Objective To analyze the influence of COPD on the structure and function of left ventricular. Methods Sixty-nine COPD patients ( mean age: 69. 0 ±7. 8 yrs) and forty healthy controls ( mean age: 67. 8 ±7. 6 yrs) were enrolled in this study. Both groups underwent Doppler echocardiography.Heart rate ( HR) were recorded. Left ventricular end-diastolic volume ( LVEDV) , left ventricular enddiastolic diameter ( LVEDD) , interventricular septum( IVS) , stroke volume ( SV) , and cardiac output ( CO)were measured. The changes of left ventricular were compared between the COPD patients and the healthy controls, and also between the COPD patients with or without chronic cor pulmonale. Results Compared with the healthy controls, movement range of IVS, LVEDD, LVEDV, and SV reduced significantly ( P lt;0. 05) , and HR raised significantly in the COPD patients ( P lt; 0. 05) . CO had no significant difference between two groups ( P gt;0. 05) . Sub-group analysis indicated that the thickness and movement range of IVSwere greater in the patients with cor pulmonale secondary to COPD than those without cor pulmonale ( P lt;0. 05) . Conclusions In COPD patients, left ventricular chamber size decreases, and left ventricular systolic function is impaired. Left ventricular function is impaired more severe in cor pulmonale secondary to COPD than COPD without cor pulmonale.
Reports about the application of transcatheter aortic valve replacement (TAVR) for patients with aortic stenosis, whose valve sizes exceed the maximum recommended annular diameter of the largest artificial valve, is rarely in China. This paper reports an aortic stenosis patient characterized by large aortic annulus diameter with severe calcification and treated by TAVR. A comprehensive and careful operation plan was made before the operation. The anterior and posterior balloon dilatation and coronary artery protection were used during the operation. The patient was followed up for 2 years and was in stable condition.
Objective To study the effect of preparation conditions for small-diameter polyurethane(PU) vascular graft on microstructure and mechanical properties. Methods The small-diameter microporous PU artificial vascular grafts were prepared by dipping and leaching method. The dimension and microstructure were controlled by changing mold diameter, PU materials, salt sizes, salt to polymer ratio, times of dipping layers etc. The mechanical properties of PU grafts including radical compliance, water permeability, longitudinal strength, burst strength, and suture tearing strength were measured and the effect of the graft dimension and microstructure on their properties were studied. Results The internal diameter of grafts prepared was 2-4 mm depending on mold diameter. The wall thickness was 0.6-1.2 mmafter dipping 4-8 layers. The density was 0.23-0.49 g/cm3. The pore was 42-95 μm in diameter. The porosity was 56%80%. The radical compliance was 1.2%-7.4%·13.3 kPa-1 and higher compliances could be obtained by using moreelastic polyurethane, higher salt to polymer ratio, longer diameter and less wall thickness. The water permeability, mainly depending on salt to polymer ratio,diameter, and wall thickness, was 0.29-12.44 g／(cm2·min). The longitudinal strength was 1.55-4.36 MPa correlating with tensile strength of polyurethane and salt to polymer ratio. The burst strength was 60-300 kPa also depending on tensile strength of polyurethane and salt to polymer ratio. The suture tearing strength was 19.5-96.2 N／cm2 depending on tensile strength of polyurethanebut not on the angle of tearing and graft axial directions. The compliance and water permeability of Chronoflex grafts were higher than those of PCU1500 grafts, but longitudinal strength, burst strength, and suture tearing strength of PCU1500 grafts were better than those of Chronoflex grafts. Conclusion Small-diameter grafts with proper pore sizes, porosity, matching compliance can be obtained by selecting PU materials and optimizing the preparation conditions.
ObjectiveTo detect the difference in the osteogenesis ability of biphasic calcium phosphate (BCP) ceramic granular materials with different mesoporous diameters prepared at different sintering temperatures through in vivo and in vitro experiments, so as to provide evidence for screening BCP materials with better clinical application parameters.MethodsThree kinds of BCP (materials 1, 2, 3) were prepared by mixing hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP) at a ratio of 8∶2 and sintered at 1 050, 1 150, and 1 250℃ for 3 hours, respectively. The internal porosity and the diameter, volume, and area of the mesopore were measured by Brunauer-Emmett-Teller test (BET); the composition of the material was evaluated by X-ray diffraction (XRD); the microscopic surface morphology of the material was observed by scanning electron microscopy (SEM). The 3rd generation bone marrow mesenchymal stem cells (BMSCs) from Sprague-Dawley rats were co-cultured with the materials 1, 2, and 3 for 7 days in vitro respectively (groups A, B, and C), and the cells adhesion on the materials was observed by SEM and phalloidine staining, respectively. Cell proliferation activity was measured by cell counting kit 8 method. In vivo, 9 muscle bags were made in dorsal muscles of 9 beagles, respectively. The muscle bags were randomly divided into 3 groups (3 per beagle in each group) and materials 1, 2, and 3 were placed into the muscle bags of groups A, B, and C, respectively. After 1, 2, and 3 months of operation, 3 beagles were anesthetized and the samples were stained with HE, Masson, and Safranin, and the bone formation area ratio in the BCP gap was calculated. Real-time fluorescence quantitative PCR (qRT-PCR) was performed to detect the expressions of bone-related genes [including alkaline phosphatase (ALP), osteopontin (OPN), and osteocalcin (OC)].ResultsThe BET test showed that with the increase of sintering temperature, the internal porosity of the particles did not change significantly, but the diameter, volume, and area of the mesopores gradually decreased. The XRD detection showed that the XRD waves of HA and β-TCP could be seen in all 3 kinds of materials; SEM showed that there were widely distributed macropores on the surface of 3 kinds of BCPs, and the interpores connected with the others. In vitro, BMSCs adhered and proliferated on the surfaces of 3 kinds of BCPs, and the cell biocompatibility of the materials in groups B and C was better than that in group A. In vivo, obvious osteoid tissue deposition could be observed in the intergranular space of 3 kinds of BCPs from 2 months after implantation. The bone formation area ratio of each group increased with time. The bone formation area ratio in group A was significantly higher than that in groups B and C at 2 and 3 months after implantation, and in group A than in group B at 1 month (P<0.05). qRT-PCR showed that the expressions of osteogenic related genes peaked at 2 months in group A, and gradually increased with time in groups B and C. The relative expressions of ALP and OPN mRNAs in group A were significantly higher than those in groups B and C at 1 month after implantation, the relative expression of OC mRNA in group A was significantly higher than that in groups B and C at 2 months after operation, the relative expression of ALP mRNA in groups B and C and the relative expression of OPN mRNA in group B were significantly higher than those in group A, all showing significant differences (P<0.05); there was no significant difference in the relative expression of each gene among the other groups at each time point (P>0.05).ConclusionThe mesoporous diameter of BCP decreases with the increase of sintering temperature. Different mesoporous diameters lead to different ectopic osteogenesis of BCP materials. BCP material with mesoporous diameter of 12.57 nm has better osteogenic ability which can activate the osteogenic gene earlier. The mesoporous diameter is expected to be an adjustable index for optimizing the osteogenic capacity of BCP materials.
To evaluate the implantation effect of artificial vascular grafts with recombinant fibrinolytic enzyme factor II (rF II)-immobil ized lumina in animal test. Methods Four mm internal diameter (ID) polyurethane (PU) artificial vascular grafts were prepared by di pping and leaching method. The micro-pore size and morphology of the graft walls were observed by SEM. The graft lumina were immobil ized with rF II. Twenty hybrid male dogs [weighing (20 ± 1) kg] were used for animal model of carotid artery defect and were randomly divided into 3 groups: rF II -immobil ized PU group, no rF II -immobil ized PU group and expanded polytetrafluoroethylene (ePTFE) group. The vascular grafts were implanted for repairing injured segments of carotid artery in dogs. The general health state of animals was recorded. At 30 days and 60 days,the patency rate of every group was calculated. At 60 days IDs were measured, cell prol iferation in neointima was inspected by l ight microscope, morphology on neointima was observed by SEM. Results The ID of the PU vascular grafts was (3.74 ± 0.06) mm, wall thickness was 0.4-0.6 mm, the wall density was 0.25 g/cm3, the porosity was 79.8%, racical compl iance was 8.57%/100 mmHg. In the wall, micropores were well distributed and opened-pores structure was observed. Pore size was (140 ± 41) μm in the outside layer, pore size was (100 ± 3) μm in the inside layer, thickness ratio of outside / inside layers was 2 ∶ 1, the pore size was (40 ± 16) μm on the lumina surface. After operation the wounds on neck healed, all the animals survived and had no compl ication. At 30 days and 60 days after implantation, the patency rate for rF II -immobil ized PU group were 100% and 66.7%, for no rF II -immobil ized PU group were 66.7% and 33.3%, and for ePTFE group were 67.7% and 0 respectively, but at 60 days there were thrombosis at anastamotic sites of some grafts occluded. Before operation the IDs for rF II-immobil ized PU group, no rF II -immobil ized PU group and ePTFE group were (3.74 ± 0.06), (3.74 ± 0.06) and (4.00 ± 0.03) mm, at 60 days after operation the IDs were (4.51 ± 0.05), (4.31 ± 0.24) and (4.43 ± 0.12) mm respectively, showing no statistically significant differences between 3 groups (P gt; 0.05). Histological inspection indicated that at 15 days a layer of plasma protein deposited on the lumina, at 30 days some cells adhered to the lumina, at 60 days neointima could be observed on the lumina. Thickness of the neointima became larger with implantation time. At 60 days neointima thickness at proximal end, middle site and distal end ofgraft were (560 ± 22), (78 ± 5) and (323 ± 31) μm respectively for rF II -immobil ized PU group. The results of SEM showed that neointima surface consisted of flat and long cells which long axes ranged with blood flow direction and was similar to lumina morphology of carotid artery of dog. Conclusion Immobil ization of rF II to lumina of grafts could enhance fibrinolytic activity and inhibited formation of thrombo-embol ia which led to an increase in patency rate after implantation.
The aim of the present experimental study is to determine the effects of sinotubular junction diameter on artificial bioprosthesis valves. An experimental study was performed for aortic root models with different sinotubular junction taper under pulsatile flow condition. The sinotubular junction diameters were modified to create four models with different sinotubular junction tapers with 0, 1, 3 and 5 degrees, respectively, using three dimensional printing techniques. After installing the testing bioprosthesis valve on the aortic root models, we conducted experiments of the pulsatile flow testing with different stroke volume in the pulsatile circulation simulation system. The testing condition was set at the pulse frequency of 70 beats/min and the stroke volume of 2–7 L/min. The status of the valves in 10 continuous pulse cycles was tested and the average results were obtained for each stroke volume. The results of testing showed that the mean transvalvular pressure gradients agreed well with the national standard, and all smaller than 10 mm Hg. The sinotubular junction taper had an influence on regurgitation fraction of the artificial bioprosthesis valve. The smaller sinotubular junction taper showed beneficial effect to decrease the regurgitation fraction. In the case of smaller stroke volume, the smaller sinotubular junction taper was beneficial to increase the effective valve orifice area. In the case of larger stroke volume, the larger sinotubular junction taper was beneficial to increase the effective valve orifice area. This study indicates that a doctor should consider the smaller sinotubular junction taper in the case of smaller stroke volume more. In the case of larger stroke volume, the doctor should consider the larger sinotubular junction taper more.
Objective To explore the effectiveness and failure causes of large-head metal-on-metal total hip arthroplasty (large-head MoM THA). Methods Between March 2007 and May 2010, 159 patients (183 hips) underwent large-head MoM THA, and the clinical data were analyzed. There were 50 females (54 hips) and 109 males (129 hips) with an average age of 50 years (range, 20-78 years). Single hip was involved in 135 cases (left hip in 69 cases and right hip in 66 cases) and double hips in 24 cases. The causes included femoral head necrosis in 74 cases (93 hips), Legg-Calve-Perthes in 1 case (1 hip), osteoarthritis in 18 cases (19 hips), developmental dysplasia of the hip in 17 cases (18 hips), osteoarthritis after hip septic infection in 8 cases (8 hips), traumatic arthritis of the hip in 6 cases (6 hips), femoral neck fracture in 17 cases (17 hips), ankylosing spondylitis in 8 cases (11 hips), rheumatoid arthritis of hip in 9 cases (9 hips), and adult onset Still’s disease in 1 case (1 hip). Before operation, visual analogue scale (VAS) was 6.59±0.87; Harris score was 45.99±8.07. Results Healing of incisions by first intention was achieved, and no operative complication occurred. The patients were followed up 1.2-8.2 years (mean, 6.1 years). Implant failure was observed in 15 cases (17 hips), and the 5-year survival rate of large-head MoM THA was 91.80% (168/183). The causes of implant failure after THA were inflammatory pseudotumor in 4 cases (4 hips), acetabular aseptic loosening in 3 cases (3 hips), osteolysis in 4 cases (5 hips), acetabular aseptic loosening combined with inflammatory pseudotumor in 3 cases (3 hips), and functional disused in 1 case (2 hips). Of them, 9 cases (11 hips) did not receive revision surgery for various reasons, while 6 cases (6 hips) underwent revision surgery at 1.2-5.4 years (mean 3.7 years) after large-head MoM THA. At last follow-up, VAS and Harris score were 1.72±1.48 and 81.37±10.75 respectively, showing significant differences when compared with preoperative scores (t=–35.547，P=0.000；t=33.823，P=0.000). The function was excellent in 44 hips, good in 89 hips, fair in 33 hips, and poor in 17 hips. Conclusion Large-head MoM THA has a high revision rate during mid- and long-term follow-up because of inflammatory pseudotumor, acetabular aseptic loosening, and osteolysis. Early revision can effectively improve the function of the hip and improve patients’quality of life.
ObjectiveTo evaluate the diagnostic efficacy of thyroglobulin in fine-needle aspirate fluid (FNA-Tg) for detecting cervical lateral lymph node metastases (LLNM) in differentiated thyroid cancer (DTC). MethodsThe clinical data of DTC patients who underwent (selective) cervical lateral lymph node dissection at the 900th Hospital of the Joint Logistics Support Force from February 1, 2021 to November 30, 2023 were retrospectively analyzed. The significance level (α) was set as 0.05. ResultsAccording to the inclusion and exclusion criteria, a total of 155 patients with 179 lymph nodes were included, among which 49 lymph nodes were not metastatic and 130 were metastatic. The results of the integral patients showed that the area under the receiver operating characteristic curve (AUC) of FNA-Tg for distinguishing cervical LLNM in the patients with DTC was superior to that of fine-needle aspiration cytology (FNAC). The AUCs (95% confidence intervals) were 0.973 (0.950, 0.995) and 0.778 (0.708, 0.849) respectively, P<0.05, and the AUC (95% confidence interval) of the combination of the two was higher [0.978 (0.959, 0.997)]. The optimal diagnostic threshold of FNA-Tg was determined to be 16.45 μg/L or FNA-Tg/serum thyroglobulin (sTg) was 1.02. After stratification based on the size of the lymph nodes, a paired analysis of the two methods (FNA-Tg and FNAC) showed that the diagnostic efficiency of FNA-Tg was significantly higher than that of FNAC only when the short diameter of the lymph node was ≤0.8 cm [0.955 (0.919, 0.992) vs. 0.718 (0.630, 0.806), P<0.001], and there was no additional benefit from the combination of the two [0.950 (0.912, 0.989)]. ConclusionsThe results of this study suggest that FNA-Tg shows a good diagnostic efficacy for cervical LLNM in patients with DTC, especially has an obvious advantage for small lymph nodes with a short-axis diameter of lymph node ≤0.8 cm. Its optimal diagnostic threshold is 16.45 μg/L or FNA-Tg/sTG is 1.02.
Objective To prepare a spider silk protein bilayer small diameter vascular scaffold using electrospinning, and to observe the blood compatibility in vitro. Methods The Arg-Gly-Asp-recombinant spider silk protein (pNSR16), polycaprolactone (PCL), gelatin (Gt), and heparin (Hep) were blended. Spider silk protein bilayer small diameter vascular scaffold (experimental group) was prepared by electrospinning, with pNSR16 ∶ PCL ∶ Hep (5 ∶ 85 ∶ 10, W/W) hybrid electrospun solution as inner spinning solution and pNSR16 ∶ PCL ∶ Gt (5 ∶ 85 ∶ 10, W/W) hybrid electrospun solution as outer spinning solution, but pNSR16 ∶ PCL (5 ∶ 85, W/W) hybrid electrospun solution was used as inner spinning solution in control group. The scaffold structure of experimental group was observed under scanning electron microscope (SEM); and the hemolysis rate, recalcification clotting time, dynamic clotting time, platelet adhesion, and platelet activation in vitro were compared between 2 groups. Results SEM results showed that bilayer fibers of scaffold were quite different in experimental group; the diameter distribution of inner layer fibers was relatively uniform with small pores, however diameter difference of the outer layer fiber was relatively big with big pores. The contact angle, hemolysis rate, recalcification clotting time, and P-selectin expression of scaffold were (35 ± 3) ° , 1.2% ± 0.1%, (340 ± 11) s, and 0.412 ± 0.027 respectively in experimental group, and were (70 ± 4) ° , 1.9% ± 0.1%, (260 ± 16) s, and 0.678 ± 0.031 respectively in control group; significant difference were found in indexes between 2 groups (P lt; 0.05). With the extension of time, the curve of coagulation time in experimental group sloped downward slowly and had a long time; the blood clotting index values before 30 minutes were significantly higher than those in control group (P lt; 0.05). Platelet adhesion test showed that the scaffold surface almost had no platelet adhesion in experimental group. Conclusion The spider silk protein bilayer small diameter vascular scaffold could be prepared through electrospinning, and it has good blood compatibility in vitro.
Objective To investigate the relationship between the tibia callus diameter ratio(CDR) and prognosis during tibial distraction and the occurrenceof late deformity or fracture. Methods We measured tibiallengthening callus diameter and added up the cases of angular deformity and fracture in 68 casesfrom January 1996 to December 2001, to calculated callus diameter ratios and compare the relationship between the tibia callus diameter during tibial distraction and the occurrence of late callus angular deformity or fracture. Results In 23 cases of CDRlt;80%, 13 cases had new bone fracture, 21 cases had angular deformity gt;5 degree. In 6 cases of 81%lt;CDRlt;85%, there were 4 cases of angular deformity gt;5 degree. In the other 39 cases of CDRgt;85%, there were no fracture and angular deformity. Conclusion When the CDR was gt;85%, there wereno angular deformity and fracture, but when the CDR was lt;80%, the complications of fracture and angular deformity occur. CDR is a better alarming index for preventing the complications occurring in tibial lengthening.