Preoperative ultrasound radiomics for predicting clinically relevant postoperative pancreatic fistula after pancreatectomy.

OBJECTIVES: To evaluate the efficacy of the radiomics model based on preoperative B-mode ultrasound (BMUS) and shear wave elastography (SWE) for predicting the occurrence of clinically relevant-postoperative pancreatic fistula (CR-POPF). METHODS: Patients who were scheduled to undergo pancreatectomy were prospectively enrolled and received ultrasound assessment within one week before surgery. The risk factors of POPF (grades B and grades C) were analyzed. Preoperative BMUS images, SWE values of pancreatic lesions and surrounding parenchyma were used to build preoperative prediction radiomics models. Radiomic signatures were extracted and constructed using a minimal Redundancy Maximal Relevance (mRMR) algorithm and an L1 penalized logistic regression. A combined model was built using multivariate regression which incorporated radiomics signatures and clinical data. RESULTS: From January 2020 to November 2021, a total of 147 patients (85 distal pancreatectomies and 62 pancreaticoduodenectomies) were enrolled. During the three-week follow-up after pancreatectomy, the incidence rates of grade B/C POPF were 28.6% (42/147). Radiomic signatures constructed from BMUS of pancreas parenchymal regions (panRS) achieved an area under the receiver operating characteristic curve (AUC) of 0.75, accuracy of 68.7%, sensitivity of 85.7 %, and specificity of 61.9 % in preoperative noninvasive prediction of CR-POPF. The AUC of the radiomics model increased to 0.81 when panRS was used for the prediction of CR-POPF after pancreaticoduodenectomy. CONCLUSIONS: Radiomics model based on ultrasound images was potentially useful for predicting CR-POPF. Patients with high-risk factors should be closely monitored when postoperation.

Pancreatic neuroendocrine tumor: prediction of tumor grades by radiomics models based on ultrasound images.

OBJECTIVE: We aimed to investigate whether the radiomics analysis based on B-mode ultrasound (BMUS) images could predict histopathological tumor grades in pancreatic neuroendocrine tumors (pNETs). METHODS: A total of 64 patients with surgery and histopathologically confirmed pNETs were retrospectively included (34 male and 30 female, mean age 52.4 ± 12.2 years). Patients were divided into training cohort (n = 44) and validation cohort (n = 20). All pNETs were classified into Grade 1 (G1), Grade 2 (G2), and Grade 3 (G3) tumors based on the Ki-67 proliferation index and the mitotic activity according to WHO 2017 criteria. Maximum relevance minimum redundancy, least absolute shrinkage and selection operator were used for feature selection. Receiver operating characteristic curve analysis was used to evaluate the model performance. RESULTS: Finally, 18 G1 pNETs, 35 G2 pNETs, and 11 G3 pNETs patients were included. The radiomic score derived from BMUS images to predict G2/G3 from G1 displayed a good performance with an area under the receiver operating characteristic curve of 0.844 in the training cohort, and 0.833 in the testing cohort. The radiomic score achieved an accuracy of 81.8% in the training cohort and 80.0% in the testing cohort, a sensitivity of 0.750 and 0.786, a specificity of 0.833 and 0.833 in the training/testing cohorts. Clinical benefit of the score also exhibited superior usefulness of the radiomic score, as shown by the decision curve analysis. CONCLUSIONS: Radiomic data constructed from BMUS images have the potential for predicting histopathological tumor grades in patients with pNETs. ADVANCES IN KNOWLEDGE: The radiomic model constructed from BMUS images has the potential for predicting histopathological tumor grades and Ki-67 proliferation indexes in patients with pNETs.

Anzhen Risk Evaluation System for Acute Aortic Syndrome (AZSCORE-AAS): protocol for a multicentre prospective cohort study in northern China.

INTRODUCTION: Acute aortic syndrome (AAS) is a group of acute and critical conditions, including acute aortic dissection (AAD), acute intramural haematoma and penetrating aortic ulcer. High mortality and morbidity rates result in a poor patient prognosis. Prompt diagnoses and timely interventions are paramount for saving patients' lives. In recent years, risk models for AAD have been established worldwide; however, a risk evaluation system for AAS is still lacking in China. Therefore, this study aims to develop an early warning and risk scoring system in combination with the novel potential biomarker soluble ST2 (sST2) for AAS. METHODS AND ANALYSIS: This multicentre, prospective, observational study will recruit patients diagnosed with AAS at three tertiary referral centres from 1 January 2020 to 31 December 2023. We will analyse the discrepancies in sST2 levels in patients with different AAS types and explore the accuracy of sST2 in distinguishing between them. We will also incorporate potential risk factors and sST2 into a logistic regression model to establish a logistic risk scoring system for predicting postoperative death and prolonged intensive care unit stay in patients with AAS. ETHICS AND DISSEMINATION: This study was registered on the Chinese Clinical Trial Registry website (http://www. chictr. org. cn/). Ethical approval was obtained from the human research ethics committees of Beijing Anzhen Hospital (KS2019016). The ethics review board of each participating hospital agreed to participate. The final risk prediction model will be published in an appropriate journal and disseminated as a mobile application for clinical use. Approval and anonymised data will be shared. TRIAL REGISTRATION NUMBER: ChiCTR1900027763.

Deep learning-based radiomics based on contrast-enhanced ultrasound predicts early recurrence and survival outcome in hepatocellular carcinoma.

BACKGROUND: Hepatocellular carcinoma (HCC) is the most common primary liver malignancy. AIM: To predict early recurrence (ER) and overall survival (OS) in patients with HCC after radical resection using deep learning-based radiomics (DLR). METHODS: A total of 414 consecutive patients with HCC who underwent surgical resection with available preoperative grayscale and contrast-enhanced ultrasound images were enrolled. The clinical, DLR, and clinical + DLR models were then designed to predict ER and OS. RESULTS: The DLR model for predicting ER showed satisfactory clinical benefits [area under the curve (AUC)] = 0.819 and 0.568 in the training and testing cohorts, respectively), similar to the clinical model (AUC = 0.580 and 0.520 in the training and testing cohorts, respectively; P > 0.05). The C-index of the clinical + DLR model in the prediction of OS in the training and testing cohorts was 0.800 and 0.759, respectively. The clinical + DLR model and the DLR model outperformed the clinical model in the training and testing cohorts (P < 0.001 for all). We divided patients into four categories by dichotomizing predicted ER and OS. For patients in class 1 (high ER rate and low risk of OS), retreatment (microwave ablation) after recurrence was associated with improved survival (hazard ratio = 7.895, P = 0.005). CONCLUSION: Compared to the clinical model, the clinical + DLR model significantly improves the accuracy of predicting OS in HCC patients after radical resection.

Prediction of Histological Grades and Ki-67 Expression of Hepatocellular Carcinoma Based on Sonazoid Contrast Enhanced Ultrasound Radiomics Signatures.

Objectives: Histopathological tumor grade and Ki-67 expression level are key aspects concerning the prognosis of patients with hepatocellular carcinoma (HCC) lesions. The aim of this study was to investigate whether the radiomics model derived from Sonazoid contrast-enhanced (S-CEUS) images could predict histological grades and Ki-67 expression of HCC lesions. Methods: This prospective study included 101 (training cohort: n = 71; validation cohort: n = 30) patients with surgical resection and histopathologically confirmed HCC lesions. Radiomics features were extracted from the B mode and Kupffer phase of S-CEUS images. Maximum relevance minimum redundancy (MRMR) and least absolute shrinkage and selection operator (LASSO) were used for feature selection, and a stepwise multivariate logit regression model was trained for prediction. Model accuracy, sensitivity, and specificity in both training and testing datasets were used to evaluate performance. Results: The prediction model derived from Kupffer phase images (CE-model) displayed a significantly better performance in the prediction of stage III HCC patients, with an area under the receiver operating characteristic curve (AUROC) of 0.908 in the training dataset and 0.792 in the testing set. The CE-model demonstrated generalizability in identifying HCC patients with elevated Ki-67 expression (>10%) with a training AUROC of 0.873 and testing AUROC of 0.768, with noticeably higher specificity of 92.3% and 80.0% in training and testing datasets, respectively. Conclusions: The radiomics model constructed from the Kupffer phase of S-CEUS images has the potential for predicting Ki-67 expression and histological stages in patients with HCC.

Preoperative prediction of microvascular invasion (MVI) in hepatocellular carcinoma based on kupffer phase radiomics features of sonazoid contrast-enhanced ultrasound (SCEUS): A prospective study.

OBJECTIVES: To establish and to evaluate a machine learning radiomics model based on grayscale and Sonazoid contrast enhanced ultrasound images for the preoperative prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC) patients. METHODS: 100 cases of histopathological confirmed HCC lesions were prospectively included. Regions of interest were segmented on both grayscale and Kupffer phase of Sonazoid contrast enhanced (CEUS) images. Radiomic features were extracted from tumor region and region containing 5 mm of peritumoral liver tissues. Maximum relevance minimum redundancy (MRMR) and Least Absolute Shrinkage and Selection Operator (LASSO) were used for feature selection and Support Vector Machine (SVM) classifier was trained for radiomic signature calculation. Radiomic signatures were incorporated with clinical variables using univariate-multivariate logistic regression for the final prediction of MVI. Receiver operating characteristic curves, calibration curves and decision curve analysis were used to evaluate model's predictive performance of MVI. RESULTS: Age were the only clinical variable significantly associated with MVI. Radiomic signature derived from Kupffer phase images of peritumoral liver tissues (kupfferPT) displayed a significantly better performance with an area under the receiver operating characteristic curve (AUROC) of 0.800 (95% confidence interval: 0.667, 0.834), the final prediction model using age and kupfferPT achieved an AUROC of 0.804 (95% CI: 0.723, 0.878), accuracy of 75.0%, sensitivity of 87.5% and specificity of 69.1%. CONCLUSIONS: Radiomic model based on Kupffer phase ultrasound images of tissue adjacent to HCC lesions showed an observable better predictive value compared to grayscale images and has potential value to facilitate preoperative identification of HCC patients at higher risk of MVI.

Exploration of the mechanism by which icariin modulates hippocampal neurogenesis in a rat model of depression.

Icariin (ICA) has a significant capacity to protect against depression and hippocampal injury, but it cannot effectively cross the blood-brain barrier and accumulate in the brain. Therefore, the mechanism by which ICA protects against hippocampal injury in depression remains unclear. In this study, we performed proteomics analysis of cerebrospinal fluid to investigate the mechanism by which ICA prevents dysfunctional hippocampal neurogenesis in depression. A rat model of depression was established through exposure to chronic unpredictable mild stress for 6 weeks, after which 120 mg/kg ICA was administered subcutaneously every day. The results showed that ICA alleviated depressive symptoms, learning and memory dysfunction, dysfunctional neurogenesis, and neuronal loss in the dentate gyrus of rats with depression. Neural stem cells from rat embryonic hippocampi were cultured in media containing 20% cerebrospinal fluid from each group of rats and then treated with 100 µM corticosterone. The addition of cerebrospinal fluid from rats treated with ICA largely prevented the corticosterone-mediated inhibition of neuronal proliferation and differentiation. Fifty-two differentially expressed proteins regulated by chronic unpredictable mild stress and ICA were identified through proteomics analysis of cerebrospinal fluid. These proteins were mainly involved in the ribosome, PI3K-Akt signaling, and interleukin-17 signaling pathways. Parallel reaction monitoring mass spectrometry showed that Rps4x, Rps12, Rps14, Rps19, Hsp90b1, and Hsp90aa1 were up-regulated by chronic unpredictable mild stress and down-regulated by ICA. In contrast, HtrA1 was down-regulated by chronic unpredictable mild stress and up-regulated by ICA. These findings suggest that ICA can prevent depression and dysfunctional hippocampal neurogenesis through regulating the expression of certain proteins found in the cerebrospinal fluid. The study was approved by the Experimental Animal Ethics Committee of Guangzhou University of Chinese Medicine of China in March 2017.

Cerebrospinal fluid proteomics reveal potential protein targets of JiaWeiSiNiSan in preventing chronic psychological stress damage.

CONTEXT: Chinese herbal formula JiaWeiSiNiSan (JWSNS) has been widely used to prevent stress-induced neuropsychiatric ailments in clinics and proven to have therapeutic anti-stress effects on rats. However, the mechanism remains unclear. OBJECTIVE: Based on the proteomics of cerebrospinal fluid (CSF), this study explores the possible mechanism and target proteins of JiaWeiSiNiSan raising stress resilience and preventing stress damage. MATERIALS AND METHODS: A 6-week Chronic Unpredictable Mild Stress (CUMS) model was applied on adult Wistar male rats to observe the effects of JWSNS on improving mental stress resilience. Tandem Mass Tag (TMT) proteomics and bioinformatics analysis were used to screen and analyze differentially expressed proteins (DEPs) in CSF. Parallel Reaction Monitoring (PRM) was used to validate target DEPs. RESULTS: Significantly decreased sucrose preference, locomotion activity level and accuracy of T-maze, as well as increased immobility time, were observed in CUMS rats compared to CON rats while JWSNS improved above depression-like behaviours. The quantitative proteomics and bioinformatics analysis showed that JWSNS decreased the expression of Rps4x, HSP90AA1, Rps12, Uba1, Rsp14, Tuba1b in CUMS rats CSF (p < 0.05, FDR < 0.5). Immunofluorescence results showed that the number of BrdU/DCX positive cells (p < 0.01) and the relative number of neurons (p < 0.01) in the hippocampus dentate gyrus (DG) of the JSWNS group significantly increased, compared with the CUMS group. CONCLUSIONS: JWSNS could increase mental stress resilience and prevent stress damage by regulating proteins in CSF. This study provides a scientific basis for further study on Chinese formulas preventing mental illness.

[Study on mechanism of Guilu Erxianjiao in treatment of post-traumatic stress disorder based on network pharmacology].

The aim of this paper was to predict the multi-compound, multi-target and multi-pathway mechanism of Guilu Erxianjiao in treating post-traumatic stress disorder(PTSD) based on network pharmacology. Active compounds and corresponding targets of Guilu Erxianjiao were obtained from TCMSP, BATMAN-TCM, Chemistry and DrugBank database, and known therapeutic targets of PTSD were obtained from OMIM, TTD and DisGeNET Database. The protein interaction network of compound-disease was then built by combining with the STRING Database. Topological parameters of the network were analyzed by Cytoscape 3.6.0 to get key active compounds and their targets. The GO biological process analysis and KEGG pathway analysis of the key targets were conducted. Based on the results of KEGG, the "compound-target-pathway" network was built by Cytoscape 3.6.0 and the results were verified by SystemsDock online molecular docking tool. The prediction results showed that there were 67 active compounds and 420 targets for Guilu Erxianjiao, and 206 known PTSD-related therapeutic targets. Besides, 66 targets, 58 terms and 22 pathways were obtained from Cytoscape 3.6.0 topological parameters analysis, GO biological process analysis, and KEGG pathway analysis, respectively. Molecular docking results showed that both target with the maximum degree value and common targets of PTSD and Guilu Erxianjiao in the pathway can be effectively combined with their corresponding active compounds through molecular docking. The results suggested that Guilu Erxianjiao could exert anti-PTSD effect by regulating synaptic plasticity, anti-apoptotic, anti-inflammatory and promoting fear memory extinction through pathways such as LTP, PI3 K/Akt/mTOR, TNF, serotonergic synapse and dopaminergic synapse. This study provides a theoretical basis for further elucidating pharmacological mechanisms of Guilu Erxianjiao in treating PTSD.

Pan-cancer analysis of iron metabolic landscape across the Cancer Genome Atlas.

Iron is an essential metal ion in the human body and usually dysregulated in cancers. However, a comprehensive overview of the iron-related genes and their clinical relevance in cancer is lacking. In this study, we utilized the expression profiling, proteomics, and epigenetics from the Cancer Genome Atlas database to systematically characterized the alterations of iron-related genes. There were multiple iron-related genes with dysregulation across 14 cancers and some of these ectopic changes may be associated with aberrant DNA methylation. Meanwhile, a variety of genes were significantly associated with patient survival, especially in kidney renal clear cell carcinoma. Then differentially expressed genes were validated in clinical samples. Finally, we found deferoxamine and erastin could inhibit proliferation in various tumor cells and influence the expression of several iron-related genes. Overall, our study provides a comprehensive analysis of iron metabolism across cancers and highlights the potential treatment of iron targeted therapies for cancers.

Transrectal microwave thermotherapy causing a short-time influence on sperm quality in Chinese chronic nonbacterial prostatitis patients.

Chronic prostatitis can affect the sperm's quality. Previous studies have shown that transrectal microwave thermotherapy (TRMT) results in symptomatic relief in patients with chronic prostatitis, but the effects on sperm have not been carefully investigated. This study evaluates the impact of TRMT on the relief or decrease of symptoms and quality of sperm when used to treat patients with chronic nonbacterial prostatitis. Sixty patients were enrolled in the study. TRMT treatment was administered over 5 days, 1 h per day. Semen examination was carried out pretreatment and immediately at the conclusion of the 5-day treatment. Also, it was repeated 1 month, 3 months, and 6 months later. The treatment's symptom relief efficacy was evaluated using the National Institutes of Health Chronic Prostatitis Symptom Index (NIH-CPSI). After the treatment, the overall NIH-CPSI scores were lower compared to those of pretreatment. In addition, the white blood cells and lecithin in expressed prostatic secretion were normal after the treatment. The sperm count was decreased by 23.8% 3 months after the treatment, sperm motility was reduced by 10.3% immediately after treatment, and sperm deformity was increased by 17.2%. The sperm volume and PH were not affected. However, the sperm quality recovered after treatment and the malformation rate was also lower at 6 months after treatment. TRMT is a favorable and safe treatment option for patients with nonbacterial chronic prostatitis. It could relieve the patient's symptoms and impact on sperm quality in the short-term.

Silodosin is effective for treatment of LUTS in men with BPH: a systematic review.

The aim of this study was to systematically review the evidence on the efficacy and safety of silodosin treatments on lower urinary tract symptoms (LUTS) in men with benign prostatic hyperplasia (BPH) from randomized controlled trials. We searched PubMed (1966-December 2011), Embase (1974-December 2011) and the Cochrane Library Database (2011, Issue 12). The assessed outcome measures were the change from baseline for the International Prostate Symptom Score (IPSS), quality of life (QoL) score, peak urine maximum flow rate (Q(max)), QoL related to urinary symptoms and adverse effects. Two authors independently assessed the study quality and extracted data. All data were analysed using RevMan 5.1. The meta-analysis included four randomized controlled trials with a total of 2504 patients. The study durations were each 12 weeks. At the follow-up end points, the pooled results showed that the change from baseline for the silodosin group was significantly higher than the placebo group for the IPSS, QoL score and Q(max)(mean difference (MD)=-2.78, P<0.00001; MD=-0.42, P=0.004; MD=1.17, P<0.00001,respectively) and patients felt more satisfied with QoL related to urinary symptoms in the silodosin group than the placebo group. Ejaculation disorder was the most commonly reported adverse effect. The pooled results also showed that the silodosin group was superior to the 0.2 mg tamsulosin group with respect to the IPSS and QoL score (IPSS: MD=-1.14, P=0.02; QoL score: MD=-0.26, P=0.02) and inferior to the 0.2 mg tamsulosin group with respect to Q(max) (MD=-0.85, P=0.01). In contrast, there was no significant difference in the incidence of ejaculation disorder and dizziness between the silodosin and 0.2 mg tamsulosin groups. The current meta-analysis suggested that silodosin is an effective therapy for LUTS in men with BPH and is not inferior to 0.2 mg tamsulosin.

Photoselective green-light laser vaporisation vs. TURP for BPH: meta-analysis.

This study sought to evaluate the efficacy and safety of photoselective vaporisation (PVP) vs. transurethral resection of the prostate (TURP) for patients with benign prostatic hyperplasia (BPH). Eligible studies were identified from electronic databases (Cochrane Library, PubMed and EMBASE). The database search, quality assessment and data extraction were performed independently by two reviewers. Efficacy (primary outcomes: maximum urinary flow rate (Q(max)), international prostate symptom score (IPSS), postvoid residual urine (PVR) and quality of life (QoL); secondary outcomes: operative time, hospital time and catheter removal time) and safety (complications, such as transfusion and capsular perforation) were explored by using Review Manager 5.0. Six randomized controlled trials (RCTs) and five case-controlled studies of 1398 patients met the inclusion criteria. A meta-analysis of the extractable data showed that there were no differences in IPSS, Q(max), QoL or PVR between PVP and TURP (mean difference (MD): prostate sizes <70 ml, Q(max) at 24 months, MD=0.01, P=0.97; IPSS at 12 months, MD=0.18, P=0.64; QoL at 12 months, MD=-0.00, P=0.96; PVR at 12 months, MD=0.52, P=0.43; prostate sizes >70 ml, Q(max) at 6 months, MD=-3.46, P=0.33; IPSS at 6 months, MD=3.11, P=0.36; PVR at 6 months, MD=25.50, P=0.39). PVP was associated with a shorter hospital time and catheter removal time than TURP, whereas PVP resulted in a longer operative time than TURP. For prostate sizes <70 ml, there were fewer transfusions, capsular perforations, incidences of TUR syndrome and clot retentions following PVP compared with TURP. These results indicate that PVP is as effective and safe as TURP for BPH at the mid-term patient follow-up, in particular for prostate sizes <70 ml. Due to the different energy settings available for green-light laser sources and the higher efficiency and performance of higher-quality lasers, large-sample, long-term RCTs are required to verify whether different energy settings affect outcomes.

Detection of nuclear matrix protein 22 and survivin baseline level in patients after radical cystectomy.

We investigated the baseline levels of urine nuclear matrix protein 22 (U-NMP22) and survivin in urine after radical cystectomy for primary invasive bladder cancer. We measured U-NMP22 and survivin values in 72 patients with four types of urinary diversion (Indiana bladder, Bricker bladder, Mainz bladder and orthotopic bladder) after radical cystectomy and 25 healthy volunteers. We also analyzed the relation between the U-NMP22 and survivin level and other variables among patients with continent urinary diversion and incontinent urinary diversion as well as healthy controls, and found that the U-NMP22 and survivin values were not associated with postoperative interval or gender. The U-NMP22 values (mean ± standard error) for continent urinary diversion, incontinent urinary diversion and healthy controls were 12.08 ± 0.10, 16.62 ± 0.15 and 0.01 ± 0.00 U/ml, respectively. The survivin values (mean ± standard error) for continent urinary diversion, incontinent urinary diversion and healthy controls were 0.47 ± 0.06, 0.69 ± 0.16 and 0.02 ± 0.03 U/ml, respectively. The U-NMP22 and survivin values in the Bricker bladder group were significantly higher than the values in the other three groups. We noted that increased levels of U-NMP22 and survivin after radical cystectomy varied according to different predictors, which may be useful for designing strategies to follow these cases.

[Guided reconstruction of soft tissue defects of the palate with n-HA/PA66 plates: an experimental study in goats.].

PURPOSE: To evaluate the effect of n-HA/PA66 plate as a guided implant for the regeneration of the soft tissue defects in palatal region of goats. METHODS: 12 goats were divided into experimental group and control group at random. 18.0 mm x 14.0 mm soft tissue defect and 15.0 mm x 13.0 mm hard tissue defect were formed artificially in hard palate. n-HA/PA66 plates were implanted to the defect in the experimental group. The tissue regeneration in the defects was observed and the structure of regenerating tissue was analyzed by histology. RESULTS: The mucoperiosteal tissue in the experimental group regenerated along the n-HA/PA66 plates and the mucoperiosteal defects were closed in 6 weeks. The soft and hard tissues were not closed up in control group in 6 weeks. CONCLUSION: n-HA/PA66 plates can guide the regeneration of mucoperiosteal tissue to close the palatal defects.

[A study on early detection for seven infectious diseases].

OBJECTIVE: To provide methods and alert thresholds which are scientific, sensitive, specific and practical for Early Warning System in Public Health Surveillance. METHODS: Alert data was based on historical infectious diseases reports. Control chart was used to detect outbreaks or epidemics. An epidemic was defined by consulting Specialists. After calculating sensitivity, specificity, positive predictive value and describing receiver-operating characteristic curve (ROC), the optimal model and thresholds were chosen. RESULTS: At 80 percentile, the sensitivities and the specificities of epidemic haemorragia fever, hepatitis A, dysentery, epidemic cerebrospinal meningitis and malaria were over 90%, and there was a high efficacy of early warning. At 90 percentile, the sensitivities and the specificities of tuberculosis and measles were over 85%, and there was a high efficacy of early warning also. CONCLUSION: Control chart based on five years was chose as a essential method in early warning system. The alert threshold for epidemic haemorragia fever, hepatitis A, dysentery, epidemic cerebrospinal meningitis and malaria was 80 percentile. The alert threshold for tuberculosis and measles was 90 percentile.

[Influence of super high molecular weight poly D,L-lactic acid on viability and new bone formation of osteoblasts].

OBJECTIVE: To investigate the influence of the viability and new bone formation of osteoblasts by the super high molecular weight poly D,L-lactic acid (SHMW-PDLLA). METHODS: 1. The osteoblasts derived from neonatal rat were grown and maintained at steep of SHMW-PDLLA and normal culture medium. The viability and function of the osteoblasts were measured with MTT array. 2. The plate and screws made of SHMW-PDLLA were implanted and fixed at the artificial fractured mandible of dogs. Specimens were gained at 3 and 6 months and examined with macroscopy and SEM. RESULTS: 1. There is no significant difference of OD values between the experimental group and the control group (P > 0.05). The SHMW-PDLLA isn't toxic to osteoblast at 1 week and 2 weeks, and the toxicity is 3% at 3 days. 2. There were a lot of new bone formed between the implanted SHMW-PDLLA plate and bone tissues under SEM. CONCLUSION: SHMW-PDLLA hasn't pathological influence on the viability and new bone formation of osteoblasts and it is feasible in tissue engineering of bone.