Objective To develop a novel transcatheter tricuspid valve replacement device and test its performance. MethodsThe transcatheter tricuspid valve stent consisted of double-layer self-expanding nitinol stent, biotissue-derived bovine pericardial leaflets, and PTFE woven. The delivery system, mainly consisting of a handle control unit and a delivery sheath, was sent to the correct position via right atrium or jugular vein. The sheath had a visualization feature, and the handle control unit could realize the functions of stable release and partial recovery of the interventional valve. In addition, this study performed animal survival experiments on the basis of in vitro experiments. A large-white pig was used as the experimental animal. Cardiopulmonary bypass was established through median thoracotomy, then the right atrium was opened, and the interventional valve was released under direct vision without cardiac arrest. Approximately 1 month after interventional valve implantation, the maneuverability and stability of the interventional tricuspid device were evaluated by autopsy. ResultsThrough the animal experiment, the interventional valve was successfully released, and the anchoring was satisfactory. Postoperative transthoracic echocardiography showed that the interventional valve opened and closed well, the flow rate of tricuspid valve was 0.6 m/s, and there was no obvious tricuspid regurgitation. One month after the operation, we dissected the large-white pig and found the interventional valve was not deformed or displaced, the leaflets were well aligned, and there was thrombus attachment in the groove between the inner and outer layers of the interventional valve. ConclusionAnimal experiment shows that the novel device can stably and firmly attach to the tricuspid annulus, with good anchoring effect, and effectively reduce paravalvular leakage.
ObjectiveTo investigate the inhibitory effect of T lymphocyte transplantation of EphrinAl-Caspase-3 on the growth of breast cancer.MethodsSix-week-old BALB/c nude mice were used to inoculate breast cancer cells to construct a nude mouse model of breast cancer. They were randomly divided into 3 groups according to random number table: PBS group received intratumoral injection of 10 μL PBS, and negative control group received intratumoral injection of 1×106 T lymphocytes uninfected with adenovirus, 1×106 EphrinAl-Caspase3-T lymphocytes were injected intratumorally into the infected group, and the tumors size (0, 3, 6, 9, 12 and 15 d) were measured with vernier calipers every 3 days until end of experiment. The content of EphrinAl-Caspase-3 in the tissues of the nude mice was measured. The presence of T lymphocytes expressing green fluorescent protein and the ratio of Caspase-3-positive and Ki-67-positive cell were observed by pathological examination.ResultsOn the day 0 and day 3, there were no significant difference in tumor volume between the 3 groups (P>0.05). On the 6th day and later, the difference between the infected group and the PBS group/negative control group were statistically significant (P<0.05), but there were no significant difference in tumor volume between the PBS group and negative control group at each time point (P>0.05). The presence of scattered green fluorescent protein-labeled EphrinAl-Caspase-3-T lymphocytes was observed in the tumor tissues of the infected group, while the presence of green fluorescent protein were not detected in the PBS group and the negative control group. In the infected cells, ratio of Caspase-3-positive cell was up-regulated and ratio of Ki-67-positive cell was down-regulated. The expression of EphrinAl-Caspase-3 could be detected on the 3rd day in the infected group, and at the peak on the 6-day, then the amount of secretion gradually decreased. The expression of EphrinAl-Caspase-3 were not detected in the PBS group and the negative control group at each time point.ConclusionEphrinAl-Caspase-3 can significantly inhibit the growth of breast cancer cells and promote apoptosis.
ObjectiveTo explore the therapeutic effect and safety of irreversible electroporation (IRE) ablation technique on esophageal cancer.MethodsAn ECM830 electroporator was used for IRE treatment on esophageal cancer cells EC109 and KYSE30. According to the different electric field intensity, five groups were assigned: a control group, a 500 V/cm group, a 1000 V/cm group, a 1500 V/cm group, and a 2 000 V/cm group. After 24 h, methyl thiazolyltetrazolium (MTT) was used to detect the cell proliferation of each group. Western blotting was performed to evaluate the expression of apoptosis proteins in cells before or after IRE treatment. Eight healthy BALB/c nude mice were equally divided into two groups: a control group (n=4) and an IRE group (n=4). EC109 was used to establish subcutaneous transplantation tumors and subsequently the mice in the IRE group were treated with flat electrode. The weight and volume of tumors were measured after 14 days. Ten healthy New Zealand white rabbits were equally divided into two groups: a control group (n=5) and an IRE group (n=5). After exposing the abdominal cavity, the abdominal esophagus of the IRE group was treated with flat electrode. Seven days later, the esophagus was extracted for HE and Masson staining.ResultsWhen the electric field intensity was low (500 V/cm), there was no change in esophageal cancer cells proliferation after IRE treatment compared to the control group (EC109: P=0.385, KYSE30: P=0.600). With the increase of electric field intensity, the influence of IRE on the proliferation of esophageal cancer cell gradually increased. When it reached 2 000 V/cm, there was basically no cell viability after IRE treatment (P<0.001). The results of Western blotting showed that the expression of cleaved caspase-3 increased after IRE treatment (P<0.01). Animal experiments indicated that the weight and volume of tumors in nude mice reduced (P<0.05) and the growth of tumors was slowed down after IRE treatment. In addition, the parenchymal cells of rabbit esophagus were largely damaged, while interstitial tissues such as fibers were well preserved.ConclusionIRE ablation has the potential to inhibit the proliferation of esophageal cancer cell and slow down the tumor growth.What’s more, it is safe for the esophagus.
Extracorporeal membrane oxygenation (ECMO) is a critical life support technique for patients with severe cardiopulmonary failure. Establishing a stable ECMO animal model is essential to further investigate the effects of ECMO on the body and provide assistance for optimizing ECMO management strategies and preventing complications in clinical practice. In recent years, rats have been widely used to establish ECMO models due to their low cost and good reproducibility. Therefore, this article provided a comprehensive review of literature on the ECMO rat model, including equipment and experimental management strategies. It offers a theoretical foundation for the development of a stable and mature ECMO rat model in the future.
ObjectiveTo develop an experimental model of gastroesophageal reflux-induced esophageal stricture in rats and explore the mechanism of esophageal stricture. MethodsA total of 30 male Sprague-Dawley (SD) rats by random number table method were randomly divided into three groups as follows: an operation+acid perfusion group, first the models of lower esophageal sphincter relaxation and hiatal hernia were made, and then the rats’ esophagus were perfused with hydrochloric acid-pepsin; acid perfusion group, the rats’ esophagus were directly perfused with hydrochloric acid-pepsin; and control group, rats’ esophagus were perfused with normal saline. After 4 weeks of continuous perfusion, the esophageal mucosal injury of SD rats in each group were observed, and the concentrations of inflammatory cytokines [tumor necrosis factor-α (TNF-α), interleukin (IL)-1β and IL-18] in esophageal tissues were detected by enzyme-linked immunosorbent assay. ResultsIn the operation+acid perfusion group, esophageal stricture was formed in 2 SD rats, but no esophageal stenosis was found in the acid perfusion group and the control group. The body weight of rats in the operation+acid perfusion group and the acid perfusion group were lower than that in the control group (P<0.05). The esophageal mucosal injury scores of rats in the operation+acid perfusion group and the acid perfusion group were higher than that in the control group (P<0.001), and the operation+acid perfusion group was higher than that in the acid perfusion group (P=0.014). The concentrations of TNF-α, IL-1β and IL-18 in esophageal tissues were higher in the operation+acid perfusion group and the acid perfusion group than that in the control group (P<0.001), and the operation+acid perfusion group was higher than that in the acid perfusion group (P<0.001). ConclusionsThe anti-reflux barrier is an important part of preventing gastroesophageal reflux disease. The destruction of anti-reflux barrier, hydrochloric acid-pepsin perfusion and inflammatory cytokines jointly induced esophageal inflammation and injury, and even caused esophageal stricture.
Objective To observe the effects of structure and function of cornea, chamber angle and retina of varying doses of Bevacizumab which was injected intravitreally in rabbits. Methods Twenty-four New Zealand albino rabbits were divided into three groups randomly, the right eyes in three groups received int ravitreal injection Avastin at dose 1.25 mg，2.5 mg and 5 mg respectively as experimental eye, the left eyes accepted intravitreal injection 0.9% normal saline at the same volume as a control eye. The anterior segment of eye and ocular fundus were examined and intraocular pressure was measured by slit-lamp microscope and direct ophthalmoscope before and after injection. It was tested by Electroretino gram (ERG) before and after injection 1, 4, 8 weeks. At the 8th week, it carried out corneal endothelium counting; then enucleated eyes to observe by the light microscope and transmission electron microscope. Results No statistically significant difference regard to IOP,corneal endothelium counting, a-and b-waves of ERG at any stage of study in every group（P＞0.05）. No obvious change at cornea, chamber angle, retinal structure and retinal ultrastructure in every group under light microscope. Conclusion This study indicated that there is no obvio us toxicity of intravitreal injection with Avastin 1.25~5.0 mg in normal rabbit eyes. （Chin J Ocul Fundus Dis，2008，24：189-192）
ObjectiveTo systematically investigate the registration status, methodology and reporting quality of the systematic review protocols for animal experiment registered on PROSPERO platform.MethodsSystematic review protocols of animal experiments registered on PROSPERO platform were searched up to December 31st, 2019. Two reviewers independently screened literature, extracted data, and performed a descriptive analysis of the methodological quality and reporting characteristics of the included studies.ResultsA total of 351 protocols from 50 countries were included, involving 22 diseases. The intervention measures were primarily "pharmaceutical chemicals". Only approximately 1/3 of the studies reported the search strategy from at least one database, approximately half of the studies were prepared to report heterogeneity analysis and publication bias, and only approximately 1/3 of the studies were prepared to report sensitivity analysis.ConclusionsThe quantity of systematic reviews of animal experiments registered on the PROSPERO platform is increasing annually, however, there are still some limitations in the methodology and reporting quality.
Objective To assessment of the echogenicity of the ultrasound-guided catheter and its associated delivery system. Methods The study consisted of in vitro characterization experiments and animal studies. In the in vitro phase, the acoustic and mechanical properties of the ultrasound-guided catheter were compared with those of the traditional MPA2 catheter, including parameters such as echo intensity, recognizability, and angle dependence. In the animal experiments, a ventricular septal defect (VSD) model was established in miniature pigs to compare the procedural performance of the ultrasound-guided delivery system versus the conventional system. Evaluation indicators included the time required for the system to cross the VSD, the detection rate of the system within the right ventricle, and the occurrence of intraoperative complications. Results The ultrasound-guided catheter demonstrated a significantly higher mean echo intensity than the MPA2 catheter[ (237.3±1.8) dB vs. (190.9±13.1) dB, P<0.001] and a markedly improved recognizability rate (82.3%±5.6% vs. 26.7±3.2%, P<0.001), along with better angle independence and image quality. In animal experiments, the ultrasound-guided delivery system significantly reduced the time required to cross the VSD (18.5±5.7 min vs. 30.3±4.5 min, P<0.001) and substantially increased the detection rate within the right ventricle (100% vs. 30%). No severe complications occurred in any experimental animal. Conclusion The ultrasound-guided catheter and its corresponding delivery system exhibited superior ultrasound visibility and operational performance in both in vitro and animal experiments, indicating strong potential for clinical application.
ObjectiveTo preliminarily explore the safety and efficacy of the Docs Valve transcatheter aortic valve replacement system. MethodsA total of 26 healthy adult sheep were selected and divided into an experimental group (n=18) and a control group (n=8). The experimental group underwent transcatheter aortic valve implantation (TAVI) via the transfemoral vascular approach, and were further subdivided into acute and chronic subgroups based on the timing of examination and anatomical exploration. Animals in the acute subgroup received anatomical exploration immediately postoperatively, while those in the chronic subgroup underwent the same exploration at 1, 3, and 6 months postoperatively. Valve position, paravalvular leak, and artificial valve leaflet tissue were observed at immediately post-operation (n=5), 1 month post-operation (n=2), 3 months post-operation (n=2), and 6 months post-operation (n=9). The control group received surgical replacement with a biological prosthetic valve, with corresponding examinations performed at 6 months postoperatively. The safety and efficacy of the valve system were analyzed using echocardiography, anatomical examination, and pathological examination. Results Seventeen sheep in the experimental group successfully completed TAVI, and 4 sheep in the control group successfully underwent surgical replacement, all surviving to the final observation period. During follow-up, valve morphology and position were normal, ultrasound imaging was clear, and the trends of changes in hemodynamics and left ventricular function were similar between the two groups. In the experimental group, 4 cases (4/17) of moderate paravalvular leakage occurred during follow-up; in the control group, 2 cases (2/4) of moderate paravalvular leakage and 1 case (1/4) of moderate regurgitation were noted. Anatomical examination revealed no thrombi, vegetations, or calcifications in either group; extensive endothelialization was observed on stents and valve leaflets, with a small amount of calcium deposition in the experimental group. Pathological examination showed no thrombus formation in core organs or brain tissues in either group. ConclusionThe results of this animal control trial preliminarily confirm the safety and efficacy of the Docs Valve transcatheter aortic valve replacement system. However, due to the limited sample size of the control group, the conclusions require further verification in larger sample sizes.
ObjectiveTo verify the feasibility of a self-designed magnetic anchoring and traction device (MATD) for assisting two-port video-assisted thoracoscopic esophagectomy.MethodsThree Beagle dogs were selected as animal models with age ranging from 1-6 years and weight ranging from 8-12 kg, and they underwent two-port video-assisted thoracoscopic esophagectomy after general anesthesia. We used the MATD to retract the esophagus to different directions, which assisted mobilizing esophagus, detecting the nerves along esophagus and dissecting paraesophagus lymph nodes. The operation time, blood loss and feasibility of the MATD were recorded.ResultsWith the aid of the MATD, we successfully retracted and mobilized the esophagus, detected the nerves and dissected the lymph nodes in three Beagle dog models. During the operation, the MATD provided sufficient and steady traction of esophagus to achieve a good exposure of the operative field, effectively decreasing the interference between working instruments. The MATD worked well. The mean operation time was 30 min, and the mean intraoperative blood loss was about 10 mL.ConclusionIt is effective to use the MATD to assist retracting esophagus during video-assisted thoracoscopic esophagectomy. The magnetic anchoring and traction technique can assist to expose the surgical field, decrease the interference between the working instruments and have the potential clinical application.
