The specific thyroid hormone transporter, MCT8, located on the X chromosome, has led to the identification a novel syndrome. The objective is to relate phenotype with several tissue-specific thyroid functions. A 1-year-old boy, who had severe psychological damage and low serum T4, had received l-T4 for 3 months. At admission, body length was normal but weight was low. Off therapy, serum TSH was mildly elevated, serum T4 and free T4 were low, and serum T3 and free T3 were high. Direct sequencing of the MCT8 gene revealed a single nucleotide change that resulted in a novel nonsense mutation at codon 261 (Q261X) in exon 3. Since serum T3 was high, peripheral markers of hyperthyroidism were looked for. Bone age was advanced, despite the presence of malnutrition and low T4. Serum SHBG, a marker of thyroid hormone action in liver, was markedly elevated. Markers of skeletal muscle catabolism, ammonemia and lactic acid, were found to be elevated. The phenotype of MCT 8 mutation might be explained by differences in the entry of thyroid hormones into different cells. In the presence of an inactive MCT8 transporter, the high blood T3 levels might not be enough to prevent brain damage early in life, while they seem to be able to induce a postnatal state of peripheral hyperthyroidism in other tissues, such as liver, bone and skeletal muscle.

Population balance equations have been used to model a wide range of processes including polymerization, crystallization, cloud formation, and cell dynamics. Rather than developing new algorithms specific to population balance equations, it is proposed to adapt the high‐resolution finite volume methods developed for compressible gas dynamics, which have been applied to aerodynamics, astrophysics, detonation waves, and related fields where shock waves occur. High‐resolution algorithms are presented for simulating multidimensional population balance equations with nucleation and size‐dependent growth rates. For sharp distributions, these high‐resolution algorithms can achieve improved numerical accuracy with orders‐of‐magnitude lower computational cost than other finite difference and finite volume algorithms. The algorithms are implemented in the ParticleSolver software package, which is applied to batch and continuous processes with one and multiple internal coordinates. © 2004 American Institute of Chemical Engineers AIChE J, 50: 2738–2749, 2004

Thirteen children with medulloblastoma, were studied after 2 to 62 months off radiotherapy and chemotherapy with methotrexate and BCNU. Ages at time of study ranged from 2.3 to 15.7 years. Eleven patients, followed for a mean of 22 months, showed a significant decrease of height score, whereas nine patients had deficient growth hormone (GH) response to provocative tests. Clinical pubertal progression was normal in all patients, and three of five girls with advanced pubertal development had menarche. No evidences of gonadotropin disturbances were found in five patients whereas seven had raised basal follicle-stimulating hormone (FSH) level or FSH response to luteinizing hormone-releasing hormone (LH-RH). Abnormalities in thyrotrophin (TSH) secretion were found in 9 of 13 patients. This study shows that poor growth and GH deficiency were frequent in our patients. The high frequency of thyroid disturbances observed point out the need of evaluating thyroid function for adequate replacement therapy. Perhaps modification of adjuvant chemotherapy in the future can diminish drug-induced gonadal damage.

The mean TSH levels achieved in children after rhTSH injections are remarkably similar to values previously reported in adults despite marked differences in clinical characteristics between children and adults. These data suggest that dose adjustments are not generally required in children and teenagers undergoing rhTSH stimulation for RAI scanning or serum-stimulated thyroglobulin determinations.

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Full-term sick newborns frequently have lower thyroid hormone levels than healthy ones. These observed thyroid hormones changes might be related to the underlying disease and could be used as a prognostic marker of the severity and fatal outcome of the patient.

Background: Congenital isolated thyrotropin (TSH) deficiency is an unusual condition characterized by low levels of thyroid hormones and TSH, usually presenting early typical signs of severe hypothyroidism. Five different β-TSH mutations have been described so far. While 4 of them affect only consanguineous families, a frameshift mutation in exon 3 (C105fs114X) has been found also in nonconsanguineous families. Objective: The aim of the present study was to characterize β-TSH mutations in Argentinean patients with congenital central hypothyroidism (CCH) and to emphasize the importance of early biochemical and molecular diagnosis of this disorder. Patients and Methods: We investigated 8 Argentinean children (3 boys, 5 girls) from 7 unrelated families with CCH based upon low levels of T₄ and T₃, and low basal and stimulated TSH levels. Mutation characterizations for the β-TSH gene were performed by PCR amplification followed by sequence and restriction enzyme analysis with SnaBI in the patients, 9 parents and in 100 newborn children. Results: All patients presented the same homozygous mutation in exon 3 of the β-TSH gene (C105fs114X), the 9 studied parents were heterozygous for the same mutation and 1 carrier was found in the 100 studied newborns. Conclusion: Our findings show that the C105fs114X mutation is prevalent in our population and may constitute a hot spot at codon 105 in the β-TSH gene. Since this mutation is easily demonstrable by a SnaBI digestion in DNA amplified from dried blood spots, its investigation would be indicated in patients in our milieu with clinical and biochemical features of CCH, allowing early L-thyroxine (LT₄) replacement and genetic counseling of the family.

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