Craig C. Orlowski

Prevalence of stimulant use for attentional dysfunction in children with phenylketonuria

Sumary: Recent data suggest that children with phenylketonuria (PKU) and poor metabolic control may have an increased prevalence of attentional dysfunction. However, few formal studies have addressed this topic in detail. We reviewed the medical records of 38 school-aged children with early and continuously treated PKU to determine the prevalence of stimulant use for attentional dysfunction, and to determine the relationship between metabolic control and attentional symptoms. Twenty-six per cent of the PKU children used a stimulant medication for attentional dysfunction. This is significantly higher than in an age- and sex-matched control group consisting of children with type I diabetes mellitus (6.5%, p<0.006), and also considerably higher than population norms for attention deficit hyperactivity disorder (ADHD) (5%). We also found a significant relationship between phenylalanine levels and stimulant use or attentional symptoms. Mean plasma phenylalanine concentration was 486 µmol/L in the non-stimulant-using group and 792 µmol/L in the stimulant-using group (p<0.02). Mean phenylalanine concentration was 462 µmol/L in the group not reporting attentional symptoms, and was 702 µmol/L in the symptomatic group (p<0.05). Parents of the stimulant-using children felt that the stimulants were efficacious in treating their childs attentional symptoms. Stimulant use and parent reports of attentional dysfunction are quite common in our PKU patients and appear to be strongly related to higher phenylalanine concentrations.

Continuous subcutaneous insulin infusion in toddlers and children with type 1 diabetes mellitus is safe and effective

Abstract:  Objective:  The aim of this study was to investigate the safety and efficacy of continuous subcutaneous insulin infusion (CSII) for type 1 diabetes mellitus (T1DM) in toddlers and children.

Comparison of Transdermal and Oral Estrogen Therapy in Girls with Turner's Syndrome

Eight girls with Turners syndrome were given low dose oral ethinyl estradiol or transdermal 17 beta-estradiol in order to compare the effect of the route of administration on selected markers of hepatic metabolism, and various hormonal concentrations. Oral estrogen was given at a dose of 100 ng/kg/day and transdermal estrogen via adhesive skin patch at 0.0125 mg/kg/day. The subjects received one form of estradiol for one month, and after a one month washout period, received the other form. Both oral and transdermal estradiol caused a significant decrease in FSH while only transdermal resulted in a significant decrease in LH. Oral estradiol, though not transdermal estradiol, increased serum high density lipoprotein, thyroxine binding protein and growth hormone binding protein. Urinary growth hormone excretion increased after both forms of therapy, while insulin-like growth factor-I and insulin-like growth factor binding protein-3 remained unchanged. Thus, in girls with Turners syndrome, estrogen replacement by the transdermal route may have less deleterious effect on hepatic metabolism than oral estrogen.

THE MAMMALIAN CELL CYCLE IN NORMAL AND ABNORMAL GROWTH

Cell division, a complex array of intracellular events, occurs in a highly ordered and carefully coordinated manner. This regulation is achieved by the sequential activation and deactivation of the members of a family of serine-threonine-specific protein kinases that consist of regulatory and enzymatic subunits, the cyclins and cyclin-dependent kinases. These enzymes, in turn, regulate the activity of other proteins involved in the mitogenic pathway. Mutations in the components of the regulatory pathways can lead to aberrant growth, including malignancies.

Cadmium Metabolism in cdm/cdm Mice

The uptake and metabolism of cadmium by cadmium-susceptible (+/+) and cadmium-resistant (cdm/cdm) strains of mice have been compared. These strains did not differ with respect to the quantitative uptake of cadmium into liver, kidney, or testis. After intraperitoneal administration of a nontoxic dose, more than 80% of the cadmium in liver and testis of both strains is bound to low molecular weight proteins. The chromatographic behavior of these cadmium-binding proteins is not affected by cdm genotype.

Young–Simpson syndrome (YSS), a variant of del(1)(p36) syndrome?

The Young–Simpson syndrome (YSS) and 1p36 deletion syndrome are both characterized by facial and heart abnormalities, congenital hypothyroidism, and severe growth and developmental retardation. However, the YSS is characterized by the presence of blepharophimosis and epicanthus inversus, findings not described in monosomy 1p36 patients. We describe a girl with YSS, who presented with the typical facial findings, global retardation, congenital hypothyroidism, and congenital dilated cardiomyopathy. Comparative genomic hybridization chromosomal microarray analysis showed a 1p36.3 deletion, a finding not previously reported in other YSS cases. We propose that YSS is a variant of the 1p36 deletion syndrome.

Regulation of Gene Expression of Rat Insulin-Like Growth Factor Binding Proteins 1 and 2

Virtually all of the insulin-like growth factors (IGFs) in extracellular fluids and cell culture medium occur complexed to specific IGF-binding proteins (IGFBPs).1,2 The IGFBPs are a family of proteins that bind IGF-I and IGF-II but are unrelated to IGF receptors. Four IGFBPs have been cloned from human and rat sources,1–8 and partial protein sequence information is available forafifthlGFBP.9–11 OthermembersoftheIGFBPfamilyundoubtedlyexist,12butspecific assignment must await amino acid or nucleotide sequencing.

Characterization and Cloning of a Rat Insulin-Like Growth Factor Binding Protein

The insulin-like growth factors, IGF-I and IGF-II, occur complexed to specific binding proteins in blood and other extracellular fluids.1 IGF-binding protein complexes of 150 kDa predominate in adult human and rat serum2,3, and also have been observed in human and porcine milk 4,5, and human fibroblast conditioned media6,7. Acid pH irreversibly dissociates the 150 kDa binding protein complex into an ~40 kDa acid-stable binding subunit.1 Recently, Baxter8 provided evidence for the existence of a second subunit of ~100 kDa that is unstable at acid pH and does not bind IGFs.

Expanding the pediatrics residency curriculum.

No abstract available.