Clinically Interpretable Machine Learning Models for Early Prediction of Mortality in Older Patients with Multiple Organ Dysfunction Syndrome (MODS): An International Multicenter Retrospective Study

BACKGROUND

Multiple organ dysfunction syndrome (MODS) is associated with a high risk of mortality among older patients. Current severity scores are limited in their ability to assist clinicians with triage and management decisions. We aim to develop mortality prediction models for older patients with MODS admitted to the ICU.

METHODS

The study analyzed older patients from 197 hospitals in the US and one hospital in the Netherlands. The cohort was divided into the young-old (65-80 years) and old-old (≥80 years), which were separately used to develop and evaluate models including internal, external and temporal validation. Demographic characteristics, comorbidities, vital signs, laboratory measurements, and treatments were used as predictors. We used the XGBoost algorithm to train models, and the SHAP method to interpret predictions.

RESULTS

34,497 young-old (11.3% mortality) and 21,330 old-old (15.7% mortality) patients were analyzed. Discrimination AUROC of internal validation models in 9,046 U.S. patients was as follows: 0.87 and 0.82, respectively; Discrimination of external validation models in 1,905 EUR patients was as follows: 0.86 and 0.85, respectively; and of temporal validation models in 8,690 U.S. patients: 0.85 and 0.78, respectively. These models outperformed standard clinical scores like SOFA and APSIII. The GCS, Charlson Comorbidity Index, and Code Status emerged as top predictors of mortality.

CONCLUSIONS

Our models integrate data spanning physiologic and geriatric-relevant variables that outperform existing scores used in older adults with MODS, which represents a proof of concept of how machine learning can streamline data analysis for busy ICU clinicians to potentially optimize prognostication and decision making.

[Feasibility and safety of fetal intravascular transfusion via the intrahepatic vein in the treatment of fetal anemia]

Objective: To investigate the feasibility and safety of fetal intravascular transfusion via the intrahepatic vein in the treatment of fetal anemia. Methods: This was a retrospective analysis of all fetuses requiring intrauterine transfusion (IUT) in the Shanghai First Maternity and Infant Hospital between January 2010 and December 2019. According to the different ways of IUT, they were divided into intrahepatic venous transfusion group and umbilical venous transfusion group, fetal outcomes and the incidence of procedure-related complications between the two groups were compared. Results: A total of 97 IUTs were performed on 48 fetuses. Among them, 16 cases were performed in the intrahepatic vein (31 transfusions), 32 cases were performed in the cord of the umbilical vein (66 transfusions).There were no significant differences between the two groups in age, labor history and the proportion of fetal hydrops before the first transfusion. In the intrahepatic venous transfusion group, the posterior placenta was 14/16, which was significantly higher than 78% (25/32) in the umbilical venous transfusion group (P<0.01). The live-birth rates of the two groups were 13/16 and 75% (24/32). There was no significant difference between the two groups (P>0.05). Before intrahepatic venous transfusion, the proportion of fetal hydrops was significantly higher than that of umbilical venous transfusion [55% (17/31) vs 24% (16/66), P<0.05]. Puncture success rate of intrahepatic venous transfusion and umbilical venous transfusion were both 100%. In the umbilical venous transfasion group, the incidence of needle slippage (5%, 3/66) and the abnormality of fetal heart rate (11%, 7/66) were higher than those in the intrahepatic venous transfasion group [0 and 3% (1/31)], but there were no significant differences between the two groups (all P>0.05). There were no cases of fetal loss within 24 hours, premature rupture of membranes, infection within 7 days and emergency cesarean section after IUT in both groups. Conclusions: Fetal intravascular transfusion via the intrahepatic vein is safe and feasible in the treatment of fetal anemia. But the requirements of puncture technique are relatively high, so it is recommended to be carried out in experienced fetal treatment center.

Antidepressant Drugs Correct the Imbalance Between proBDNF/p75NTR/Sortilin and Mature BDNF/TrkB in the Brain of Mice with Chronic Stress

Depression is a worldwide problem with a great social and economic burden in many countries. In our previous research, we found that the expression of proBDNF/p75NTR/sortilin is upregulated in patients with major depressive disorder. In addition, the treatment of proBDNF antibodies reversed both the depressive behaviors and the reduced BDNF mRNA detected in our rodent chronic stress models. Antidepressant drugs are usually only effective in a subpopulation of patients with major depression with a delayed time window of 2-4 weeks to exert their efficacy. The mechanism underlying such delayed response is not known. In this study, we hypothesize that antidepressant drugs exert their therapeutic effect by modulating proBDNF/p75NTR and mature BDNF/TrkB signaling pathways. To test the hypothesis, C57 mice were randomly divided into normal control, chronic unpredictable mild stress (CUMS), vehicle (VEH), fluoxetine (FLU), and clozapine (CLO) groups. Behavioral tests (sucrose preference, open field, and tail suspension tests) were performed before and after 4 weeks of CUMS. The gene and protein expression of proBDNF, the neurotrophin receptor (p75NTR), sortilin, and TrkB in the cortex and hippocampus were examined. At the protein level, CUMS induced a significant increase in proBDNF, p75NTR, and sortilin production while the TrkB protein level was found to be lower in the cortex and hippocampus compared with the control group. Consistently, at the mRNA level, p75NTR expression increased with reduced BDNF/TrkB mRNA in both cortex and hippocampus, while sortilin increased only in the hippocampus after CUMS. FLU and CLO treatments of CUMS mice reversed all protein and mRNA expression of the biomarkers in both cortex and hippocampus, except for sortilin mRNA in the cortex and proBDNF in the hippocampus, respectively. This study further confirms that the imbalance between proBDNF/p75NTR/sortilin and mBDNF/TrkB production is important in the pathogenesis of depression. It is likely that antidepressant FLU and antipsychotic CLO exert their antidepressant-like effect correcting the imbalance between proBDNF/p75NTR/sortilin and mBDNF/TrkB.

Connexin 36 is expressed and associated with zonula occludens-1 protein in PC-12 cells

Connexin 36 (Cx36) is the predominant connexin isoform expressed in the mammalian neurons of the central nervous system (CNS). PC-12 cells, a neuronal-like cell line, are widely used for neuron functional studies. Many connexins have been shown to interact with zonula occludens-1 protein (ZO-1), a tight junction associated with protein. The present study is intended to investigate whether Cx36 is expressed in PC-12 cells and is associated with ZO-1. Cx36 transcripts were amplified and verified by RT-PCR. 2.9 kb Cx36 mRNA was detected in PC-12 cells through Northern blot hybridization. Western blotting showed a 36-kDa protein band in the homogenates of PC-12 cells. Immunofluorescence labeling revealed that Cx36 was present in cell-cell contacts of PC-12 cells and colocalized with ZO-1. The association of Cx36 and ZO-1 in PC-12 cells was also demonstrated by coimmunoprecipitation. In conclusion, PC-12 cells express Cx36 mRNA and Cx36 proteins that are associated with ZO-1. These results enhanced our understanding of the function of Cx36 in PC-12 cells.

Maternal milk regulation of cell infiltration and interleukin 18 in the intestine of suckling rat pups

BACKGROUND

and aims: In neonates the gastrointestinal tract is exposed to food and bacterial antigens at a time when the gut mucosal immune system has not developed the ability to induce oral tolerance. This increases the risk for an inappropriate immune response to oral antigens. Transforming growth factor beta (TGF-beta) is an immunoregulatory cytokine present in high concentration in maternal milk. Interleukin 18 (IL-18) is a cytokine that mediates early immune events, and drives T cell development. We assessed the role of TGF-beta in mediating mucosal immune development and specifically the effect on endogenous IL-18.

METHODS

Rat pups were randomly assigned to the following groups, naturally suckled, maternal milk via cannula, and formula fed with and without physiological levels of TGF-beta2. A comparison of the immune response profile was then carried out. Cytokine profiles, dendritic cell, intestinal mast cell, and eosinophil numbers were assessed.

RESULTS

We show that feeding formula deficient in TGF-beta2 resulted in accumulated IL-18 protein release from intestinal epithelial cells and IL-18 mRNA up regulation. A proinflammatory cytokine profile resulted in the gut, along with increased numbers of activated dendritic cells, eosinophils, and mast cells. Supplementation of the formula with TGF-beta2 down regulated the proinflammatory cytokine mRNA as well as the number of activated lymphocytes, eosinophils, mast cells, CD80, and CD86 positive dendritic cells.

CONCLUSION

The data suggests an important role for maternal milk, in regulating immune responses after exposure to food antigens, which might otherwise induce deleterious immune responses in the intestine of suckling neonates. This regulation is potentially mediated by milk TGF-beta2, as well as endogenous IL-18.