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•Fluoride may disrupt thyroid function in pregnant women.•Fluoride exposure was associated with alterations in maternal thyroid hormone levels.•Urinary fluoride was associated with ...significantly higher TSH among those pregnant with females.•Adjustment for maternal iodine status did not change the results.
Fluoride exposure may increase the risk of hypothyroidism, but results from previous studies are inconsistent at low-level fluoride exposure (i.e., ≤0.7 mg/L). Human studies of fluoride and thyroid hormone levels in pregnancy are scarce.
We examined associations between fluoride exposure and maternal thyroid hormone levels in a Canadian pregnancy cohort, with consideration for fetal sex-specific effects.
We measured fluoride concentrations in drinking water and spot urine samples collected during each trimester from 1876 pregnant women enrolled in the Maternal-Infant Research on Environmental Chemicals (MIREC) study. We also measured maternal thyroid stimulating hormone (TSH), free thyroxine (FT4), and total thyroxine (TT4) levels during the first trimester of pregnancy. We used linear and non-linear regression models to estimate associations between fluoride exposure and levels of TSH, FT4, and TT4. We explored effect modification by fetal sex and considered maternal iodine status as a potential confounder.
A 1 mg/L increase in urinary fluoride was associated with a 0.30 (95 %CI: 0.08, 0.51) logarithmic unit (i.e., 35.0 %) increase in TSH among women pregnant with females, but not males (B = 0.02; 95 %CI: −0.16, 0.19). Relative to women with urinary fluoride concentrations in the first quartile (0.05–0.32 mg/L), those with levels in the third quartile (0.49–0.75 mg/L) had higher FT4 and TT4 (i.e., inverted J-shaped associations), but the association was not statistically significant after adjustment for covariates (p = 0.06). Water fluoride concentration showed a U-shaped association with maternal FT4, whereby women with water fluoride concentrations in the second (0.13–0.52 mg/L) and third (0.52–0.62 mg/L) quartiles had significantly lower FT4 compared to those with levels in the first quartile (0.04–0.13 mg/L). Adjustment for maternal iodine status did not change the results.
Fluoride exposure was associated with alterations in maternal thyroid hormone levels, the magnitude of which appeared to vary by fetal sex. Given the importance of maternal thyroid hormones for fetal neurodevelopment, replication of findings is warranted.
While fluoride can have thyroid-disrupting effects, associations between low-level fluoride exposure and thyroid conditions remain unclear, especially during pregnancy when insufficient thyroid ...hormones can adversely impact offspring development.
We evaluated associations between fluoride exposure and hypothyroidism in a Canadian pregnancy cohort.
We measured fluoride concentrations in drinking water and three dilution-corrected urine samples and estimated fluoride intake based on self-reported beverage consumption. We classified women enrolled in the Maternal-Infant Research on Environmental Chemicals Study as euthyroid (n = 1301), subclinical hypothyroid (n = 100) or primary hypothyroid (n = 107) based on their thyroid hormone levels in trimester one. We used multinomial logistic regression to estimate the association between fluoride exposure and classification of either subclinical or primary hypothyroidism and considered maternal thyroid peroxidase antibody (TPOAb) status, a marker of autoimmune hypothyroidism, as an effect modifier. In a subsample of 466 mother-child pairs, we used linear regression to explore the association between maternal hypothyroidism and child Full-Scale IQ (FSIQ) at ages 3-to-4 years and tested for effect modification by child sex.
A 0.5 mg/L increase in drinking water fluoride concentration was associated with a 1.65 (95 % confidence interval CI: 1.04, 2.60) increased odds of primary hypothyroidism. In contrast, we did not find a significant association between urinary fluoride (adjusted odds ratio aOR: 1.00; 95%CI: 0.73, 1.39) or fluoride intake (aOR: 1.25; 95%CI: 0.99, 1.57) and hypothyroidism. Among women with normal TPOAb levels, the risk of primary hypothyroidism increased with both increasing water fluoride and fluoride intake (aOR water fluoride concentration: 2.85; 95%CI: 1.25, 6.50; aOR fluoride intake: 1.75; 95%CI: 1.27, 2.41). Children born to women with primary hypothyroidism had lower FSIQ scores compared to children of euthyroid women, especially among boys (B coefficient: −8.42; 95 % CI: −15.33, −1.50).
Fluoride in drinking water was associated with increased risk of hypothyroidism in pregnant women. Thyroid disruption may contribute to developmental neurotoxicity of fluoride.
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•Fluoride may disrupt thyroid function.•Thyroid dysfunction in pregnancy can adversely impact offspring development.•Fluoride in water increased risk of hypothyroidism in pregnant women.•Boys had lower IQ scores if their mothers were hypothyroid in pregnancy.•Thyroid disruption may contribute to developmental neurotoxicity of fluoride.
Social and cultural capital are critical components of success among college students. In this paper, we examine the creation, accumulation, and distribution of social and cultural capital by and ...among underserved college students who participated in a summer bridge program at one regional public state university. Using qualitative data from interviews with participants, the analysis highlights the importance of trust, sense of belonging and use of noncognitive strategies. We argue that in addition to traditional achievement measures such as GPA and test scores, social and cultural capital need to be considered. While quantitative measures often label these students as below benchmarks, this study highlights how social and cultural capital are assets to be nurtured and facilitated.
This study examined how exposure to a computer-generated, avatar-based environment influences student composition of an essay in response to a writing prompt. Drawing on the distinctions between ...firsthand and secondhand experiences, this article sketches an ecological model of writing that attempts to explain why students exposed to an avatar-based environment wrote first-person essays in the present tense, whereas students exposed to a comparable web page-based environment wrote third-person essays in the past tense.
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Dostopno za:
BFBNIB, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Since several studies indicated that farmers and agricultural workers had an excess risk of brain cancer, the National Institute for Occupational Safety and Health initiated the Upper Midwest Health ...Study to examine risk of intracranial glioma in the non-metropolitan population. This population-based, case-control study evaluated associations between gliomas and rural and farm exposures among adults (ages 18 to 80) in four upper midwestern states (Iowa, Michigan, Minnesota, Wisconsin). At diagnosis/selection, participants lived in non-metropolitan counties where the largest population center had fewer than 250,000 residents. Cases were diagnosed 1 January 1995 through 31 January 1997. Over 90% of 873 eligible ascertained cases and over 70% of 1670 eligible controls consented to participate. Participants and nonparticipants, evaluated for "critical questions" on main and refusant questionnaires, differed significantly in farming and occupational experience, ethnicity, education, and lifestyle. The 1,175 controls were more likely than the 798 cases to have reported ever drinking alcohol (77% vs. 73%, adjusted odds ratio (OR) 0. 73, 95% confidence interval (CI) 0.59-0.92) and having had panoramic dental x-rays (34% vs. 29%, OR 0. 75, CI 0.61-0.92). Controls spent a greater percentage of their lives in non-metropolitan counties (78% vs. 75%, OR 0.81, CI 0.67-1.09). Among ever-farmers, controls were more likely to have had exposure to farm insecticides (57% vs. 50%, OR 0.75, CI 0.59-0.95) and farm animals (96% vs. 91%, OR 0.48, CI 0.25-0.90). Moving to a farm as an adolescent (ages 11 to 20) vs. as an adult was associated with a greater risk of glioma. In our study sample, farm or rural residence and summary farm exposures were associated with decreased glioma risk. However, nonparticipation by never-farming eligible controls could have affected results. Comparisons of farm chemical exposures may clarify associations between farming and glioma that others have reported.
The relation of carbon disulphide (CS2) exposure to risk factors for ischaemic heart disease was recently examined using data from a 1979 cross sectional study of 410 male textile workers, of whom ...165 were exposed and 245 were unexposed to CS2. Average eight hour CS2 exposure concentrations ranged from 0.6 to 11.8 ppm by job title category among the exposed workers. A significant and positive linear trend in low density lipoprotein cholesterol concentration (LDLc) and diastolic blood pressure with increasing CS2 exposure was found after adjustment for potential confounders. When exposure was examined as a categorical variable (none, low, moderate, and high), the high exposure group had an adjusted mean LDLc that was 0.32 mmol/l greater than the non-exposed group (p = 0.02), and an adjusted mean diastolic blood pressure that was 3.16 mm Hg greater than the non-exposed group (p = 0.09). The effect of CS2 on diastolic blood pressure was strengthened in analyses limited to exposed workers: the high exposure group had an adjusted mean diastolic blood pressure that was 5 mm Hg greater than that of the low exposed group (p = 0.03). Triglyceride, high density lipoprotein cholesterol, and fasting glucose concentration, and systolic blood pressure were not affected by exposure. Blood lead concentration was positively associated with systolic and diastolic blood pressure. The results indicate that relatively modest exposure to CS2 may raise LDLc concentration and diastolic blood pressure and suggest mechanisms by which exposure to CS2 may influence risk of ischaemic heart disease. Also the results provide further support for the hypothesis of a possible association between blood lead concentration and blood pressure.
Garth Drabinsky, chairman and CEO of Livent Inc, is preparing to restore the legenday Oriental Theater in Chicago. A profile of Darbinsky is presented.
A profile of Toronto Raptors forward Marcus Camby is offered. Only in his second season in the NBA, Camby has already been the subject of scandal for accepting gifts from prospective agents when he ...was still a senior at the University of Massachusetts.
As UMass advanced to the Final Four in New Jersey, Wesley Spears paid for Camby's mother to buy a new dress and purse. "Sure, it was all a mistake," Camby says, insisting that the off-court hoopla ...did not affect his play during his teams 81-74 loss against Kentucky in the semifinal game. A few days after the defeat, Camby visited Spears in West Hartford. As they talked about the season and his future, Spears offered $1,000 in cash. Camby accepted. "That was the only time I took anything directly from him," Camby says. "It was stupid." No-one told Spears. The lawyer arranged his own session, in New York, where promotional opportunities for Camby would be discussed with potential sponsors. A few days later, Todd Glasco took a call from Spears and broke the news: Camby would not be choosing him as his agent. Spears erupted. As police described the conversation, Spears told Glasco that "he had $75,000 invested in Camby and his friends, and Camby promised him face to face he would sign with him... He also told Glasco that he had Camby on video taking money from him and witnesses from clothing stores. According to Glasco, Spears insisted that refusing to select him as Camby's agent will result in a lawsuit 'that will tarnish Camby's image...and UMass will get in trouble.'" In mid-May, Spears persisted, calling Camby, Tamia Murray, and Todd Glasco to a meeting at his house. Once again, Glasco delivered the news, telling Spears that the basketball star had already selected ProServ, of Washington, D.C., to represent him. Spears boiled over in anger. In his version to the police, Glasco quoted Spears as telling Camby, "You told me you are going to sign with me, and you are going to sign with me. If Todd wasn't here, I wouldn't be even talking with you. I would serve your new agent lawsuit papers and it would be in the newspapers.
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