Recombinant growth hormone therapy for prepubertal children with idiopathic short stature in Korea: a phase III randomized trial.

PURPOSE: Several studies have evaluated the effects of growth hormone (GH) on auxological and biochemical parameters in children with non-GH-deficient, idiopathic short stature (ISS). This study evaluated the efficacy and safety of Growtropin®-II (recombinant human GH) in Korean patients with ISS. METHODS: This was a 1-year, open-label, multicenter, phase III randomized trial of Growtropin®-II in Korean patients with ISS. In total, 70 prepubertal subjects (39 males, 31 females) between 4 and 12 years of age were included in the study. All patients were naive to GH treatment. RESULTS: Annual height velocity was significantly higher in the treatment group (10.68 ± 1.95 cm/year) than the control group (5.72 ± 1.72, p < 0.001). Increases in height and weight standard deviation scores (SDSs) at 26 weeks were 0.63 ± 0.16 and 0.64 ± 0.46, respectively, for the treatment group, and 0.06 ± 0.15 and 0.06 ± 0.28, respectively, for the control group (p < 0.001). Serum insulin-like growth factor (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) increased significantly in the treatment group at week 26 compared to baseline. However, the SDS for body mass index (BMI) at 26 weeks did not change significantly in either group. Growtropin®-II was well tolerated and safe over 1 year of treatment. CONCLUSIONS: One-year GH treatment for prepubertal children with ISS demonstrated increased annualized velocity, height and weight SDSs, and IGF-1 and IGFBP-3 levels, with a favorable safety profile. Further evaluations are needed to determine the optimal dose, final adult height, and long-term effects of ISS treatment.

Pharmacogenomics of insulin-like growth factor-I generation during GH treatment in children with GH deficiency or Turner syndrome.

Individual responses to growth hormone (GH) treatment are variable. Short-term generation of insulin-like growth factor-I (IGF-I) is recognized as a potential marker of sensitivity to GH treatment. This prospective, phase IV study used an integrated genomic analysis to identify markers associated with 1-month change in IGF-I (ΔIGF-I) following initiation of recombinant human (r-h)GH therapy in treatment-naïve children with GH deficiency (GHD) (n=166) or Turner syndrome (TS) (n=147). In both GHD and TS, polymorphisms in the cell-cycle regulator CDK4 were associated with 1-month ΔIGF-I (P<0.05). Baseline gene expression was also correlated with 1-month ΔIGF-I in both GHD and TS (r=0.3; P<0.01). In patients with low IGF-I responses, carriage of specific CDK4 alleles was associated with MAPK and glucocorticoid receptor signaling in GHD, and with p53 and Wnt signaling pathways in TS. Understanding the relationship between genomic markers and early changes in IGF-I may allow development of strategies to rapidly individualize r-hGH dose.

Automated spherical aberration correction in scanning confocal microscopy.

Mismatch between the refractive indexes of immersion media and glass coverslips introduces spherical aberrations in microscopes especially for high numerical aperture objectives. This contribution demonstrates an automated adjustment of the coverslip correction collar in scanning confocal microscopy to compensate for spherical aberrations due to coverslip thickness mismatch. With a motorized coverslip correction collar, the adjustment procedure consists of xz image scans, image processing, correction quality evaluation, the mismatch estimation, and eventually the optimal adjustment of the correction collar. For fast correction with less photodamage, coarse-fine Gaussian fitting algorithms are proposed and evaluated with various specimen for their estimation accuracy. The benefits of the proposed automated correction are demonstrated for various coverslips with biological specimens, showing the optimized resolution of the confocal microscope.

Clinical characterization and molecular classification of 12 Korean patients with pseudohypoparathyroidism and pseudopseudohypoparathyroidism.

CONTEXT: Pseudohypoparathyroidism (PHP) is defined as resistance toward parathyroid hormones. PHP and pseudopseudohypoparathyroidism (PPHP) are rare disorders resulting from genetic and epigenetic aberrations within or upstream of the GNAS locus. This study investigated the clinical characteristics and performed a molecular analysis of PHP and PPHP. METHODS: A total of 12 patients with (P)PHP from 11 unrelated families (4 with PHP-Ia, 6 with PHP-Ib, and 2 with PPHP) were characterized using both clinical and molecular methods. Clinical features included the presenting symptoms, Albright hereditary osteodystrophy features, and resistance to hormones. Comprehensive analysis of the GNAS and STX16 loci was undertaken to investigate the molecular defects underlying (P)PHP. RESULTS: All PHP-Ib patients displayed hypocalcemic symptoms. All PHP-Ia patients showed resistance toward TSH, in addition to PTH. In most patients with PHP, when the diagnosis of PHP was first established, hypocalcemia and hyperphosphatemia were associated with a significant increase in serum PTH levels. One patient with PHP-Ia was diagnosed with growth hormone deficiency and showed a good response to human recombinant growth hormone therapy. 6 patients with PHP-Ia and PPHP showed 5 different mutations in the GNAS gene. 5 patients with PHP-Ib displayed a loss of differentially methylated region (DMR) imprints of the maternal GNAS. One PHP-Ib patient showed a de novo microdeletion in STX16 and a loss of methylation of exon A/B on the maternal allele. No patients revealed paternal disomy among 4 patients with PHP-Ib. CONCLUSIONS: Identification of the molecular causes of PHP and PPHP explains their distinctive clinical features and enables confirmation of the diagnosis and exact genetic counseling.

A pharmacogenomic approach to the treatment of children with GH deficiency or Turner syndrome.

OBJECTIVE: Individual sensitivity to recombinant human GH (r-hGH) is variable. Identification of genetic factors contributing to this variability has potential use for individualization of treatment. The objective of this study was to identify genetic markers and gene expression profiles associated with growth response on r-hGH therapy in treatment-naïve, prepubertal children with GH deficiency (GHD) or Turner syndrome (TS). DESIGN: A prospective, multicenter, international, open-label pharmacogenomic study. METHODS: The associations of genotypes in 103 growth- and metabolism-related genes and baseline gene expression profiles with growth response to r-hGH (cm/year) over the first year were evaluated. Genotype associations were assessed with growth response as a continuous variable and as a categorical variable divided into quartiles. RESULTS: Eleven genes in GHD and ten in TS, with two overlapping between conditions, were significantly associated with growth response either as a continuous variable (seven in GHD, two in TS) or as a categorical variable (four more in GHD, eight more in TS). For example, in GHD, GRB10 was associated with high response (≥ Q3; P=0.0012), while SOS2 was associated with low response (≤ Q1; P=0.006), while in TS, LHX4 was associated with high response (P=0.0003) and PTPN1 with low response (P=0.0037). Differences in expression were identified for one of the growth response-associated genes in GHD (AKT1) and for two in TS (KRAS and MYOD1). CONCLUSIONS: Carriage of specific growth-related genetic markers is associated with growth response in GHD and TS. These findings indicate that pharmacogenomics could have a role in individualized management of childhood growth disorders.

Successful liver transplantation for a child with life-threatening recurrent bleeding episodes due to congenital factor X deficiency: a case report.

Factor X (FX) deficiency is a rare, autosomal-recessive coagulation disorder. Diagnosis can be confirmed by a factor X assay. Although fresh frozen plasma and prothrombin complex concentrates have been used as a temporary treatment of bleeding symptoms and preparation for surgery, frequent transfusion has its risk and prothrombin complex is not available in Korea. We report the first pediatric case of successful liver transplantation for the correction of a severe congenital FX deficiency in a child with recurrent life-threatening hemorrhagic episodes.

Clinical phenotype and mutation spectrum of the CYP21A2 gene in patients with steroid 21-hydroxylase deficiency.

Steroid 21-hydroxylase deficiency is caused by inactivating mutations in the CYP21A2 gene. This paper reports on the mutation spectrum and the genotype-phenotype correlation of 21-hydroxylase deficiency. 72 unrelated patients with congenital adrenal hyperplasia (CAH) were included. Molecular analysis of CYP21A2 was performed, via the multiplex ligation-dependent probe amplification (MLPA) analysis and sequence-specific differenzial PCR amplification of the CYP21A2 and CYP21A1P genes, using 4 pair-wise sequence-specific primers, followed by sequencing of the entire CYP21A2 gene. Large gene deletions were identified in 45 (31.3%) of the 144 unrelated CAH alleles, whereas the most frequent point mutations were intron 2 splice mutations (c.293-13A>G) (41/144, 28.5%). The MLPA analysis successfully identified 23 of 72 patients (31.9%) with single copy deletion in CYP21A2. This paper describes a rapid and accurate method for the molecular diagnosis of 21-hydroxylase deficiency, which relies on the identification of point mutations and structural rearrangements within the CYP21A2 gene.

Oral V2 receptor antagonist (RWJ-351647) in patients with cirrhosis and ascites: a randomized, double-blind, placebo-controlled, single ascending dose study.

BACKGROUND: RWJ-351647 is a selective V2 receptor antagonist that inhibits vasopressin-induced water reabsorption in the kidney. AIM: To investigate the safety and tolerability of RWJ-351647 compared with placebo after single oral dose administration to patients with cirrhosis and ascites, on a stable treatment with furosemide and spironolactone. METHODS: Single oral doses of 1, 2 and 5 mg of RWJ-351647 were administered to 24 patients with ascites on stable concomitant diuretic treatment. RESULTS: RWJ-351647 had a tmax of 1 to 1.1 h and mean half-life of 10.4-17.4 h. There was no affect on the pharmacokinetics of concomitant diuretics. Increases in cumulative urine volume and free water excretion, and a decrease in urine osmolality were noted in a dose-dependent manner reaching the statistical significance at the 5-mg dose. Four patients exhibited a decrease of > 2 kg in weight in the 24 h after dosing. RWJ-351647 was well tolerated, with no evidence of a dose-related increase in adverse events when compared with placebo. No changes in either serum chemistry or plasma AVP (arginine vasopressin) and renin levels were observed despite the observed aquaresis. CONCLUSION: RWJ-351647 is an effective aquaretic causing dose-dependent increases in urine output and free water clearance, when co-administered with conventional diuretics in patients with cirrhosis and ascites.

Characteristics of CADASIL in Korea: a novel cysteine-sparing Notch3 mutation.

OBJECTIVE: To elucidate the phenotype, genotype, and MRI findings of Korean patients with cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) and mutation carriers. METHODS: The authors studied 40 members of nine unrelated Korean CADASIL families. After genetic analysis of Notch3, clinical and MRI findings were correlated in 27 mutation carriers. RESULT: Notch3 mutation sites were C174R (one family, n = 3), R133C (one family, n = 3), R587C (one family, n = 1), R544C (two families, n = 5), and R75P (four families, n = 15). The clinical features were typical of CADASIL, but the frequency of migraine in the Korean population appears low. MRI abnormalities were found in 54% of the mutant carriers, the most common being white matter hyperintensities. The prevalence of lacunes and microbleeds increased with patient age. Anterior temporal areas were less often involved in subjects with R75P mutations than in those where mutations occurred in other sites (p = 0.02). Gradient echo imaging identified microbleedings in 33% of mutation carriers (64% of those with abnormal MRI), whereas diffusion-weighted MRI showed abnormal findings in only one patient. Neurologic disability was related to the number of lacunar infarcts and the lesion volume of white matter hyperintensities (p < 0.001) whereas MMSE score was related to the number of lacunar infarcts (p < 0.005). CONCLUSIONS: Although Korean cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) mutation carriers show similar clinical and MRI findings, these abnormalities appear less frequently than in other populations. Relatively frequent microbleedings on gradient echo imaging suggest that treatment should be individualized according to MRI findings. The novel mutation of R75P, not involving a cysteine residue, is related to less frequent involvement of the anterior temporal area, thus broadening the spectrum of CADASIL.

Two cases of citrullinaemia presenting with stroke.

Urea cycle disorders are known to be unusual causes of stroke. We report two infant cases of citrullinaemia that both initially presented with a stroke and suggest that urea cycle disorders should be included in the differential diagnosis of unexplained stroke during infancy and childhood.

Localized proton MR spectroscopy in infants with urea cycle defect.

SUMMARY: Urea cycle defect is an inborn error of ammonium metabolism caused by a deficient activity of the enzymes involved in urea synthesis. Localized short-TE proton MR spectroscopy, performed in two infants who had citrullinemia and ornithine transcarbamylase deficiency, respectively, showed a prominent increase of glutamine/glutamate and lipid/lactate complex in both cases. N-acetylaspartate, total creatine, and myo-inositol were decreased in the infant with citrullinemia. Proton MR spectroscopy provided useful information for the diagnosis and understanding of the pathophysiology of urea cycle enzyme defect.

Six novel mutations of the fibrillin-1 gene in Korean patients with Marfan syndrome.

BACKGROUND: Mutations in the FBN1 gene, encoding fibrillin-1, result in Marfan syndrome (MFS). According to previous reports, the mutations in FBN1 share certain characteristics in each family with variable penetrance and overlapping symptoms, even in the same genotype. In the present study, we report six novel mutations and evaluate the clinical significance of these nucleotide changes. METHODS: To screen for nucleotide changes in all 65 exons of the FBN1 gene in 38 unrelated Korean patients, we performed polymerase chain reaction, single-strand conformational polymorphism (SSCP) and sequencing for the shift of the band in SSCP. RESULTS: We identified six mutations: a 2253 del 7 b.p., N1043S, C1254S, L1421F, C1895R and S2662P. CONCLUSIONS: These results suggest that many different mutations are responsible for MFS in the Korean population.

Identification of four novel mutations in five unrelated Korean families with Fabry disease.

Fabry disease is a X-linked recessively inherited metabolic disorder, which results from the deficient activity of the lysosomal hydrolase alpha-galactosidase A leading to the systemic deposition of glycosphingolipids with terminal alpha-galactosyl moieties. Single-strand conformation polymorphism (SSCP) analysis was performed, followed by DNA sequencing of PCR amplified exons of the human alpha-galactosidase A gene in 5 unrelated Korean patients with classic Fabry disease. Five different mutations were identified; two nonsense mutations (Y86X and R342X), one missense mutation (D266N), and two small deletions (296del2 and 802del4). Except for R342X mutation, four were novel mutations (Y86X, D266N, 296del2, 802del4). A T to G transversion at nucleotide position 5157 in exon 2 caused a tyrosine-to-stop substitution at codon 86. A G to A transition at position 10287 in exon 5 substituted an asparagine for an aspartate at codon 266. Mutation 296del2 in exon 2 resulted in a frame shift with a stop signal at the 22th codon downstream from the mutation, whereas mutation 802del4 resulted in a stop codon at the site of 4 bp deletion. In addition, the 802del4 was found to be a de novo mutation. This is the first report on mutation analysis of the human alpha-galactosidase A gene in Korean patients with Fabry disease.

Plasma and cerebrospinal fluid pharmacokinetics of O6-benzylguanine and analogues in nonhuman primates.

O6-Benzylguanine (BG) is a potent, specific inactivator of the DNA repair protein, O6-alkylguanine-DNA alkyltransferase, that enhances the sensitivity of tumor cell lines and tumor xenografts to chloroethylnitrosoureas. To search for BG analogues with greater penetration into the cerebrospinal fluid (CSF), we evaluated plasma and CSF pharmacokinetics of BG, 8-aza-O6-benzylguanine (8-azaBG), O6-benzyl-8-bromoguanine (8-BrBG), O6-benzyl-8-oxoguanine (8-oxoBG), O6-benzyl-8-trifluoromethylguanine (8-tfmBG), and O6-benzyl-2'-deoxyguanosine (B2dG) after i.v. administration of 200 mg/m2 of drug through an indwelling Ommaya reservoir in a nonhuman primate model. BG and its analogues were quantified in plasma and CSF using reverse-phase high-performance liquid chromatography assays. The plasma clearances of the four 8-substituted BG analogues were similar (0.04-0.06 l/h/kg), but half-lives ranged from <2 to >24 h. BG was converted to 8-oxoBG, an equally potent O6-alkylguanine-DNA alkyltransferase inactivator, and the elimination of 8-oxoBG was much slower than that of BG. As a result, the plasma area under the curve of 8-oxoBG was 3.5-fold greater than that of BG. B2dG was metabolized to BG and 8-oxoBG, but this pathway accounted for only 20% of B2dG elimination. The CSF penetration percentages (based on the ratio of AUC(CSF): AUCplasma) for BG, 8-azaBG, 8-oxoBG, 8-tfmBG, 8-BrBG, and B2dG were 3.2, 0.18, 4.1, 1.4, <0.3, and 2.0%, respectively. The CSF penetration of BG and its active metabolite 8-oxoBG is greater than the penetration of 8-azaBG, 8-BrBG, 8-tfmBG, and B2dG.

Synthesis and cytotoxicity of 2-methyl-1-substituted-imidazo [4,5-g]quinoline-4,9-dione and 7,8-dihydro-10H-[1,4]oxazino[3',4':2,3]imidazo[4,5-g]quinoline-5,12-dio ne derivatives.

2-Methyl-1-substituted-imidazo[4,5-g]quinoline-4,9-diones and 7,8-dihydro-10H-[1,4]oxazino-[3',4':2,3]imidazo[4,5-g]quinoline-5, 12-dione (19) derivatives have been synthesized from 6,7-dichloro-5,8-quinolinedione for developing the new anticancer drugs. Our study on the cytotoxicity of imidazoquinolinedione derivatives has revealed that 7,8-dihydro-10H-[1,4]oxazino-[3',4':2,3]imidazo[4,5-g]quinoline-5, 12-dione (19), a tetracyclic heteroquinone analogue, exhibited high cytotoxicity on human colon tumor cell (HCT 15) in vitro SRB assay. The IC50 value of this compound was 0.026 microg/mL whereas those of doxorubicin and cisplatin were 0.023 microg/mL and 1.482 microg/mL, respectively. Meanwhile compounds 5-7 and 12 in the series of 1-substituted-imidazoquinolinediones showed relatively good activity on human brain tumor cell lines (XF 498).

Clinical correlations of peripheral blood microchimerism after liver transplantation.

The aim of this study was to evaluate microchimerism after human liver transplantation (LT). This study included 13 female recipients who received hepatic allograft from male donors at Asan Medical Center. A nested PCR specific for Y-chromosome gene (DYZ3) was used to analyze the small number of male cells in the peripheral blood mononuclear cells of the female recipients. Microchimerism was observed in 6 of 13 recipients and 16 out of 35 samples. Only 3 patients showed microchimerism 3 months after LT. There was no statistical difference between the presence of microchimerism and clinical findings such as type of donor, type of immunosuppression, episode of rejection and age of recipient. This study did not show any clinical relevance of microchimerism and further larger study are needed to confirm the results.

Cytotoxic effects of pyridino[2,3-f]indole-4,9-diones on human tumor cell lines.

The cytotoxicities of pyridino[2,3-f]indole-4,9-dione derivatives were examined against human lung tumor cell lines (A 549), human ovarian tumor cell lines (SK-OV-3), human melanoma tumor cell lines (SK-MEL-2), human CNS tumor cell lines (XF 498) and human colon tumor cell lines (HCT 15) in vitro using a Sulforhodamine B assay. 3-Ethoxycarbonyl-1-(2-methoxyethyl)-2-methyl-1H-pyridino[2,3-f]ind ole-4,9-dione (5) showed excellent cytotoxicity against XF 498 and HCT 15. The ED50 values of 5 were 0.006 microg/ml against XF 498 and 0.073 microg/ml against HCT 15, while those of doxorubicin were 0.012 and 0.264 microg/ml, respectively. 1-Benzyl-3-ethoxycarbonyl-2-methyl-1H-pyridino[2,3-f]indole-4,9-di one (7) (ED50 value 0.065 microg/ml) was also significantly more cytotoxic against HCT 15 compared with doxorubicin.