Jen-Her Lu

Characteristics of Kawasaki disease in infants younger than six months of age.

Background: Kawasaki disease is the leading cause of acquired heart disease in childhood. However, there are only a few reports in infants younger than 6 months. The objective of this study is to investigate the clinical and laboratory characteristics of Kawasaki disease in infants younger than 6 months. Methods: From 1994 to 2003, 120 patients with Kawasaki disease diagnosed at our institution were included. Group 1 consisted of 20 (17%) patients younger than 6 months, and group 2 consisted of 100 (83%) patients older than 6 months. Clinical manifestations, laboratory results, echocardiographic findings, treatment and outcome were compared between these 2 groups. Results: Clinical manifestations (hydrops of gallbladder: 0% versus 16%, P < 0.001) and laboratory results (white blood cell count 21,740 ± 11,706 versus 11,830 ± 4390/mm3, P < 0.001; hemoglobin 9.98 ± 1.25 versus 10.8 ± 1.37 g/dL, P = 0.015; platelet 483 ± 393 versus 355 ± 138 × 1000/mm3, P = 0.011; triglyceride 138 ± 77.5 versus 107 ± 17 mg/dL, P < 0.001) were different between patients with Kawasaki disease younger and older than 6 months, respectively. Younger infants were more likely to have incomplete presentation (35% versus 12%, P = 0.025), coronary involvement (65% versus 19%, P < 0.001), late intravenous immunoglobulin treatment and relatively poor outcome. Conclusions: Infants younger than 6 months with prolonged unexplained febrile illnesses should be suspected as having Kawasaki disease, despite the incomplete clinical presentation. Because early diagnosis and timely treatment are difficult in younger infants with Kawasaki disease because of delayed and incomplete clinical presentations, echocardiogram becomes an important implement for diagnosis. Early intravenous immunoglobulin treatment is required in view of the highest risk of coronary involvement in them.

Heparinization on pericardial substitutes can reduce adhesion and epicardial inflammation in the dog

OBJECTIVE Primary concerns about currently available pericardial substitutes include adhesion and epicardial reaction. The purpose of this study is to evaluate host reaction to pericardial substitutes with and without incorporating slow heparin release. METHODS To avoid biologic variation among these pericardial patches, we made a composite of six membranes. The composite membrane consisted of epoxy-fixed patches with (1) or without (2) ionically bound heparin, a glutaraldehyde-fixed patch with (3) or without (4) ionically bound heparin, an expanded polytetrafluoroethylene patch (5), and a polyester polymeric patch (6). Ten recipient dogs weighing from 12 to 19 kg (mean 13.6 kg) were used to assess the composite membranes as pericardial substitutes. The implanted composite membranes were retrieved 1 week (one dog), 2 weeks (one dog), 4 weeks (one dog), 8 weeks (one dog), and 12 weeks (six dogs) after implantation. RESULTS Overall, the synthetic patches had a more notable inflammatory reaction than the biologic patches with or without ionically bound heparin. The heparin-bound patches caused significantly less inflammation than their nonheparinized counterparts. The heparinized porcine patches cross-linked with different compounds were found to have less fibrous formation than the nonheparinized patches and the synthetic patches. CONCLUSIONS Heparinized pericardial substitutes may cause less adhesion and inflammatory reaction than nonheparinized material.

Prevalence and parental origin in tetralogy of Fallot associated with chromosome 22q11 microdeletion

Objective. Tetralogy of Fallot is a common cardiac anomaly that is associated with chromosome 22q11 microdeletion. In this study we examined the mode of transmission as well as the parental origin of microdeletion in patients with tetralogy of Fallot. Methods. Eighty-four children with sporadic tetralogy of Fallot (40 boys and 44 girls; mean age, 34 months) were analyzed for microdeletion at chromosome 22q11 by genotype analysis, using five microsatellite markers, D22S427, D22S941, D22S944, D22S264 and D22S311, and confirmed by quantitative polymerase chain reaction, using TUPLE1 and D22S264. All parents of these subjects consented to their own participation and their childs participation in the clinical evaluation and molecular study. To provide a molecular characterization of microdeletion, we isolated DNA from the parents and typed their DNA with each of the five polymorphic markers. Results. Sixty-six patients were associated with pulmonary stenosis; and 8 of these cases (12%) had microdeletion. Eighteen patients were associated with pulmonary atresia, and 6 (33%) of these cases had microdeletion. The parental origins of the 14 patients with microdeletion were paternal in 3 cases and maternal in 11 cases. The most common mode of transmission was de novo without parental hemizygosity (93%). Transmission by autosomal dominant heredity was uncommon (7%). Conclusions. Biased parental origin was consistently found in tetralogy of Fallot patients with chromosomal 22q11 microdeletion. Our results indicated a higher prevalence of microdeletion because of inheritance of maternal microdeletion (78%).

Monozygotic Twins with Chromosome 22q11 Microdeletion and Discordant Phenotypes in Cardiovascular Patterning

Abstract. Monozygotic twins with chromosome 22q11 microdeletions offer an ideal situation to observe the association of microdeletion and disrupted cardiovascular patterning. We report monozygotic twins concordant for 22q11.2 microdeletion but discordant for cardiovascular patterning. Both twins showed identical intracardiac defects including tetralogy of Fallot with pulmonary atresia. Nevertheless, their great vessel patternings were variable. These twins show that the mispatterning of the great vessels may not correlate with intracardiac morphogenesis. The discordant development of the great vessels, especially in the pulmonary vascular system, has clinical significance for prognosis. The phenotypic variability of cardiovascular anomalies seen in 22q11 microdeletion cannot be explained on the basis of genotypic difference.

Molecular Characterization of Tetralogy of Fallot Within DiGeorge Critical Region of the Chromosome 22

Abstract. The purpose of this study was to determine whether the levels of heterozygosity and microdeletion of specific loci within the DiGeorge critical region (del22q11) are associated with different phenotypes of tetralogy of Fallot (TF). Examinations were conducted on 84 sporadic TF patients and their unaffected parents for del22q11, using the following 9 simple tandem repeat polymorphic microsatellite markers: D22S420, D22S427, D22S941, D22S944, D22S264, D22S311, D22S425, D22S303, D22S257. The microdeletions were confirmed using quantitative PCR with markers TUPLE1, exon 2 of the UFD1L gene, and D22S264; the boundaries of these microdeletions were estimated using genotypic analyses of the unaffected family members. The del22q11 was identified in 14 patients (16.6%). The boundary of the shortest region of deletion overlap (SRO) in these 14 TF patients was identified, proximally using D22S427 and distally using the TUPLE 1 gene. The deletion of exon 2 of the UFD1L gene and TUPLE1 gene was identified in 13 patients (13/14 cases; 93%). The SRO in TF patients with del22q11 was at or close to the ADU breakpoint and centromeric to the UFD1L gene. The level of heterozygosity for the marker D22S944 in TF patients without del22q11 (n= 70) was found to be significantly lower than expected. Overall, this study demonstrated the significantly low level of heterozygosity within DiGeorge critical region in TF patients with or without del22q11. Our results suggest that the genetic factors leading to DiGeorge/velocardiofacial syndrome might also be partly responsible for TF phenotypes.

Soluble Interleukin-10 and Transforming Growth Factor-β in Children with Acute Exacerbation of Allergic Asthma

Cytokine-mediated interactions among inflammatory cells may contribute to pathogenesis of allergic asthma. To understand the role of soluble interleukin-10 (IL-10) and transforming growth factor-β (TGF-β) on the disease activity and regulation in asthma, changes in serum concentrations of IL-10 and TGF-β elaborated by activated T-lymphocyte before and after prednisolone therapy with clinical improvement were determined. Circulating levels of IL-10 and TGF-β in sera from 16 normal control subjects and in sera from 22 allergic asthmatic children with acute exacerbation and in stable condition were respectively detected by commercially available enzyme-linked immunosorbent assay kits. The mean concentrations of serum IL-10 in asthmatics with acute exacerbation (6.77 ± 4.08 pg/mL) and during stable condition (5.14 ± 1.17 pg/mL) were lower than that in control subjects (7.15 ± 4.72 pg/mL). However, the difference was not statistically significant among these three study groups. The mean concentration of serum TGF-β in stable asthmatics (40.73 ± 15.95 pg/mL) was significantly higher than that in asthmatics with acute exacerbation (27.64 ± 3.66 pg/mL; p < 0.05) and that in healthy control group (28.77 ± 8.35 pg/mL; p < 0.05), while there was no statistical difference between the latter two groups. This study provides further evidence that serum TGF-β, rather than IL-10, may play a role in regulation of disease activity and serve as an indicator for clinical control of allergic asthmatics.

Clinical efficacy of house dust mite-specific immunotherapy in asthmatic children.

BACKGROUND Immunotherapy has been widely used in the treatment of allergic diseases. We evaluated the clinical efficacy of specific immunotherapy with extracts of Dermatophagoides pteronyssinus (Dp) and Dermatophagoides farinae (Df) in children with asthma. METHODS All 40 children had moderate-to-severe asthma and positive allergen tests for Dp and Df. All required daily medication. They were randomly assigned to two groups: Half of them received immunotherapy with subcutaneous injections of Dp and Df extracts, while the other half were not given immunotherapy. Participants were followed up for more than 6 months. RESULTS Children in both groups had apparent improvements in medication use and symptoms after 6 months. The mean medication scores declined from 3.6 +/- 1.14 to 1.7 +/- 0.66 in the immunotherapy group (p < 0.01) and from 3.35 +/- 0.87 to 2.4 +/- 1.09 in the control group (p < 0.01). There was a significant difference between the two groups (mean difference 0.95; p < 0.01). The symptom score improved in the immunotherapy group from 2.65 +/- 0.98 to 1.20 +/- 1.00 (p < 0.01) and in the control group from 2.55 +/- 0.99 to 1.40 +/- 0.88 (p < 0.01), with a significant difference between the two groups (mean difference 0.3; p < 0.01). The number of office visits in the immunotherapy group was greater than that of the controls, but the frequencies of emergency room visits and hospitalization decreased. CONCLUSION Our study showed that specific immunotherapy with Dp and Df was beneficial for asthmatic children.

Sphingosine-1-phosphate induces VEGF-C expression through a MMP-2/FGF-1/FGFR-1-dependent pathway in endothelial cells in vitro

Aim:To investigate whether sphingosine-1-phosphate (S1P), a potent angiogenic factor, induced vascular endothelial growth factor-C (VEGF-C) expression in endothelial cells in vitro and to examine its underlying mechanisms.Methods:Human umbilical vein endothelial cells (HUVECs) were examined. VEGF-C mRNA expression in the cells was assessed using real-time PCR. VEGF-C protein and FGFR-1 phosphorylation in the cells were measured with ELISA. RNA interference was used to downregulate the expression of matrix metalloproteinase-2 (MMP-2), fibroblast growth factor-1 (FGF-1) and FGF receptor-1 (FGFR-1).Results:Incubation of HUVECs with S1P (1, 5, and 10 μmol/L) significantly increased VEGF-C expression. The effect was blocked by pretreatment with the MMP inhibitor GM6001 or the FGFR inhibitor SU5402, but not the EGFR inhibitor AG1478. The effect was also blocked in HUVECs that were transfected with FGFR-1 or MMP-2 siRNA. Furthermore, incubation of HUVECs with S1P (5 μmol/L) significantly increased FGFR-1 phosphorylation, which was blocked by GM6001. Moreover, knockdown of FGF-1, not FGF-2, in HUVECs with siRNAs, blocked S1P-induced VEGF-C expression.Conclusion:S1P induces VEGF-C expression through a MMP-2/ FGF-1/FGFR-1-dependent pathway in HUVECs.

Interleukin-1β expression is required for lysophosphatidic Acid-induced lymphangiogenesis in human umbilical vein endothelial cells.

Lysophosphatidic acid (LPA) is a lipid mediator which binds to G-protein-coupled receptors and regulates various cellular responses, including inflammation of endothelial cells. Interleukin- (IL-) 1β, a proinflammatory cytokine, is elevated upon LPA treatment in human umbilical vein endothelial cells (HUVECs). Previous studies indicated that LPA upregulates vascular endothelial growth factor- (VEGF-) C and lymphatic marker expressions in HUVECs. However, the relationships between LPA-induced VEGF-C and IL-1β expressions are not clear. In this paper, we demonstrated that, in the presence of AF12198, an inhibitor of the IL-1 receptor abolished LPA-induced VEGF-C and lymphatic marker expressions in HUVECs. Furthermore, LPA-induced in vitro tube formation of HUVECs was also suppressed by pretreatment with AF12198. Our results suggest that LPA-stimulated lymphangiogenesis in HUVECs is mediated through IL-1β-induced VEGF-C expression.

Visualization of Secundum Atrial Septal Defect Using Transthoracic Three-Dimensional Echocardiography in Children: Implications for Transcatheter Closure.

Background: The objective of this study was to evaluate the efficacy of quantitative measurements of secundum atrial septal defect (ASD) with dynamic transthoracic three‐dimensional (3–D) echocardiography. Methods: Twenty‐six patients (age, 13 months to 14 years; mean age, 37 months) with secundum ASDs underwent 3‐D echocardiographic imaging generated from transthoracic echocardiographic interrogation before surgery. Four specific cut planes were defined: four‐chamber view, transverse view, en face view from right and left atrial side. The images obtained from 16 patients clearly demonstrated all four defined cut planes for the quantitative measurement. Results: The defect sizing determined by the 3‐D images correlated well with surgical findings. These images may be interactively manipulated to optimize visualization of the defect to allow the cardiologist to perform transcatheter occlusion. A significant correlation was demonstrated to the limbic band tissue assessment by four‐chamber and transverse views. Unusual atrial structures such as muscle bands and the fore‐shortening of the en face view might induce biased measurements. Conclusions: The transthoracic approach was successful in capturing sufficient data to create 3‐D images, which can provide an accurate assessment of secundum ASD. The possibility of underestimation should always be taken into account with the en face view. Multiple cut planes were essential to ensure correct sizing for adequate selection of the occluder.