Objective:To establish a competing risk model to predict the cumulative hazard risk probability of the outcomes (unhealed or hyperthyroidism recurrence) of Graves disease (GD) treated with 131I. Methods:From January 2020 to May 2021, 61 GD patients (13 males, 48 females; age (46.0±13.8) years) who received 131I treatment in Zhangzhou Affiliated Hospital of Fujian Medical University were enrolled. The outcomes of treatment were recovery, unhealed or hyperthyroidism recurrence (event 1), and hypothyroidism (event 2). Follow-up was started 1 month after 131I treatment and ended 1 year later. It was terminated in the following conditions: one of the two events occurred; no event occurred after 1 year of follow-up; the research deadline was up. The Fine-Gray test was used to analyze the factors related to event 1, and then the competitive risk model was established. Results:Thirty-nine patients had hypothyroidism, 17 patients were unhealed or had hyperthyroidism recurrence, 2 patients lost follow-up, and 3 patients had normal thyroid function after 1 year follow-up. Multivariate analysis showed that effective half-life (hazard ratio ( HR)=1.74, 95% CI: 1.10-2.75, β=0.55, P=0.019) and thyroid volume ( HR=1.12, 95% CI: 1.07-1.17, β=1.12, P<0.001) were risk factors for event 1, while the elasticity of thyroid was a protective factor ( HR=0.17, 95% CI: 0.06-0.54, β=-1.76, P=0.003). The C index of the nomogram constructed based on the multi-factor competitive risk model was 0.784(95% CI: 0.633-0.935). Conclusions:Thyroid volume, elastic value, and effective half-life are associated with treatment outcomes of 131I. The competitive risk model can predict the therapeutic outcomes of GD patients treated with 131I.

Chitinase AO-801 is a hydrolase secreted by Arthrobotrys oligospora during nematode feeding, while its role remained elusive. This study analyzed the molecular characteristics of recombinant chitinase of Arthrobotrys oligospora (reAO-801). AO-801 belongs to the typical glycoside hydrolase 18 family with conserved chitinase sequence and tertiary structure of (α/β)8 triose-phosphate isomerase (TIM) barrel. The molecular weight of reAO-801 was 42 kDa. reAO-801 effectively degraded colloidal and powdered chitin, egg lysate, and stage I larval lysate of Caenorhabditis elegans. The activity of reAO-801 reached its peak at 40˚C and pH values between 4-7. Enzyme activity was inhibited by Zn2+, Ca2+, and Fe3+, whereas Mg2+ and K+ potentiated its activity. In addition, urea, sodium dodecyl sulfate, and 2-mercaptoethanol significantly inhibited enzyme activity. reAO-801 showed complete nematicidal activity against C. elegans stage I larvae. reAO-801 broke down the C. elegans egg shells, causing them to die or die prematurely by hatching the eggs. It also invoked degradation of Haemonchus contortus eggs, resulting in apparent changes in the morphological structure. This study demonstrated the cytotoxic effect of reAO-801, which laid the foundation for further dissecting the mechanism of nematode infestation by A. oligospora.