Clinical and genetic characteristics of children with primary dilated cardiomyopathy / 中国当代儿科杂志

OBJECTIVES@#To study the genetic characteristics, clinical characteristics, and prognosis of children with primary dilated cardiomyopathy (DCM).@*METHODS@#A retrospective analysis was performed on the medical data of 44 children who were diagnosed with DCM in Hebei Children's Hospital from July 2018 to February 2023. According to the genetic testing results, they were divided into two groups: gene mutation-positive group (n=17) and gene mutation-negative group (n=27). The two groups were compared in terms of clinical data at initial diagnosis and follow-up data.@*RESULTS@#Among the 44 children with DCM, there were 21 boys (48%) and 23 girls (52%). Respiratory symptoms including cough and shortness of breath were the most common symptom at initial diagnosis (34%, 15/44). The detection rate of gene mutations was 39% (17/44). There were no significant differences between the two groups in clinical characteristics, proportion of children with cardiac function grade Ⅲ or Ⅳ, brain natriuretic peptide levels, left ventricular ejection fraction, and left ventricular fractional shortening at initial diagnosis (P>0.05). The median follow-up time was 23 months, and 9 children (20%) died, including 8 children from the gene mutation-positive group, among whom 3 had TTN gene mutation, 2 had LMNA gene mutation, 2 had TAZ gene mutation, and 1 had ATAD3A gene mutation. The gene mutation-positive group had a significantly higher mortality rate than the gene mutation-negative group (P<0.05).@*CONCLUSIONS@#There is no correlation between the severity of DCM at initial diagnosis and gene mutations in children. However, children with gene mutations may have a poorer prognosis.

Recent research on childhood hypertrophic cardiomyopathy caused by MYH7 gene mutations / 中国当代儿科杂志

Hypertrophic cardiomyopathy (HCM) is the most common monogenic inherited myocardial disease in children, and mutations in sarcomere genes (such as MYH7 and MYBPC3) are the most common genetic etiology of HCM, among which mutations in the MYH7 gene are the most common and account for 30%-50%. MYH7 gene mutations have the characteristics of being affected by environmental factors, coexisting with multiple genetic variations, and age-dependent penetrance, which leads to different or overlapping clinical phenotypes in children, including various cardiomyopathies and skeletal myopathies. At present, the pathogenesis, course, and prognosis of HCM caused by MYH7 gene mutations in children remain unclear. This article summarizes the possible pathogenesis, clinical phenotype, and treatment of HCM caused by MYH7 gene mutations, in order to facilitate the accurate prognostic evaluation and individualized management and treatment of the children with this disorder.

Mechanism of circulating microparticles involving in atherosclerosis progress / 心血管康复医学杂志

Microparticles are vesicle-like structures with a diameter of 0.1 to 1.0 μm.It′s produced after cell activa-tion or apoptosis,which possesses physiological and pathological effects.Microparticle level rises in many cardiovas-cular diseases.Its elevation in plasma is thought to be a biomarker of vascular function change.The present article aimed at summarizing and providing newest research progress for microparticles playing role in atherosclerotic in-flammation.

Preparation and identification of monoclonal antibodies against Chlamydia trachomatis Tarp protein / 南方医科大学学报

<p><b>OBJECTIVE</b>To obtain monoclonal antibodies (mAbs) against Chlamydia trachomatis Tarp protein.</p><p><b>METHODS</b>Chlamydia trachomatis serovar D recombinant Tarp fusion protein was cloned and expressed. Balb/c mice were immunized with recombinant Tarp fusion protein, and the spleen cells of the immunized mice were fused with SP2/0 mouse myeloma cells. The hybridoma cell lines secreting mAbs against Tarp protein were screened by an indirect immunofluorescence assay and subcloned by limiting dilution culture. The specificities of these mAbs to Tarp were determined by ELISA, and their isotype and chlamydial species specificity identified by an indirect immunofluorescence assay.</p><p><b>RESULTS</b>Recombinant GST-Tarp fusion protein with a relative molecular mass of about 136 000 was successfully cloned and expressed. Seven hybridoma cell lines stably secreting specific mAbs against Tarp protein were obtained. All the 7 mAbs reacted strongly with Tarp protein but not with other chlamydial proteins. Two mAbs were identified to belong to IgG2a isotype and the other 5 to IgG1 isotype. All the 7 mAbs reacted strongly with chlamydia serovar A, D, and L2, but not with MoPn, 6BC, or AR39.</p><p><b>CONCLUSION</b>The highly specific mAbs against Tarp protein have been obtained to facilitate further study of the structure and function of Chlamydia Tarp protein.</p>

Cloning and expression of Chlamydia trachomatis OmcBc gene and antigenicity analysis of the protein / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the antigenicity of recombinant Chlamydia trachomatis (Ct) OmcBc protein and search for the new target for early diagnosis of Chlamydia infection and Chlamydia vaccine development.</p><p><b>METHODS</b>The C fragment of OmcB encoding the amino acids from T270 to T553 was amplified from Chlamydia serovar D genomic DNA. The pGEX-6p-Ct OmcBc expression plasmid was constructed and transformed into E.coli XL-1blue. The expression of recombinant Ct OmcBc protein was induced by IPTG. Serum samples were collected from 120 patients with urogenital Chlamydia infection. The antiserum samples were collected from 7 New Zealand white rabbits and 5 Balb/C mice immunized subcutaneously and intraperitoneally with Ct serovar D inactivated EB, respectively, and from 9 Balb/C mice intranasally infected with Ct serovar D live EB. The anti-Chlamydia specific antibody were titrated by an immunofluorescence assay (IFA). The reactivity of the recombinant OmcBc protein with all the above antisera was detected by ELISA.</p><p><b>RESULTS</b>The pGEX-6p-Ct OmcBc expression plasmid was successfully constructed. DNA sequencing showed that the inserted OmcBc was about 852 bp, encoding a protein with 284 amino acids. The expression of the recombinant GST-OmcBc was induced by IPTG, producing a fusion protein with a molecular weight of about 57 kD. The titer of the specific antibodies to Chlamydia in all the antisera was high. ELISA results showed strong reactivities of the recombinant GST-OmcBc fusion protein with all the above antisera.</p><p><b>CONCLUSIONS</b>OmcBc protein is an immunodominant protein of Chlamydia. The recombinant GST-OmcBc with strong antigenicity may provide a basis for further study of early diagnosis of chlamydia infection and development of Chlamydia vaccine.</p>