Objective To investigate the perioperative safety of patients with myasthenia gravis who take high doses of oral glucocorticoids. Methods A retrospective analysis was conducted on the clinical data of patients with myasthenia gravis who received oral glucocorticoids and underwent thoracoscopic thymectomy at the Department of Thoracic Surgery, the University of Hong Kong-Shenzhen Hospital from April 2013 to October 2019. Patients were divided into a high-dose steroid group and a medium-to-low dose steroid group based on the dosage of oral steroids, and the clinical data of the two groups were compared. Results A total of 102 patients were included, including 19 (18.62%) males and 83 (81.37%) females, with an average age of (32.25±9.83) years. There were 75 patients in the medium-to-low dose steroid group and 27 patients in the high-dose steroid group. All patients in both groups successfully completed the surgery without major intraoperative bleeding, conversion to open chest surgery, delayed extubation, severe infection, or perioperative death. The daily oral steroid dose for the high-dose steroid group was (35.81±4.29) mg, and for the medium-to-low dose steroid group it was (15.29±2.17) mg. There was no statistical difference in the operation time [(124.69±23.51) min vs. (117.89±21.46) min, P=0.172] and intraoperative blood loss [(21.19±3.48) mL vs. (20.56±3.41) mL, P=0.419] between the two groups. Postoperatively, 12 (11.76%) patients developed complications: one patient of myasthenic crisis (the medium-to-low dose steroid group), which was improved after short-term respiratory support and intravenous immunoglobulin treatment; 11 patients of respiratory/swallowing difficulties (9 in the medium-to-low dose steroid group and 2 in the high-dose steroid group), which were improved after anticholinergic treatment to reduce oral secretions and sputum suction, and the patients were discharged smoothly. There was no statistical difference in the incidence of postoperative complications between the two groups (P=0.637). Conclusion On the basis of good perioperative management, it is safe and feasible for patients with myasthenia gravis who take high dose of oral steroids to undergo thymectomy, and they have the same perioperative safety as patients with medium-to-low dose steroids.

Objective:To develop a camelid single-domain antibody (SdAb) recognizing linear B-cell epitopes in glutamate dehydrogenase of Clostridium difficile(CD-GDH), and to apply it in Western blot and ELISA. Methods:Purified recombinant CD-GDH was used as bait to screen phage-displayed camelid SdAb library and obtain positive clones. Then those clones were confirmed by Western blot, and their variable domain of heavy chain of heavy chain antibody(VHH) nucleotide sequence were determined. The VHH sequence was synthesized after codon optimization and cloned into the expression vector pET28a. The SdAb was then expressed and purified, and its ability to detect CD-GDH protein in multiple assays was further explored.Results:Six positive clones were obtained, among which clone GA4 was chosen for recombinant expression in Escherichia coli and further purification. The purified GA4 binded well with CD-GDH with a Kd value of 3 nmol/L. In Western blot and ELISA, GA4 was proven to be able to selectively detect both recombinant and endogenous CD-GDH. Conclusions:A camelid SdAb targeting a linear B-cell epitope in CD-GDH is successfully developed, which provides a very useful tool for detecting CD-GDH.

Objective To use imaging features of pulmonary nodules to predict the risk of lymph node metastasis in patients with cT1-stage non-small cell lung cancer (NSCLC), providing a reference for clinical decision-making. Methods A retrospective analysis was conducted on the imaging features and postoperative pathological results of cT1 NSCLC patients who underwent surgical treatment at Linyi People’s Hospital from July 2019 to July 2022. Patients were grouped and analyzed according to lymph node metastasis status. Results A total of 1 123 patients were included, comprising 471 males and 652 females, with a median age of 59 (52, 66) years. Comparative analysis revealed that sex, age, nodule location, nodule size on imaging, solid component size, consolidation tumor ratio (CTR), average CT value, and tumor proximity to the pleura all influenced lymph node metastasis. A nomogram was constructed, indicating that the probability of lymph node metastasis in cT1 NSCLC was positively correlated with solid component size, CTR, and average CT value of the pulmonary nodule, and negatively correlated with patient age. The area under the receiver operating characteristic curve was 0.929. Conclusion For cT1 NSCLC patients, the probability of lymph node metastasis can be predicted by measuring the solid component size, CTR, and average CT value of the pulmonary nodule, in conjunction with patient age. However, relying solely on pulmonary nodule imaging characteristics is insufficient to determine a specific lymph node dissection strategy.

Objective To explore function-structure covariant patterns in Alzheimer's disease(AD)and mild cognitive impairment(MCI),and to investigate their associations with cognitive function and activities of daily living.Methods three-way parallel group independent component analysis(three-way pGICA),was used to identify the covariant patterns of resting-state functional MRI temporal data,gray matter density maps,and fractional anisotropy(FA)maps,and the differences between different groups were compared.Furthermore,the associations of covariant patterns with the Montreal Cognitive Assessment-Basic(MoCA_B)Scale scores and Activities of Daily Living Scale scores were analyzed.Results The function-structure covariant patterns in AD and MCI were characterized by the enhanced negative functional connectivity between the left posterior salience network and the right default mode network,the decreased gray matter density in the bilateral dorsolateral prefrontal cortex,and the reduced FA values in the left superior corona radiata(correlations:P<0.001,FDR corrected).Compared with HC group,AD group showed significant abnormalities in all identified covariant patterns(P<0.01,FDR corrected),but MCI group only exhibited a significant decrease in gray matter density in the bilateral dorsolateral prefrontal cortex(P<0.05,FDR corrected).Additionally,AD group had significantly lower FA value in the left superior corona radiata than MCI group(P<0.05,FDR corrected).The loadings reflecting the degree of covariation were significantly correlated with the Activities of Daily Living Scale scores(P<0.05,FDR corrected)but not with MoCA_B Scale scores.Conclusion The function-structure covariant patterns in AD and MCI are consistent with the declines in activities of daily living.The multimodal fusion analysis(three-way pGICA)provides a novel approach to understand the brain damage mechanisms underlying the covariant evolution of MCI and AD.

Objective:To analyze the risk factors of in-hospital mortality in patients with femoral neck fracture and establish a prediction model for in-hospital mortality.Methods:From 2014 to 2023, a total of 4,028,102 hospitalized patients from six directly affiliated hospitals and two co-constructed affiliated hospitals of Peking University were retrospectively analyzed. Among them, 4,744 patients were hospitalized with femoral neck fractures, including 1,486 males and 3,258 females, aged 74±13.3 years (range, 19-103 years). Gender, age, length of hospital stay, hospitalization costs, preoperative comorbidities, treatment methods, anesthesia methods, and in-hospital mortality were extracted from the medical records. According to the presence or absence of in-hospital death, the patients were divided into death group and survival group. The differences in general data and clinical indicators between the two groups were compared, and the indicators with statistically significant differences were included in binary logistic regression analysis to screen the risk factors for in-hospital death in patients with femoral neck fracture. The receiver operating characteristic (ROC) curve for predicting in-hospital mortality of femoral neck fracture was drawn, and the area under the curve (AUC) was calculated.Results:There were 30 cases in the death group and 4,714 cases in the survival group, with a mortality rate of 0.63%. Among the dead patients, 20 had undergone hip replacement, and 10 had received non-surgical treatment. In the death group, age ( t=7.524, P<0.001), length of hospital stay ( t=3.802, P<0.001), hospitalisation cost ( t=3.961, P<0.001), rate of non-surgical treatment ( P<0.001), anaesthesia modality ( P=0.002), dementia ( P=0.045), malignant tumour ( P<0.001), renal insufficiency (χ 2=27.901, P<0.001), hypertension (χ 2=4.155, P=0.042), cerebral infarction (χ 2=8.271, P=0.004), urinary infections ( P=0.043), electrolyte disorders (χ 2=16.660, P<0.001), post-cholecystectomy ( P=0.070), abnormal liver function ( P=0.015), schizophrenia ( P=0.062), myocardial infarction (χ 2=19.057, P<0.001), diabetes mellitus with end-organ damage ( P=0.036), congestive heart failure (χ 2=93.122, P<0.001), and chronic obstructive pulmonary disease (χ 2=27.714, P<0.001) were greater than in the survival group, and the differences were statistically significance ( P<0.10). Bicategory logistic regression analysis showed age ( OR=1.08, P=0.008), non-surgical treatment ( OR=2.87, P=0.017), combined malignancy ( OR=9.35, P<0.001), renal insufficiency ( OR=4.07, P=0.004), hypertension ( OR=4.45, P=0.007), cerebral infarction ( OR=2.42, P=0.040), electrolyte disorders ( OR=4.29, P=0.009), schizophrenia ( OR=41.23, P=0.002), chronic obstructive pulmonary disease ( OR=3.84, P=0.002), and congestive heart failure ( OR=7.08, P<0.001) were the independent risk factors for in-hospital mortality of femoral neck fracture. The AUC and its 95% confidence interval (CI) for the predictive model were 0.908(0.84, 0.97), indicating excellent predictive value. Conclusion:Elderly, non-surgical treatment, malignant tumor, renal insufficiency, hypertension, cerebral infarction, electrolyte disturbance, schizophrenia, chronic obstructive pulmonary disease, congestive heart failure are associated with higher in-hospital mortality in patients with femoral neck fracture.

Objective To investigate alterations in interhemispheric functional connectivity(FC)in the cerebral cortices connected via the corpus callosum in patients with Alzheimer's disease(AD),and to explore their relationships with cognitive function and activities of daily living.Methods Resting-state functional magnetic resonance imaging data were collected from 28 patients with Alzheimer's dementia(d-AD),47 patients with mild cognitive impairment(MCI),and 37 healthy controls(HC).Using a trancallosal tract template,32 pairs of homologous cortical brain regions directly connected to 32 subregions of the corpus callosum were selected as regions of interest for interhemispheric FC analysis.Further correlation analyses were performed between FC values in patient groups and their scores on the Montreal Cognitive Assessment-Basic(MoCA-B)Scale and the Activities of Daily Living(ADL)Scale.Results Compared with HC group,both MCI and d-AD groups exhibited hyperconnectivity(significantly increased FC)in interhemispheric non-homologous brain regions.Specifically,hyperconnectivity in the MCI group was scattered across the frontal,parietal,temporal,and occipital lobes,while in the d-AD group,it was concentrated within the precentral and postcentral gyri.Notably,hyperconnectivity involving the prefrontal and occipital lobes in the MCI group showed significant declines in the d-AD group.The interhemispheric homologous FC in the d-AD group reduced more significantly than the MCI group.Additionally,in the d-AD group,2 interhemispheric FC within the prefrontal lobe(between the bilateral orbital parts of the inferior frontal gyrus,and between the left medial frontal gyrus and the right middle frontal gyrus)were correlated with MoCA-B scores,and 2 FC(between the bilateral middle occipital gyri,and between the left inferior parietal lobule and the right middle frontal gyrus)were correlated with ADL scores.Conclusion MCI and d-AD exhibit distinct patterns of interhemispheric FC alterations,and the interhemispheric FC changes in AD patients are non-progressive.The close relationships between interhemispheric homologous/non-homologous FC and MoCA-B/ADL scores in d-AD patients provide an objective basis and reference for clinical neuromodulation.

Objective To investigate alterations in interhemispheric functional connectivity(FC)in the cerebral cortices connected via the corpus callosum in patients with Alzheimer's disease(AD),and to explore their relationships with cognitive function and activities of daily living.Methods Resting-state functional magnetic resonance imaging data were collected from 28 patients with Alzheimer's dementia(d-AD),47 patients with mild cognitive impairment(MCI),and 37 healthy controls(HC).Using a trancallosal tract template,32 pairs of homologous cortical brain regions directly connected to 32 subregions of the corpus callosum were selected as regions of interest for interhemispheric FC analysis.Further correlation analyses were performed between FC values in patient groups and their scores on the Montreal Cognitive Assessment-Basic(MoCA-B)Scale and the Activities of Daily Living(ADL)Scale.Results Compared with HC group,both MCI and d-AD groups exhibited hyperconnectivity(significantly increased FC)in interhemispheric non-homologous brain regions.Specifically,hyperconnectivity in the MCI group was scattered across the frontal,parietal,temporal,and occipital lobes,while in the d-AD group,it was concentrated within the precentral and postcentral gyri.Notably,hyperconnectivity involving the prefrontal and occipital lobes in the MCI group showed significant declines in the d-AD group.The interhemispheric homologous FC in the d-AD group reduced more significantly than the MCI group.Additionally,in the d-AD group,2 interhemispheric FC within the prefrontal lobe(between the bilateral orbital parts of the inferior frontal gyrus,and between the left medial frontal gyrus and the right middle frontal gyrus)were correlated with MoCA-B scores,and 2 FC(between the bilateral middle occipital gyri,and between the left inferior parietal lobule and the right middle frontal gyrus)were correlated with ADL scores.Conclusion MCI and d-AD exhibit distinct patterns of interhemispheric FC alterations,and the interhemispheric FC changes in AD patients are non-progressive.The close relationships between interhemispheric homologous/non-homologous FC and MoCA-B/ADL scores in d-AD patients provide an objective basis and reference for clinical neuromodulation.

Objective:To analyze the risk factors of in-hospital mortality in patients with femoral neck fracture and establish a prediction model for in-hospital mortality.Methods:From 2014 to 2023, a total of 4,028,102 hospitalized patients from six directly affiliated hospitals and two co-constructed affiliated hospitals of Peking University were retrospectively analyzed. Among them, 4,744 patients were hospitalized with femoral neck fractures, including 1,486 males and 3,258 females, aged 74±13.3 years (range, 19-103 years). Gender, age, length of hospital stay, hospitalization costs, preoperative comorbidities, treatment methods, anesthesia methods, and in-hospital mortality were extracted from the medical records. According to the presence or absence of in-hospital death, the patients were divided into death group and survival group. The differences in general data and clinical indicators between the two groups were compared, and the indicators with statistically significant differences were included in binary logistic regression analysis to screen the risk factors for in-hospital death in patients with femoral neck fracture. The receiver operating characteristic (ROC) curve for predicting in-hospital mortality of femoral neck fracture was drawn, and the area under the curve (AUC) was calculated.Results:There were 30 cases in the death group and 4,714 cases in the survival group, with a mortality rate of 0.63%. Among the dead patients, 20 had undergone hip replacement, and 10 had received non-surgical treatment. In the death group, age ( t=7.524, P<0.001), length of hospital stay ( t=3.802, P<0.001), hospitalisation cost ( t=3.961, P<0.001), rate of non-surgical treatment ( P<0.001), anaesthesia modality ( P=0.002), dementia ( P=0.045), malignant tumour ( P<0.001), renal insufficiency (χ 2=27.901, P<0.001), hypertension (χ 2=4.155, P=0.042), cerebral infarction (χ 2=8.271, P=0.004), urinary infections ( P=0.043), electrolyte disorders (χ 2=16.660, P<0.001), post-cholecystectomy ( P=0.070), abnormal liver function ( P=0.015), schizophrenia ( P=0.062), myocardial infarction (χ 2=19.057, P<0.001), diabetes mellitus with end-organ damage ( P=0.036), congestive heart failure (χ 2=93.122, P<0.001), and chronic obstructive pulmonary disease (χ 2=27.714, P<0.001) were greater than in the survival group, and the differences were statistically significance ( P<0.10). Bicategory logistic regression analysis showed age ( OR=1.08, P=0.008), non-surgical treatment ( OR=2.87, P=0.017), combined malignancy ( OR=9.35, P<0.001), renal insufficiency ( OR=4.07, P=0.004), hypertension ( OR=4.45, P=0.007), cerebral infarction ( OR=2.42, P=0.040), electrolyte disorders ( OR=4.29, P=0.009), schizophrenia ( OR=41.23, P=0.002), chronic obstructive pulmonary disease ( OR=3.84, P=0.002), and congestive heart failure ( OR=7.08, P<0.001) were the independent risk factors for in-hospital mortality of femoral neck fracture. The AUC and its 95% confidence interval (CI) for the predictive model were 0.908(0.84, 0.97), indicating excellent predictive value. Conclusion:Elderly, non-surgical treatment, malignant tumor, renal insufficiency, hypertension, cerebral infarction, electrolyte disturbance, schizophrenia, chronic obstructive pulmonary disease, congestive heart failure are associated with higher in-hospital mortality in patients with femoral neck fracture.

Objective To explore function-structure covariant patterns in Alzheimer's disease(AD)and mild cognitive impairment(MCI),and to investigate their associations with cognitive function and activities of daily living.Methods three-way parallel group independent component analysis(three-way pGICA),was used to identify the covariant patterns of resting-state functional MRI temporal data,gray matter density maps,and fractional anisotropy(FA)maps,and the differences between different groups were compared.Furthermore,the associations of covariant patterns with the Montreal Cognitive Assessment-Basic(MoCA_B)Scale scores and Activities of Daily Living Scale scores were analyzed.Results The function-structure covariant patterns in AD and MCI were characterized by the enhanced negative functional connectivity between the left posterior salience network and the right default mode network,the decreased gray matter density in the bilateral dorsolateral prefrontal cortex,and the reduced FA values in the left superior corona radiata(correlations:P<0.001,FDR corrected).Compared with HC group,AD group showed significant abnormalities in all identified covariant patterns(P<0.01,FDR corrected),but MCI group only exhibited a significant decrease in gray matter density in the bilateral dorsolateral prefrontal cortex(P<0.05,FDR corrected).Additionally,AD group had significantly lower FA value in the left superior corona radiata than MCI group(P<0.05,FDR corrected).The loadings reflecting the degree of covariation were significantly correlated with the Activities of Daily Living Scale scores(P<0.05,FDR corrected)but not with MoCA_B Scale scores.Conclusion The function-structure covariant patterns in AD and MCI are consistent with the declines in activities of daily living.The multimodal fusion analysis(three-way pGICA)provides a novel approach to understand the brain damage mechanisms underlying the covariant evolution of MCI and AD.

Objective:To develop a camelid single-domain antibody (SdAb) recognizing linear B-cell epitopes in glutamate dehydrogenase of Clostridium difficile(CD-GDH), and to apply it in Western blot and ELISA. Methods:Purified recombinant CD-GDH was used as bait to screen phage-displayed camelid SdAb library and obtain positive clones. Then those clones were confirmed by Western blot, and their variable domain of heavy chain of heavy chain antibody(VHH) nucleotide sequence were determined. The VHH sequence was synthesized after codon optimization and cloned into the expression vector pET28a. The SdAb was then expressed and purified, and its ability to detect CD-GDH protein in multiple assays was further explored.Results:Six positive clones were obtained, among which clone GA4 was chosen for recombinant expression in Escherichia coli and further purification. The purified GA4 binded well with CD-GDH with a Kd value of 3 nmol/L. In Western blot and ELISA, GA4 was proven to be able to selectively detect both recombinant and endogenous CD-GDH. Conclusions:A camelid SdAb targeting a linear B-cell epitope in CD-GDH is successfully developed, which provides a very useful tool for detecting CD-GDH.