LASSO-based nomogram predicts the risk factors of low anterior resection syndrome for middle and low rectal cancer underwent robotic surgery.

BACKGROUND: This study aims to analyze the influencing factors of postoperative Low Anterior Resection Syndrome (LARS) in patients with middle and low rectal cancer who underwent robotic surgery. It also seeks to predict the probability of LARS through a visual, quantitative, and graphical nomogram. This approach is expected to lower the risk of postoperative LARS in these patients and improve their quality of life through effective prevention and early intervention. PATIENTS AND METHODS: This research involved patients with middle and low rectal cancer who underwent robotic surgery in the Department of Gastrointestinal Surgery at the First Affiliated Hospital of Nanchang University from January 2015 to October 2022. A series of intestinal dysfunction symptoms arising from postoperative rectal cancer were diagnosed and graded using LARS scoring criteria. After the initial screening of all variables related to LARS with Lasso regression, they were included in logistic regression for further univariate and multivariate analysis to identify independent risk factors for LARS. A prediction model was then constructed. RESULTS: The study included 358 patients. The parameters identified by Lasso regression included obstruction, BMI, tumor localization, maximum tumor diameter, AJCC stage, stoma, neoadjuvant therapy (NAT), and postoperative adjuvant therapy (AT). Univariate and multivariate analyses indicated that a higher BMI, lower tumor localization, higher AJCC stage, neoadjuvant therapy, and postoperative adjuvant therapy were independent risk factors for total LARS. The AUC of the prediction nomogram was 0.834, with a sensitivity of 0.825 and specificity of 0.741. The calibration curve demonstrated excellent concordance with the nomogram, indicating the prediction curve fit the diagonal well. CONCLUSION: Higher BMI, lower tumor localization, higher AJCC stage, neoadjuvant therapy, and adjuvant therapy were identified as independent risk factors for total LARS. A new predictive nomogram for postoperative LARS in patients with middle and low rectal cancer undergoing robotic surgery was developed, proving to be stable and reliable. This tool will assist clinicians in managing the postoperative treatment of these patients, facilitating better clinical decision-making and maximizing patient benefits.

Content study of N-nitroso impurities in 5 types of β-blockers / 中国药房

OBJECTIVE To determine the contents of N-nitroso impurities in raw materials/formulations of propranolol， metoprolol， atenolol， esmolol and bisoprolol， and clarify the attention threshold. METHODS Ultra-high performance liquid chromatography-quadrupole/electrostatic field orbitrap high-resolution mass spectrometry（UPLC-Q/Orbitrap HRMS）was adopted. An ACE Excel 3 C18-AR column was used for the separation and a mixture of 0.2% formic acid solution with 0.01 mol/L ammonium acetate and methanol was employed as the mobile phase by gradient elution， at a flow rate of 0.60 mL/min. The column temperature was set at 40 ℃ ， and the sample size was 5 μL. The heated electrospray ionization source was employed in the positive full mass spectra-selected ion monitoring mode. The contents of N-nitroso impurities in raw materials/formulations of 15 batches of β-blockers from 10 manufacturers were determined by this method. Discovery Studio software was applied to predict the toxicity of the impurities and estimate the attention threshold. RESULTS Among 5 kinds of β-blockers， the linear ranges of N-nitroso propranolol， N-nitroso metoprolol， N-nitroso atenolol， N-nitroso esmolol and N-nitroso bisoprolol were 1.01-503.38， 1.02-508.38， 0.97-483.63， 1.11-554.27 and 1.05-523.92 ng/mL， respectively （r＞0.999）. The limits of quantitation were 1.04， 0.25， 0.05， 0.55 and 1.05 ng/mL， and the limits of detection were 0.52， 0.08， 0.02， 0.17 and 0.52 ng/mL， respectively. RSDs of precision， reproducibility， recovery， stability and durability tests were all lower than 7.5% （n＝6 or n＝5）. Among the 15 batches of samples， except for 1 batch， N-nitroso propranolol （1.07-8.91 ng/mg）， N-nitroso metoprolol （1.43-3.37 ng/mg）， N-nitroso atenolol （1.33 ng/mg）， N-nitroso esmolol （0.19 ng/mg） and N-nitroso bisoprolol （1.27 ng/mg） were detected in all other batches. According to predictions， the above 5 impurities had varying degrees of reproductive toxicity， mutagenicity and carcinogenicity， with attention thresholds of 1.0， 0.4， 4.3， 0.2 and 46.7 ng/mg， respectively. CONCLUSIONS The established method is simple， rapid， sensitive and specific， the estimated attention thresholds are clear， which can be used for the control of N-nitroso impurities in various β-blockers.

Meta-Analysis of Doxorubicin-Eluting Beads via Transcatheter Arterial Chemoembolization in the Treatment of Unresectable Hepatocellular Carcinoma.

BACKGROUND/AIMS: To evaluate the efficacy and safety of doxorubicin-eluting beads combined with transcatheter arterial chemoembolization (DEB-TACE) compared with conventional TACE (cTACE). METHODOLOGY: PubMed, EMBASE, MEDLINE and Cochrane Controlled Trials Register were searched for articles published to identify randomized controlled trials evaluating efficacy and side effects between DEB-TACE and cTACE. The RR (relative risk) with a 95% confidence interval (CI) was calculated by the Revman 5.0 software. RESULTS: Totally 4 studies, including 527 patients, compared the efficacy and safety of DEB-TACE with cTACE. The DEB-TACE achieved fewer side effects in alopecia (p = 0.0002, RR = 0.05, 95% CI: 0.01-0.24) and myelosuppression (p = 0.009, RR = 0.32, 95% CI: 0.14-0.75). Meanwhile, there was no significant difference in efficacy evaluation including complete response (p = 0.16, RR = 1.36, 95% CI: 0.89-2.08), partial response (p = 0.48, RR = 1.14, 95% CI: 0.80-1.62), stable disease (p = 0.73, RR = 0.93,95% CI: 0.60-1.40), progressive disease (p 0.19, RR = 0.80, 95% CI: 0.56-1.12), objective response (p = 0.26, RR 0.91, 95% CI: 0.48-1.72) and disease control (p = 0.05, RR = 1.18, 95% CI: 1.00-1.39). CONCLUSIONS: DEB-TACE shows similar therapeutic efficacy to cTACE method and fewer adverse events.

The development of the system of blood flow block by using magnetic compression abdominal large vascular / 中国医疗器械杂志

A new system of blood flow block for control of bleeding in abdominal operation is composed of an abdominal magnetic blocking unit, an abdominal external electromagnet unit and other non-magnetic operation instrument. The abdominal external electromagnetic unit is placed in advance in the operation bed. The abdominal magnetic blocking unit can be placed directly on the ventral of the large vessels when need to blocking the abdominal large vessels during the operation. According to the non-contact suction characteristics of magnetic materials, the two magnetic units will attract each other and compression the vessels. Using this system for vascular occlusion does not need clear exposure and without separating vessel. There is the advantage of rapid, accurate and reliable for the system.

Tissue-engineered soft tissue oriented manufacturing technologies and additive manufacturing / 中国组织工程研究

BACKGROUND:In recent years, many manufacturing techniques have been recently developed for soft tissue engineering scaffolds. Especialy additive manufacturing with a unique material accumulated forming principle can be feasible and reliable to manufacture the highly precise scaffolds with gradient structures and multi-materials for large soft tissue defect repairing. OBJECTIVE:To summarize scaffolds manufacturing technologies in the soft tissue engineering applications developed in recent years and to predict the direction of development. METHODS: A retrieval was performed for the literature about the manufacturing methods of soft tissue scaffolds using key words of “additive manufacturing, microfabrication, vascular tissue engineering, muscle tissue engineering, cartilage tissue engineering, stereolithography, 3D printing, biodegradable hydrogel” in English and Chinese, which were published between January 2010 and September 2013 in PubMed Database and China National Knowledge Infrastructure (CNKI) Database. RESULTS AND CONCLUSION:For large soft tissue defects repairing, structure design of the scaffolds has been shifted from a simple planar structure to a more complex three-dimensional structure, and integration of scaffold structure, materials and cels, and growth factors during the manufacturing procedure can be used to obtain the resolution of vascularization. Additive manufacturings become one of the most promising approaches for the ideal soft tissue scaffolds with gradient and complex structure and multi-materials. In particular, the hydrogel/cellcomposite scaffolds fabrication, a hot but promising approach to develop the soft tissue engineering wil be made progress by the accurate principles and processes of the hydrogel additive manufacturing combined with the introduction of living cels and growth factors.

Physicochemical properties and cytotoxicities of Sr-containing biphasic calcium phosphate bone scaffolds.

This study demonstrates a new biomaterial system composed of Sr-containing hydroxyapatite (Sr-HA) and Sr-containing tricalcium phosphate (Sr-TCP), termed herein Sr-containing biphasic calcium phosphate (Sr-BCP). Furthermore, a series of new Sr-BCP porous scaffolds with tunable structure and properties has also been developed. These Sr-BCP scaffolds were obtained by in situ sintering of a series of composites formed by casting various Sr-containing calcium phosphate cement (Sr-CPC) into different rapid prototyping (RP) porous phenol formaldehyde resins, which acted as the negative moulds for controlling pore structures of the final scaffolds. Results show that the porous Sr-BCP scaffolds are composed of Sr-HA and Sr-TCP. The phase composition and the macro-structure of the Sr-BCP scaffold could be adjusted by controlling the processing parameters of the Sr-CPC pastes and the structure parameters of the RP negative mould, respectively. It is also found that both the compressive strength (CS) and the dissolving rate of the Sr-BCP scaffold significantly vary with their phase composition and macropore percentage. In particular, the compressive strength achieves a maximum CS level of 9.20 +/- 1.30 MPa for the Sr-BCP scaffold with a Sr-HA/Sr-TCP weight ratio of 78:22, a macropore percentage of 30% (400-550 microm in size) and a total-porosity of 63.70%, significantly higher than that of the Sr-free BCP scaffold with similar porosity. All the extracts of the Sr-BCP scaffold exhibit no cytotoxicity. The current study shows that the incorporation of Sr plays an important role in positively improving the physicochemical properties of the BCP scaffold without introducing obvious cytotoxicity. It also reveals a potential clinical application for this material system as bone tissue engineering (BTE) scaffold.

Preparation of chitosan-gelatin hybrid scaffolds with well-organized microstructures for hepatic tissue engineering.

The structural organization of natural liver is instrumental in the multifunctionality of hepatocytes, and mimicking these specific architectures in tissue-engineered scaffold plays an important role in the engineering of an implantable liver equivalent in vitro. To achieve this goal, we have developed a novel fabrication process to create chitosan-gelatin hybrid scaffolds with well-organized architectures and highly porous structures by combining rapid prototyping, microreplication and freeze-drying techniques. The scaffolds obtained not only have analogous configurations of portal vein, central vein, flow-channel network and hepatic chambers, but also have high (>90%) porosity, with the mean pore size of 100microm. Swelling and degradation studies showed that the scaffold has excellent properties of hydrophilicity and biodegradability. A hepatocyte culture experiment was conducted to evaluate the efficiency of the well-defined chitosan-gelatin scaffold in facilitating hepatocyte growth in the inner layer of the scaffold in vitro. Scanning electron microscopy and histological analysis showed that hepatocytes could form large colonies in the predefined hepatic chambers, and these cavities could the completely filled with hepatocytes during 7 day culture. Albumin secretion and urea synthesis further indicated that the well-organized scaffolds were more suitable for hepatocyte culture.

Design and fabrication of custom mandible titanium tray based on rapid prototyping.

UNLABELLED: During the past few years, the combination of medical imaging and rapid manufacturing technique has proven to be a very important development. On the other hand, the conventional method has some drawbacks. For example, it takes longer time to complete an operation and it also presents some difficulty in matching the repaired contours. With advanced software and hardware, an image of an undamaged bone similar to that of the patient can be made from computerised tomography (CT); and a physical object constructed by the mirror-processed image data can be quickly fabricated with a high degree of fitting with the patient's bone. This paper presents a methodology for the design and fabrication of an individual titanium tray for the repair of mandible defects. Methods for the tray modeling using CAD system are presented: A 3D model of the bony defect is generated after the acquisition of helical CT data. An individual tray is designed using freeform surfaces geometries and fabricated by rapid prototyping (RP) technology. The results of tray filling with bone-grafting materials are then presented. RESULT: the tray is inserted into the patient mandible segment. The symmetry and reconstruction quality contour of the repaired mandible was satisfactory. Thus, the patient is able to eat normally. The bone-grafting material harvested from the anterior ilium was low. The clinical experience showed that rapid prototyping and reverse engineering software are effective methods of fabricating custom trays for mandibular reconstruction after bone loss due to a tumor.

The application of rapid prototyping in oral and maxillofacial prosthesis(1)——The revertible design of artificial mandible substitutes / 实用口腔医学杂志

Objective: To enable an artificial mandible substitute to be mostly suitable for mandibular reconstructon in individual patients. Methods: Use rapid prototypinlg and surface imitating as the primary technology for individualized design and manufacturing of the artificial mandible substitute. Results: An individualized artificial mandible substitute was designed and prepared. Conclusion: Rapid prototyping is feasible in individualized bone substitute preparation.

The application of rapid prototyping to the oral and maxillofacial prosthesis(2)——The individualized manufacturing of artificial mandible substitutes / 实用口腔医学杂志

Objective: To enable an artificial mandible substitute to be with individualized shape in the individual patient. Methods: Rapid prototyping and surface imitating were used as the primary technology in the individualized design and manufacturing of the artificial mandible substitute. Results: The shape and size of the manufactured artificial mandibe were almost the same to those of the original natural one. Conclusion: Rapid prototyping may be used in individualized bone substitute preparation.