Fetal Hypothyroidism and Maternal Thyroid Status in Severe Endemic Goiter*

Thilly, Claude Hector; Delange, François; Lagasse, Raphaël; Bourdoux, Pierre; Ramioul, Liliane; Berquist, H; Ermans, A. M.

doi:10.1210/jcem-47-2-354

Cited by 135 publications

(78 citation statements)

References 15 publications

(18 reference statements)

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The results of the present experiments show that this mechanism is indeed operative in the neonatal rat, because T3 was maintained within normal limits in the face of markedly decreased (<10% of The weight of the animals is given in Table V. IOP, 10 mg/100 g bw, was injected intraperitoneally 40 Table III. § P < 0.01 with respect to A.…”

Section: Resultsmentioning

confidence: 53%

Comparison of Iodothyronine 5′-Deiodinase and Other Thyroid-Hormone-dependent Enzyme Activities in the Cerebral Cortex of Hypothyroid Neonatal Rat

Silva¹,

Larsen²

1982

J. Clin. Invest.

118

View full text Add to dashboard Cite

A B S T R A C T Recent studies have shown that -75% of the nuclear 3,5,3'-triiodothyronine (T3) present in adult rat cerebral cortex (Cx) derives from 5'-deiodination of thyroxine (T4) within this tissue. The activity of iodothyronine 5'-deiodinase (I 5'D), the enzyme catalyzing T4 to T3 conversion, increases rapidly after thyroidectomy, suggesting that this could be a compensatory response to hypothyroxinemia. To evaluate this possibility during the period of central nervous system maturation, we studied several thyroid hormone-responsive enzymes (aspartic transaminase [AT], succinic dehydrogenase [S.D.], and Na/K ATPase) in the Cx of 2-, 3-, and 4-wk-old rats. The rats were made congenitally hypothyroid by placing 1, 2, 5, and 20 mg methimazole (MMI) in 100 ml of the mothers' drinking water from day 16 of gestation throughout the nursing period and to the litters after weaning. In addition, serum thyroid hormones, I 5'D, and, in some experiments, in vivo T4 to T3 conversion in Cx were measured in the same pups. Serum T4 concentrations varied from <1 to 40 ng/ml and were generally inversely related to maternal MMI dose. Serum T3 was less affected by MMI than was T4. At 2 wk, decreases in AT, S.D., and ATPase were present in the 20-mg-MMI group but not in the 5-mg-MMI pups despite low serum T4 (<10 ng/ml) in the latter. At 3 and 4 wk, both 5-and 20-mg-MMI groups had significant reductions in these cortical enzymes despite a normal serum T3 in the 5-mg-MMI rats. Cortical I 5'D activity was 10-fold the control value in 5-and 20-mg-MMI animals at 2 wk but increased only three-to fivefold at 3 and 4 wk. I 5'D correlated inversely with serum T4 (r 2 0.96) at all ages, but the less marked elevation of this enzyme in 3-and 4-wk-old pups was not accompanied by an increase in serum T4. Serum T3 increased or remained the same between 2 and 3 wk. These results suggested that the 10-fold increase in I 5'D at 2 wk protected the 5-mg-MMI group from tissue hypothyroidism, but that the three-to fivefold increase at 3 and 4 wk could not. Injection of -250 ng T4/100 g body weight to 2-wk-old, 20-mg-MMI pups (onesixth the normal T4 production rate) led to both a 1.8-ng/g cortical tissue increment in cortical T3 and a significant increase in AT at 24 h, compared with a 0.38-ng/g cortical tissue T3 increment and no change in AT in euthyroid controls. The larger increment in T3 of the 20-mg-MMI pups was due in great part to increased fractional T4 to T3 conversion. Although the latter resulted in greater serum T3 concentrations, three-fourths of the newly formed T3 in the cortex was generated in situ, and it was blocked by iopanoic acid as was the increase in AT. We conclude that 70-80% of the T3 in the Cx of the neonatal rat is produced locally. Serum T4 appears to serve both as a precursor for T3 and as a critical signal for increases in cortical I 5'D. The increased I 5'D can result in normal or nearnormal cerebrocortical T3 concentrations despite marked reductions in serum T4. This mechanism seems to be particularly effective aro...

show abstract

Section: Resultsmentioning

confidence: 53%

Comparison of Iodothyronine 5′-Deiodinase and Other Thyroid-Hormone-dependent Enzyme Activities in the Cerebral Cortex of Hypothyroid Neonatal Rat

Silva¹,

Larsen²

1982

J. Clin. Invest.

118

View full text Add to dashboard Cite

show abstract

“…The trial from Zaire further revealed that administration of iodized-oil injections was effective in reducing infant mortality and improving neurologic outcome even when given in midpregnancy. [207][208][209] community-based evidence. Apart from the data from Zaire and Papua New Guinea, our search identified 1 additional community-based trial of iodine supplementation (Table 9).…”

Section: Iodine Supplementationmentioning

confidence: 99%

Community-Based Interventions for Improving Perinatal and Neonatal Health Outcomes in Developing Countries: A Review of the Evidence

et al. 2005

View full text Add to dashboard Cite

ABSTRACT. Background. Infant and under-5 childhood mortality rates in developing countries have declined significantly in the past 2 to 3 decades. However, 2 critical indicators, maternal and newborn mortality, have hardly changed. World leaders at the United Nations Millennium Summit in September 2000 agreed on a critical goal to reduce deaths of children <5 years by two thirds, but this may be unattainable without halving newborn deaths, which now comprise 40% of all under-5 deaths. Greater emphasis on wide-scale implementation of proven, cost-effective measures is required to save women's and newborns' lives. Approximately 99% of neonatal deaths take place in developing countries, mostly in homes and communities. A comprehensive review of the evidence base for impact of interventions on neonatal health and survival in developingcountry communities has not been reported.Objective. This review of community-based antenatal, intrapartum, and postnatal intervention trials in developing countries aimed to identify (1) key behaviors and interventions for which the weight of evidence is sufficient to recommend their inclusion in communitybased neonatal care programs and (2) key gaps in knowledge and priority areas for future research and program learning.Methods. Available published and unpublished data on the impact of community-based strategies and interventions on perinatal and neonatal health status outcomes were reviewed. Evidence was summarized systematically and categorized into 4 levels of evidence based on study size, location, design, and reported impact, particularly on perinatal or neonatal mortality. The evidence was placed in the context of biological plausibility of the intervention; evidence from relevant developed-country studies; health care program experience in implementation; and recommendations from the World Health Organization and other leading agencies.Results. A paucity of community-based data was found from developing-country studies on health status impact for many interventions currently being considered for inclusion in neonatal health programs. However, review of the evidence and consideration of the broader context of knowledge, experience, and recommendations regarding these interventions enabled us to categorize them according to the strength of the evidence base and confidence regarding their inclusion now in programs. This article identifies a package of priority interventions to include in programs and formulates research priorities for advancing the state of the art in neonatal health care.Conclusions. This review emphasizes some new findings while recommending an integrated approach to safe motherhood and newborn health. The results of this study provide a foundation for policies and programs related to maternal and newborn health and emphasizes the importance of health systems research and evaluation of interventions. The review offers compelling support for using research to identify the most effective measures to save newborn lives. It also may facilitate dialogue with policy...

show abstract

“…The most extensive available data on thyroid function during pregnancy in populations with an I intake below 25 µg/d are from New Guinea (Choufoer et al 1965;Pharoah et al 1984) and the Democratic Republic of Congo (RDC; former Zaire; Thilly et al 1978;Delange et al 1982).…”

Section: Thyroid Function In the Mothersmentioning

confidence: 99%

The role of iodine in brain development

Delange¹

2000

Proc. Nutr. Soc.

Self Cite

160

View full text Add to dashboard Cite

I is required for the synthesis of thyroid hormones. These hormones, in turn, are required for brain development, which occurs during fetal and early postnatal life. The present paper reviews the impact of I deficiency (1) on thyroid function during pregnancy and in the neonate, and (2) on the intellectual development of infants and children. All extents of I deficiency (based on I intake (μg/d); mild 50–99, moderate 20–49, severe > 20) affect the thyroid function of the mother and neonate, and the mental development of the child. The damage increases with the extent of the deficiency, with overt endemic cretinism as the severest consequence. This syndrome combines irreversible mental retardation, neurological damage and thyroid failure. Maternal hypothyroxinaemia during early pregnancy is a key factor in the development of the neurological damage in the cretin. Se deficiency superimposed on I deficiency partly prevents the neurological damage, but precipitates severe hypothyroidism in cretins. I deficiency results in a global loss of 10–15 intellectual quotient points at a population level, and constitutes the world’s greatest single cause of preventable brain damage and mental retardation.

show abstract

Fetal Hypothyroidism and Maternal Thyroid Status in Severe Endemic Goiter*

Cited by 135 publications

References 15 publications

Comparison of Iodothyronine 5′-Deiodinase and Other Thyroid-Hormone-dependent Enzyme Activities in the Cerebral Cortex of Hypothyroid Neonatal Rat

Comparison of Iodothyronine 5′-Deiodinase and Other Thyroid-Hormone-dependent Enzyme Activities in the Cerebral Cortex of Hypothyroid Neonatal Rat

Community-Based Interventions for Improving Perinatal and Neonatal Health Outcomes in Developing Countries: A Review of the Evidence

The role of iodine in brain development

Contact Info

Product

Resources

About