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OBJECTIVE Serum amino-terminal propeptide of C-type natriuretic peptide (NT-proCNP) levels have been proposed as a biomarker of linear growth in healthy children. The usefulness of NT-proCNP in patients with achondroplasia (ACH)/hypochondroplasia (HCH) remains to be elucidated. The objective was to study whether serum NT-proCNP level is a good biomarker for growth in ACH/HCH and other patients of short stature. DESIGN This was a longitudinal cohort study. PATIENTS Sixteen children with ACH (aged 0·4-4·3 years), six children with HCH (2·7-6·3 years), 23 children with idiopathic short stature (ISS) (2·2-9·0 years), eight short children with GH deficiency (GHD) (2·9-6·8 years) and five short children born small for gestational age (SGA) (2·0-6·6 years). Patients with ACH/HCH received GH treatment for 1 year. MEASUREMENTS Serum NT-proCNP levels and height were measured. RESULTS NT-proCNP levels positively correlated with height velocity in these short children (P < 0·05, r = 0·27). NT-proCNP levels inversely correlated with age in children with ISS alone (P < 0·01, r = -0·55). Serum NT-proCNP levels in patients with ACH/HCH were increased 3 months following the initiation of GH treatment (P < 0·05). Height SDS gain during GH treatment for 1 year was positively correlated with the changes in NT-proCNP levels after the initiation of GH (P < 0·01, r = 0·72). CONCLUSION Serum NT-proCNP levels may be a good biomarker to indicate the effect of GH treatment on growth in patients with ACH/HCH at least in the first year and height velocity in short stature patients.

Background/Aims: Vitamin D-deficient rickets (DR) has recently re-emerged among developed countries. Vitamin D deficiency can influence biochemical results of patients with fibroblast growth factor 23 (FGF23)-related hereditary hypophosphatemic rickets (HR), making differential diagnosis difficult. In the present study we evaluated the utility of serum FGF23 levels in the diagnosis of DR and during its treatment. Methods: The study group comprised 24 children with DR and 8 children with HR. Serum FGF23 levels and bone metabolism-related measurements were assessed. Results: Serum FGF23 levels in patients with DR were less than 19 pg/ml, while those in patients with HR were more than 57 pg/ml. There were significant differences in serum levels of calcium, phosphate, parathyroid hormone, and 1,25-dihydroxyvitamin D, as well as tubular maximum phosphate reabsorption per glomerular filtration rate between patients with DR and HR, but these values were not fully mutually exclusive. In addition, serum FGF23 and phosphate levels were increased following treatment. Conclusion: Serum FGF23 level is the most critical biochemical marker for distinguishing DR from HR and might be a good indicator of biochemical response to the intervention. Serum FGF23 levels show utility for the diagnosis of DR and in the assessment of its response to treatment.

Recessive dystrophic epidermolysis bullosa (RDEB) is a severe skin disorder. Although the patients are at risk for cutaneous squamous cell carcinoma (SCC), no case of cutaneous SCC derived from RDEB with humoral hypercalcemia of malignancy (HHM) has been reported. We present the first case report of a male patient with HHM with leukocytosis caused by cutaneous SCC resulting from RDEB. A 20-yr-old Japanese male patient with RDEB; the diagnosis was confirmed by electron microscopic examination, suffered an intractable skin ulcer and hypercalcemia and leukocytosis. PTH-rP, SCC antigen and Granulocyte colony-stimulating factor (G-CSF) levels were elevated. The histological diagnosis of the skin lesion was made well-differentiated SCC. Immunohistochemical staining showed the expression of PTH-rP in atypical tumor cells. For the control of hypercalcemia before an amputation, we used zoledronate safely and could control the serum Ca concentration in the normal range. After the amputation of his right leg including SCC, leukocytosis improved immediately and PTH-rP in blood decreased to the normal range. One month after the amputation, local recurrence of cutaneous SCC and multiple lung metastases were observed. PTH-rP increased gradually associated with hypercalcemia. Although the patient reached an unfortunate turning point about 4 mo after the amputation, we propose that zoledronate is an effective and safe treatment for HHM with cardiorenal complications.

We report a male infant with FATCO syndrome, an acronym for fibular aplasia, tibial campomelia, and oligosyndactyly. Courtens et al. reported an infant with oligosyndactyly of the left hand, complete absence of the right fibula, bowing of the right tibia, and absence of the right fifth metatarsal and phalanges. They noted 5 patients with similar clinical features, and proposed the FATCO syndrome. Our patient had a left-sided cleft lip, cleft palate, oligosyndactyly of the right hand and bilateral feet, and bilateral anterior bowing of the limbs associated with overlying skin dimpling. Radiographs showed a short angulated tibia with left fibular aplasia and right fibular hypoplasia. We consider our case the 6th patient with FATCO syndrome, and the cleft lip and palate, not reported in the previous 5 patients, may allow us to further understand the development of the extremities and facies.

We recently found a constitutively active mutant of natriuretic peptide receptor 2 (caNPR2; V883M), which synthesizes larger amounts of cyclic guanosine monophosphate (cGMP) intracellularly without any ligand stimulation than existing drugs. The aim of this study was to investigate the therapeutic effects of gene transduction using caNPR2 for pulmonary arterial hypertension (PAH). In vitro gene transduction into human pulmonary arterial smooth muscle cells using Sendai virus (SeV) vectors carrying caNPR2 induced 10,000-fold increases in the synthesis of cGMP without ligand stimulation, and the proliferation of caNPR2-expressing cells was significantly attenuated. The PAH model rats generated by hypoxia and the administration of SU5416 were then treated with SeV vectors through a direct injection into the left pulmonary artery. Right ventricular systolic pressure was significantly decreased 2 weeks after the treatment, while systemic blood pressure remained unchanged. Histological analyses revealed that the medial wall thickness and occlusion rate of pulmonary arterioles were significantly improved in caNPR2-treated lungs. Neither the systemic integration of virus vectors nor side effects were observed. The massive stimulation of cGMP synthesis by gene therapy with caNPR2 was safe and effective in a PAH rat model and, thus, has potential as a novel therapy for patients with severe progressive PAH.

Caffey disease, also known as infantile cortical hyperostosis, is a rare bone disease characterized by acute inflammation with swelling of soft tissues and hyperostosis of the outer cortical surface in early infancy. The common heterozygous mutation of the COL1A1 gene, p.Arg1014Cys, has been reported in patients with Caffey disease. However, its pathogenesis remains to be elucidated, and the reason for the incomplete penetrance and transient course of the disease is still unclear. In the present study, we performed mutation analysis of the COL1A1 and COL1A2 genes and measured bone mineral density in two Japanese familial cases of Caffey disease. The index case and two clinically healthy members of one family carry the common heterozygous mutation; in contrast, no mutation in COL1A1 or COL1A2 was identified in the affected members of the second family. In addition, we found normal bone mineral density in adult patients of both families who have had an episode of cortical hyperostosis regardless of the presence or absence of the common p.Arg1014Cys mutation. Conclusion: The results reveal that Caffey disease is genetically heterogeneous and that affected and unaffected adult patients with or without the common COL1A1 mutation have normal bone mineral density.

Fibroblast growth factor 23 (FGF23) plays a central role in phosphate (P) homeostasis. However, the precise mechanism of how FGF23 secretion is regulated remains to be elucidated. In the present study, we examined the effect of intravenous pamidronate administration on serum levels of FGF23. Thirteen patients with osteogenesis imperfecta were treated with two cycles of 3-day pamidronate infusion. Blood samples at pre- and post-drip pamidronate infusion were evaluated for serum calcium, P, intact PTH (iPTH), 1,25(OH)(2)D, intact FGF23 (FGF23), type I collagen cross-linked N-telopeptides (NTx), bone-specific alkaline phosphatase (BAP), and TmP/GFR. During the two cycles, FGF23 levels decreased significantly preceding the decline in P levels. Although the change in P levels became less apparent during the second cycle, the reduction in FGF23 levels was similar during both cycles. Moreover, absence of correlation between FGF23 and P indicates that FGF23 attenuation is independent of the decrease in P levels during pamidronate infusion. Significant correlation between NTx suppression and the decrease in FGF23 levels during the 1st cycle (r = 0.665, P = 0.013) suggests that inhibition of osteoclast function may have some role in suppressing FGF23 levels. Because pamidronate dose was most associated with the decrease in FGF23 levels during the second cycle, pamidronate may directly attenuate osteocyte/osteoblast-mediated FGF23 production. This is the first evidence of a rapid fall in FGF23 levels following pamidronate infusion, raising the possibility that inhibition of bone resorption and/or direct effects of pamidronate may suppress secretion of FGF23.

A 10-year-old boy was injured in a traffic accident, and computed tomography revealed cavitary pulmonary lesions in the left lower lobe. Although there was no evidence of bacterial infection, thrombocytopenia due to disseminated intravascular coagulation progressed. We performed a left lower lobectomy, and the patient improved rapidly.

The chronic intravenous toxicity of cefodizime sodium (THR-221) was studied in beagle dogs. Groups of 6 males and 6 females were treated with THR-221 at doses of 0 (saline), 200, 400, 800 and 1600 mg/kg/day for 6 months. The THR-221 related symptoms were vomiting, excessive drinking behavior and salivation. The paleness of the visible mucosa and discoloration of vascular color by funduscopy due to systemic anemia were observed in one animal each of 800 and 1600 mg/kg/day groups. Body weight was depressed transiently or continuously in a few animals of 400 - 1600 mg/kg/day groups. The hematological, serum chemical and urinalysis findings in a few animals of 400 - 1600 mg/kg/day groups revealed decreases in RBC count, PCV and hemoglobin, an increase in reticulocyte count, a decrease in WBC count, a decrease in platelet count, slight increase in TP. and albumin, a decrease in AlP, and an increase in urinary Na. Light microscopically, deposition of hemosiderin and increased extramedullary hematopoiesis in the liver and spleen, and deposition of fibroid substance in the white pulp of the spleen and diffuse fibrosis in the bone marrows were detected in a few animals of 800 and 1600 mg/kg/day groups. Electron microscopically, no significant toxic changes were observed. The maximum nontoxic doses of THR-221 are estimated as 200 mg/kg/day in male and less than 200 mg/kg/day in female.