How did we eliminate the hazards of water-borne excessive iodine in northern China?

Drinking water is the main cause of iodine excess among Chinese residents and we have found that water iodine concentration (WIC) reduction was the effective intervening measure. In this study, to eliminate the hazards of water-borne excessive iodine, we firstly investigated the WIC of villages in Tianjin in 2017 to determine the distribution range. Secondly, the risk characterization of excessive iodine on residents in 6∼< 9 years old, 9∼< 12 years old, 12∼< 15 years old, 15∼< 18 years old and adults were evaluated, and the safe upper limit of WIC was determined. Finally, WIC was investigated again after the completion of WIC reduction in water-borne excessive-iodine villages in 2020, and the differences in urinary iodine concentration (UIC) and thyroid volume (Tvol) of children aged 8-10 years before and after WIC reduction were analyzed. The WIC of 2459 villages surveyed was 22.30 (8.60-58.80) µg/L and the maximum was 514 µg/L. There were 422 villages with WIC > 100 µg/L. Under the conditions of non-iodized salt intake, recommended amount of iodized salt intake and actual amount intake, the maximum of excessive iodine exposure hazard quotient (HQ) were the highest in the age group of 6∼< 9 years, which were 2.300, 2.663 and 2.771, the safe upper WIC limits were 223 µg/L, 142 µg/L and 118 µg/L and villages with HQ> 1 accounted for 4.14%, 6.09% and 6.88% of all villages, respectively. After the WIC reduction, the WIC of the former water-borne iodine-excess villages decreased to < 100 µg/L, and the UIC and Tvol of children decreased (both P < 0.001) and was within normal range. Determining the distribution range of water-borne iodine-excess areas, exploring appropriate intervening measure, carrying out risk assessment, determining the WIC safe upper limit, intervening and evaluating the intervention effect can be the process to eliminate the hazards of water-borne excessive iodine.

Modifying effects of green space on the relationships between air pollution and ischemic cerebrovascular event recurrence in Tianjin, China.

This study aimed to explore how air pollution and green space influence ICE recurrence and whether they might interact with each other. A case-cross design was used in this study, which was carried out in Tianjin, China. A total of 8306 patients with recurrent ICE were collected from 2019 to 2020. The maximum effects of PM2.5, PM10, SO2, NO2, CO were 1.012 (95%CI: 1.004, 1.019), 1.010 (95%CI: 1.004, 1.016), 1.035 (95%CI: 0.982, 1.091), 1.067 (95%CI: 1.043, 1.091) and 1.012 (95%CI: 1.004, 1.021) , respectively, and the risk was higher in males and in the 50-60 age group. In the stratification of greening, it was found that air pollution except O3 had the highest risk of ICE recurrence for those with lower green space. Our study found that air pollution (except O3) can increase the risk of ICE recurrence, and this risk can be reduced by increasing green space.

NiH-Catalyzed Proximal-Selective Hydroamination of Unactivated Alkenes with Anthranils.

The regioselective hydroamination of unactivated alkenes is a long-standing challenge in organic synthesis. Herein, we report a NiH-catalyzed proximal-selective hydroamination of unactivated alkenes with 8-aminoquinoline (AQ) as a bidentate auxiliary and anthranils as aminating reagents. A wide range of primary aryl amines bearing an ortho-carbonyl group were installed in both terminal and internal unactivated alkenes, delivering a variety of valuable ß- and γ-amino acid building blocks, respectively, with excellent regiocontrol. The utility of this transformation was further demonstrated by the conversion of the multifunctionalized aryl amines into useful N-heterocycles.

Iodine in household cooking salt no longer plays a crucial role in iodine status of residents in Tianjin, China.

PURPOSE: The contribution of household cooking salt to population iodine status is decreasing in China, the applicability of the coverage rate of iodized salt (IS), proportion of adequately iodized salt (AIS), and salt iodine concentration (SIC) of household cooking salt used for iodine status assessment of residents requires further investigation. METHODS: Through the IDD control project, 16,445 children and 4848 pregnant women were recruited from Tianjin, China and the relationship between the coverage rate of IS, proportion of AIS, SIC, and population iodine status was analyzed. Additionally, through the thyroid health survey project, 856 children with IS or noniodized salt were recruited. The effects of different household cooking salts on individual iodine status and thyroid health were analyzed. RESULTS: After adjusting for confounding factors, no relationship was found between the coverage rate of IS, proportion of AIS, SIC of household cooking salt, and iodine status of children and pregnant women (all P > 0.05). No differences in levels of thyroid function and structural indicators were found in children with different household cooking salts (all P > 0.05). Additionally, no relationship was found between noniodized salt exposure and goiter, overt hyperthyroidism, overt hypothyroidism, thyroid nodules, antibody single positivity, or subclinical hypothyroidism (all P > 0.05). CONCLUSION: Iodine in household cooking salt no longer plays a crucial role in iodine status in Tianjin, China. Other indicators must be identified as beneficial supplements for precise iodine status evaluation not only in Tianjin but also in other large cities in China.

Nickel-Catalyzed Hydroamination of Olefins with Anthranils.

A nickel-catalyzed polarity-reversed hydroamination of olefins has been achieved with anthranils as the electrophilic aminating agents and hydrosilane as the reductant. This protocol provides a facile access to N-alkyl-2-aminobenzophenones that are versatile intermediates in organic synthesis. A wide range of olefins and anthranils are compatible in this transformation, delivering the desired amines in useful to excellent yields (38 examples, up to 92% yield). The utility of this protocol is exhibited in the late-stage functionalization of drug molecules and the valuable derivatives of the obtained amination products.

Optimal empiric treatment for KPC-2-producing Klebsiella pneumoniae infections in critically ill patients with normal or decreased renal function using Monte Carlo simulation.

BACKGROUND: Limited clinical studies describe the pharmacodynamics of fosfomycin (FOS), tigecycline (TGC) and colistin methanesulfonate (CMS) in combination against KPC-producing Klebsiella pneumoniae (KPC-Kp). Population pharmacokinetic models were used in our study. Monte Carlo simulation was conducted to calculate probability of target attainment (PTA) and cumulative fraction of response (CFR) of each agent alone and in combination against KPC-Kp in patients with normal or decreased renal function. RESULTS: The simulated regimen of FOS 6 g q8h reached ≥90% PTA against a MIC of 64 mg/L in patients with normal renal function. For patients with renal impairment, FOS 4 g q8h could provide sufficient antimicrobial coverage against a MIC of 128 mg/L. And increasing the daily dose could result to the cut-off value to 256 mg/L in decreased renal function. For TGC, conventional dosing regimens failed to reach 90% PTA against a MIC of 2 mg/L. Higher loading and daily doses (TGC 200/400 mg loading doses followed by 100 mg q12h/200 mg q24h) were needed. For CMS, none achieved 90% PTA against a MIC of 2 mg/L in normal renal function. Against KPC-Kp, the regimens of 200/400 mg loading dose followed by 100 q12h /200 mg q24h achieved > 80% CFRs regardless of renal function, followed by CMS 9 million IU loading dose followed by 4.5/3 million IU q12h in combination with FOS 8 g q8h (CFR 75-91%). CONCLUSIONS: The use of a loading dose and high daily dose of TGC and CMS in combination with FOS can provide sufficient antimicrobial coverage against critically ill patients infected with KPC-Kp.

Fluoride exposure, dopamine relative gene polymorphism and intelligence: A cross-sectional study in China.

BACKGROUND: Excessive fluoride exposure is related to adverse health outcomes, but whether dopamine (DA) relative genes are involved in the health effect of low-moderate fluoride exposure on children's intelligence remain unclear. OBJECTIVES: We conducted a cross-sectional study to explore the role of DA relative genes in the health effect of low-moderate fluoride exposure in drinking water. METHODS: We recruited 567 resident children, aged 6-11 years old, randomly from endemic and non-endemic fluorosis areas in Tianjin, China. Spot urine samples were tested for urinary fluoride concentration, combined Raven`s test was used for intelligence quotient test. Fasting venous blood were collected to analyze ANKK1 Taq1A (rs1800497), COMT Val158Met (rs4680), DAT1 40 bp VNTR and MAOA uVNTR. Multivariable linear regression models were used to assess associations between fluoride exposure and IQ scores. We applied multiplicative and additive models to appraise single gene-environment interaction. Generalized multifactor dimensionality reduction (GMDR) was used to evaluate high-dimensional interactions of gene-gene and gene-environment. RESULTS: In adjusted model, fluoride exposure was inversely associated with IQ scores (ß = -5.957, 95% CI: -9.712, -2.202). The mean IQ scores of children with high-activity MAOA genotype was significantly lower than IQ scores of those with low-activity (P = 0.006) or female heterozygote (P = 0.016) genotype. We detected effect modification by four DA relative genes (ANKK1, COMT, DAT1 and MAOA) on the association between UF and IQ scores. We also found a high-dimensional gene-environment interaction among UF, ANKK1, COMT and MAOA on the effect of IQ (testing balanced accuracy = 0.5302, CV consistency: 10/10, P = 0.0107). CONCLUSIONS: Our study suggests DA relative genes may modify the association between fluoride and intelligence, and a potential interaction among fluoride exposure and DA relative genes on IQ.

The cholinergic system, intelligence, and dental fluorosis in school-aged children with low-to-moderate fluoride exposure.

Disruption of cholinergic neurotransmission can affect cognition, but little is known about whether low-to-moderate fluoride exposure affects cholinergic system and its effect on the prevalence of dental fluorosis (DF) and intelligence quotient (IQ). A cross-sectional study was conducted to explore the associations of moderate fluoride exposure and cholinergic system in relation to children's DF and IQ. We recruited 709 resident children in Tianjin, China. Ion selective electrode method was used to detect fluoride concentrations in water and urine. Cholinergic system was assessed by the detection of choline acetyltransferase (ChAT), acetylcholinesterase (AChE) and acetylcholine (ACh) levels in serum. Compared with children in the first quartile, those in fourth quartile the risk of either developing DF or IQ < 120 increased by 19% and 20% for water and urinary fluoride. The risk of having both increased by 58% and 62% in third and fourth quartile for water fluoride, 52% and 65% for urinary fluoride. Water fluoride concentrations were positively associated with AChE and negatively associated with ChAT and ACh, trends were same for urinary fluoride except for ACh. The risk of either developing DF or having non-high intelligence rose by 22% (95%CI: 1.07%, 1.38%) for the fourth quartile than those in the first quartile of AChE, for having the both, the risk was 1.27 (95%CI: 1.07, 1.50), 1.37 (95%CI: 1.17, 1.62) and 1.44 (95%CI: 1.23, 1.68) in second, third and fourth quartiles. The mediation proportion by AChE between water fluoride and either developing DF or IQ < 120 was 15.7%. For both to exist, the proportion was 6.7% and 7.2% for water and urinary fluoride. Our findings suggest low-to-moderate fluoride exposure was associated with dysfunction of cholinergic system for children. AChE may partly mediate the prevalence of DF and lower probability of having superior and above intelligence.

Stopping the supply of iodized salt alone is not enough to make iodine nutrition suitable for children in higher water iodine areas: A cross-sectional study in northern China.

BACKGROUND: For the sake of children's health, iodized salt supply has been stopped in many areas with excessive iodine in the drinking water, but children's iodine nutrition status and thyroid function after terminating the iodized salt supply is unknown. Objective We assessed the iodine nutrition, thyroid function and influencing factors for thyroid abnormalities in children from areas with different concentrations of water iodine; the supply of iodized salt has been stopped in high water iodine areas. This study aimed to evaluate whether the strategy of stopping the supplies of iodized salt alone is enough to avoid thyroid dysfunction in all areas with excess water iodine while still meeting the iodine nutrition needs of children. METHODS: A cross-sectional study was conducted in children from four areas with different drinking water iodine concentrations in Tianjin, China. The drinking water samplings and spot urine samples were collected to estimate the external and internal iodine exposure levels. The thyroid volume was measured, and blood samples were collected to assess thyroid function. Logistic regression analysis was used to analyze risk factors for thyroid abnormalities. A dietary survey was conducted to determine the sources of iodine nutrition among the areas with different iodine concentrations in the drinking water. RESULTS: In the area with a drinking water iodine concentration ≥300 µg/L, the median urinary iodine concentration (UIC) in children was 476.30 (332.20-639.30) µg/L, which was higher than that in other groups (all P < 0.05), and the prevalence of thyroid nodules and the thyroid goiter rate were higher than those in the <100 µg/L, 100-150 µg/L and 150-300 µg/L areas (all P < 0.01). Binary logistic regression analysis indicated that the risk of thyroid abnormalities was significantly increased in the UIC 200-299 µg/L group (OR: 4.534; 95% CI: 1.565, 13.135; bootstrapped 95% CI: 1.689, 21.206, P = 0.004) and in the UIC ≥ 300 µg/L group (OR: 6.962; 95% CI: 2.490, 19.460; bootstrapped 95% CI: 2.838, 32.570, P = 0.001) compared to the 100-199 µg/L group. The iodine contribution rates from water in areas with water iodine concentrations ≥300 µg/L are up to 63.04%. CONCLUSIONS: After termination of the iodized salt supply, the level of iodine nutrition of children in the area with drinking water iodine concentrations ≥300 µg/L is still excessive. The water source needs to be replaced in this area. In the area with a water iodine concentration of 150-300 µg/L, it is proposed that stopping the supply of iodized salt is sufficient to achieve the proper iodine nutrition status in children.

The role of long non-coding RNAs in multiple myeloma.

Multiple myeloma (MM) is still an incurable disease, and its pathogenesis involves cytogenetics and epigenetics. In recent years, the roles of long non-coding RNAs (lncRNAs) in MM have been deeply studied by scholars. LncRNAs are defined as a class of non-protein-coding transcripts greater than 200 nucleotides in length, which are involved in a large spectrum of biological processes, including proliferation, differentiation, apoptosis, invasion, and chromatin remodeling. However, little is known about the specific mechanisms of these lncRNAs. They can act as oncogenic and/or tumor-suppressive factors in the development and progression of MM. But that how do they work remains unclear. In this review, the recent progress in the study of functional lncRNAs associated with MM was summarized and the present knowledge about their expression and roles was discussed, to provide guidance for the in-depth functional study of lncRNAs.

3-Methyladenine alleviates excessive iodine-induced cognitive impairment via suppression of autophagy in rat hippocampus.

Drinking water with high levels of iodine has been identified as the key contributor to iodine excess, but the mechanisms of neurotoxicity induced by excessive iodine remain elusive. The present study aimed to explore the role of autophagy in the neurotoxic effect induced by excessive iodine in vivo. The Morris water maze test results demonstrated that excessive iodine impaired the learning and memory capabilities of rats, which were associated with marked body weight and brain weight abnormalities. In addition, iodine treatment increased malondialdehyde accumulation, decreased superoxide dismutase activity and glutathione (GSH) level, and enhanced levels of autophagy markers in the hippocampus. Notably, inhibition of autophagy with 3-methyladenine (3-MA) could significantly alleviate excessive iodine-induced cognitive impairment. These data imply that autophagy is involved in the cognitive impairment elicited by excessive iodine as a pathway of cell death, and inhibition of autophagy via 3-MA may significantly alleviate the above damage.

Comparative Analysis of miRNA Expression Profiles of Multiple Myeloma with 1q21 Gains and Normal FISH.

BACKGROUND: Multiple myeloma (MM) with 1q21 gains invariably has a poor prognosis. Many recent studies have reported the relationship between micro (mi)RNA expression and MM prognosis. However, there is little information on the association between miRNA alterations and 1q21 gains. METHODS: We compared the miRNA expression profiles of MM with 1q21 gains and MM with normal fluorescence in situ hybridisation (FISH) by gene expression array. Differentially expressed miRNAs were identified using Affymetrix TAC software. Thresholds were defined as a false discovery rate <0.05, p value <0.05, and n-fold change >2. RESULTS: Six miRNAs (let-7f-5p and -7g-5p, and miR-29a-3p, -29b-1-5p, -331-3p, and -223-3p) were downregulated and 4 (miR-30e-5p, -17-3p, -18b-5p, and -19a-3p) were upregulated in MM with 1q21 gains relative to MM with normal FISH. CONCLUSIONS: The identified set of miRNAs can serve as biomarkers for distinguishing MM with 1q21 gains from MM with normal FISH.

Dopamine receptor D2 gene polymorphism, urine fluoride, and intelligence impairment of children in China: A school-based cross-sectional study.

OBJECTIVE: We aimed to study the association of urine fluoride with intelligence quotient (IQ) in children with a careful consideration of up to 30 potential confounding factors as well as possible heterogeneity of the relation between urine fluoride levels and IQ scores across children with different dopamine receptor-2 (DRD2) Taq 1A genotypes (CC, CT, and TT). METHODS: A school-based cross-sectional study design was applied. A total of 323 children (2014-2015, 7-12 years old) were enrolled from four schools in both historical endemic and non-endemic areas of fluorosis in Tianjin of China using a cluster sampling method. Urine fluoride levels and age-specific IQ scores in children were measured at the enrollment. Polymerase chain reaction-restriction fragment length polymorphism methods were used to genotype DRD2 Taq 1A polymorphism with genomic DNA isolated from whole blood collected at the enrollment. Multiple linear regression models were applied to evaluate the relationship between urine fluoride levels and IQ scores overall and within the DRD2 Taq 1A SNP = CC/CT and TT subgroups. Model robustness was tested through bootstrap, sensitivity analysis, and cross-validation techniques. A safety threshold of urine fluoride levels for IQ impairment was determined in the subgroup TT. RESULTS: In overall participants, the DRD2 Taq 1A polymorphism itself was not related to IQ scores in children who had a high level of urine fluoride. In the CC/CT subgroup, urine fluoride levels and IQ scores in children were unrelated (adjusted ß (95% confidence interval (CI)) = - 1.59 (- 4.24, 1.05), p = 0.236). Among the participants carrying the TT genotype, there was a strong and robust negative linear relationship between log-urine fluoride and IQ scores in children (adjusted ß (95% CI) = - 12.31 (- 18.69, - 5.94), p < 0.001). Urine fluoride levels had a stronger association with IQ in children carrying the TT genotype (adjusted ß = - 12.31, bootstrapped standard error (SE) = 1.28), compared to that in overall participants (adjusted ß = - 2.47, bootstrapped SE = 3.75) (Z = 2.483 and bootstrapped p = 0.007). The safety threshold of urine fluoride levels in the subgroup TT was 1.73 mg/L (95% CI = (1.51, 1.97) (mg/L)). CONCLUSIONS: There is heterogeneity in the relation between urine fluoride and IQ across children carrying different DRD2 Taq 1A genotypes. Large-scale epidemiological studies are needed to confirm our findings.

Oxidative stress-mediated autophagic cell death participates in the neurotoxic effect on SH-SY5Y cells induced by excessive iodide.

Excessive iodide could induce intellectual damage in children, which has attracted broad attention. To investigate the neurotoxic effect of iodide and its mechanism, a human dopaminergic neuroblastoma cell line (SH-SY5Y) was treated with different concentrations of potassium iodide (KI). The results showed that excessive iodide could decrease cell viability, reduce glutathione (GSH) and superoxide dismutase (SOD), and increase the degree of autophagy (by changing the cellular ultrastructure and raising the autophagy-related mRNA and protein expression of LC3, Beclin1, and p62), which were correlated with the immunofluorescence labeling. Furthermore, treatment with the autophagy inhibitor 3-methyladenine (3MA), antioxidant N-acetylcysteine (NAC) and 30 mM KI for 24 h was conducted in the following research. 3MA significantly decreased autophagy-related mRNA and protein expression and improved cell viability, indicating that excess iodide induced autophagic cell death. In addition, oxidative stress regulated autophagy, reflected by the results that NAC decreased the mRNA and protein expression of LC3, Beclin1, and p62. In summary, autophagic cell death mediated by oxidative stress may participate in excessive iodide-induced SH-SY5Y cell death.

A Meta-Analysis of the Prevalence of Children Goiter in High Water Iodine Areas of China.

Although there are now a large number of studies confirming that high iodine levels can cause goiter, there is controversy and a lack of quantitative data. A systematic search of PubMed, Web of Science, China National Knowledge Infrastructure, Wanfang Database, and China Biomedical Database for literature on high iodine and goiter in children was performed with a time limit from January 2013 to October 2023. After screening the literature based on the inclusion criteria, extracting the literature data, and evaluating the risk of bias of the included studies, a single-arm meta-analysis was performed using R 4.0.4 software. Twenty-three studies with a total of 50,980 subjects were included. Meta-analysis showed that the prevalence of goiter among children in water-borne iodine-excess areas was 6.0% [95% CI (4.3%, 7.6%)], and subgroup analyses showed that the prevalence of goiter in children with water iodine 100.1-150 µg/L, 150.1-300 µg/L, and > 300 µg/L was 7.5% [95% CI (0.0%, 15.8%)], 5.5% [95% CI (3.1%, 8.0%)], and 10.2% [95% CI (6.7%, 13.6%)], respectively, and the difference was statistically significant (P < 0.01); The prevalence of goiter among children in the northern China (5.8% [95% CI (4.1%, 7.5%)]) was higher than that in the southern China (3.5% [95% CI (1.0%, 6.0%)]) (P < 0.01); the prevalence of goiter in children with urinary iodine levels 100-199 µg/L, 200-299 µg/L, and ≥ 300 µg/L was 2.4% [95% CI (1.9%, 2.9%)], 3.3% [95% CI (1.9%, 4.8%)], and 7.3% [95% CI (4.4%, 9.9%)], respectively, the difference was statistically significant (P < 0.01); the prevalence of goiter in children aged 8, 9, 10, 11, and 12 years old was 5.1% [95% CI (3.9%, 6.4%)], 8.0% [95% CI (4.0%, 11.9%)], 6.2% [95% CI (3.9%, 8.5%)], 5.5% [95% CI (0.0%, 13.2%)], and 5.4% [95% CI (0.0%, 15.1%)], and when age ≥ 9 years, the relationship between goiter prevalence and age showed a trend toward decreasing with age, but the relationship between different age was no statistical difference in the prevalence of goiter between ages. urinary iodine. The prevalence of goiter in children was higher in areas with high water iodine; the prevalence of goiter in children in the north was significantly higher than that in the south; the prevalence of goiter in children tends to increase with increased urinary iodine levels.

Fluoride-elicited developmental testicular toxicity in rats: roles of endoplasmic reticulum stress and inflammatory response.

Long-term excessive fluoride intake is known to be toxic and can damage a variety of organs and tissues in the human body. However, the molecular mechanisms underlying fluoride-induced male reproductive toxicity are not well understood. In this study, we used a rat model to simulate the situations of human exposure and aimed to evaluate the roles of endoplasmic reticulum (ER) stress and inflammatory response in fluoride-induced testicular injury. Sprague-Dawley rats were administered with sodium fluoride (NaF) at 25, 50 and 100mg/L via drinking water from pre-pregnancy to gestation, birth and finally to post-puberty. And then the testes of male offspring were studied at 8weeks of age. Our results demonstrated that fluoride treatment increased MDA accumulation, decreased SOD activity, and enhanced germ cell apoptosis. In addition, fluoride elevated mRNA and protein levels of glucose-regulated protein 78 (GRP78), inositol requiring ER-to-nucleus signal kinase 1 (IRE1), and C/EBP homologous protein (CHOP), indicating activation of ER stress signaling. Furthermore, fluoride also induced testicular inflammation, as manifested by gene up-regulation of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in a nuclear factor-κB (NF-κB)-dependent manner. These were associated with marked histopathological lesions including injury of spermatogonia, decrease of spermatocytes and absence of elongated spermatids, as well as severe ultrastructural abnormalities in testes. Taken together, our results provide compelling evidence that ER stress and inflammation would be novel and significant mechanisms responsible for fluoride-induced disturbance of spermatogenesis and germ cell loss in addition to oxidative stress.

Mitochondrial dysfunction and drug targets in multiple myeloma.

Multiple myeloma (MM) is the second most common hematological cancer that has no cure. Although currently there are several novel drugs, most MM patients experience drug resistance and disease relapse. The results of previous studies suggest that aberrant mitochondrial function may contribute to tumor progression and drug resistance. Mitochondrial DNA mutations and metabolic reprogramming have been reported in MM patients. Several preclinical and clinical studies have shown encouraging results of mitochondria-targeting therapy in MM patients. In this review, we have summarized our current understanding of mitochondrial biology in MM. More importantly, we have reviewed mitochondrial targeting strategies in MM treatment.

Reference Intervals for Thyroid Hormones and Thyroid Volume in Children Aged 7 ~ 13 Years from Iodine-Sufficient Areas in Tianjin, China.

Reference intervals (RIs) for serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3), and free thyroxine (FT4) suitable for local children are urgently needed in northern China. The reference interval for thyroid volume (Tvol) in Chinese children also differed greatly from that recommended by the WHO. This study aimed to establish TSH, FT3, FT4, and Tvol RIs suitable for children in northern China. A total of 1070 children aged 7 ~ 13 were recruited from iodine nutrition-sufficient areas in Tianjin, China, from 2016 to 2021. Four hundred fifty-eight children aged 7 ~ 13 years, and 815 children aged 8 ~ 10 years were eventually included to study RIs for the thyroid hormones and Tvol. RIs for thyroid hormones were established in accordance with the Clinical Laboratory Standards Institute (CLSI) document C28-A3 guidelines. Quantile regression was used to analyze the influencing factors of Tvol. RIs for TSH, FT3, and FT4 were 1.23 (1.14 ~ 1.32) to 6.18 (5.92 ~ 7.26) mIU/L, 5.43 (5.29 ~ 5.52) to 7.89 (7.66 ~ 7.98) pmol/L, and 13.09 (12.85 ~ 13.73) to 22.22 (21.61 ~ 22.51) pmol/L. There was no need to establish RIs by age and gender. Our RIs could increase the prevalence of subclinical hyperthyroidism (P < 0.001) and reduce the prevalence of subclinical hypothyroidism (P < 0.001). Body surface area (BSA) and age are correlated with the 97th percentile of Tvol (both P < 0.001). Our reference interval could increase the goiter rate in children from 2.97 to 4.96% (P = 0.007). The thyroid hormones' reference intervals suitable for local children should be established. In addition, BSA and age should be considered when establishing Tvol reference interval.

Association between dental fluorosis prevalence and inflammation levels in school-aged children with low-to-moderate fluoride exposure.

Inflammation mediates the neurological deficits caused by fluoride. Thus, whether inflammation is the underlying mechanism of dental fluorosis (DF) in school-aged children is worth exploring. A cross-sectional study was conducted to investigate the association between inflammation and the prevalence and severity of DF with low-to-moderate fluoride exposure. Fasting morning urine and venous blood samples were collected from 593 children aged 7-14 years. The fluoride content in the water and urine samples was measured using a fluoride ion-selective electrode assay. The levels of interleukin-1ß (IL-1ß) and C-reactive protein (CRP) were detected using an enzyme-linked immunosorbent assay. The Dean's index was used when performing dental examinations. Regression, stratified, and mediation analyses were performed to analyze the association between fluoride exposure, inflammation, and DF prevalence. In the adjusted regression models, the prevalence of mild DF was 1.723-fold (95% confidence interval [CI]:1.612, 1.841) and 1.594-fold (1.479, 1.717) greater than that of normal DF for each 1 mg/L increase in water and urinary fluoride content, respectively. The prevalence of mild DF increased by 3.3% for each 1 pg/mL increase in the IL-1ß level and by 26.0% for each 1 mg/L increase in the CRP level. Stratified analysis indicated a weaker association between fluoride concentration and DF prevalence in boys than in girls, and susceptibility in the boys was reflected by the association of IL-1ß with very mild and moderate DF prevalence. For every 1 mg/L increase in water and urinary fluoride levels, the proportion of IL-1ß-mediated effects on the prevalence of mild DF was 10.0% (6.1%, 15.8%) and 8.7% (4.8%, 15.2%), respectively, and the proportion of CRP-mediated effects was 9.2% (5.5%, 14.9%) and 6.1% (3.3%, 11.0%), respectively. This study indicates that the DF prevalence may be sex-specific. Inflammatory factors may partially mediate the increased prevalence of mild DF in school-aged children with low-to-moderate fluoride exposure.

[Studies of fluoride on the thyroid cell apoptosis and mechanism].

OBJECTIVE: To explore the toxic effect of fluoride on the human thyroid cells (Nthy-ori 3-1) and its mechanism. METHODS: Nthy-ori 3-1 cells were exposed to 0.0, 0.1, 1.0, 3.0 mmol/L of sodium fluoride (NaF) in vitro. After 24 hours incubation, 3 (4,5-Dimethylthiazol-z-yl)-3, 5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase (LDH) assay were used to measure cell viability and the LDH leakage rate. Reactive oxygen species (ROS) level, constituent ratio of the cell cycle, and apoptosis rate were measured by flow cytometry. RESULTS: Comparing to viability of control group (set as 100.00%), the cell viability of the 1.0, 3.0 mmol/L fluoride-treated groups (76.64 +/- 9.13)%, (64.04 +/- 6.32)% were significantly decreased (all P values <0.01). LDH leakage rate and ROS level of the 3.0 mmol/L fluoride-treated group ((48.66 +/-7.15)%, (29993.50 +/- 1786. 86) FI) were significantly increased (all P values <0.01) compared to control group ((35.24 +/- 3.02)%, (13021.33 +/- 1067.55) FI). The G0/G1 phase cells of the 1.0 mmol/L fluoride-treated group ((40.76 +/- 5.65)%) were lower than control group (60.09 +/- 1.76)% (P < 0.01), yet the percentage of cells in S phase ((54.05 +/- 4.59)%) were higher than the control group (32.59 +/- 2.43) % (P < 0.01). Comparing to control group ((9.64 +/- 3.44)%), the percentage of apoptosis cells increased in the 3.0 mmol/L fluoride-treated group ((20.09 +/- 3.22)%) (P < 0.01). CONCLUSION: To Nthy-ori 3-1 cells, fluoride under experimental concentrations decreases cell viability, improve the LDH leakage rate, and ROS level. It blocks the cells in S phase and induce cell apoptosis.