Lipoblastoma with aberration in the long arm of chromosome 8.

We report a case of lipoblastoma in a 6-month-old girl with a new chromosomal aberration, 46, XX, der (2) add (2) (p23) del (2) (q33), add (8) (q1?). In addition to the patient's age and pathological features, aberration of long arm of chromosome 8 in lipoblastoma can assist the differential diagnosis from myxoid or well differentiated liposarcoma.

Inactivation of N-terminal signaling domain of Sonic hedgehog by forming a disulfide bond.

The N-terminal domain of mouse Sonic hedgehog (Shh-N) expressed in mammalian cells showed four-fold bands on non-reduced SDS-PAGE, though it was homogeneous under reduced conditions. It contains three cysteine residues, Cys-25, Cys-103, and Cys-184, which may be concerned with this heterogeneity. Therefore, we examined the formation of a disulfide bond in the recombinant Shh-N and identified three kinds of disulfides with a combination of peptide mapping and NH(2)-terminal amino acid sequencing analysis. Among them, one type of the Shh-N containing a disulfide bond of Cys-103/Cys-184 could be separated from the other Shh-Ns using reverse phase HPLC and had no activity of alkaline phosphatase induction in C3H10T1/2 cells. This molecule could also be made by denaturation of the purified Shh-N with guanidine-HCl under non-reduced conditions. On the other hand, the reduced Shh-N and the reduced S-methylated Shh-N at cysteine residues showed approximately 10-fold higher activity compared to the originally purified Shh-N. These results suggested that Shh-N was synthesized as an active form whose three cysteine residues did not form disulfide and inactivated finally by forming a disulfide bond between Cys-103 and Cys-184.

Intermittent jaundice in patients with acute leukaemia: a common mutation of the bilirubin uridine-diphosphate glucuronosyltransferase gene among Asians.

The Gly71Arg mutation of the hepatic bilirubin UDP glucuronosyl-transferase (B-UGT) gene associated with Gilbert syndrome prevails among Japanese and its gene frequency is 0.13. Among 20 patients with acute leukaemia, 4 patients showed intermittent unconjugated hyperbilirubinaemia during the course of combined chemotherapy. The Gly71Arg mutation was detected in all 4 patients with hyperbilirubinaemia, but was not found in 16 patients without hyperbilirubinaemia. Two of them were heterozygotes and one was a homozygote for the Gly71Arg mutation, and the other was a compound heterozygote of the Gly71Arg mutation and TA insertion mutation in the TATA box of the B-UGT gene. In addition to the complications leading to hyperbilirubinaemia, including liver damage due to drugs, viral infections or tumour cell infiltrations and alloimmune haemolysis, carrier status for the Gly71Arg mutation should be considered in a patient with leukaemia showing intermittent hyperbilirubinaemia during the course of chemotherapy, especially among Japanese, Koreans and Chinese owing to its prevalence in those populations.

Identification and characterization of a novel protein, periostin, with restricted expression to periosteum and periodontal ligament and increased expression by transforming growth factor beta.

We had previously identified the cDNA for a novel protein called osteoblast-specific factor 2 (OSF-2) from an MC3T3-E1 cDNA library using subtraction hybridization and differential screening techniques. Here we describe the localization, regulation, and potential function of this protein. Immunohistochemistry using specific antiserum revealed that in adult mice, the protein is preferentially expressed in periosteum and periodontal ligament, indicating its tissue specificity and a potential role in bone and tooth formation and maintenance of structure. Based on this observation and the fact that other proteins have been called OSF-2, the protein was renamed "periostin." Western blot analysis showed that periostin is a disulfide linked 90 kDa protein secreted by osteoblasts and osteoblast-like cell lines. Nucleotide sequence revealed four periostin transcripts that differ in the length of the C-terminal domain, possibly caused by alternative splicing events. Reverse transcription- polymerase chain reaction analysis revealed that these isoforms are not expressed uniformly but are differentially expressed in various cell lines. Both purified periostin protein and the periostin-Fc recombinant protein supported attachment and spreading of MC3T3-E1 cells, and this effect was impaired by antiperiostin antiserum, suggesting that periostin is involved in cell adhesion. The protein is highly homologous to betaig-h3, a molecule induced by transforming growth factor beta (TGF-beta) that promotes the adhesion and spreading of fibroblasts. Because TGF-beta has dramatic effects on periosteal expansion and the recruitment of osteoblast precursors, this factor was tested for its effects on periostin expression. By Western blot analysis, TGF-beta increased periostin expression in primary osteoblast cells. Together, these data suggest that periostin may play a role in the recruitment and attachment of osteoblast precursors in the periosteum.

The NH2-terminal region of the active domain of sonic hedgehog is necessary for its signal transduction.

The NH2-terminal domain of sonic hedgehog (residue 25-198) was expressed in both yeast and animal cells. The yeast-derived NH2-terminal domain of sonic hedgehog was less active by far than the animal cell-derived counterpart. The yeast-derived NH2-terminal domain of sonic hedgehog lacked 10 amino acids from the NH2-terminus. This cleavage of the yeast-derived NH2-terminal domain of sonic hedgehog might due to Kex 2. In contrast, a mutant yeast-derived NH2-terminal domain of sonic hedgehog (Lys-33 to Thr) retained its NH2-terminus and its activity was comparable to that of the animal cell-derived NH2-terminal domain of sonic hedgehog. The NH2-terminal deleted NH2-terminal domain of sonic hedgehog completely lost its activity, nevertheless it inhibited the alkaline phosphatase activity induced by the animal cell-derived NH2-terminal domain of sonic hedgehog in a dose-dependent manner. These data suggest that the NH2-terminal deleted NH2-terminal domain of sonic hedgehog retains a receptor-binding ability and that the NH2-terminal peptide of the NH2-terminal domain of sonic hedgehog is necessary for its signal transduction.

Novel breakpoints of the EWS gene and the WT1 gene in a desmoplastic small round cell tumor.

We report here a 15-year-old boy with an intraabdominal desmoplastic small round cell tumor (DSRCT). Cytogenetic analysis of the tumor cells showed the chromosomal translocation (11;22). Reverse-transcriptase polymerase chain reaction and sequencing analysis revealed a chimeric transcriptional message of the EWS gene exon 10 fused to the WT1 gene exon 8. The typical chimeric transcript seen in DSRCT is an in-frame fusion of EWS exon 7 to WT1 exon 8. The tumor in this case had a novel and longer chimeric transcript, which should be a potent transcription factor. Genetic analysis is a very powerful and specific aid in the differential diagnosis of small round cell tumors.

Multiple sulphatase deficiency and haemophagocytic syndrome.

A 3-year-old boy with multiple sulphatase deficiency, complicated by a haemophagocytic syndrome, recovered with conventional treatment. Haemophagocytic syndrome can be a complication of many disorders including metabolic diseases, frequently triggered by intracellular viral and bacterial infections or even by drug administration.

Severe bleeding tendency in a patient with Bernard-Soulier syndrome associated with a homozygous single base pair deletion in the gene coding for the human platelet glycoprotein Ibalpha.

PURPOSE: The genetic basis of Bernard-Soulier syndrome (BSS) was studied to clarify a relationship between severe clinical manifestations and gene abnormality. PATIENT AND METHODS: A patient with BSS had a severe bleeding tendency that was sometimes life threatening. Flow cytometric analysis of the patient's and normal control platelets was performed to study which glycoprotein (GP) was impaired in glycoprotein Ib/V/IX complex. The genes encoding GPIbalpha from the patient's and control genomic DNA were amplified and directly sequenced. RESULTS: Flow cytometric analysis revealed a defect of GPIbalpha on the surface of the patient's platelets. A homozygous single base pair deletion was identified in seven repeats of adenine at positions 1932 to 1938 in the GPIbalpha gene. This mutation, which has been previously reported, results in a frameshift and predicts a premature stop codon leading to a truncated peptide that cannot fix on the platelet membrane. CONCLUSION: This patient's severe clinical phenotype would be explained by this mutation in the GPIbalpha gene.

Muscular dystrophy associated with extra-abdominal desmoid tumor showing aberrant chromosome 1 [46,XX,add(1)(p36)].

We report on a 2-year-old girl with probable limb-girdle muscular dystrophy associated with an extra-abdominal desmoid tumor of the right mandible. This association is previously undescribed. The tumor was totally removed. Cytogenetic analysis of the tumor showed a clonal karyotypic abnormality: 46,XX,add(1)(p36) in 3 of 20 cells analyzed. Since an association of a neoplasm with limb-girdle muscular dystrophy has previously been reported in 3 cases, the two abnormalities are likely related causally. The chromosome abnormality in our patient may play a role in the occurrence of her desmoid tumor.

CD48 expression on leukocytes in infectious diseases: flow cytometric analysis of surface antigen.

BACKGROUND: The function of CD48, one of the pan leukocyte cell surface antigens, is not yet well understood. CD48 was recently shown to enhance the CD40-mediated activating signal to B lymphocytes. As CD48 is one of the activation antigens of monocytes, neutrophils and lymphocytes, a change of its expression on the cells could be expected in infectious diseases. METHODS AND RESULTS: Leukocytes from 27 healthy controls and 97 patients with various infectious diseases were stained with anti CD48 antibody and analyzed by flow cytometry. On monocytes and neutrophils, the CD48 expression was increased in all of the patients with varicella, measles, rubella, infectious mononucleosis, streptococcus tonsillitis, sepsis and appendicitis. On lymphocytes, a significant increase of CD48 was also detected in the patients with the same diseases, except those with sepsis or appendicitis. The normalization of increased CD48 expression was confirmed on monocytes at the convalescent phase. CONCLUSION: These data suggest that CD48 expression on leukocytes reflects the disease activity of infectious diseases, especially of viral infections.

Defective signal transduction through the thromboxane A2 receptor in a patient with a mild bleeding disorder: deficiency of the inositol 1,4,5-triphosphate formation despite normal G-protein activation.

We describe an 11-year-old girl with a mild bleeding disorder since early childhood. The disorder was characterized by a prolonged bleeding time, and the patient's platelets showed defective aggregation responses to thromboxane A2 (TXA2) mimetic U46619 and arachidonic acid. In contrast, the platelets showed normal responses to thrombin and Ca ionophore A23187. When the platelet TXA2 receptor was examined with the [3H]-labeled TXA2 agonist U46619, the equilibrium dissociation rate constants (kd) and the maximal concentration of binding sites (Bmax) of the patient's platelets were within normal ranges. Normal GTPase activity was also induced in the patient's platelets by stimulation with U46619, however, inositol 1,4,5-triphosphate (IP3) formation was not induced by U46619. These results suggests that the patient's platelets had a defect in phospholipase C activation beyond TXA2 receptors.

Microangiopathic hemolytic anemia and thrombocytopenia in a child with atrial septal defect and pulmonary hypertension.

Microangiopathic hemolytic anemia and thrombocytopenia have been reported in patients with primary pulmonary hypertension, but not in patients with congenital heart disease even if accompanied with pulmonary hypertension. We present a 7-year-old boy with atrial septal defect and pulmonary hypertension who developed microangiopathic hemolysis and thrombocytopenia. Microangiopathic hemolytic anemia and thrombocytopenia should be remarked as a complication in patients with congenital heart disease.

Severe hypertension and cardiac failure associated with neuroblastoma: a case report.

The authors report on 3-year-old-girl with neuroblastoma complicated by severe hypertension and cardiac failure. She had cardiomegaly and pleural and pericardial effusions. Echocardiogram showed left ventricular hypertrophy and decrease of the left ventricular ejection fraction to 0.36 (normal > .40). Abdominal computed tomographic scan indicated a 7 x 7-cm tumor in the left suprarenal area. There was a marked increase in catecholamines and metabolites in her body fluids. After hypertension was controlled with doxazosin (a long-acting alpha 1 adrenergic blocker), her cardiac function gradually improved. A tumor was surgically removed and diagnosed as a poorly differentiated ganglioneuroblastoma. Preoperative differentiation between neuroblastoma and pheochromocytoma was not possible on the basis of catecholamine analysis or imaging studies including computed tomography scan and magnetic resonance imaging. It is important to control hypertension quickly in the patients with catecholamine-induced cardiomyopathy to facilitate surgical intervention for diagnosis and treatment.

Increased expression of CD48 on neutrophils activated in childhood patients with aplastic anemia.

Activation-associated antigens such as CD11b, CD14 and CD64 of neutrophils have been reported. Although CD48 is an activation antigen of lymphocytes and monocytes, whether it is an activation antigen of neutrophils has not previously been examined. Herein, using FACS analysis, we examined the expression of surface CD48 on neutrophils activated in vivo by G-CSF administered for the treatment of idiopathic aplastic anemia. CD48 expression was increased 24 h after the initial G-CSF infusion and peaked within 1 week. Within a few days after discontinuation of G-CSF administration, it returned to the pretreatment level. This indicates that CD48 is an activation antigen of neutrophils.

Detection of transforming growth factor alpha in human urine and plasma.

A sensitive enzyme-linked immunosorbent assay (ELISA) system for human transforming growth factor alpha (TGF alpha) was developed in combination with polyclonal and monoclonal antibodies. Employing this assay system, we detected TGF alpha like activity in normal human plasma as well as in cancer patients' urine and plasma. These TGF alpha were analyzed by chromatography, immunoreactivity, and EGF-TGF alpha receptor binding assay and found to be identical to authentic human TGF alpha. The presence of TGF alpha circulating in normal adult plasma suggests a new role of TGF alpha in the human body.

Topographic analysis of human epidermal growth factor by monospecific antibodies and synthetic peptides.

The mode of interaction between human epidermal growth factor (hEGF) and its receptor has been investigated by immunochemical studies and a synthetic peptide approach. Two types of monoclonal and five different monospecific polyclonal antibodies against hEGF have been prepared, whose epitopes are regions 1-13, 13-32, 33-53, 33-43, 22-32, and discontinuous sequences of hEGF. Antibody against 22-32 (Type I) and antibody against 33-53 (PRE 4) inhibited the binding of 125I-hEGF to membrane receptor on A 431 cells more markedly than the other antibodies. When hEGF was bound to the receptor, only antibody against 13-32 (PRE 2) could bind to hEGF-receptor complex whereas antibody against 22-32 (Type I) could not. These data suggest that region 13-20 is exposed outside during receptor-binding and both region 22-32 and region 33-53 contact the hEGF receptor. The activity of synthetic peptides corresponding to the amino acid residues 1-13, 13-32, 33-53, 13-20, 22-32, and 33-43 of hEGF was also examined. Out of the six peptides, only 13-32 stimulated DNA synthesis of BALB 3T3 cells. The activity was approximately 1/10(6) of that of intact hEGF. All of these data suggest that region 22-32 is responsible for binding to the receptor for signal transduction and region 33-53 binds to the receptor to stabilize the ligand-receptor interaction. This dual binding model fits in well with the three-dimensional hEGF structure deduced from NMR spectra.