Multivariate analyses of factors that affect neonatal screening thyroid stimulating hormone.

AIMS: All screening programmes in the UK use a primary thyroid stimulating hormone (TSH) screen for congenital hypothyroidism. Recent attention has been paid to aspects of screening, such as the relation between blood spot TSH levels and birth weight or gestational age. The aim of our study was to determine the factors affecting screening neonatal TSH levels. METHODS: We conducted a retrospective analysis of blood spot screening TSH levels of all infants screened at a single regional screening laboratory. RESULTS: There were 6498 infants screened during a 12-week period. Screening TSH level showed negative correlation with gestational age and birth weight. Multiple linear regression analysis revealed low birth weight as the only independent factor affecting screening TSH level. CONCLUSIONS: Low birth weight infants appear to be at risk of thyroidal dysfunction. Our study showed that there were clinically significant but weak correlation between higher screening TSH levels and low birth weight. The clinical importance of these findings requires larger prospective studies to further elucidate the relevance of these factors affecting TSH screening levels.

Abnormal urinary steroid profiles in four hypertensive obese children.

BACKGROUND: There is a poorly understood association between obesity and hypertension. We demonstrated abnormalities of adrenal androgen and cortisol metabolites in four hypertensive obese children. PATIENTS: Four males (aged 10 to 15 years) were evaluated for systolic blood pressures consistently above the 99.6th percentile. All were overweight with BMI ranging from 27-35. Clinical examinations, renal ultrasound and DMSA scans were normal. Plasma electrolytes, renin, aldosterone, cortisol, testosterone, ACTH and TSH were normal. 24-Hour urinary steroid profiles showed a generalised excess of adrenal androgen and cortisol metabolites in all cases. Relevant recognised disorders of adrenal androgen and cortisol metabolism were excluded. CONCLUSION: There is no clinical condition explaining these abnormal urinary steroid profiles. These results support previous findings and provide new data on abnormal urinary adrenal androgen excretion in obese hypertensive patients. Further studies may determine the relationship between obesity, hypertension and the observed abnormalities of urinary steroid excretion.

A novel presentation of inappropriate antidiuretic hormone secretion in Leigh syndrome with the myoclonic epilepsy and ragged red fibers, mitochondrial DNA 8344A>G mutation.

A 17-month-old infant presented with a 2-week history of lethargy, anorexia, and an abnormal respiratory pattern on a previous 4-month history of hypotonia and gross motor delay, suggesting a clinical phenotype of Leigh syndrome. The patient experienced no epileptic seizures. Biochemical investigations were normal other than showing evidence of inappropriate secretion of antidiuretic hormone, and cerebral magnetic resonance imaging (MRI) showed symmetrical lesions in the cervical cord and lower brain stem. Initial screening investigations for a mitochondrial cytopathy were negative. Muscle histochemistry demonstrated reduced staining of cytochrome c oxidase but no ragged red fibers. Blood and muscle-derived DNA demonstrated a high level (92% and 82%, respectively) of the m.8344A>G mutation seen in patients with the mitochondrial cytopathy, ''myoclonic epilepsy with ragged red fibers on muscle biopsy.'' This infant's early presentation including inappropriate antidiuretic secretion due to presumed renal salt loss and rapid course appears to be unique to this mutation.

Three year field test of a plant growth promoting rhizobacteria enhanced phytoremediation system at a land farm for treatment of hydrocarbon waste.

Phytoremediation of total petroleum hydrocarbons (TPH) has the potential to be a sustainable waste management technology if it can be proven to be effective in the field. Over the past decade, our laboratory has developed a system which utilizes plant growth promoting rhizobacteria (PGPR) enhanced phytoremediation (PEP) that, following extensive greenhouse testing, was shown to be effective at remediating TPH from soils. This system consists of physical soil manipulation and plant growth following seed inoculation with PGPR. PGPR elicit biomass increases, particularly in roots, by minimizing plant stress in highly contaminated soils. Extensive development of the root system enhances degradation of contaminants by the plants and supports an active rhizosphere that effectively promotes TPH degradation by a broad microbial consortium. Following promising greenhouse trials, field tests of PEP were performed over a period of three years at a Southern Ontario site (approximately 130 g kg(-1) TPH) used for land farming of refinery hydrocarbon waste for many years. The low molecular weight fractions (the Canadian Council of Ministers of the Environment (CCME) fractions 1 and 2) were removed through land farming and bioremediation; the high molecular weight, recalcitrant fractions (CCME fractions 3 and 4) remained at high levels in the soil. Using PEP, we substantially remediated fractions 3 and 4, and lowered TPH from 130 g kg(-1) to approximately 50 g kg(-1) over a three year period. The amount of plant growth and extent of oil remediation were consistently enhanced by PGPR.

A reference interval for sweat chloride in infants aged between five and six weeks of age.

BACKGROUND: This study was designed to establish a reference interval for sweat chloride for infants without evidence of cystic fibrosis (CF), aged between 5 wk and 6 wk, a time when sweat testing is an integral part of newborn screening for CF. In addition, we compared the gold standard method of sweat testing (quantitative pilocarpine iontophoresis [QPIT, coulometry]) with an emerging methodology (Macroduct [ISE]). METHODS: This was a prospective study on healthy infants at 5-6 wk of age. Sweat collection was undertaken at home on both outer thigh areas using two methods (QPIT and Macroduct ). The order of testing was randomly assigned. Filter paper samples (QPIT) were analysed using flame photometry and coulometry. Macroduct samples were analysed using ion-selective electrodes (ISE, Abbott Architect c8000, UK). RESULTS: Insufficient sweat was collected on 28 occasions with the QPIT (coulometry) method and on 31 with the Macroduct (ISE) capillary system. We achieved a 92% success rate in undertaking two sweat collections consecutively (n = 177). Sweat chloride concentrations were normally distributed with excellent limits of agreement between the two methods of sweat collection and analysis (n = 150). Median (IQR) sweat chloride was 11.2 mmol/L (8-13) with QPIT (coulometry) method with a 99.5th centile (n = 165) of 24 mmol/L. CONCLUSION: The Macroduct (ISE) capillary sweat collection system is valid in this age group. Sweat chloride concentrations above 30 mmol/L should prompt assessment in a specialist CF centre.

Tuberculous meningitis: protracted course and clinical response to interferon-gamma.

A 12-year-old girl with protracted tuberculous meningitis received standard chemotherapy and dexamethasone and had a progressive cerebrospinal fluid neutrophilia, raised protein and depressed glucose levels. Her temperature was raised for 5 months until a second course of dexamethasone was given. At week 15, multiple tuberculomas and hydrocephalus were detected followed by acute hydrocephalus (week 58), which required a ventricular-peritoneal shunt. Tuberculomas resolved after a second course of dexamethasone but recurred 15 months later. Immunological investigations were normal including integrity of the type 1 cytokine pathway. From month 24, interferon-gamma was given subcutaneously (initially 50 microg/m(2)) and continued for 19 months. Within 2 weeks she responded clinically followed by a reduction in inflammatory signs on magnetic resonance imaging scan (but not in the tuberculomas). At month 44, when chemotherapy was stopped, the cerebrospinal fluid/serum albumin quotient was 57x10(-3) (normal <6.0x10(-3)), which supports continuing major impairment of the blood-brain barrier. Gene expression in peripheral blood mononuclear cells before and during treatment with interferon-gamma, assessed by gene array analysis, showed reduction in a number of cytokine and chemokine genes. The response to interferon-gamma might have been secondary to downregulation of certain cytokine and chemokine genes.

Carotenemia in infancy and its association with prevalent feeding practices.

Carotenemia in infancy is a relatively rare but benign condition, invariably of dietary origin, that can be confused with jaundice. It is characterized by an abnormal yellowish orange pigmentation of the skin, most prominently seen in the palms, soles, and naso-labial folds. Infant feeding patterns have shown an increasing trend toward the usage of homogenized and pureed vegetables as well as meat-based commercial preparations. Whether this is reflected in an increased incidence of carotenemia in this age group still remains unclear. We report a series of infants identified by a retrospective review of records, observed over a 3-year period (1999-2002) in a tertiary children's hospital, who developed the condition that resolved spontaneously without intervention, as they grew older, on a changing diet.

Dilated cardiomyopathy and adipic aciduria in nutritional rickets.

Hypocalcemia secondary to nutritional rickets is a rare cause of dilated cardiomyopathy. It is also not a recognized cause of dicarboxylic aciduria. We report the first case of adipic aciduria, presenting with dilated cardiomyopathy, secondary to hypocalcemia.