opacidade de cápsula posterior (OCP) é a complicação tardia mais comum após a remoção da catarata. Caracteriza-se pelo desenvolvimento de uma nova barreira à passagem da luz, principalmente quando localizada no eixo óptico, promovendo perda gradativa da visão. Várias técnicas foram desenvolvidas com o intuito de se evitar a OCP. O objetivo deste trabalho foi avaliar o efeito do tratamento da superfície de LIOs acrílicas utilizando-se plasma de Flúor ou polietilenoglicol (PEG) na prevenção da OCP. Foram utilizados 40 olhos de coelhos, submetidos à cirurgia de facoemulsificação, e distribuídos em quatro grupos experimentais (n=10), sendo, grupo Controle (CG), coelhos sem implante de LIO; grupo com LIO tratada com plasma de polietilenoglicol (GPEG), grupo com LIO tratada com plasma de Flúor (GF), e grupo com LIO comercial (GL). As cápsulas posteriores das lentes dos grupos foram avaliadas por meio de análise histopatológica, incluindo morfometria e imunohistoquímica. Os grupos GPEG e GL apresentaram menor espessura da cápsula posterior na avaliação inicial (12 semanas) em relação ao controle. No período final de avaliação (seis meses), os tratamentos da superfície da LIO à base deplasma de flúor e polietilenoglicol não reduziram o desenvolvimento das alterações histológicas associadas à opacidade de cápsula posterior. O tratamento das superfícies das lentes intraoculares com plasma de flúor e polietilenoglicol pode ser realizado como adjuvante na prevenção da opacidade de cápsula posterior, pois não causa alterações na morfologia da lente após facoemulsificação
Abstract: The posterior capsule opacification (PCO) is the most common late complication after cataract removal. It is characterized by the development of a new barrier to the passage of light, especially when located on the optical axis, promoting gradual loss of vision. Various techniques have been developed with the aim of preventing PCO. The objective of this study was to evaluate the effect of surface treatment of acrylic IOLs using Fluorine plasma or polyethylene glycol (PEG) in prevent for PCO. Forty rabbit eyes that underwent phacoemulsification were used and distributed into four experimental groups (n = 10): Control group (CG), rabbits without IOL implantation; IOL group treated with polyethylene glycol plasma (GPEG), IOL group treated with fluoride plasma (GF), and commercial IOL group (GL). The posterior capsule of the lens were evaluated by histopathological analysis, including morphometric and immunohistochemical studies. The GPEG and GL groups presented thinner posterior capsule at initial assessment (12 weeks) compared to control group. At the end of evaluation (six months), the treatment of IOL surface with fluorine and polyethylene glycol plasma did not reduce the development of histological changes associated with posterior capsule opacification. The surface treatment of IOLs with Fluoride and polyethylene glycol can be performed as an adjuvant in prevention PCO, because it does not cause changes in the morphology of lens after phacoemulsification surgery
Mestre

Two factorial experiments were conducted to determine if high dietary fluoride would inhibit selenite toxicity in rats. In each study, two levels of selenite (0.05 and 5 mg/kg diet) were matched against two levels of fluoride (1 and 150 mg/kg diet) for either 6 or 8 weeks. Fluoride failed to prevent the depressive effect of selenite on food intake and body weight gain in either study. Although liver selenium concentration was slightly (15%) but significantly (P < 0.005) reduced when the highest fluoride and selenium level were combined in the first study, this effect could not be repeated. These three measures therefore failed to provide evidence for a fluoride and selenium interaction. Fluoride, however, prevented hepatic necrosis seen in most of the selenite-toxic rats. Hepatic lesions seen histologically in selenite-toxic rats were not observed for either kidney or heart. With regard to a possible mechanism for the fluoride effect upon selenite liver pathology, fluoride partially (26%) but significantly (P < 0.025) reduced thiobarbituricreactive substances (an indicator of peroxidative cell membrane damage) in selenite-toxic rats, but there was no fluoride effect on an enzyme system (liver xanthine oxidase) that potentially could generate an initiator of lipid peroxidation. In agreement with results of others, fluoride deposition into bone was inconsistently affected by selenite, Overall, the protective effect of fluoride on selenite toxicity appears to be confined to liver pathology. The exact mechanism for this effect, however, remains unclear.
Graduation date: 1992

Text in Afrikaans
Die tydruimtelike variasie in die fluoriedinhoud vannatuurlike drinkwater en in die voorkoms van tandfluorose, die verband tussen hierdie veranderlikes asook hulle kovariasie is op 'n hoe resolusievlak in geselekteerde endemiese gebiede ondersoek. Die drie studiegebiede verskil grootliks van mekaar wat sommige fisies- en menslik-geografiese kenmerke betref, maar ondergrondse water was oral die belangrikste bron van drinkwater. Ioonspesifieke analise en laboratoriumtegnieke is gebruik om die fluoriedinhoud van die drinkwater uit 517 bronne te bepaal. Die tande van 3 068 kinders is klinies en fotografies ondersoek. Die erkende Tooth Fluorosis Index en die indeks van Dean is gebruik om die voorkoms van fluorose te beskryf. Grafiese tegnieke, beskrywende statistieke en nieparametriese analise van variansietoetse is gebruik om die voorkoms en tydruimtelike variasiepatrone van die sleutelveranderlikes in elke studiegebied, asook die verskillende ruimtelike eenhede binne die studiegebiede, te beskryf. Die verband tussen die sleutelveranderlikes asook hul intra- en interareale kovariasie is ontleed. Daar is gevind dat die fluoriedinhoud van die ondergrondse water in die Pilanesberg- en Hammanskraal-studiegebied relatief hoog tot hoog is en die in die Vrystaat-studiegebied relatief laag. Ruimtelike veranderlikheid met groot verskille oor klein afstande kenmerk die fluoriedinhoud van ondergrondse water ongeag die gesteentes waaruit dit onttrek word. Middelwaardes bied ontoereikende beskrywings van die fluoriedgehalte van die drinkwater. Die skep van nuwe drinkwaterbronne veroorsaak langtermynvariasie in die fluoriedinhoud van die beskikbare drinkwater. Fluoroseprevalensie in die studiegebiede bet van 62% tot 87% gewissel, met meer ernstige aantasting in die Pilanesberg- en Hammanskraal-gebied as in die Suid-Vrystaat. Beduidende intra-areale ruimtelike variasie is 'n wesenlike kenmerk van die voorkoms van fluorose in al drie studiegebiede. In alle gevalle het die variasiepatroon in die fluoriedinhoud van die drinkwater die in die voorkoms van fluorose slegs gedeeltelik verklaar. Sporadiese en/of periodieke kortstondige blootstelling aan hoe fluoriedkonsentrasies lei tot emstige aantasting ten spyte van die gereelde gebruik van water met 'n laefluoriedinhoud. Ligte fluorose ontwikkel geredelik in assosiasie met <0,5 mgF-/l en matige fluorose in assossiasie met 0,5-0,7 mgF-/l, die optimum konsentrasieinterval vir fluoridasie in Suid-Afrika.
The spatiotemporal variation in the fluoride content of natural drinking water and the occurrence of dental fluorosis, the relation between these variables as well as their covariation were investigated at a high resolution level in selected endemic areas. Groundwater was the most important source of drinking water in all three study areas, but they differed markedly in respect of some physical and human geographical characteristics. Ion specific analysis and laboratory techniques were used to determine the fluoride content of the water from 517 sources. The teeth of 3 068 children were examined clinically and photographically. The fluorosis was scored according to the Tooth Fluorosis Index and Dean's classification. Graphical techniques, descriptive statistics and nonparametric analysis of variance were used to describe the occurrence and variation patterns of the key variables in the different spatial units is each study area. The relation between the variables as well as their intra and interareal covariation were analysed. The fluoride content of the groundwater in the Pilanesberg and Hammanskraal areas was relatively high to high; in the southern Free State it was relatively low. Spatial variability and significant differences over small distances typify the fluoride content of the groundwater, irrespective of the aquifer. Central statistics inadequately describe the fluoride quality of the natural drinking water. The development of new water sources causes long term variation in the fluoride content of the available drinking water. Fluorosis prevalence varied form 62% to 87%, with more severe fluorosis in Pilanesberg and Hammanskraal than in the southern Free State. Significant intra-areal spatial variation is an attribute of fluorosis in all three study areas. In all cases the variation pattern in the fluoride content of the drinking water partly explained the spatial pattern in the occurrence of fluorosis. Sporadic and/or periodic brief exposure to high fluoride concentrations leads to severe fluorosis despite regul~ usage of water with a low fluoride content. Mild fluorosis readily develops in association with <0,5 mgF-1~ and medium fluorosis in association with 0,5-0,7 mgF-/l, the optimum concentration interval for fluoridation in South Africa.
Geography
D. Phil. (Geografie)

Includes bibliographical references (leaves 232-247). Obtained information on dental caries and fluorosis among a representative sample of Vietnamese children. Also collected information on factors likely to influence caries experience and dental fluorosis and undertook statistical analyses to examine the relationship between fluoride in drinking water, dental caries and dental fluorosis

Obtained information on dental caries and fluorosis among a representative sample of Vietnamese children. Also collected information on factors likely to influence caries experience and dental fluorosis and undertook statistical analyses to examine the relationship between fluoride in drinking water, dental caries and dental fluorosis
Thesis (M.Sc.Dent.) -- University of Adelaide, Dental School, 2002

O flúor pertence ao grupo dos halogéneos da tabela periódica e é um elemento com elevada reatividade que está amplamente distribuído no meio ambiente sendo encontrado no solo, ar, rochas, alimentos e na água sob a forma de fluoretos. Por ter sido comprovada a sua eficácia na prevenção da cárie dentária, o flúor tem vindo a ser adicionado a produtos dentífricos, suplementos e à água. A fluoretação das águas foi primeiramente instituída nos EUA, sendo aceite pela Organização Mundial de Saúde (OMS), que estabeleceu um limite de 1,5 mg/L de fluoretos na água de consumo humano. No entanto, apesar dos benefícios da sua utilização, a ingestão excessiva pode acarretar efeitos tóxicos para o ser humano afetando diversos sistemas biológicos e estruturas orgânicas. Esta toxicidade pode dar-se de uma forma aguda ou crónica sendo que os efeitos adversos dependem de vários fatores como por exemplo, tempo de ingestão e quantidade ingerida, idade, presença de problemas cardiovasculares ou renais e alterações genéticas. Os efeitos adversos mais conhecidos da ingestão excessiva de flúor são a fluorose dentária e esquelética, estando também associados outros efeitos como défices cognitivos, citotoxicidade, hipotiroidismo, dislipidemias, alterações enzimáticas e eletrolíticas e cancro. A presente monografia visa abordar e compilar tanto os benefícios como os efeitos prejudiciais da ingestão de flúor na saúde humana com base em estudos científicos realizados nos últimos anos.
Fluorine belongs to the group of halogens of the periodic table and is an element with high reactivity that is widely distributed in the environment being found in soil, air, rocks, food and water in the form of fluorides. Due to its efficacy in prevention of dental caries, fluorine has been added to toothpaste, supplements and water. Water fluoridation was initially introduced in USA being accepted by the World Health Organization (WHO) that established a limit of 1.5 mg/L of fluoride in drinking water. However, despite of the benefits of its use, excessive intake can lead to toxic effects to several biological systems and organic structures. This toxicity can be acute or chronic, and its adverse effects depend on several factors such as ingestion period and ingested amount, age, presence of cardiovascular or renal problems and genetic alterations. The most common adverse effects of excessive fluoride intake are dental and skeletal fluorosis, with association with other effects like cognitive impairment, cytotoxicity, hypothyroidism, dyslipidemia, enzymatic and electrolyticchanges and cancer. This work aims the collection and discussion of the benefits as well as adverse effects of fluorine ingestion in human health based on scientific studies published in recent years.