Hydrogen is the most abundant chemical element in the universe, and has been used as an inert gas for a long time. More recent studies have shown that molecular hydrogen as a kind of antioxidant, anti-inflammatory, anti-apoptosis, gene expression and signal modulation molecule, can be used for the treatment of many diseases. This review mainly focuses on the research progresses of hydrogen in various medical fields and the possible action mechanisms.

Objectives: The aim of our study was to elucidate the association between severity of postoperative hypocalcemia and the prognosis of the patients with 22q11DS. Methods: Data retrospectively were collected from 23 children with 22q11DS who underwent cardiac correction surgery. Area under the receiver operating characteristic curve (AUC) and diagnostic odds ratio were calculated to determine the tendency of perioperative mortality rate, according to the minimum levels of serum calcium and the duration of hypocalcemia. A novel risk assessment system for perioperative mortality was established according to these valid parameters. Results: The death group had lower minimum levels of serum calcium and longer duration of hypocalcemia. The AUC of minimum levels of serum calcium was 0.912 (95% CI: 0.753-1; P = .003) and qualified its high accuracy for perioperative mortality. The AUC of duration of hypocalcemia was 0.804 (95% CI: 0.561-1; P = .03) and qualified its moderate accuracy. The tendency analyses also indicated the correlation between these two parameters and perioperative mortality. Based on the cut-off values from ROC analysis, a novel risk assessment system for perioperative mortality was established according to these two parameters. The patients with the lowest serum calcium level <0.885 mmol/L or duration of the hypocalcemia > 90.33 hours would be sorted into a high-risk group; others were divided into a low-risk group. The diagnostic odds ratio for this assessment system was 143(95% CI: 5.13-3982.52). No significant difference was found with regard to patient age, weight, preoperative serum total calcium, cardiopulmonary bypass (CPB) time, and aortic cross-clamp time between the high- and low-risk groups. Conclusions: The minimum levels of serum calcium and duration of hypocalcemia were valid predictors for preoperative mortality of 22q11DS patients.

Objective: Pulmonary atresia (PA) is a rare type of complex cyanotic congenital heart defect characterized primarily by an undeveloped pulmonary valve or pulmonary artery. Therefore, defining a disease-causing gene mutation in a pulmonary atresia family is a possible method of genetic counseling, future prenatal diagnosis, and therapeutic approaches for pulmonary atresia. Methods: Blood samples were collected from six PA family members, and genomic DNA was extracted using the QIAamp DNA Blood Mini Kit. Gene detection was performed using a second-generation sequencing gene panel. Results: Genetic testing results indicated that a heterozygous mutation originating from maternal inheritance was detected in the BMPR2 gene of the proband's genomic DNA. The pathogenic gene was c.2804C>T (p. A935V). The mutation was also detected in the genomic DNA of the proband's elder brother (III-1), but not in other family members. Conclusion: To the best of our knowledge, this is the first study to report the BMPR2 variant responsible for pulmonary atresia. The frequency of the c.2804C>T (p. A935V) mutation detected in this family is extremely low in the normal population (1/246048). The mutation was highly conserved among different species. Sorting intolerant from tolerant (SIFT) predicts it to be a harmful mutation.