The radical compliance of small diameter artificial vascular grafts was measured by a device made of laser micrometer, pressure transducer, A/D card, micro computer and pulsed circulation loop, the volumetric compliance was measured by a device made of micro-syringe and pressure transducer; the longitudinal compliance was calculated from volumetric compliance and radical compliance. The research results showed that the radical compliance, volumetric compliance and longitudinal compliance would rise not only with the increase in polyurethane (PU) elasticity and salt/polymer ratio (or porosity), but also with the decrease in dipping layers (or wall thickness). Circumferential moduli E zeta and longitudinal moduli E theta could be calculated from volumetric compliance and longitudinal compliance respectively; E theta and E zeta would decrease with the increase in PU elasticity and salt/polymer ratio, but was independent on number of dipping layers. Small diameter PU artificial vascular grafts with compliance close to natural vein or artery can be prepared by choosing of more elastic PU materials (Chro or PCU1500), optimization of salt/polymer ratio (6:1), and the number of dipping layers (4-6 layers).
Biocompatible Materials ; chemistry ; Blood Vessel Prosthesis ; Compliance ; Elasticity ; Humans ; Polyurethanes ; chemistry

Objective:To explore the effects of self-made Huoxue Xiaozhong Xunxi Decoction combined with functional exercise on postoperative swelling of affected limbs, bone metabolism and recovery of knee function in patients with traumatic fracture of tibial plateau (FTP).Methods:Randomized controlled trial. totally 80 patients after FTP surgery in the Qidong Hospital of Traditional Chinese Medicine were enrolled and divided into two groups by random number table method from January 2018 to January 2022, with 40 cases in each group. After surgery, control group was treated with functional exercise, while observation group was additionally treated with self-made Huoxue Xiaozhong Xunxi Decoction. All were treated continuously for 8 weeks. The perioperative indexes (operation time, incision length, intraoperative blood loss, postoperative drainage volume, leaving bed time) in the two groups were recorded. The postoperative swelling and pain of affected limbs were observed, and detumescence time, pain relief time, fracture healing time and complete weight-bearing time were recorded. The knee function was evaluated by Hospital for Special Surgery (HSS). The level of serum bone morphogenetic protein-2 (BMP-2) was detected by ELISA, and total n-terminal propeptide of typeⅠprecollagen (t-PINP) and β-crossLaps (β-CTX) were detected by full-automatic immunoluminescence analyzer. The occurrence of postoperative complications in the two groups was recorded.Results:There was no significant difference in operation time, incision length, intraoperative blood loss, postoperative drainage volume or leaving bed time between the two groups ( P>0.05). The total effective rate of the observation group was 97.5% (39/40), while the control group was 80.0% (32/40), with statistical significance ( χ2=6.14, P=0.013). The detumescence time, pain relief time, fracture healing time and complete weight-bearing time were earlier in the observation group than control group ( P<0.01). After 10 d of treatment, VAS score and swelling degree in observation group were lower than those in the control group ( t=7.05, 3.81, P<0.01). After 8 weeks of treatment, levels of serum BMP-2 [(625.16±67.43) μg/L vs. (542.35±53.27) μg/L, t=6.10], t-PINP [(54.16±7.29) μg/L vs. (50.34±6.12) μg/L, t=2.54] and β-CTX [(1.26±0.38) μg/L vs. (1.04±0.23) μg/L, t=3.13] in observation group were higher than those in the control group ( P<0.05). During treatment, the incidence of complications in the observation group was 2.5% (1/40) and the control group was 7.5% (3/40), without statistical significance ( χ2=1.05, P=0.305). Conclusion:Self-made Huoxue Xiaozhong Xunxi Decoction combined with functional exercise is beneficial to improve pain and swelling of affected limbs and bone metabolism, and promote the recovery of knee function in patients after FTP surgery.

Objective:To explore the clinical and imaging characteristics of mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) caused by mitochondrial DNA 14453G>A (m.14453G>A) mutation.Methods:A case of MELAS caused by m.14453G>A mutation in the First Affiliated Hospital of Harbin Medical University on October 12, 2021 was reported. At the same time, the reported cases of MELAS and Leigh syndrome (LS) caused by the m.14453G>A mutation were reviewed. This enabled a comprehensive summarization, analysis, and comparison of these cases.Results:The patient was a female. She has suffered from the disease since 13-year old with seizures, accompanied by the disturbance of mood and the loss of memory. Brain magnetic resonance imaging findings consisted of lesions in frontal, parietal, occipital, temporal lobe and cerebellar. The patient was initially considered with autoimmune encephalitis and posterior reversible encephalopathy syndrome. Since direct sequencing of the complete mitochondrial genome from blood of the patient revealed m.14453G>A mutation in ND6 gene, and the mutation rate was 17.0%, the patient eventually diagnosed with MELAS based on clinical manifestations, imaging examinations, and genetic testing results. Using "m.14453G>A" as the search term, the relevant literature in China and abroad was retrieved and those with complete clinical data were identified. A total of 11 cases of m.14453G>A mutation including this case were reported, of whom 5 patients were diagnosed as MELAS, and 6 patients were diagnosed as LS. Among the 11 patients, those being adolescent or adult and with lesions in the cortex and subcortical white matter were probably be MELAS; those being infant or young child and with lesions in basal ganglia, thalamus and brainstem could be LS. Conclusions:Mitochondrial disease caused by m.14453G>A gene mutation shows a great heterogeneity, which can cause MELAS and LS. The clinical phenotype of the m.14453G>A mutation may be related to the age of onset and lesion′ s location.

Objective    To explore the safety and feasibility of spontaneous breathing anesthesia combined with tubeless uniportal thoracoscopy in pulmonary bullae surgery. Methods    Totally 112 patients with pulmonary bullae in the Affiliated Hospital of Inner Mongolia Medical University from March 2015 to May 2017 were enrolled. According to the random number chosen by computer, the patients were randomly divided into two groups: a tubeless group (spontaneous breathing anesthesia combined with tubeless uniportal thoracoscopy) and a control group (uniportal thoracoscopy by general anesthesia with tracheal intubation) . There were 49 males and 7 females with an average age of 25.5±6.5 years in the tubeless group, and 50 males and 6 females with an average age of 23.5±4.5 years in the control group. The difference of the lowest intraoperative arterial oxygen saturation (SaO2), SaO2 at postoperative one hour, operation time, postoperative awakening time, hospital stay, hospitalization cost and postoperative pain score were analyzed. Results    There was no significant difference between the two groups in the operation time, the lowest SaO2, SaO2 at one hour after the operation and the partial pressure of carbon dioxide (PaCO2). The awakening time and duration of postoperative hospital stay in the tubeless group was shorter than those in the control group (P=0.000). The cost of hospitalization in the tubeless group was less than that in the control group (P=0.000). The discomfort caused by urinary tract and visual analogue score (VAS) in the tubeless group were better than those in the control group. Conclusion    It is safe and feasible to use spontaneous breathing anesthesia combined with tubeless uniportal thoracoscopy in pulmonary  bullae resection.