[Analysis of prognostic factors of pediatric kidney transplantation]

Objective: To evaluate the short-and mid-term efficacy of pediatric kidney transplantation and the risk factors for kidney graft and recipient. Methods: The baseline data and postoperative complications of pediatric donors and recipients of 284 kidney transplants were retrospectively analyzed in the Department of Kidney Transplantation in the First Affiliated Hospital of Zhengzhou University from August 2010 to May 2021 and all subjects were followed up until December 31, 2021. According to the survival status of donors and recipients, they were divided into the graft-loss group and the graft-survival group, and the recipient death group and survival group, respectively. Univariate comparison between groups was performed by Log-rank test, and Cox proportional risk model was used to explore the independent risk factors for the graft and recipient survival. Results: Among the 284 children recipients, 184 cases (64.8%) were male and 100 cases(35.2%) were female, and 19 cases (6.7%) were living relative donor renal transplantation, 19 cases (6.7%) were preemptive transplantation, and 8 cases were secondary transplantation. The age of 284 recipients at the time of transplantation was 13.0 (9.0, 15.0) years, among whom 29 cases aged 0-6 years, 96 cases aged 7-11 years old, and 159 cases aged 12-18 years. The 1, 3, and 5 year survival rates were 92.3%, 88.9% and 84.8% for the kidney grafts, and were 97.1%, 95.6% and 94.4% for the recipients, respectively. Multivariate analysis showed postoperative acute rejection (HR=3.14, 95%CI 1.38-7.15, P=0.006) and perioperative vascular complications (HR=4.73, 95%CI 2.03-11.06, P<0.001) were independent risk factors for the survival of kidney graft. Postoperative infection (HR=14.23, 95%CI 3.45-58.72, P<0.001) was an independent risk factor for the postoperative mortality of recipients. Conclusions: Pediatric kidney transplantation shows a good short-and mid-term prognosis. Postoperative acute rejection and perioperative vascular complications are the risk factors for the survival of kidney graft, and postoperative infection is the risk factor affecting the survival of recipient.

Trehalose synthesis in Saccharomycopsis fibuligera does not respond to stress treatments

Synthesis of trehalose in Saccharomycopsis fibuligera sdu under various stress conditions was investigated. Neither the activation of trehalose-6-phosphate synthase (SfTPS1) nor the change in trehalose content was observed under stress exposure of S. fibuligera sdu cells. The results of reverse transcription polymerase chain reaction, which was performed with the specific primers designed to target the SfTPS1 gene fragment cloned from this strain, also showed that all stress treatments did not increase the expression of SfTPS1 gene. These results demonstrated that synthesis of trehalose in response to stress conditions in S. fibuligera sdu clearly differs from that of Saccharomyces cerevisiae and most other fungi. The phylogenetic analysis of the amino acid sequence deduced from the SfTPS1 gene fragment showed that the SfTPS1 sequence formed a separate family that was far related to S. cerevisiae TPS1. The yeast strain, which can accumulate a large amount of trehalose under normal growth conditions, has many applications and TPS1 gene in such strain may have unique use in transgenic organisms.

Trehalose accumulation in a high-trehalose-accumulating mutant of Saccharomycopsis fibuligera sdu does not respond to stress treatments

The isolation of high-trehalose-accumulating mutant A11 from Saccharomycopsis fibuligera sdu has been previously described. In this paper, accumulation of trehalose under various stress conditions in S. fibuligera A11 was investigated. Neither activation of trehalose-6-phosphate synthase (SfTps1) nor change in trehalose content was observed under stress exposure of S. fibuligera A11 cells. A fragment of the Sftps1 gene in this strain was also cloned by degenerate PCR using the CoDeHOP strategy and multiply-aligned Tps1 sequences. This sequence allowed us to investigate the expression of the Sftps1 gene, which was also kept constant under the various stress conditions. Altogether, these results indicate that trehalose metabolism in S. fibuligera A11 in response to stress conditions clearly differs from that of Saccharomyces cerevisiae and most other fungi. The expression of the Sftps1 gene was not responsive to different stress treatments.