A new view of treatment for bronchiolitis / 中国实用儿科杂志

Bronchiolitis is a common lower respiratory tract infection in infants and young children, mostly caused by respiratory syncytial virus. At present, the treatment mainly includes oxygen therapy, control of wheezing, maintenance of internal environment stability and so on. Most cases of bronchiolitis still lack specific antimicrobial agents. To explore a new treatment method for bronchiolitis is helpful to improve the symptoms, shorten hospitalization days,and improve the prognosis of children with moderate to severe bronchiolitis, especially those younger than 6 months with high risk factors.

Role of transient receptor potential vanilloid 1 in airway inflammation in asthmatic mice / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the effects of the change in transient receptor potential vanilloid 1 (TRPV1) channel activity on the degree of airway inflammation in asthmatic mice.</p><p><b>METHODS</b>BALB/c mice were randomly divided into control, asthma, capsaicin (TRPV1 agonist), capsazepine (TRPV1 antagonist), and dexamethasone groups. The asthmatic mouse model was established by intraperitoneal injection of mixed ovalbumin-aluminium hydroxide solution and ultrasonic atomization with OVA for sensitization and challenge. The capsaicin, capsazepine, and dexamethasone groups were given intraperitoneal injection of capsaicin (30 μg/kg), capsazepine (10 μmol/kg), and dexamethasone (2 mg/kg) respectively, at 30 minutes before challenge. Hematoxylin and eosin staining was used to observe the degree of pulmonary inflammation. ELISA was used to measure the content of interleukin-8 (IL-8) and interleukin-13 (IL-13) in bronchoalveolar lavage fluid (BALF). Real-Time PCR was used to measure the relative content of TRPV1 mRNA in lung tissue.</p><p><b>RESULTS</b>Compared with the asthma group, the capsazepine and dexamethasone groups showed reduced pulmonary inflammation, while the capsaicin group showed aggravated pulmonary inflammation. Compared with the control group, the asthma and capsaicin groups showed increases in the content of IL-13 and IL-8 in BALF and the mRNA expression of TRPV1 in lung tissue (P<0.05). Compared with the asthma group, the capsazepine and dexamethasone groups showed reductions in the content of IL-13 and IL-8 in BALF and the mRNA expression of TRPV1 in lung tissue (P<0.05). The capsaicin group showed increases in the content of IL-13 and IL-8 in BALF (P<0.05).</p><p><b>CONCLUSIONS</b>TRPV1 channel agonist and antagonist can influence the degree of airway inflammation in asthmatic mice. Dexamethasone may reduce airway inflammation through regulating TRPV1 level.</p>

Investigation and OCRL mutation analysis of a family with oculocerebrorenal syndrome of Lowe / 中国当代儿科杂志

Oculocerebrorenal syndrome of Lowe (OCRL) is an X-linked recessive disorder. This study investigated the history of a Chinese family with OCRL and used direct DNA sequencing to screen all exons of OCRL gene for mutations. A missense mutation (1736 A→G) in exon 15 was revealed, which resulted in the change of His (H) 507 to Arg (R). The patient's mother was the carrier of the heterozygous mutation in X-chromosome. To our knowledge, H507R mutation in OCRL gene has not been reported in Chinese people.

Site-directed mutagenesis and protein expression of SCN5A gene associated with congenital long QT syndrome / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To construct the sodium channel gene SCN5A-delQKP1507-1509 mutation associated with congenital long QT syndrome, and its eukaryotic expression vector, and to examine the expression of mutation protein in human embryonic kidney (HEK) 293 cells.</p><p><b>METHODS</b>Eukaryotic expression vector PEGFP-delQKP-hH1 for SCN5A-delQKP1507-1509 mutation was constructed by rapid site-directed mutagenesis. HEK293 cells were transfected with the wild or mutant vector using lipofectamine, and then subjected to confocal microscopy. The transfected cells were immunostained to visualize intracellular expression of the mutant molecules.</p><p><b>RESULTS</b>Direct sequence and electrophoresis analysis revealed 9 basic group absences at position 1507-1509. The delQKP1507-1509 mutation eukaryotic expression vector was expressed in HEK293 cells. Immunostaining of transfected cells showed the expression of both wild type and mutant molecules on the plasma membrane and there was no difference in the amount of protein, which suggested that the mutant delQKP1507-1509 did not impair normal protein expression in HEK293 cells.</p><p><b>CONCLUSIONS</b>Successful construction of mutant SCN5AdelQKP1507-1509 eukaryotic expression vector and expression of SCN5A protein in HEK293 cells provides a basis for further study on the functional effects of congenital long QT syndrome as a cause of SCN5A mutation.</p>

Clinical manifestations and gene mutations of a Chinese family with MYH9-related syndrome / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To explore the method for early diagnosis and pathogenesis of MYH9-related syndrome through analysis of the clinical manifestation and gene mutation of a Chinese family with MYH9-related syndrome.</p><p><b>METHODS</b>Peripheral blood samples were collected from a three-generation Chinese family with MYH9-related syndrome (11 individuals, including 3 patients) and 100 healthy individuals. Polymerase chain reaction (PCR) amplification and direct sequencing of DNA were performed to analyze mutations of MYH9 gene.</p><p><b>RESULTS</b>Thrombocytopenia, increased volume of platelet, and granulocyte inclusion bodies were found in the patients with MYH9-related syndrome via a peripheral blood test. A missense mutation of a base pair (G-A) in exon 30 was revealed by PCR amplification and direct sequencing of MYH9 of the proband. That lead to Asp-Asn substitution at position 1424 (D1424N mutation). The mutation was the same as in other patients with MYH9-related syndrome. It was not found in healthy people from the Chinese family or in the other 100 healthy individuals.</p><p><b>CONCLUSIONS</b>Patients with MYH9-related syndrome show diverse symptoms. Mutation of MYH9 gene may be the molecular mechanism of MYH9-related syndrome, and D1424N mutation of MYH9 has not been reported in Chinese people. Early diagnosis of MYH9-related syndrome can be carried out by investigating family history and making early examinations.</p>

Site-directed mutagenesis and protein expression of KCNQ2 gene associated with neonatal convulsions / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the protocol of construction of a KCNQ2-c.812G>T mutant and it's eukaryotic expression vector, the c.812G>T (p.G271V) mutation which was detected in a Chinese pedigree of benign familial infantile convulsions, and to examine the expression of mutant protein in human embyonic kidney (HEK) 293 cells.</p><p><b>METHODS</b>A KCNQ2 mutation c.812G>T was engineered on KCNQ2 cDNAs cloned into pcDNA3.0 by sequence overlap extension PCR and restriction enzymes. HEK293 cells were co-transfected with pRK5-GFP and KCNQ2 plasmid (the wild type or mutant) using lipofectamine and then subjected to confocal microscopy. The transfected cells were immunostained to visualize the intracellular expression of the mutant molecules.</p><p><b>RESULTS</b>Direct sequence analysis revealed a G to T transition at position 812. The c.812G>T mutation was correctly combined to eukaryotic expressive vector pcDNA3.0 and expressed in HEK293 cells. Immunostaining of transfected cells showed the expression of both the wild type and mutant molecules on the plasma membrane, which suggested that the c.812G>T mutation at the pore forming region of KCNQ2 channel did not impair normal protein expression in HEK293 cells.</p><p><b>CONCLUSIONS</b>Successful construction of mutant KCNQ2 eukaryotic expression vector and expression of KCNQ2 protein in HEK293 cells provide a basis for further study on the functional effects of convulsion-causing KCNQ2 mutations and for understanding the molecular pathogenesis of epilepsy.</p>

WASP gene mutation analysis of a family of X-linked thrombocytopenia / 中国当代儿科杂志

<p><b>OBJECTIVE</b>This study investigated the history and gene mutations of a family with X-linked thrombocytopenia, in order to understand the clinical characteristic and molecular pathogenesis of the disease.</p><p><b>METHODS</b>A three-generation X-linked thrombocytopenia family with 13 family members was investigated using PCR-DNA direct sequencing method to screen the exons of WASP gene for mutation analysis.</p><p><b>RESULTS</b>The WASP gene sequencing of the proband revealed a missense mutation in exon 2 (G291A), resulting in a change of amino acid 86 from arginine to histidine. The patient's mother was the carrier of the heterozygosis mutation in X-chromosome.</p><p><b>CONCLUSIONS</b>WASP mutations may be attributed to the molecular mechanism of X-linked thrombocytopenia. G291A is one of the mutations of WASP.</p>

Linkage analysis and gene mapping of one Chinese family with benign familial infantile convulsions / 中国当代儿科杂志

<p><b>OBJECTIVE</b>The present study performed linkage analysis and gene mapping to find the possible chromosome locus harboring in one family with benign familial infantile convulsions (BFIC) and investigate the possible molecular pathogenesis of BFIC.</p><p><b>METHODS</b>A four-generation family with BFIC was investigated. The family was genotyped using eight hypervariable microsatellite markers covering four loci: D19S245 and D19S250 for the 19q12-13.1 region, D16S3131 and D16S3133 for the 16p12-q12 region, D2S156 and D2S286 for the 2q24 region, and D20S480 and D20S481 for the 20q13.3 region. Polymorphism fragments were amplified using polymerase chain reaction (PCR) method. PCR products for the markers were subjected to electrophoresis on 8% denatured polyacrylamide gel and silver staining for length judgment of amplification fragment. Linkage analysis was performed by use of MLINK in the LINKAGE computer package. Two-point LOD scores were calculated to estimate the linkage relationship.</p><p><b>RESULTS</b>The two-point LOD scores were less than -2.0 for the genetic markers at chromosomes 19q12-13.1, 16p12-q12 and 2q24 at the recombination rate between 0.000 and 0.01. The two-point LOD scores for D20S481 at the 20q13.3 region were 0.3 and 0.25 at the recombination rate of 0.000 and 0.01, respectively.</p><p><b>CONCLUSIONS</b>There is no evidence that this family with BFIC is linked to one of the following loci: 19q12-13.1, 16p12-q12 and 2q24, but a possible linkage with 20q13.3 region cannot be excluded.</p>

Gene mutation analysis of a Chinese family of congenital long Q-T syndrome type three / 中华儿科杂志

<p><b>OBJECTIVE</b>The congenital long QT syndrome (LQTs) is a hereditary disorder in which most affected family members have delayed ventricular repolarization manifested on the electrocardiogram (ECG) as QT interval prolongation. The disorder is associated with an increased propensity to arrhythmogenic syncope, polymorphous ventricular tachycardia (torsade de pointes), and sudden arrhythmic death. LQTs is due to mutations involving principally the myocyte ion-channels, and this monogenetic disorder has an autosomal inheritance pattern. This study investigated the gene mutation of a Chinese family of LQTs with multiple phenotypes including dilated cardiomyopathy (DCM) and cardiac conduction defects, thus to understand the molecular pathogenesis of the diseases.</p><p><b>METHODS</b>A three-generation Chinese LQTs family with multiple phenotypes was investigated. Blood sample was collected from the 8 family members and 100 unassociated normal individuals. Polymerase chain reaction (PCR)-DNA direct sequencing was performed to screen all exons and their flanking introns of SCN5A gene for mutation analysis. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to exclude polymorphism.</p><p><b>RESULTS</b>PCR amplification and subsequent direct sequencing of SCN5A from proband revealed a heterozygous deletion of nine base pairs (CAGAAGCCC) in exon 26, corresponding to the three amino acid residues Gln1507-Lys1508-Pro1509 (QKP). This mutation is localized in the linker region between DIII-DIV of SCN5A. The same mutation was found in another patient (her grandmother) and excluded in the remaining living subjects in this family. This mutation was confirmed using SSCP in 100 unassociated healthy individuals. Similar analysis excluded possible mutations that would lead to amino acid changes in KCNQ1, KCNH2 and LAMIN A/C commonly associated with LQTs and DCM with conduction disorders, no new mutations that would lead to amino acid changes was found.</p><p><b>CONCLUSION</b>The result of the present study suggests that SCN5A mutation delQKP1507-1509 exists in patients with LQTs. The delQKP1507-1509 of SCN5A is a novel mutation in Chinese people. The same mutation was previously reported in a French family with only a single LQTs phenotype. Further studies on functional expression of SCN5A mutation delQKP1507-1509 will be helpful to understand the mechanism of the multiple phenotypes.</p>

A novel mutation in KCNQ2 gene causes benign familial infantile convulsions (BFIC) in a Chinese family / 中华儿科杂志

<p><b>OBJECTIVE</b>Benign familial infantile convulsions (BFIC) is a form of idiopathic epileptic syndrome characterized by onset of afebrile seizures between 3 and 12 months of life, Spontaneous remission after several weeks or months, and autosomal dominant mode of inheritance. Previous linkage analysis in western countries defined three susceptible loci on chromosomes 19q12.0-13.1, 16p12-q12, and 2q23-31, but studies performed in several Chinese families with BFIC got negative results of these previously reported loci. The authors investigated the relation of voltage-gated potassium channel gene KCNQ2 to BFIC in a Chinese family and thus to understand the molecular pathogenesis of BFIC.</p><p><b>METHODS</b>A four-generation Chinese BFIC family was investigated. All the affected 17 members had similar pattern of seizures starting from 2 to 6 months of age. In 15 of them, the seizures disappeared spontaneously within the first year of life. The phenotype extended beyond infancy only in two patients. Blood sample was collected from the 41 family members and 75 unassociated normal individuals. Polymerase chain reaction (PCR)-DNA direct sequencing was performed to screen all exons and their flanking introns of KCNQ2 gene for mutation analysis. Polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) was used to ascertain the co-segregation of genotype and phenotype and to exclude polymorphism.</p><p><b>RESULTS</b>PCR amplification and subsequent direct sequencing of KCNQ2 from the DNA of proband revealed a heterozygous guanine to thymine nucleotide exchange (G812T) in exon 5, leading to the substitution of glycine by valine at amino acid position 271 (G271V) of the predicted protein. The same mutation with a comparable localization has been previously described for KCNQ3 in benign familial neonatal convulsions (BFNC). The glycine at this position (G271) is located in pore region of KCNQ2 protein and is evolutionarily highly conserved. The same SSCP variant as that of the proband was shown in the rest of the affected members of this family but not in the unaffected members enrolled in the study of this family and all the 75 unrelated normal individuals.</p><p><b>CONCLUSION</b>Previously reported mutations of KCNQ2 were mainly identified in BFNC family in which at least one individual had an onset of seizures during the first week of life, a hallmark of the BFNC disorder. The results of the present study suggest the possibility that KCNQ2 mutation exist in patients with BFIC diagnosis. G812T of KCNQ2 gene is a novel mutation found in BFIC and functional expression of KCNQ2 G812T is required for understanding the mechanism of BFIC and other idiopathic epilepsy.</p>