Case control study of periconceptional folic acid intake and nervous system tumors in children.

Purpose: Since 1992, the Centers for Disease Control and Prevention recommends that women of childbearing age consume 400 µg of folic acid per day to reduce the risk of neural tube defects (NTD). It has been speculated that both NTD and nervous system tumors (NST) may share common mechanisms of altered development. It examines the association between folic acid supplementation and the risk for childhood NST.

Developmental neuropathology of environmental agents.

The developing central nervous system (CNS) is more vulnerable to injury than the adult one. Although a great deal of research has been devoted to subtle effects of developmental exposure, such as neurobehavioral changes, this review instead focuses on a number of chemicals that have been shown, in several experimental models as well as humans, to cause morphological changes in the developing nervous system. Chemicals that are discussed include methylmercury (MeHg), lead (Pb), antiepileptic drugs, and ethanol.

Changing trends in the epidemiology of pediatric lead exposure: interrelationship of blood lead and ZPP concentrations and a comparison to the US population.

Objectives: To determine blood lead and zinc protoporphyrin (ZPP) concentrations in a pediatric population, confirm their interrelationship at low blood lead concentrations, and assess changing trends through comparison of these data with those found in a similar population 10 years earlier and to US national values.

Study Design And Methods: The study was conducted in a large pediatric hospital in the Washington DC area (CNMC) on patient whole blood specimens (n = 4908) (0-17 years) accrued from January 2001 to June 2002. Pediatric blood lead concentrations were determined by atomic absorption spectrophotometry, and ZPP by hematofluorometry.

Seroprevalence of Toxoplasma gondii infection among veterinary staff in Ontario, Canada (2002): implications for teratogenic risk.

Background: Toxoplasma gondii infection is embryotoxic in humans. It is mainly transmitted through raw/undercooked meat and ingestion of oocysts in cat feces. There remains controversy about the actual risk of cats transmitting the disease to humans.

Lack of a relation between human neonatal thyroxine and pediatric neurobehavioral disorders.

The growth and differentiation of the central nervous system are closely related to the presence of iodine and thyroid hormones. It has been hypothesized that neurobehavioral disabilities of childhood, such as attention deficit hyperactivity disorder (ADHD), learning disorders, and autism can be attributed to fetal thyroidal endocrine disruption in utero. To determine whether there is an association between neonatal thyroid status and a subsequent diagnosis of a neurobehavioral disability, neonatal thyroxine (T(4)) levels have been used as the indicator of the presence of intrauterine thyroidal dysfunction.

Urinary iodine percentile ranges in the United States.

Background: The status of iodine nutrition of a population can be determined by measurement of urinary iodine concentrations since it is thought to indicate dietary iodine intake. Normally, these results are compared to population-based criteria, since there are no reference ranges for urinary iodine.

Objective: To determine the percentile ranges for urinary iodide (UI) concentrations in normal individuals in the United States.

Pediatric reference ranges for zinc protoporphyrin.

Objective: To determine pediatric reference ranges for zinc protoporphyrin (ZPP).

Design And Methods: The study was conducted in a large pediatric hospital on patient blood specimens (n = 6,478) (0-17 y) accrued from January 2001 to June 2002. The data was analyzed employing the Hoffman approach, which was computer adapted.

Controversies in urinary iodine determinations.

Iodine deficiency (ID) is associated with increased prevalence of goiter, increased risk for neurodevelopmental disorders, and is the world's leading cause of intellectual deficits. Iodine nutritional status of a population is assessed by measurements of urinary iodine concentrations which are also used to define, indicate, survey and monitor iodine deficiency and consequently its treatment. Several methods are available for urinary iodine determination.

Blood lead concentrations in children: new ranges.

Background: Lead exposure in young children may have adverse neurodevelopmental effects. Currently, an increased blood lead concentration is defined as >or=10 microg/dl for males and females of all ages, including children younger than 6 years. Using a large hospital population (n=11145), we define more specific ranges for pediatric blood lead concentrations.

Potential prevention of neural tube defects by assessment of women of childbearing age through monitoring of folate.

Background: Three quarters of neural tube defects (NTD) can be prevented by sufficient dietary folate supplementation. Despite this knowledge, most women do not supplement their diet effectively. Red cell folate concentrations correlate with the risk of NTD, and levels of less than 900 nM are associated with an increased risk of these serious congenital anomalies.

Newborn thyroxine levels and childhood ADHD.

Objectives: Normal brain development is highly dependent on adequate levels of iodine and thyroid hormone. It has been suggested that Attention Deficit Hyperactivity Disorder (ADHD) is the consequence of prenatal thyroidal endocrine disruption. The hypothesis was examined using neonatal thyroxine levels as a bio-marker of prenatal thyroid status and comparing it to subsequent development of ADHD.