[The diagnostic value of machine-learning-based model for predicting the malignancy of solid nodules in multiple pulmonary nodules]

Objective: To examine the efficiacy of a machine learning diagnostic model specifically for solid nodules in multiple pulmonary nodules constructed by combining patient clinical information and CT features. Methods: Totally 446 solid nodules resected from 287 patients with multiple pulmonary nodules in Department of Thoracic Surgery, Peking University People's Hospital from January 2010 to December 2018 were included. There were 117 males and 170 females, aging (61.4±9.9) yeras (range: 33 to 84 years). The nodules were randomly divided into training set (228 patients with 357 nodules) and test set (59 patients with 89 nodules) by a ratio of 4∶1. The extreme gradient boosting (XGBoost) algorithm was used to generate a predictive model (PKU-ML model) on the training set. The accuracy was verified on the test set and compared with previous published models. Finally, an independent single solid nodule set (155 patients, 95 males, aging (62.3±8.3) years (range: 37 to 77 years)) was used to evaluate the accuracy of the model for predictive value of single solid nodules. Area of receiver operating characteristic curve (AUC) was used to evaluate diagnostic values of models. Results: In the training set, the AUC of the PKU-ML model was 0.883 (95%CI: 0.849 to 0.917). In the test set, the performance of the PKU-ML model (AUC=0.838, 95%CI: 0.754 to 0.921) was better than the models designed for single pulmonary nodules (Brock model: AUC=0.709, 95%CI: 0.603 to 0.816, P=0.04; Mayo model: AUC=0.756, 95%CI: 0.656 to 0.856, P=0.01; VA model: AUC=0.674, 95%CI: 0.561 to 0.787, P<0.01), similar with PKUPH model (AUC=0.750, 95%CI: 0.649 to 0.851, P=0.07). In the independent single solid nodules set, the PKU-ML model also achieved good performance (AUC=0.786, 95%CI: 0.701 to 0.872). Conclusion: The machine learning based PKU-ML model can better predict the malignancy of solid nodules in multiple pulmonary nodules, and also achieved a good performance in predicting the malignancy of single solid pulmonary nodules compared to mathematical models.

[The multi-dimensional molecular characteristics of the indolent pulmonary ground-glass nodules]

With the dramatically increasing detection rate of ground-glass nodules (GGN), exact understanding and treatment strategy of them has become the hottest issue currently. More and more studies have begun to explore the underlying mechanisms of their indolent characteristics and favorable prognosis from the perspectives of molecular evolution and immune microenvironment. GGN has different dominating gene mutations at different evolutional stages. The pure GGN has a lower tumor mutation burden and genomic instability, while a gradually evolutionary feature of genomic mutation along with the pathological progression can be observed. GGN has less infiltration of immune cells, and they are under the pressure of immune surveillance with weakened immune escape. With the increase of solid components, an inhibitory immune microenvironment is gradually established and immune escape is gradually enhanced, leading to rapid tumor growth. Further exploration of the molecular characteristics of GGN will help to more precisely distinguish these highly heterogeneous lesions, which could be helpful to make personalized treatment plans.

Role of circulating tumor DNA in the management of early-stage lung cancer

Lung cancer is one of the most common cancers and the predominant cause of cancer‐related death in the world. The low accuracy of early detection techniques and high risk of relapse greatly contribute to poor prognosis. An accurate clinical tool that can assist in diagnosis and surveillance is urgently needed. Circulating tumor DNA (ctDNA) is free DNA shed from tumor cells and isolated from peripheral blood. The genomic profiles of ctDNA have been shown to closely match those of the corresponding tumors. With the development of approaches with high sensitivity and specificity, ctDNA plays a vital role in the management of lung cancer as a result of its reproducible, non‐invasive, and easy‐to‐obtain characteristics. However, most previous studies have focused on advanced lung cancer. Few studies have investigated ctDNA in the early stages of the disease. In this review, we focus on ctDNA obtained from patients in the early stage of lung cancer, provide a summary of the related literature to date, and describe the main approaches to ctDNA and the clinical applications.

Signaling protein signature predicts clinical outcome of non-small-cell lung cancer

BACKGROUND

Non-small-cell lung cancer (NSCLC) is characterized by abnormalities of numerous signaling proteins that play pivotal roles in cancer development and progression. Many of these proteins have been reported to be correlated with clinical outcomes of NSCLC. However, none of them could provide adequate accuracy of prognosis prediction in clinical application.

METHODS

A total of 384 resected NSCLC specimens from two hospitals in Beijing (BJ) and Chongqing (CQ) were collected. Using immunohistochemistry (IHC) staining on stored formalin-fixed paraffin-embedded (FFPE) surgical samples, we examined the expression levels of 75 critical proteins on BJ samples. Random forest algorithm (RFA) and support vector machines (SVM) computation were applied to identify protein signatures on 2/3 randomly assigned BJ samples. The identified signatures were tested on the remaining BJ samples, and were further validated with CQ independent cohort.

RESULTS

A 6-protein signature for adenocarcinoma (ADC) and a 5-protein signature for squamous cell carcinoma (SCC) were identified from training sets and tested in testing sets. In independent validation with CQ cohort, patients can also be divided into high- and low-risk groups with significantly different median overall survivals by Kaplan-Meier analysis, both in ADC (31 months vs. 87 months, HR 2.81; P <  0.001) and SCC patients (27 months vs. not reached, HR 9.97; P <  0.001). Cox regression analysis showed that both signatures are independent prognostic indicators and outperformed TNM staging (ADC: adjusted HR 3.07 vs. 2.43, SCC: adjusted HR 7.84 vs. 2.24). Particularly, we found that only the ADC patients in high-risk group significantly benefited from adjuvant chemotherapy (P = 0.018).

CONCLUSIONS

Both ADC and SCC protein signatures could effectively stratify the prognosis of NSCLC patients, and may support patient selection for adjuvant chemotherapy.

Optimal flexible laryngeal mask airway size in children weighing 10 to 20 kg

This prospective, randomised study was conducted to assess the effect of flexible laryngeal mask airway (FLMA) size on oropharyngeal leak pressure (OLP) in children at the recommended intracuff pressure. A total of 120 children undergoing elective ophthalmic surgery were randomly assigned to the size 2 FLMA group or size 2.5 FLMA group. The primary measurement was OLP at an intracuff pressure of 40 cmH₂O. Secondary outcomes included the incidence of OLP <10 cmH₂O, insufficient ventilation, gastric insufflation, insertion time, successful first-attempt insertion rate, fibreoptic view grade and pharyngolaryngeal adverse events. The median OLP was comparable for the size 2 and size 2.5 FLMA (18 cmH₂O versus 18 cmH₂O, P=0.38). However, the size 2 FLMA group had a higher incidence of OLP <10 cmH₂O and insufficient ventilation (13.3% versus 0, P=0.006). In subgroup analyses based on weight, the size 2.5 FLMA had a lower occurrence of OLP <10 cmH₂O and insufficient ventilation (27% versus 0, P=0.0046) in children 16-20 kg. We conclude that at a 40 cmH₂O intracuff pressure, the OLP with the size 2 and size 2.5 FLMA was similar in children weighing 10-15.9 kg. However, in children weighing 16-20 kg, size 2 devices had a higher incidence of low OLP and insufficient ventilation, so a 2.5 FLMA may be preferable in this subgroup.

[A clinical prediction model for N2 lymph node metastasis in clinical stage I non-small cell lung cancer]

OBJECTIVE

To estimate the probability of N2 lymph node metastasis and to assist physicians in making diagnosis and treatment decisions.

METHODS

We reviewed the medical records of 739 patients with computed tomography-defined stage I non-small cell lung cancer (NSCLC) that had an exact tumor-node-metastasis stage after surgery. A random subset of three fourths of the patients (n=554) were selected to develop the prediction model. Logistic regression analysis of the clinical characteristics was used to estimate the independent predictors of N2 lymph node metastasis. A prediction model was then built and externally validated by the remaining one fourth (n=185) patients which made up the validation data set. The model was also compared with 2 previously described models.

RESULTS

We identified 4 independent predictors of N2 disease: a younger age, larger tumor size, central tumor location, and adenocarcinoma or adenosquamous carcinoma pathology. The model showed good calibration (Hosmer-Lemeshow test: P=0.923) with an area under the receiver operating characteristic curve (AUC) of 0.748 (95% confidence interval, 0.710-0.784). When validated with all the patients of group B, the AUC of our model was 0.781 (95% CI: 0.715-0.839) and the VA model was 0.677 (95% CI: 0.604-0.744) (P =0.04). When validated with T1 patients of group B, the AUC of our model was 0.837 (95% CI: 0.760-0.897) and Fudan model was 0.766 (95% CI: 0.681-0.837) (P < 0.01).

CONCLUSION

Our prediction model estimated the pretest probability of N2 disease in computed tomography-defined stage I NSCLC and was more accurate than the existing models. Use of our model can be of assistance when making clinical decisions about invasive or expensive mediastinal staging procedures.

Application of endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of mediastinal lesions

BACKGROUND

Mediastinal lesions are often difficult to diagnose in clinical practice because of the unique anatomical position of the mediastinum, which makes performance of biopsy difficult. The value of endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis of lung cancer and mediastinal lymph node staging has been widely accepted. However, few studies have been conducted on the value of endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis and differential diagnosis of mediastinal lesions. The current study was conducted to investigate the value of endobronchial ultrasound-guided transbronchial needle aspiration in the diagnosis and differential diagnosis of isolated mediastinal lesions without lung abnormalities.

METHODS

We retrospectively analyzed the data of patients with isolated mediastinal lesions without lung abnormalities for whom endobronchial ultrasound-guided transbronchial needle aspiration examination was performed at the Department of Thoracic Surgery of Peking University People's Hospital, between September 2009 and December 2010. For patients who could not be diagnosed with endobronchial ultrasound-guided transbronchial needle aspiration, surgical biopsy or more than 6 months of clinical and imaging follow-up was carried out.

RESULTS

Endobronchial ultrasound-guided transbronchial needle aspiration was performed for 60 patients with isolated mediastinal lesions. Correct diagnosis was made in 48 cases. Nineteen cases were malignant, and 29 were benign. The rate of correct diagnosis was 80%. The sensitivity, specificity, and accuracy of endobronchial ultrasound-guided transbronchial needle aspiration in distinguishing benign from malignant mediastinal lesions were 95%, 100%, and 98%, respectively. The examination was tolerable for all patients. No associated complications were observed.

CONCLUSION

Endobronchial ultrasound-guided transbronchial needle aspiration is a safe and effective method of diagnosing mediastinal lesions.

Thymidine block does not synchronize L1210 mouse leukaemic cells: implications for cell cycle control, cell cycle analysis and whole-culture synchronization

It has been predicted that whole-culture methods of synchronization cannot synchronize cells. We have tested whether thymidine block, one type of whole-culture synchronization, can synchronize L1210 cells. We demonstrate experimentally that the thymidine block method cannot produce a synchronized culture. Although thymidine-treated cells are arrested primarily with an S-phase amount of DNA, there is no narrowing of the cell size distribution and there is no synchronized division pattern following release from the thymidine block. In contrast to a whole-culture synchronization method, cells produced by a selective (i.e. non-whole-culture) method not only have a specific DNA content, but also have a narrow size distribution and divide synchronously. Generalizing the results to other cell lines, we suggest that these conclusions call into question experimental measurements of gene expression during the division cycle based on thymidine inhibition synchronization.

[Study on relationship between brain function and syndrome differentiation-typing of TCM in non-insulin dependent diabetes mellitus]

The relationship between brain function and syndrome-types of TCM in 51 patients with non-insulin dependent diabetes mellitus (NIDDM) was observed. The syndromes were divided into three types. (1) Yin Deficiency with internal excessive Heat (YDIEH), 15 cases; (2) Qi-Yin Deficiency (QYD), 21 cases; (3) Deficiency of both Yin and Yang (DYY), 15 cases. The control group consisted of 30 healthy subjects matched in age, sex and educational level. The brain function were tested by neurobehavioral and neuroelectrophysiological tests. The former included short-term memory, thinking, eye-hand coordination and emotion tests; the latter consisted of brainstem auditory evoked potentials (BAEP), visual evoked potentials (VEP) and somatosensory evoked potentials (SEP). The results showed that the brain function in YDIEH group approached normal controls, and the brain function in QYD and QYY groups were significantly deteriorated. The results suggested that the brain function were correlated with the syndrome-types of patients with NIDDM. This would be valuable for diagnosis and treatment of NIDDM in TCM.

[The effect of Coptis chinensis on lipid peroxidation and antioxidases activity in rats]

In order to make a systematic study of the effect of Coptis chinensis on free radicals, the authors used the method that the drug and the brain homogenate of rat were mixed and incubated to investigate the effect of Coptis on lipid peroxidation. The result showed that the malondialdehyde (MDA) product of rat brain homogenate inhibited by 5% Coptis was significantly different from control (P < 0.001). On the basis of the above-mentioned results, the effect of Coptis on lipid peroxidation and diabetes of rats induced by alloxan was investigated. The result showed: (1) The MDA product of both pancreas and liver homogenate in Coptis group was significantly less than that in control and alloxan group (P < 0.01, P < 0.05). (2) Superoxide dismutases (SODs) in erythrocytes activity was the same for all groups (P > 0.50). (3) The blood catalase (CAT) activity in alloxan group markedly decreased compared with control group (P < 0.05), but no significant change between Coptis and alloxan group (P > 0.05). (4) The value of serum glucose in alloxan group was significantly increased in comparing with control group (P < 0.05). There was a trend to decrease the value of serum glucose in Coptis group compared with alloxan group, but no significant difference between two groups (P > 0.05). The experiment indicated that there was very strong inhibitory effect of Coptis to the lipid peroxidation in vitro and in vivo. Coptis could protect rat from diabetes inducing by alloxan and that probably was due to the fact that Coptis was able to inhibit alloxan inducing free radicals.

Effects of desipramine treatment on the biliary, fecal and urinary excretion of methadone in the rat

The effects of desipramine (DMI) given i.p. 1 hour before administration of 14C-methadone (5 mg/kg s.c.) on the excretion of methadone in bile, feces and urine were studied. Rats with cannulated bile ducts excreted 52% of administered 14C into bile within 4 hours, 60% of the excretion as 2-ethylidine-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 30% as water-soluble metabolite (WSM). The percentages of 14C excreted within 48 hours into the feces and urine of rats without biliary fistula were 60.6 and 17.4%, respectively. The excretion of 14C in feces consisted mostly of EDDP. Urinary excretion consisted of unchanged methadone, EDDP and WSM in the first 12 hours and consisted mostly of WSM thereafter. DMI treatment increased biliary flow but decreased the biliary excretion of 14C, mainly by a decrease in WSM. The fecal output was greatly decreased by DMI, thus decreasing fecal excretion of 14C in the first 12 hours. DMI treatment markedly decreased urinary volume but did not change the urine pH. The decreased urinary excretion of WSM in DMI-treated rats during the first 12-hour urine sample accounted for most of the decreased elimination of 14C. It is suggested that DMI-induced inhibition of methadone metabolism in the liver is a major factor responsible for the observed decreases in the biliary and urinary excretion of WSM...