Advanced Faster RCNN: a non-contrast CT-based algorithm for detecting pancreatic lesions in multiple disease stages / 南方医科大学学报

OBJECTIVE@#To propose a non-contrast CT-based algorithm for automated and accurate detection of pancreatic lesions at a low cost.@*METHODS@#With Faster RCNN as the benchmark model, an advanced Faster RCNN (aFaster RCNN) model for pancreatic lesions detection based on plain CT was constructed. The model uses the residual connection network Resnet50 as the feature extraction module to extract the deep image features of pancreatic lesions. According to the morphology of pancreatic lesions, 9 anchor frame sizes were redesigned to construct the RPN module. A new Bounding Box regression loss function was proposed to constrain the training process of RPN module regression subnetwork by comprehensively considering the constraints of the lesion shape and anatomical structure. Finally, a detection frame was generated using the detector in the second stage. The data from a total of 728 cases of pancreatic diseases from 4 clinical centers in China were used for training (518 cases, 71.15%) and testing (210 cases, 28.85%) of the model. The performance of aFaster RCNN was verified through ablation experiments and comparison experiments with 3 classical target detection models SSD, YOLO and CenterNet.@*RESULTS@#The aFaster RCNN model for pancreatic lesion detection achieved recall rates of 73.64% at the image level and 92.38% at the patient level, with an average precision of 45.29% and 53.80% at the image and patient levels, respectively, which were higher than those of the 3 models for comparison.@*CONCLUSION@#The proposed method can effectively extract the imaging features of pancreatic lesions from non-contrast CT images to detect the pancreatic lesions.

A radiomic approach to differential diagnosis of renal cell carcinoma in patients with hydronephrosis and renal calculi / 南方医科大学学报

To explore the application of radiomic analysis in differential diagnosis of renal cell carcinoma in patients with hydronephrosis and renal calculi using supervised machine learning methods.The abdominal CT scan data were retrospectively analyzed for 66 patients with pathologically confirmed hydronephrosis and renal calculi, among whom 35 patients had renal cell carcinoma. In each case 18 non-texture features and 344 texture features were extracted from the region of interest (ROI). Infinite feature selection (InfFS)-based forward feature selection method coupled with support vector machine (SVM) classifier was used to select the optimal feature subset. SVM was trained and performed the prediction using the selected feature subset to classify whether hydronephrosis with renal calculi was associated with renal cell carcinoma.A total of 12 texture features were selected as the optimal features. The area under curve (AUC), accuracy, sensitivity, specificity, false positive rate and false negative rate of the SVM- InfFS model for predicting accompanying renal tumors in patients with hydronephrosis and calculi were 0.907, 81.0%, 70.0%, 90.9%, 9.1%, and 30.0%, respectively. The diagnostic accuracy, sensitivity, specificity, false positive and false negative rates by the clinicians provided with these classification results were 90.5%, 80.0%, 100%, 0.00%, and 20.0%, respectively.The computer-aided classification model based on supervised machine learning can effectively extract the diagnostic information and improve the diagnostic rate of renal cell carcinoma associated with hydronephrosis and renal calculi.

Expression of C3aR and C5aR in trichloroethylene-sensitized mouse liver / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the expression of C3aR and C5aR in trichloroethylene-sensitized mouse liver injury and discuss the pathogenesis of Dermatitis Medicamentosa-like of TCE (DMLT).</p><p><b>METHODS</b>6∼8 w female BALB/c mouse were randomly divided into blank control group, solvent control group and TCE treatment group. TCE was given to the mouse for sensitization at 1th, 4th, 7th, 10th day and challenge at 17th day and 19th day. Before killing mouse, liver weight and body weight were recorded. The livers were separated at 24 h, 48 h, 72 h and 7 d after challenge. And the liver sections were used for immunofluorescence stain and RT-PCR to detect the expression levels of C3aR and C5aR.</p><p><b>RESULTS</b>Microscopic examination showed no significant change in liver structure or organization in TCE non-sensitized group, while liver cell oedema, cell necrosis and inflammatory cell infiltration were clearly observed in TCE-sensitized groups. The expression levels of C3aR and C5aR in 24 h, 48 h, 72 h and 7 d TCE-sensitized groups were significant higher than blank control group, solvent control group and related TCE non-sensitized groups (P < 0.05).</p><p><b>CONCLUSION</b>Complement activation was involved in TCE-induced liver injury and C3aR and C5aR might play essential role in the process.</p>

Study on the expression of bradykinin and its receptors B1R and B2R in the kidney immune injury in trichloroethylene-sensitized mouse / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the expression of bradykinin and its receptors B1R and B2R in the kidney immune injury in trichloroethylene-sensitized mouse and discuss the pathogenesis of Dermatitis Medicamentosa-like of TCE (ODMLT).</p><p><b>METHODS</b>On the first days, intradermal injection by 50% TCE and the amount of FCA mixture 100 µl for initial sensitization; on 4, 7, 10 days, painted abdominal skin by 100 µl 50% TCE for three sensitization, on 17, 19 days, painted on the back skin by 100 µl 30% TCE for initial excitation and the last challenge; 24 h before each challenge, PKSI-527+TCE group received intraperitoneal injection by inhibitor PKSI-527 (50 mg/kg); solvent control group treat without TCE and sensitization and excitation reagent the same proportion of olive oil and acetone mixture, blank control group without any treatment. Before killing the mouse, renal weight and body weight were recorded. The renals and plasma were separated at 24 h, 48 h, 72 h and 7 d after the last challenge and observed pathological of the renals. Expression of B1R and B2R in renal were examined by immunofluorescence technique. Plasma were examined by ELISA for BK.</p><p><b>RESULTS</b>The renal pathological examination revealed the apparent damage of TCE sensitized mice which compared to solvent control group showed obvious cellular infiltration, vacuolar degeneration of renal tubular epithelial cells. The renal damage of PKSI-527+TCE-sensitized groups which compared to the corresponding point of TCE-sensitized groups showed significantly reduced. The expression of BK in 24 h, 48 h and 72 h TCE-sensitized groups were significant higher than solvent control group and related TCE non-sensitized groups (P < 0.05) and 72 h point compared to the corresponding point of PKSI-527+TCE group was also increased, the difference was statistically significant (P < 0.05). The expression levels of B1R and B2R in the kidney in 24 h, 48 h, 72 h and 7 d TCE-sensitized groups were obviously higher than solvent control group and related TCE non-sensitized groups. The expression levels of B1R and B2R in the kidney in the four point of PKSI-527+TCE sensitized group were relatively lower than the corresponding point of TCE sensitized group.</p><p><b>CONCLUSION</b>KKS activation may involved in the renal immune injury of trichloroethylene-sensitized mouse and the expression change of bradykinin and its receptors B1R and B2R which may play an important role in the process.</p>

Levels of complement components C3a and C5a in renal injury among trichloroethylene-sensitized BALB/c mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To determine the levels of complement components C3a and C5a in the kidneys of trichloroethylene (TCE)-sensitized BALB/c mice, and to investigate the role of complement components in TCE-induced renal injury among BALB/c mice.</p><p><b>METHODS</b>Sixty-two female BALB/c mice were randomly divided into blank control group, vehicle control group, and TCE sensitization group. The mice in TCE sensitization group were sensitized by one intracutaneous injection and one abdominal smear of TCE. At 24 h, 48 h, 72 h, and 7 d after the second sensitization, mice were sacrificed, and the blood and kidneys were collected. An automatic biochemical analyzer was used in the determination of serum blood urea nitrogen (BUN) and creatinine (Cr). The levels of C3a and C5a in the kidneys were determined by immunohistochemistry.</p><p><b>RESULTS</b>The sensitization rate of TCE sensitization group was 42.0%. Kidney coefficient and serum levels of BUN and Cr were significantly increased in the TCE sensitization group as compared with the vehicle control group at 48 h and 72 h after sensitization (P < 0.05). The kidney coefficients of the TCE sensitization group at 48 h and 72 h were significantly higher than those of the control groups (P < 0.05). In comparison with the vehicle control group, however, no significant change was found in kidney coefficient, serum BUN, or serum Cr at 7 d after TCE sensitization (P > 0.05). Levels of C3a and C5a at 48 h (3.80±0.84 and 4.00±1.00, respectively) and 72 h (4.40 ± 1.14 and 4.40 ± 1.14, respectively) after sensitization were all significantly higher than those of the vehicle control group (P < 0.05), but no significant difference was found in level of C3a (1.80±0.45) or C5a (2.00 ± 0.71) at 7 d (P > 0.05).</p><p><b>CONCLUSION</b>TCE sensitization can induce renal injury in mice. Levels of complement components C3a and C5a are elevated in the kidneys of sensitized mice, indicating that C3a and C5a may be involved in the renal injury induced by TCE sensitization.</p>

Biosynthesis of amorpha-4,11-diene, a precursor of the antimalarial agent artemisinin, in Escherichia coli through introducing mevalonate pathway / 生物工程学报

Artemisinin-based combination therapies (ACTs) are recommended to be the most effective therapies for the first-line treatment of uncomplicated falciparum malaria. However, artemisinin is often in short supply and unaffordable to most malaria patients, which limits the wide use of ACTs. Production of amorpha-4,11-diene, an artemisinin precursor, was investigated by engineering a heterologous isoprenoid biosynthetic pathway in Escherichia coli. The production of amorpha-4,11-diene was achieved by expression of a synthetic amorpha-4,11-diene synthase gene in Escherichia coli DHGT7 and further improved by about 13.3 fold through introducing the mevalonate pathway from Enterococcus faecalis. After eliminating three pathway bottlenecks including amorpha-4,11-diene synthase, HMG-CoA reducase and mevalonate kinase by optimizing the metabolic flux, the yield of amorpha-4,11-diene was increased by nearly 7.2 fold and reached at 235 mg/L in shaking flask culture. In conclusion, an engineered Escherichia coli was constructed for high-level production of amorpha-4,11-diene.