Phylogeny, expression and enzyme activity of zebrafish cyp19 (P450 aromatase) genes.

The cyp19 encodes P450 aromatase, the enzyme catalyzing the conversion of estrogens from androgens. Estrogens affect the dimorphic, anatomical, functional and behavioral aspects of development of both males and females. In zebrafish, two cyp19 genes, cyp19a and cyp19b were found. They are expressed in ovary and brain, respectively. Expression of cyp19b can be detected by 11 days post-fertilization (dpf) by in situ hybridization in the olfactory bulbs, ventral telencephalic region and the hypothalamus of the brain in both male and female, where it is generally known to be affecting the reproductive function and sexual behavior. COS-1 clones permanently expressing the enzymes have been isolated. Both aromatase enzymes encoded by these two genes are functional in COS-1 cells and they can use androstenedione and testosterone equally efficiently. The presence of two functional cyp19 in zebrafish has its evolutionary and physiological importance.

The activity of cytochrome P450IA1 in stable cultured rat hepatocytes.

In this study, a stable, differentiated culture format (primary hepatocytes cultured between two layers of collagen gel) was used to study the effect of the inducer 3,3',4,4'-tetrachlorobiphenyl (TCB) on the activity of cytochrome P50IA1. P450IA1 (ethoxyresorufin O-deethylase) enzymatic activity was measured using the rate of conversion of ethoxyresorufin (ER) to resorufin (R). After 14 days of induction with 10(-6), M TCB, hepatocytes in the double collagen gel configuration exhibited a maximum activity of 180.3 +/- 46.8 pmol R/mug, DNA/hr (3.6 +/- 0.9 nmol R/10(6), cells/hr) compared with 34.9 +/- 3.8 pmol R/mug DNA/hr for cells cultured on a single layer of gel. At a TCB level of 10(-5), m, the P450IA1 activity in the double-gel configuration peaked at 220.8 +/- 37.0 pmol R/mug DNA/hr. Cessation of 10(-6), M TCB induction produced a decrease in activity to 25.8 +/- 4.1 pmol R/mug DNA/hr within 4 hr. Subsequent re-application of the inducer caused an increase in activity to 76.5 +/- 11.1 pmolR/mug DNA/hr within 6 hr, reaching a maximal value of 131.0 +/- 38.6 pmol R/mug DNA/hr within 12 hr. Since TCB is rapidly metabolized by hepatocytes, a continuous perfusion culture system was developed to examine the effect of exposure to a constant level of TCB. Continuous perfusion of the cells with 10(-8) or 10(-7), M TCB, resulted in activities significantly higher than those of cultures induced by daily application of induction medium. A mechanistic model of TCB-dependent induction of P450IA1 was developed using kinetic parameters estimated from static culture data. The model accurately predicted cyclic variations in P450IA1 activity in static culture, and the steady-state activity level of perfusion cultures. This work describes procedures for exposing stable hepatocyte cultures to either continuous or declining levels of consumable inducers and for measuring the activity of cytochrome P50IA1 in cultured hepatocytes by a non-invasive method.

Serum dehydroepiandrosterone sulfate and androstenedione concentrations in children with adrenal disorders.

This study evaluated the clinical usefulness of serum dehydroepiandrosterone sulfate (DHAS) and androstenedione concentrations in diagnosing adrenal disorders in children. Serum concentrations of DHAS and androstenedione were determined in 20 children with adrenal disorders, including virilizing adrenal tumor (3), classic congenital adrenal hyperplasia (16), and Addison's disease (1). For comparison, the sera of 276 age-matched normal children were studied. All three children with virilizing adrenal tumors had elevated serum concentrations of DHAS and androstenedione. All of the 16 children with classic congenital adrenal hyperplasia had elevated serum androstenedione concentrations and 11 had elevated serum DHAS concentrations. The serum concentrations of DHAS and androstenedione of the patient with Addison's disease were within the normal range for his age. Our findings demonstrate the value and limitations of the determination of serum DHAS and androstenedione concentration for the diagnosis of adrenal hyperandrogenic disorders in children. We suggest that the determination of serum DHAS and androstenedione concentrations may be of limited clinical value in the diagnosis of adrenal hypofunction due to Addison's disease in children.

Hypothalamic hamartoma and precocious puberty: report of a case.

Hypothalamic hamartoma is reported to be associated with precocious puberty. Here, the authors present a seven-year-old girl whose onset of puberty occurred at the age of two. Under the impression of idiopathic precocious puberty, cyproterone acetate was initially tried. Since the effect of her medication was not satisfactory, it was discontinued at the age of five years and 11 months. However, rapid advance of bone age and vaginal spotting recurred after the withdrawal of treatment. She was re-evaluated at the age of six, and a magnetic resonance image (MRI) study of the head revealed a hypothalamic hamartoma. At that time, a long-acting analog of luteinizing hormone-releasing hormone (LHRHa), leuprolide acetate, was prescribed. Her secondary sex characteristics regressed and her hypothalamic-pituitary-gonad axis was suppressed after treatment. The clinical presentation, mechanism and treatment of precocious puberty caused by hypothalamic hamartomas are fully discussed in this report.

Autoimmune thyroiditis in children with Turner syndrome.

PURPOSE: To determine the frequency of autoimmune thyroiditis (AIT) and the risk of development of thyroid dysfunction in children with Turner syndrome. METHODS: From 1988 to 1998, 77 children with Turner syndrome were prospectively followed up at National Taiwan University Hospital. The mean (+/- standard deviation) age of these patients was 10.0 +/- 4.7 years at diagnosis of Turner syndrome and 17.4 +/- 5.2 years at the end of the present study. Antithyroglobulin antibody, antimicrosomal antibody, and thyroid function were assessed once every 6 months during the study period. RESULTS: Thyroid autoantibodies were detected in 21 of the 77 (27%) patients. The mean age at the detection of thyroid autoantibodies was 12.2 +/- 5.2 years. The cumulative frequency of AIT at 10 years after diagnosis of Turner syndrome was 36%. Both patients with a ring X chromosome developed AIT. Three of the 21 patients (14%) with AIT developed thyroid dysfunction. One patient developed hypothyroidism at the time of the detection of thyroid autoantibody. Two other patients were noted to have hyperthyroidism 0.5 and 2.5 years, after the detection of thyroid autoantibodies, respectively. CONCLUSIONS: Our data demonstrated a high frequency of AIT in Taiwanese children with Turner syndrome. Some of these patients later developed thyroid dysfunction. Hence, this study has confirmed that regular follow-up assessment of thyroid autoantibody and thyroid function in Taiwanese children with Turner syndrome regardless of their age is necessary for timely diagnosis of thyroid dysfunction and administration of appropriate treatment.

Genotype of classic congenital adrenal hyperplasia and the 60-minute adrenocorticotropic hormone stimulation test.

Twelve Taiwanese patients with classic congenital adrenal hyperplasia and 86 family members underwent human leukocyte antigen (HLA) genotyping and the 60-minute adrenocorticotropic hormone (ACTH) stimulation test. The baseline serum 17-hydroxyprogesterone level (mean +/- SEM) before ACTH testing was 1.595 +/- 792 nmol/L in homozygotes, 4.6 +/- 0.5 nmol/L in heterozygotes, and 2.1 +/- 0.8 nmol/L in the unaffected group. The stimulated serum 17-hydroxyprogesterone level (mean +/- SEM) was 1.926 +/- 778 nmol/L in homozygotes, 20.6 +/- 0.9 nmol/L in heterozygotes, and 6.8 +/- 0.6 nmol/L in the unaffected group. There was minimal overlap among the heterozygote and unaffected groups. The 60-minute ACTH stimulation test can provide clinicians with hormonal criteria for the assessment of the genotype of classic 21-hydroxylase deficiency in the Chinese population.

Partial DiGeorge anomaly associated with 10p deletion.

We report a girl with partial DiGeorge anomaly associated with a distal chromosome 10p deletion. The initial manifestation was hypocalcemia convulsion at the age of 14 days. The patient was small for her gestational age and showed symptoms of poor feeding and inspiratory stridor. Facial dysmorphisms included a cupped ear, hypertelorism downslanted and short palpebral fissures frontal bossing, anteverted nostrils, a flat nasal bridge, and micrognathia. Developmental delay was also noted. Hypoplasia of the thymus was detected by ultrasound examination, but results of immunologic studies were all normal at 6 weeks of age. The echocardiogram, brain ultrasound, electroencephalogram, and magnetic resonance images of the brain were normal, but brainstem auditory evoked potentials showed bilateral sensorineural hearing loss. Chromosomal analysis showed 16, XX, del(10)(p12.3); the parents had normal karyotypes. After treatment with vitamin D, calcium gluconate, and magnesium sulfate, the patient's serum calcium and magnesium levels were within normal limits. She was discharged and received regular follow-up at our clinic for physical therapy and to ensure adequate supply of divalent cations. Complex partial seizure was noted at the age of 1 year and was controlled with carbamazepine. To our knowledge, this is the first Taiwanese reported to have partial DiGeorge anomaly associated with 10p deletion. We recommend that standard karyotyping should be performed in children suspected to have this anomaly.

Sexual precocity due to intracranial human chorionic gonadotropin-secreting tumor: report of a case.

Human chorionic gonadotropin (HCG)-secreting tumors are one of the causes of isosexual precocity in boys. A seven-year-old boy had been noted to have an increased appetite, accelerated growth and the development of pubic hair in the previous three months. He had an elevated serum testosterone level (16.79 ng/mL). However, the response of luteinizing-hormone and follicle-stimulating-hormone to gonadotropin releasing hormone stimulation was suppressed. An intracranial tumor at the left thalamus was disclosed by a magnetic resonance image scan of the head, and an elevated HCG level (120 mIU/mL) was also noted. Sexual precocity due to an intracranial HCG-secreting tumor was diagnosed and a partial resection of the tumor followed by radiotherapy was carried out. His serum testosterone and HCG levels became undetectable, and the secondary sexual characteristics regressed after treatment.

Renal malformations in children with Turner's syndrome.

Between 1988 and 1999, renal sonography and intravenous urography were performed to detect renal malformations in 54 patients with Turner's syndrome (TS). The mean age of these patients at diagnosis of TS was 9.2 +/- 4.6 years. Renal malformations were detected in 21 patients by intravenous urography and there was no significant difference in the frequency of renal malformations among different karyotype groups. Horseshoe kidney was the most common renal malformation, followed by duplex kidney. Fifteen of 21 renal malformations were not detected by renal sonography. We conclude that these TS patients had a high frequency of renal malformations, and that the detection rate of horseshoe kidney and duplex kidney by renal sonography was not satisfactory. Although renal sonography alone can be used to detect more severe renal malformations that may need further management, it may underestimate the frequency of renal malformation in children with TS.

Intellectual outcome of patients with congenital hypothyroidism detected by neonatal screening.

BACKGROUND AND PURPOSE: Mental retardation is a major sequela of delayed treatment for congenital hypothyroidism; congenital hypothyroidism can be treated early if detected with neonatal screening. We evaluated the intellectual outcomes of 62 patients with congenital hypothyroidism detected by neonatal screening at a major teaching hospital in northern Taiwan. The effects of thyroid pathology, age at the initiation of treatment, socioeconomic status, and severity of hypothyroidism on intellectual outcome were also analyzed. METHODS: All patients had euthyroid status at the time of intelligence testing. The Chinese Fourth Revision of the Binet-Simon Scales was used to evaluate the patients' intelligence between the ages of 3 and 6 years. RESULTS: The mean intelligence quotient (IQ) score was 102 +/- 18. Only four of the 62 patients were mentally retarded. Patients with lower initial serum thyroxine concentrations (T4; < 2 micrograms/dL) at the time of diagnosis of congenital hypothyroidism had significantly lower IQs (95 +/- 19, n = 26) than those with higher initial T4 concentrations (106 +/- 16, n = 36; p < 0.05). Patients with fewer than three ossification centers had lower IQs (91 +/- 20, n = 12) than those with three or more (104 +/- 17, n = 36; p < 0.05). Significantly lower IQs were also found in patients with a smaller femoral epiphysis area (< 0.1 cm2) (92 +/- 20, n = 15) than in those with larger epiphyses (106 +/- 15, n = 21; p < 0.05). The type of pathology (ectopia, athyrosis, dyshormonogenesis), age at the start of treatment (before or after 30 days of age), and socioeconomic status did not significantly affect the intellectual outcome. CONCLUSIONS: Our results indicate that intellectual outcome in Taiwanese patients with congenital hypothyroidism has been improved by neonatal screening and that the severity of hypothyroidism at diagnosis is the most important prognostic factor affecting intellectual outcome in these patients.

Intellectual outcomes of patients with congenital hypothyroidism not detected by neonatal screening.

Mental retardation is a major sequela of delayed treatment of congenital hypothyroidism. In this study, we investigated the intellectual outcomes of patients with congenital hypothyroidism diagnosed before a nationwide screening project started. Eighty-two patients had intelligence tests done while in the euthyroid state. Their mean intelligence quotient (IQ) was 78 +/- 21 (+/- SD) (n = 79). The mean verbal IQ was significantly higher than the mean full-scale IQ. The mean IQs of both ectopic thyroid (84 +/- 21, n = 28) and dyshormonogenic patients (85 +/- 14, n = 18) were significantly higher than that of patients with athyrosis (64 +/- 18, n = 19) (p < 0.05). Patients who were treated before 3 months of age had significantly higher mean IQs (90 +/- 16, n = 16) than those treated after 3 months (75 +/- 21, n = 63) (p < 0.01). Our results confirm that both patients with ectopic thyroids and those with dyshormonogenesis have better intellectual outcomes than athyrotic patients do, and that early treatment improves the intellectual outcome of patients with congenital hypothyroidism.

Nephrocalcinosis in childhood.

Charts of 16 children with nephrocalcinosis between 1990 and 1997 were reviewed. The cause of nephrocalcinosis was believed to be iatrogenic in 7 patients (43.8%) and non-iatrogenic in 9 (56.2%). Vitamin D therapy was responsible for 5 patients of iatrogenic nephrocalcinosis, and furosemide therapy for the remaining iatrogenic patients. Non-iatrogenic cases consisted of 3 patients with renal tubular acidosis, 3 patients with idiopathic hypercalciuria, and the 3 other patients with rare underlying conditions. Abdominal X-ray detected nephrocalcinosis in only 2 (12.5%) of the total 16 patients. None showed resolution of nephrocalcinosis during these years of follow-up.

Cloning of zebrafish cDNA for 3beta-hydroxysteroid dehydrogenase and P450scc.

P450scc and 3beta-HSD cDNA were isolated from a zebrafish lambda gt10 cDNA library using trout SCC and 3beta-HSD cDNA as the probes. The zebrafish SCC cDNA encodes a protein of 509 amino acids, which shares a 78% similarities with the trout SCC and 58% with the human SCC. As for 3beta-HSD, two forms of cDNA were isolated, termed HSD 5 and HSD 17, which may have resulted from alternative splicing. HSD 5 and HSD 17 encode proteins of 374 and 341 amino acids respectively. Both share 77% amino acid similarities with trout 3beta-HSD and 53% similarities with the mouse 3beta-HSD. Zebrafish has been increasingly used as a genetic model system to study organ development and to investigate human diseases. The cloning and the characterization of zebrafish P450scc and 3beta-HSD should facilitate study of steroidogenesis and human disease associated with steroid imbalance.

Gastrointestinal perforation in infants: cases unrelated to necrotizing enterocolitis.

From January 1984 to March 1992, there were 19 infants admitted to our hospital with gastrointestinal perforation not associated with necrotizing enterocolitis. Seven patients (37%) were premature. Six patients (32%) had their perforations located in the stomach, 9 (47%) in the small intestine, and 3 (16%) in the colon. The most common clinical presentation was abdominal distention (95%). Pneumoperitoneum was noted only in 12 (63%) patients. About 60% of the patients had the perforation occur before 4 days of age. The predominant cause of perforation was unknown, so called spontaneous perforation (8/19, 42%), followed by ischemia or infarction (5/19, 26%). The overall mortality rate was 32%. The non-survivors had more severe metabolic acidosis than the survivors, but there were no differences in the birthweight and gestational ages of these two groups. Sepsis accounted for 83% of the deaths. Early diagnosis and treatment are the best ways to promote survival.

An unusual testicular metastasis from transitional cell carcinoma of the ureter: a case report.

Testicular tumor metastasis from transitional cell carcinoma (TCC) of the ureter is very rare. Herein, we report a case who presented with a palpable mass of left testis, after he underwent radical nephroureterectomy and bladder cuff excision and adjuvant radiotherapy and chemotherapy for the TCC of left ureter tumor for 5 months. We performed left radical orchiectomy and histology revealed a TCC identical to the original ureteral tumor. In a review of the literature, we found this case was the second case of metastatic testicular tumor from the ureteral TCC. In patients presenting the symptom of a palpable testicular mass, if they are known to have a ureteral TCC, metastatic neoplasm should be considered in the differential diagnosis, even if in the absence of other systemic metastasis.

Urinary N-acetyl-beta-D-glucosaminidase activity in children with insulin-dependent diabetes mellitus.

Urinary N-acetyl-beta-D-glucosaminidase (NAG) is a sensitive indicator of renal tubular injury. The aim of the study is to determine the status of urinary NAG excretion in Chinese children with insulin-dependent diabetes mellitus (IDDM) but without any clinical evidence of nephropathy, and to try to find the possible associated factors of such tubular injury if any. Thirty-one children (8 males and 23 females) with IDDM who have normal serum creatinine, 24-hour urinary creatinine clearance and urinary total protein excretion were enrolled in the study. The mean age of the patients was 11.6 +/- 3.7 years. The random urinary NAG levels of the patients and the normal controls were 10.76 +/- 6.32 and 3.65 +/- 1.84 U/g Cr, respectively (p < 0.001). The diabetic patients were divided into 4 groups according to their duration of disease ( < 3, 3-5, 5-10 and 10-16 years). The random urinary NAG level of each group was significantly higher than that of the control group, but there was no statistically significant difference among any 2 of these 4 groups. No good correlation was noted in our study between urinary NAG and patients' age (r = -0.23, p = 0.21), serum cholesterol (r = 0.04, p = 0.84), insulin dosage (r = 0.13, p = 0.49), 24 hour urinary creatinine clearance (r= -0.41, p - 0.085) or urinary total protein excretion (r = -0.28, p = 0.26). However, the plasma HbAlc level correlated significantly with urinary NAG (r = 0.50, p < 0.01). We concluded that urinary NAG is increased in Chinese IDDM children without any clinical evidence of nephropathy. Such increased excretion is correlated with the plasma HbAlc level. Our results suggests that there is tubular dysfunction in the early stage of IDDM children even before there is any clinical evidence of nephropathy, and urinary NAG may reflect glycemic control in such patients.

Characterization of duplicated zebrafish cyp19 genes.

The zebrafish has recently been developed as a good genetic model system. We report here the use of zebrafish to study the regulation of estrogen biosynthesis. The CYP19 gene encodes cytochrome P450 aromatase, which catalyzes the synthesis of estrogens. Two cyp19 genes, termed cyp19a and cyp19b, have been isolated from zebrafish. Sequence comparison shows that Cyp19a and Cyp19b belong to two separate Cyp19 subfamilies. The cyp19a gene is expressed in the ovary, whereas cyp19b is expressed in the brain. The cyp19a and cyp19b genes are located on zebrafish chromosomes LG 18 and 25, respectively. Our data indicate that these gene loci arose through an ancient chromosomal duplication event. The expression of duplicated genes in distinct tissues may have evolutionary significance.