ObjectiveTo investigate the effect of the femoral tunnel angle on the femoral tunnel after anterior cruciate ligament (ACL) reconstruction in rabbits. MethodsFifty-four healthy 4-5 months old rabbits (weighing, 1.8-2.3 kg, male or female) were randomly divided into 3 groups (n=18). The ACL reconstruction models of the right knee were established in 3 experimental groups using its Achilles tendons, and the left knee served as the control group. On the coronal position, the angle between the femoral tunnel and the femoral shaft axis was 30°, 45°, and 60°. The level of tumor necrosis factor α (TNF-α) in the synovial fluid at 1, 2, and 4 weeks, the maximum load of the ligament and the rate of bone tunnel enlargement at 4, 8, and 12 weeks were detected. ResultsThe level of TNF-α significantly increased, and the maximum load of the ligament significantly decreased in the 3 experimental groups when compared with ones in the control group (P<0.05), but no significant difference was found among 3 experimental groups (P>0.05). The bone tunnel enlargement was observed in 3 experimental groups at each time point and reached the peak at 4 weeks, but no significant difference was shown among 3 groups (P>0.05). ConclusionThe 30-60° angle between the femoral tunnel and the femoral shaft axis in the coronal position has no significant effect on the femoral tunnel enlargement after ACL reconstruction in rabbits.
ObjectiveTo explore the influence of norepinephrine on the prediction of fluid responsiveness by passive leg raising (PLR) during septic shock. MethodsForty-six septic shock patients in intensive care unit of Nanjing Drum Tower Hospital were prospectively observed from September to November 2012. Among which 36 septic shock patients were enrolled with a positive PLR test (defined by an increase in stroke volume index ≥10%). A PLR test was performed at baseline (PLR1). A second PLR test (PLR2) was performed at returning to supine position for 10 min and the dose of norepinephrine was increased to maintain MAP ≥65 mmHg for 20 min. The changes of heart rate(HR),mean arterial pressure(MAP),central venous pressure(CVP),cardiac index(CI),stroke volume index(SVI),index of systemic vascular resistance(SVRI),global end-diastolic volume index(GEDVI),and cardiac function index(CFI) were monitored by transpulmonary thermodilution technique (PiCCO). ResultsPLR1 significantly increased SVI by (20.54±9.63)%,CI by (20.57±9.89)%,MAP by (7.64±5.77)%,and CVP by (25.83±23.39)%. As the dose of norepinephrine increased,SVI was increased by (16.97±9.06)%,CI by (16.78±8.39)%,GEDVI by (9.08±4.47)%,MAP by (28.07±12.48)%,and CVP by (7.86±8.52)%. PLR2 increased SVI by (13.74±8.79)%,CI by (13.79±9.08)%,MAP by (2.93±5.06)%,and CVP by (13.36±14.74)%. The PLR2 and the dose increase of norepinephrine augmented SVI to a significantly lesser extent than the PLR1 performed at baseline (both P<0.05). However,SVI increased by <10% in 6 patients while the baseline PLR was positive in these patients. ConclusionIn septic patients with a positive PLR at baseline,norepinephrine increases cardiac preload and cardiac output and influences the fluid responsiveness.
【Abstract】Objective To investigate the protective effect of improving the pancreatic ischemia and calcium channel blockers on preventing the progression of acute pancreatitis. Methods Twenty-four patients with mild acute pancreatitis were randomly divided into two groups： control group and treated group. Within the first 72 hours from the onset of AP, routine conservative managements were performed in control group, improving the pancreatic ischemia and preventing Ca2+ overload were performed in treated group for two weeks. The hemorrheological parameters were measured at 1,4,7,14 days after adimission, simultanously, serum TNFα, IL-1β, C-reactive protein and plasma TXB2, 6-keto-PGF1α levels were determined with ELISA methods. Results The hemorrheological changes were improved in treated group, serum TNFα, IL-1β, C-reactive protein and plasma TXB2, 6-keto-PGF1α levels were significantly decreased each time point in treated group as compared with control group. Conclusion Improving the pancreatic ischemia and calcium channel blockers have protective effect through reducing the generation of cytokines and inflammatory mediators on preventing the progression of acute pancreatitis.
To introduce a rat model of the conversion of acute edematous pancreatitis (AEP) to necrotizing pancreatitis (ANP). One hundred and seven Sprague-Dawley rats were randomized in three experimental groups as follows: sham operation control group and AEP group and ANP group. AEP was induced by pancreatic duct ligation and exocrine stimulation, ANP was induced same as AEP，but with a large dose of dextran-110 (500mg/kg) intravenously. The serum concentration of amylase increased significantly in AEP group and ANP group. Cytosolic free Ca2+ concentration in isolated pancreatic acinar cells increased consistently after induction of ANP. Homorrhage, parenchymal necrosis and calcium deposits in acinar cells were observed in pancreas in ANP group. Ultrastructural examination showed desquamation and necrosis of the endothelium of the pancreatic capillary in ANP group. These results suggest that ischemia may induce the conversion of AEP to ANP via acinar cell Ca2+ overloading. The rat model would seem to be a suitable animal model for studying aggravating mechanism of acute pancreatitis.
Objective To evaluate the influence of tidal volume on the accuracy of stroke volume variation ( SVV) to predict volume state of pigs with ventilation.Methods Thirty-six healthy pigs were anesthetized after tracheal intubation and ventilated. With the envelope method, they were randomized into a normovolemia group, a hemaerrhagic shock group, and a hypervolemia group, with 12 pigs in each group. The pigs in the hemaerrhagic shock group were removed 20 percent of blood, and the pigs in the hypervolemia group received additional infusion of 20 percent 6% hydroxyethyl starch. In each group, ventilator settings were changed in a randomized order by changing VT [ VT = 5 mL/kg ( VT5 ) , VT =10 mL/kg ( VT10 ) , and VT =15 mL/kg ( VT15 ) ] . Hemodynamic measurements [ heart rate ( HR) , mean arterial boold pressure ( MAP) , systemic vascular resistance index ( SVRI) , cardiac index ( CI) , stroke volume index ( SVI) , intrathoracic blood volume index( ITBVI) , and SVV] were obtained after 10 minutes of stabilization. Results SVV was increased in the hemaerrhagic shock group comparing with the normovolemia group for VT10 [ ( 21 ±5) % vs. ( 11 ±2) % , P lt;0. 05] , but SVV was decreased in the hypervolemia group comparing with the normovolemia group [ ( 7 ±2) % vs. ( 11 ±2) % , P lt; 0. 05] . The variation tendency for VT15 was the same with VT10 , moreover SVV were all above 12% for the hemaerrhagic shock group, the normovolemia group, and the hypervolemia group [ ( 30 ±7) % , ( 19 ±3) % , and ( 15 ±4) % ] . There were no significant diffrences among the hemaerrhagic shock group, hypervolemia group and normovolemia group [ ( 8 ±6) % ,( 7 ±5) % , and ( 7 ±4) % , P gt; 0. 05] for VT5 . Conclusions SVV was a precise indicator of cardiac preload, but SVV was less sensitive to the changes of volume during low tidal volume ( 5 mL/kg) ventilation. The threshold of SVV for predicting fluid responsiveness maybe above 12% with a high tidal volume ( 15 mL/kg) ventilation.
Objective To explore the effect of rolling compression loading bioreactor on chondrogenesis of rabbit bone marrow mesenchymal stem cells (BMSCs) with different loading parameters. Methods BMSCs were isolated from New Zealand rabbits, aged 2.5 months. BMSCs at passage 3 were used to prepare BMSCs-agarose gels (4 mm in diameter and height, respectively). Samples were divided into 8 groups: 10% (group A1), 20% (group A2), and 30% (group A3) compression groups (0.4 Hz, 3 h/ d) and 20 minutes (group B1), 3 hours (group B2), and 12 hours (group B3) rolling time groups and static culture (control groups). The living cell rate, the collagen type II and Aggrecan gene expressions, and glycosaminoglycan (GAG) content were determined, and histological staining was done at 24 hours, 7 days, 14 days, and 21 days after culture. Results At 14 and 21 days, the living cell rates of groups A1 and A2 were significantly higher than that of group A3 (P lt; 0.05), groups B1 and B2 were significantly higher than group B3 (P lt; 0.05). Collagen type II and Aggrecan gene expressions of the experimental groups at each time point were significantly higher than those of the control groups (P lt; 0.05); at 14 and 21 days, collagen type II and Aggrecan gene expressions of groups A1 and A2 were significantly higher than those of group A3, and groups B1 and B2 were also significantly higher than group B3 (P lt; 0.05). At 14 and 21 days, the GAG contents of groups A1 and A2 were significantly higher than those of group A3 (P lt; 0.05); groups B1 and B2 were also significantly higher than group B3 (P lt; 0.05). At 21 days, toluidine blue staining showed that obvious blue-staining and even cartilage lacunae were seen in groups A2 and B2, but light and quite rare blue-staining in groups A1, A3, B1, and B3. Conclusion The rolling compression loading bioreactor has great promotion effect on chondrogenesis of rabbit BMSCs with rolling parameters of 0.4 Hz, 3 hours, and 20% compression.
Objective To review the recent research progress of the bioreactor biophysical factors in cartilage tissue engineering. Methods The related literature concerning the biophysical factors of bioreactor in cartilage tissue engineering was reviewed, analyzed, and summarized. Results Oxygen concentration, hydrostatic pressure, compressive force, and shear load in the bioreactor system have no unified standard parameters. Hydrostatic pressure and shear load have been in controversy, which restricts the application of bioreactors. Conclusion The biophysical factors of broreactor in cartilage tissue engineering have to be studied deeply.
To evaluate the efficacy and the surgical procedures of submandibular sialoadenectomy by a modified retroauricular approach. Methods Between October 2008 and April 2009, 8 patients with benign submandibular gland disorders underwent removal of benign submandibular gland lesions using a retroauricular approach. There were 4 males and 4 females with an average age of 38.5 years (range, 32-54 years), including 3 pleomorphic adenoma and 5 chronic sialadenitis with sialol ithiasis. The disease duration was from 2 months to 5 years. The anterior facial vein and the facial artery were reserved only by the l igation of branching vessels in the submandibular gland. Results Submandibular sialoadenectomy were successfully performed in 8 cases. The operative time was 45-75 minutes (mean, 60 minutes). All incisions obtained heal ing by first intention. No nerve paralysis occurred, including marginal mandibular branch of the facial nerve, the l ingual nerve, and hypoglossal nerve. One patient had poor blood circulation of flap due to excessive traction during operation, but it returned normal after 24 hours without special treatment. Other flaps had good blood circulation. All patients were followed up 1-6 months (mean, 3 months). The incision scars were hidden with satisfactory appearance. Conclusion The modified retroauricular approach has some advantages such as simple operation, better cosmetic outcome, and no compl ication.
Objective To evaluate the effect of polymethylmethacrylate (PMMA) augmentation on cervical stabil ity after anterior cervical interbody fusion (ACIF) before and after fatigue. Methods Twelve porcine cervical spines (C3-7) were subjected to testing angular displacement parameters, including the range of motion (ROM), neutral zone (NZ), and elastic zone (EZ), in nondestructive flexion and extension, right/left lateral bending, and left/right rotation on Motion Analysis motion capture system and MTS-858 servo-hydraul ic testing machine. Intact cervical spines served as control group (group A); oneleveldiscectomy and fusion was performed with anterior plate fixation based on group A as group B; flexion and extension,left/right lateral bending (5 000 cycles) fatigue testing based on group B as group C; the augmentation screw channel was used based on group C as group D; and flexion and extension, left/right lateral bending fatigue testing were performed based on group D as group E. Results The ROM, NZ, and EZ in group A were significantly different from those in other groups (P lt; 0.05) at flexion/extension, left/right bending, and left/right rotation. The ROM, NZ, and EZ in group B were significantly smaller than those in group C (P lt; 0.05) in flexion/extension, left/right bending, and left/right rotation, but there was no significant difference when compared with group D (P gt; 0.05). The ROM and NZ in flexion/extension and the EZ in flexion in group B were significant smaller than those in group E (P lt; 0.05), but there was no significant difference in the other indexes (P gt; 0.05). The ROM, NZ, and EZ in group C in flexion and extension, left/right lateral bending, and left/right rotation were significantly higher than those in groups D and E (P lt; 0.05). The ROM and NZ in flexion and extension and left/right lateral bending, and the ROM in left/right rotation, and the EZ in flexion and extension, right bending, and left/right rotation in group D were significantly smaller than those in group E (P lt; 0.05), but there was no significant difference in the other indexes (P gt; 0.05). Conclusion PMMA augmentation can significantly increase the instant cervical stabil ity and provide a biomechanics basis in cervical anterior plate fixation.
To investigate the change of bacterial load appl ied with iodophors and rivanol of diabetic foot ulcers (DFUs), furthermore to evaluate the effect of both in removing superficial microbes of DFUs. Methods From March 2006 to March 2007, 30 patients were randomly divided into control group (group A, n=10), iodophor group (group B, n=10) and rivanol group (group C, n=10). There were 18 males and 12 females with an average age of 59.8 years (range 46-78 years). The wound size ranged from 3 cm × 2 cm to 15 cm × 10 cm. The disease course was 6 weeks to 6 months (mean 2.1months). Each wound was debrided and irrigated before process, then drug was compressed on the wound for 5 minutes, and irrigated again. The samples gained for three times, before, immediately and 24 hours after the process. Each sample was diluted before cultivation, the bacteria of wound were counted and compared among 3 groups. Results The cultures of specimens showed that the load decreased in every group, each cultured colony of specimen grew well, and there were no significant differences between 3 groups immediately after procedure (P gt; 0.05). There were significant differences between group B and groups A, C (P lt; 0.05), but there were no significant difference between group A and group C 24 hours after treatment (P gt; 0.05). Conclusion Both iodophors and rivanol could remove the bacteria on the surface of wound. Topical germicide could reduced bacterial load in the wound of diabetic foot, the role of steril izing and bacteriostasis of iodophors were better than that of rivanol.