Objective To explore the occurrence and influencing factors of delayed cerebral ischemia(DCI)after clipping surgery in patients with anterior circulation aneurysms.Methods A retrospective analysis was conducted on 248 patients with anterior circulation aneurysms who underwent clipping surgery in our hospital from May 2018 to May 2023.The patients were divided into the DCI group and the non-DCI group based on the occurrence of DCI after surgery.A1∶1 propensity score matching method was used to match 54 patients in the DCI group with 54 patients in the non-DCI group.The random forest algorithm was employed to rank the importance of factors influencing DCI.Multivariable Logistic regression analysis was performed to identify independent risk factors for DCI,and the E-value method was used to assess the sensitivity of model parameters.A DCI risk prediction model was constructed,and the discriminative ability and accuracy of the model were evaluated using ROC curve and Hosmer-Lemeshow test.Results After matching,no statistically significant differences were observed between the two groups in terms of gender,age,body mass index(BMI),smoking history,alcohol consumption,history of cerebral infarction,history of subarachnoid hemorrhage,aneurysm location,and maximum aneurysm diameter(all P＞0.05).Compared to the non-DCI group,the DCI group had a higher proportion of modified Fisher grade 3-4 and Hunt-Hess grade IV patients,higher levels of D-dimer(D-D),total bilirubin(TBIL),TNF-α,high-sensitivity C-reactive protein(hs-CRP),IL-6,and glutamate,and lower levels of immunoglobulin(Ig)G,IgM,and IgA(all P＜0.05).The random forest analysis showed that including Hunt-Hess grade,modified Fisher grade,D-D,glutamate,TB1L,IgA,and IL-6 in the multivariable regression analysis achieved the lowest out-of-bag error rate.Multivariable analysis revealed that Hunt-Hess grade Ⅳ,modified Fisher grade 3-4,D-D,glutamate,TBIL were independent risk factors for DCI,while IgA was a protective factor(all P＜0.05).The risk prediction equation was as follows:P=1/[1+e(3.142+1.307 Hunt-Hess grade+1.086 modified Fisher grade+0.976 D-D+0.748 glutamate+0.552 TBIL-0.524 IgA+0.487 IL-6)].A patient with a risk probability P＞0.65 was considered to have a postoperative occurrence of DCI.The ROC curve results showed that after internal validation,the AUC of the model was 0.869(95％CI:0.836-0.897),with sensitivity and specificity of 81.08％and 97.34％,respectively,indicating good discrimination of the model.The Hosmer-Lemeshow test results showed that after internal validation,the goodness of fit of the model wasx2=4.219,P=0.561,indicating good fit of the model.Conclusions Hunt-Hess grade Ⅳ,modified Fisher grade 3-4,D-D,glutamate,TBIL,and IL-6 are identified as independent risk factors for DCI,while IgA is a protective factor.The predictive model constructed using these factors demonstrates high accuracy and discriminative ability.A risk probability P＞0.65 indicates a postoperative occurrence of DCI in patients.

OBJECTIVETo clone and identify the gene encoding human ubiquitin binding enzyme 2 and study its expression pattern.

METHODSAccording to the sequence of human EST, which is highly homologous to the mouse ubiquitin binding/conjugating enzyme (E2), primers were synthesized to screen the human fetal brain cDNA library. The gene was analyzed by bioinformatics technique and its expression pattern was studied by using multiple-tissue Northern blot.

RESULTSTwo cDNA clones encoding human ubiquitin conjugating enzyme have been isolated and identified. Both containing the ubiquitin conjugating domain, the 2 cDNA clones are 88% identical in amino acid sequences and splicing isoforms to each other only with an exon excised to form the short sequence. They belong to a highly conserved and widely expressed E2 enzyme family. Northern blot shows that they are expressed exclusively in adult human heart, placenta, and pancreas but no transcripts can be detected in brain, lung, liver, skeletal muscle or kidney.

CONCLUSIONSThe gene encoding human ubiquitin binding enzyme is expressed under temporal control. As a key enzyme in the degradation of proteins, ubiquitin conjugating enzymes play a central role in the expression regulation on the level of post-translation.

Amino Acid Sequence ; Animals ; Base Sequence ; Cloning, Molecular ; DNA, Complementary ; genetics ; Female ; Humans ; Mice ; Molecular Sequence Data ; Myocardium ; metabolism ; Pancreas ; metabolism ; Placenta ; metabolism ; Rats ; Sequence Alignment ; Sequence Analysis, DNA ; Ubiquitin ; genetics ; Ubiquitin-Conjugating Enzymes ; biosynthesis ; chemistry ; genetics