[Analysis of clinical presentation and genetic characteristics of malignant infantile osteopetrosis].

Objective: To investigate the clinical presentation and genetic characteristics of malignant infantile osteopetrosis. Methods: This was a retrospective case study. Thirty-seven children with malignant infantile osteopetrosis admitted into Beijing Children's Hospital from January 2013 to September 2022 were enrolled in this study. According to the gene mutations, the patients were divided into the CLCN7 group and the TCIRG1 group. Clinical characteristics, laboratory tests, and prognosis were compared between two groups. Wilcoxon test or Fisher exact test were used in inter-group comparison. The survival rate was estimated with the Kaplan-Meier method and the Log-Rank test was used to compare the difference in survival between groups. Results: Among the 37 cases, there were 22 males and 15 females. The age of diagnosis was 0.5 (0.2, 1.0) year. There were 13 patients (35%) and 24 patients (65%) with mutations in CLCN7 and TCIRGI gene respectively. Patients in the CLCN7 group had an older age of diagnosis than those in the TCIRGI group (1.2 (0.4, 3.6) vs. 0.4 (0.2, 0.6) years, Z=-2.60, P=0.008). The levels of serum phosphorus (1.7 (1.3, 1.8) vs. 1.1 (0.8, 1.6) mmol/L, Z=-2.59, P=0.010), creatine kinase isoenzyme (CK-MB) (457 (143, 610) vs. 56 (37, 82) U/L, Z=-3.38, P=0.001) and the level of neutrophils (14.0 (9.9, 18.1) vs. 9.2 (6.7, 11.1) ×109/L, Z=-2.07, P=0.039) at diagnosis were higher in the CLCN7 group than that in the TCIRG1 group. However, the level of D-dimer in the CLCN7 group was lower than that in the TCIRGI group (2.7 (1.0, 3.1) vs. 6.3 (2.5, 9.7) µg/L, Z=2.83, P=0.005). After hematopoietic stem cell transplantation, there was no significant difference in 5-year overall survival rate between the two groups (92.3%±7.4% vs. 83.3%±7.6%, χ²=0.56, P=0.456). Conclusions: TCIRGI gene mutations are more common in children with osteopetrosis. Children with TCIRGI gene mutations have younger age, lower levels of phosphorus, CK-MB, and neutrophils and higher level of D-dimer at the onset. After hematopoietic stem cell transplantation, patients with CLCN7 or TCIRGI gene mutations have similar prognosis.

[The incidence and risk factors of catheter-related-thrombosis during induction chemotherapy in acute lymphocytic leukemia children].

Objective: To investigate the current status of catheter-related-thrombosis (CRT) and the risk factors of Chinese acute lymphocytic leukemia (ALL) children with peripherally inserted central catheter (PICC) . Methods: The clinical data of the 116 inpatients preliminarily diagnosed ALL in the Leukemia Ward of Beijing Children's Hospital with PICC from 1(st) March 2014 to 31(st) December 2014 were collected prospectively. Results: ①Refer to the B-ultrasound on the 15(th) day after catheterization, the incidence of CRT was 28.4% (33/116 cases) , all cases were symptom-free. ②There were no statistical differences in terms of gender, age distribution, degree, immunotype between CRT and CRT-free groups. This study revealed no statistical differences of blood routine test items, coagulation function items, co-infection and catheterization vein between the two groups. While there was significant statistical difference of catheterization side, the frequency of right catheterization was higher in CRT group[75.8% (25/33) vs 55.4% (46/83) , P=0.043]. ③On the 15(th) day after catheterization, significant statistical difference of D-Dimer between the two groups was revealed[0.18 (0.05-2.45) mg/L vs 0.11 (0.01-5.34) mg/L, P=0.001], while no statistical differences of blood routine test items and other coagulation function items. Multivariate Logistic regression analysis verified catheterization on right was a risk factor of CRT. ④During the observation, there were 3 cases of catheter-related complications other than CRT, all of which were CRI, 2 of them had CRT meanwhile. ⑤The B-ultrasound on the 33(rd) day after catheterization showed that 73.1% of the cases had reduced thrombosis, 3.8% had growth thrombosis, 23.1% had no obvious change respectively. Conclusion: CRT was a common catheter related complication among ALL children during induction chemotherapy, and CRT cases with symptoms were rare. Catheterization on right was a risk factor for CRT, and regular test of D-Dimer and B ultrasound contributed to detect CRT. Most of the CRT cases had reduced thrombosis without specific management.

Modification of vectors for functional genomic analysis in plants.

Simple, efficient, and economical recombinant plant binary expression vectors for deciphering large-scale functional genomic research in plants and promoting crop improvement by genetically engineering and biotechnology is in great demand. In this research, using the pCHF3, pCAMBIA1301, pCAMBIA3300, pCAMBIA3301 vectors, we successfully constructed general plant binary expression vectors carrying CaMV35S and Arabidopsis rd29A promoters mediating multiple cloning sites ( MCS: SacI, KpnI, SmaI, BamHI, XbaI, SalI, and PstI). Meanwhile, a series of applicative binary expression vectors that can be utilized for subcellular localization were constructed by fusion of the MCS and eGFP. Subsequently, the recombinant vectors were successfully transferred into Arabidopsis thaliana and Nicotiana benthamiana for further investigation of functional elements in these plant binary expression vectors. Our results demonstrated that this system was a convenient and versatile vector system for phenotypic, functional, subcellular localization, and promoter activity analysis, and it provided a relatively high-efficiency and reliable platform for researchers in vector construction and may facilitate large-scale functional genomics analysis in plants.

[Plasmid fingerprinting technique analysis of Pseudomonas aeruginosa isolated from a burn unit].

We used plasmid fingerprinting technique to analyse 50 strains of Pseudomonas aeruginosa isolated from our burn unit and 15 strains of Pseudomonas aeruginosa from other wards. The results revealed that the carrier rate of R-plasmid was 100%. All 50 strains of Pseudomonas aeruginosa from burn units contained one plasmid with approximate molecular weight of 55 kb. Among 15 strains of Pseudomonas aeruginosa from other wards, 10 strains contained one plasmid with the same molecular weight. However, 3 strains were found to possess an additional 12.5-kd plasmid and 2 strains contained 77-kb plasmid. This proves that R-plasmid carrying Pseudomonas aeruginosa is prevalent in the burn unit, and R-plasmid is disseminated in the hospital.