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This study aimed to explore the link between block copolymers' interfacial properties and nanoscale carrier formation and found out the influence of length ratio on these characters to optimize drug delivery system. A library of diblock copolymers of PEG-PCL and triblock copolymers with additional PEI (PEG-PCL-PEI) were synthesized. Subsequently, a systematic isothermal investigation was performed to explore molecular arrangements of copolymers at air/water interface. Then, structural properties and drug encapsulation in self-assembly were investigated with DLS, SLS and TEM. We found the additional hydrogen bond in the PEG-PCL-PEI contributes to film stability upon the hydrophobic interaction compared with PEG-PCL. PEG-PCL-PEI assemble into smaller micelle-like (such as PEG-PCL4006-PEI) or particle-like structure (such as PEG-PCL8636-PEI) determined by their hydrophilic and hydrophobic block ratio. The distinct structural architectures of copolymer are consistent between interface and self-assembly. Despite the disparity of constituent ratio, we discovered the arrangement of both chains guarantees balanced hydrophilic-hydrophobic ratio in self-assembly to form stable construction. Meanwhile, the structural differences were found to have significant influence on model drugs incorporation including docetaxel and siRNA. Taken together, these findings indicate the correlation between molecular arrangement and self-assembly and inspire us to tune block compositions to achieve desired nanostructure and drug loading.
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Objective@#To investigate the mechanism of cell autophagy for regulating skeletal muscle wasting of rats after severe burns.@*Methods@#Seventy-two Sprague-Dawley rats were collected and divided into sham injury group, simple burn group, burn+ phosphate buffer solution (PBS) group, and burn+ 3-methyladenine (3-MA) group according to the random number table, with 18 rats in each group. Rats in simple burn group, burn+ PBS group, and burn+ 3-MA group were inflicted with 30% total body surface area full-thickness scald (hereinafter referred to as burns). Rats in sham injury group were sham injured. Immediately after burns and fluid resuscitation, rats in burn+ PBS group were intraperitoneally injected with 1 mL PBS, and rats in burn+ 3-MA group were intraperitoneally injected with 1 mL 3-MA (125 g/L). On post injury day 3 and 7, the weights of anterior tibial muscle of right hind limbs and body of rats were measured to calculate percentage of anterior tibial muscle of right hind limbs weight. Protein expressions of microtubule related protein 1 light chain 3A (LC3A) and Beclin-1 of anterior tibial muscle were observed by immunofluorescence method and detected by Western blotting, and ratio of microtubule related protein 1 LC3A-Ⅱ to LC3A-Ⅰ was calculated. Data were processed with analysis of variance of factorial design, one-way analysis of variance, t-test and Bonferroni correction.@*Results@#On post injury day 3 and 7, percentages of anterior tibial muscle of right hind limbs weight of rats in simple burn group were (0.148±0.009)% and (0.134±0.018)%, respectively, which were significantly lower than those in sham injury group [(0.203±0.009)%, (0.181±0.015)%, t=10.585, 4.913, P<0.01]. Percentages of anterior tibial muscle of right hind limbs weight of rats in burn+ 3-MA group were (0.187±0.004)% and (0.192±0.009)%, respectively, which were obviously higher than those in burn+ PBS group [(0.162±0.005)%, (0.167±0.005)%, t=9.564, 5.948, P<0.01]. On post injury day 3 and 7, protein expressions of Beclin-1 and microtubule related protein 1 LC3A of anterior tibial muscle of rats in simple burn group were significantly higher than those in sham injury group, while protein expressions of Beclin-1 and microtubule related protein 1 LC3A of anterior tibial muscle of rats in burn+ 3-MA group were significantly lower than those in burn+ PBS group. Ratios of microtubule related protein 1 LC3A-Ⅱ to LC3A-Ⅰ of anterior tibial muscle of rats in simple burn group were significantly higher than those in sham injury group (t=3.461, 3.353, P<0.05), while ratios of microtubule related protein 1 LC3A-Ⅱ to LC3A-Ⅰ of anterior tibial muscle of rats in burn+ 3-MA group were significantly lower than those in burn+ PBS group (t=3.129, 3.977, P<0.05).@*Conclusions@#Cell autophagy induced by severe burns is involved in the process of skeletal muscle wasting of rats, and inhibition of cell autophagy may contribute to the remission of skeletal muscle wasting of rats induced by burns.
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<p><b>OBJECTIVE</b>To study the key points of treatment and amputation in patients with frostbite, so as to increase the successful rate of the treatment.</p><p><b>METHODS</b>Five hundred and sixty-eight patients with frostbite admitted to our department from January 2005 to December 2014. (1) For the patients admitted to our department within one week after injury, the frostbite wounds were soaked in 42 °C herbal fluid (twice per day, 30 min for each time) and irradiated with infrared or red light (three times per day, 40 min for each time) from the day of admission to the 7th day after injury. Meanwhile, treatment for improvement of microcirculation, vasodilation, and anti-infection were also given. Then they received infrared or red light irradiation to the wound sites. For the patients admitted to our department longer than one week after frostbite, the frostbite wounds were irradiated with infrared or red light, and treated with antibiotics if inflammation was found around the wound. Among all the patients, 5 cases suffered from frozen stiff, and they were given fluid resuscitation as well as above-mentioned treatments after admission. (2) All patients were given wound treatment immediately after admission. The superficial partial-thickness wounds and deep partial-thickness wounds of 264 patients were given routine dressing change. The full-thickness wounds in 79 patients were treated with exposure therapy after routine dressing change first, and then granulation tissue of these wounds were grafted with autologous thigh split-thickness skin grafts. After debridement and exposure therapy, amputation was done in 225 patients 3 to 4 weeks after injury when the underlying bone was exposed. In 4 patients with exposure of calcaneus, the wounds were covered with reverse sural nerve nutrient vessels island flap. Mean healing time of superficial partial-thickness wound and deep partial-thickness wound, survival rate of skin graft in full-thickness wound, and survival rate of flap covering wound deep to bone at the heel were all recorded. The amputation rate of patients injured in December, January, February, and other months, that of patients admitted shorter than 1 day after frostbite, 1 to 3 days after frostbite, longer than 3 days and shorter than or equal to 5 days after frostbite, and longer than 5 days after frostbite, that of patients caused by drunkenness, mental disorders, improper protection, going astray, and trauma including traffic accident etc., and that of patients treated with rewarming under room temperature, rubbing with snow, wrapping with quilt, and soaking in warm water before admission were all recorded and analyzed. Parts of the data were processed with χ(2) test.</p><p><b>RESULTS</b>All patients were survived after treatment. Average wound healing time of superficial partial -thickness wound and deep partial-thickness wound was respectively 10 and 23 days. The survival rate of skin graft on full-thickness wound was about 95%. Survival rate of flap on wound deep to bone at the heel was 100%. Amputation rates of patients injured in December and January were respectively 47.46% (84/177), 42.56% (103/242), and both were significantly higher than those of patients injured in February and the other months [respectively 29.55% (26/88), 13.11% (8/61), with χ(2) values from 42.595 to 220.900, P values below 0.01]. Amputation rate of patients with admission time shorter than 1 day after frostbite was 32.06% (84/262), which was obviously lower than that of patients with admission time from 1 to 3 days after frostbite, longer than 3 days and less than or equal to 5 days after frostbite, or longer than 5 days after frostbite [respectively 40.48% (68/168), 49.02% (50/102), 52.78% (19/36), with χ(2) values from 107.284 to 165.350, P values below 0.01]. Amputation rates of patients with frostbite occurring after getting drunkenness, mental disorders, and trauma including traffic accident etc. were respectively 42.06% (106/252), 43.48% (60/138), and 53.12% (17/32), and they were all significantly higher than those of patients with frostbite caused by improper protection and going astray [respectively 27.45% (28/102), 22.73% (10/44), with χ(2) values from 187.260 to 209.738, P values below 0.01]. Amputation rates of patients undergoing treatment of rewarming under room temperature, rubbing with snow, wrapping with quilt before admission were respectively 44.29% (62/140), 48.28% (84/174), and 35.38% (46/130), and they were significantly higher than the amputation rate of patients who received the treatment of soaking in warm water [23.39% (29/124), with χ(2) values from 97.364 to 136.189, P values below 0.01].</p><p><b>CONCLUSIONS</b>Early diagnosis and treatment, properly rewarming at early stage, and correct wound treatment are the key points for reducing amputation rate of patients after frostbite. Attention should be paid to the occurrence of frostbite in December and January, and also to protection of high-risk groups (patients with mental disorders and drunker).</p>
Subject(s)
Humans , Amputation, Surgical , China , Debridement , Frostbite , Pathology , Therapeutics , Granulation Tissue , Microcirculation , Negative-Pressure Wound Therapy , Skin , Skin Transplantation , Methods , Surgical Flaps , Treatment Outcome , Wound HealingABSTRACT
BACKGROUND:Periprosthetic femoral fracture after total knee arthroplasty is related with the osteoporosis, bone defects, prosthesis, frail patients and high complication rate, so it is difficult to prevent and treat. OBJECTIVE:To explore the risk factor, classification, treatment, rehabilitation and prophylaxis of periprosthetic femoral fracture after total knee arthroplasty based on the reviewed and summarized articles published in recent years. METHODS:A computer-based online search was conducted in PubMed database from January 1, 1990 to December 31, 2011 and in SpringerLink database from 1980 to 2011 for the related articles with the key words of“periprosthetic fracture, knee”in English. A total of 626 articles were retrieved. RESULTS AND CONCLUSION:According to inclusion and exclusion criteria, the articles were screened and 40 articles were included final y. The results showed that with the extensive development of total knee arthroplasty, the incidence of periprosthetic femoral fracture was increased gradual y;due to the poor prognosis, we should pay attention to the prevention. The risk factors of periprosthetic femoral fracture included patients’ internal factor that was hard to control, and some external factors such as the surgical techniques. Rorabeck classification was commonly applied for periprosthetic femoral fracture after total knee arthroplasty, but it was not perfect in clinical application. Kim classification wil be better for clinical guidance. The treatment of periprosthetic femoral fracture included nonoperative treatment, open reduction and internal fixation, retrograde intramedul ary nailing and revision arthroplasty. An appropriate treatment is chosen depending on fracture classification, local bone quality, patients’ medical and nutritional status. At present, however, there is not a perfect guideline for the selection of appropriate treatment method. But the early functional exercise is beneficial to prevent the related complications caused by longtime immobilization and the loss of joint function. Therefore, the indications must be under strict control in the treatment of periprosthetic femoral fracture after total knee arthroplasty. Except the firm fixation, early exercise for the patients should be encouraged at the same time.
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BACKGROUND:Navigation assisted minimal y invasive posterior lumbar interbody fusion and pedicle screw fixation can precisely real-time guide a variety of operation under minimal y invasive sleeve, and implant the pedicle screws and interbody fusion cage and other implants safely and accurately, thus can determine the decompression parts. Minimal y invasive transforaminal lumbar interbody fusion is the typical approach in recent years for the successful application of minimal y invasive spine surgery techniques with the advantages of smal incision, less bleeding, slight tissue damage and faster recovery. OBJECTIVE:To evaluate the short-term effect of minimal y invasive transforaminal lumbar interbody fusion with real-time three-dimensional navigation system and open posterior transforaminal lumbar interbody fusion. METHODS:Forty cases with single-level lumbar disc herniation were retrospectively analyzed. The patients were treated with minimal y invasive transforaminal lumbar interbody fusion with real-time three-dimensional navigation system (20 cases) and open posterior transforaminal lumbar interbody fusion (20 cases) respectively for the comparative analysis. The fusion duration, intraoperative blood loss, postoperative drainage volume, the length of postoperative hospital stay and the length of hospital stay were compared between two groups. The wound pain and function were evaluated after treatment with visual analogue scale score and Japanese Orthopaedic Association score. RESULTS AND CONCLUSION:Al patients were fol owed-up for 7.7 months. The operative duration in the minimal y invasive transforaminal lumbar interbody fusion group was longer than that in the open posterior transforaminal lumbar interbody fusion group, and the difference was significant (P0.05).The results indicate that minimal y invasive transforaminal lumbar interbody fusion with real-time three-dimensional navigation system is an effective method for lumbar disc herniation with the advantages of less intraoperative blood loss, less postoperative drainage volume, smal trauma, short hospital stay and short-term efficacy.