Objective To evaluate the sclerosing effects of several chemical sclerosants on the gallbadder mucosa in vivo. Methods Twentyeight rabbits were randomly divided into： Normal saline was used as contrast agent, and 95% ethanol, 5% tetracycline and compound phenol as sclerosants respectively. The cystic duct was ligated and cholecystostomy was performed for each animal. Sclerosants and contrast agent were injected into the gallbladder through a tube respectively and were kept in the gallbladder for 15 minutes. Animals were killed two weeks later; the gallbladder, bile duct and adjacent liver tissue were obtained for histopathological examination. Results With the naked eye, normal saline and 5% tetracycline made the cavity of the gallbladder unchanged; 95% ethanol made two gallbladder cavities occluded, two smaller, and three unchanged; and compound phenol made four gallbladder cavities occluded, and three smaller. In histopathological observations, 95% ethanol and compound phenol could make seven rabbits’ gallbladder mucosa completely destroyed (7/7); compared with normal saline (1/7), there was significant difference (P＜0.01). Five percent tetracycline had some effect of ablating the gallbladder mucosa (5/7), but compared with normal saline, there was no difference (Pgt;0.05). Conclusion Ninety-five percent ethanol can be clinically applied as an effective and safe sclerosant.
Muscle atrophy of the residual limb after lower-limb amputation is a disadvantage of amputees' rehabilitation. To investigate the biomechanics mechanism of muscle atrophy of the residual limb, we built a finite element model of a residual limb including muscle, skeletons and main vessels based on magnetic resonance images of a trans-femoral amputee, and studied the biomechanics effects of the socket of the lower-limb prosthesis on the soft tissue and vessels in the residual limb. It was found that the descending branch of the lateral femoral circumflex artery suffered the most serious constriction due to the extrusion, while that of the deep femoral artery was comparatively light. Besides, the degree of the constriction of the descending branch of the lateral femoral circumflex vein, femoral vein and deep femoral vein decreased in turn, and that of the great saphenous vein was serious. The stress-strain in the anterior femoral muscle group were highest, while the stress concentration of the inferior muscle group was observed at the end of the thighbone, and other biomechanical indicators at the inferior region were also high. This study validated that the extrusion of the socket on the vessels could cause muscle atrophy to some degree, and provided theoretical references for learning the mechanism of muscle atrophy in residual limb and its effective preventive measures.
This study analyzed the inherent relation between arterial blood mass flow and muscle atrophy of residual limb to provide some necessary information and theoretical support for the clinical rehabilitation of lower limb amputees. Three-dimensional arterial model reconstruction was performed on both intact side and residual limb of a unilateral transfemoral amputee who is the subject. Then hemodynamic calculation was carried out to comparatively analyze the mass flow state at each arterial outlet of both lower extremities. The muscle atrophy ratio of residual limb was calculated by measuring the cross-sectional area of bilateral muscles. Based on the blood supply relationship, the correlation between arterial blood flow reduction ratio and muscle atrophy ratio was discussed. The results showed that the mass flow of superficial femoral arteries and lateral circumflex femoral arteries severely reduced. Meanwhile rectus femoris, vastus lateralis and vastus medialis which were fed by these arteries showed great atrophy too. On the contrary, the mass flow of deep femoral arteries and medial femoral circumflex arteries slightly reduced. Meanwhile gracilis, adductor longus, long head of biceps which were fed by these arteries showed mild atrophy too. These results indicated that there might be a positive and promotion correlation between the muscle atrophy ratio and the blood mass flow reduction ratio of residual limb during rehabilitation.
ObjectiveTo discuss the influence of artificial ankle elastic improved inserts (hereinafter referred to as “improved inserts”) in reducing prosthesis micromotion and improving joint surface contact mechanics by finite element analysis. Methods Based on the original insert of INBONE Ⅱ implant system (model A), four kinds of improved inserts were constructed by adding arc or platform type flexible layer with thickness of 1.3 or 2.6 mm, respectively. They were Flying goose type_1.3 elastic improved insert (model B), Flying goose type_2.6 elastic improved insert (model C), Platform type_1.3 elastic improved insert (model D), Platform type_2.6 elastic improved insert (model E). Then, the CT data of right ankle at neutral position of a healthy adult male volunteer was collected, and finite element models of total ankle replacement (TAR) was constructed based on model A-E prostheses by software of Mimics 19.0, Geomagic wrap 2017, Creo 6.0, Hypermesh 14.0, and Abaqus 6.14. Finally, the differences of bone-metal prosthesis interface micromotion and articular surface contact behavior between different models were investigated under ISO gait load. Results The tibia/talus-metal prosthesis interfaces micromotion of the five TAR models gradually increased during the support phase, then gradually fell back after entering the swing phase. The improved models (models B-E) showed lower bone-metal prosthesis interface micromotion when compared with the original model (model A), but there was no significant difference among models A-E (P>0.05). The maximum micromotion of tibia appeared at the dome of the tibial bone groove, and the micromotion area was the largest in model A and the smallest in model E. The maximum micromotion of talus appeared at the posterior surface of the central bone groove, and there was no difference in the micromotion area among models A-E. The contact area of the articular surface of the insert/talus prosthesis in each group increased in the support phase and decreased in the swing phase during the gait cycle. Compared with model A, the articular surface contact area of models B-E increased, but there was no significant difference among models A-E (P>0.05). The change trend of the maximum stress on the articular surface of the inserts/talus prosthesis was similar to that of the contact area. Only the maximum contact stress of the insert joint surface of models D and E was lower than that of model A, while the maximum contact stress of the talar prosthesis joint surface of models B-E was lower than that of model A, but there was no significant difference among models A-E (P>0.05). The high stress area of the lateral articular surface of the improved inserts significantly reduced, and the articular surface stress distribution of the talus prosthesis was more uniform. Conclusion Adding a flexible layer in the insert can improve the elasticity of the overall component, which is beneficial to absorb the impact force of the artificial ankle joint, thereby reducing interface micromotion and improving contact behavior. The mechanical properties of the inserts designed with the platform type and thicker flexible layer are better.
Objective To compare the in vitro inhibition activity of three mimic peptides at lipopolysaccharide binding protein (LBP)／CD14 binding sites for LPS-induced inflammatory response.Methods Enzyme-linked immunoSorbent assay(ELISA)was applied for the detection of the affinity between the mimic peptides and CD14 as well as the competitive inhibition activity of LBP.Mature U937 cells induced by PMA were co-cultured with LPS and intervened by mimic peptide.The effect of the mimic peptide on the TNF-α expression of U937 was detected by RT-PCR.Alveolar macrophages(AMs)of rats were co-cultured with FITC-LPS，and mimic peptide intervention was conducted.The effect of the mimic peptide on combination of LPS and AMs was observed by fluorescence microscope . Results Affinity between No.1 mimic peptide(FHRWPTWPLPSP，10 μg／mL)and CD14 was significantly higher than those of No.2 and No.3(20.3±4.1 11.8±2.4 and 13.7±3.3，Plt;0.01 or Plt;0.05).The competitive inhibitory activity of No.1 mimic peptide(10 μg／mL)for LBP was higher than those of No.2 and No.3[(57.2土11.2)％ vs(39.4±9.7)％ and(37.9±8.3)％ ，Plt;0.01].All of the three mimic peptides(10 μg／mL)could significantly inhibit the LPS-induced expression of TNF-α by U937 at mRNA level(Plt;0.01 or Plt;0.05)，moreover，the inhibitory activity of No.1 peptide was the highest(0.239±0.053 vs 0.406±0.112 and 0.493±0.121，Plt;0.01).In addition，No.1 mimic peptide markedly inhibited LPS combination with rat lung AMs(2157±514 vs 2763±453，plt;0.01).Conclusion No.1 mimic peptide(FHRWPTWPLPSP)have a relatively higher affinity with CD14 and high competitive inhibition activity for LBP，therefore it have the potential ability of anti-inflammatory response induced by LPS.
Objective To explore the application methods and values of using health failure mode and effect analysis (HFMEA) to prevent surgical site infection (SSI) in patients undergoing bone fracture and craniotomy surgery with class Ⅰ incision. Methods Patients undergoing bone fracture and craniotomy surgery with class Ⅰ incision at the Chengdu Pidu District People’s Hospital between January 2020 to December 2021 were selected. Based on whether receiving HFMEA-based risk management or not, the patients were divided into conventional group and intervention group. The compliance rates with infection control measures, changes in risk priority numbers (RPN) at various stages (1 month and 10 months after intervention) of HFMEA implementation, and the incidence of SSI between the conventional group and the intervention group were compared. Results A total of 884 surgeries were included. Among them, there were 399 cases in the conventional group and 485 cases in the intervention group; 16 cases SSI occurred. A total of 7 SSI prevention and control measures had been formulated. Except for proper surgical attire (P＞0.05), there were statistically significant differences in the compliance rate of the other prevention and control measures between the two groups of patients (P＜0.05). In the intervention group, the RPN values of pre-operative, intra-operative, and post-operative risk factors at the 10th month after intervention were all lower than those at the 1st month after intervention (P<0.05). Except for the incidence of SSI during craniotomy surgery (6.1% vs. 1.8%, P=0.375), there were statistically significant differences in the total SSI incidence (3.3% vs. 0.6%) and bone fracture surgery SSI incidence (2.7% vs. 0.5%) between the conventional group and the intervention group (P>0.05). Conclusion Applying HFMEA-based risk management techniques to prospectively identify, assess, analyze, manage and track the risk of SSI in bone fracture and craniotomy surgery with class Ⅰ incision can effectively enhance the adherence of preventive measures and reduce the incidence rate of SSI.