Decellularized nerve matrix hydrogel and glial‐derived neurotrophic factor modifications assisted nerve repair with decellularized nerve matrix scaffolds

Nerve defects are challenging to address clinically without satisfactory treatments. As a reliable alternative to autografts, decellularized nerve matrix scaffolds (DNM‐S) have been widely used in clinics for surgical nerve repair. However, DNM‐S remain inferior to autografts in their ability to support nerve regeneration for long nerve defects. In this study, we systematically and clearly presented the nano‐architecture of nerve‐specific structures, including the endoneurium, basement membrane and perineurium/epineurium in DNM‐S. Furthermore, we modified the DNM‐S by supplementing decellularized nerve matrix hydrogel (DNMG) and glial‐derived neurotrophic factor (GDNF) and then bridged a 50‐mm sciatic nerve defect in a beagle model. Fifteen beagles were randomly divided into three groups (five per group): an autograft group, DNM‐S group and GDNF‐DNMG‐modified DNM‐S (DNM‐S/GDNF@DNMG) group. DNM‐S/GDNF@DNMG, as optimized nerve grafts, were used to bridge nerve defects in the same manner as in the DNM‐S group. The repair outcome was evaluated by behavioural observations, electrophysiological assessments, regenerated nerve tissue histology and reinnervated target muscle examinations. Compared with the DNM‐S group, limb function, electrophysiological responses and histological findings were improved in the DNM‐S/GDNF@DNMG group 6 months after grafting, reflecting a narrower gap between the effects of DNM‐S and autografts. In conclusion, modification of DNM‐S with DNMG and GDNF enhanced nerve regeneration and functional recovery, indicating that noncellular modification of DNM‐S is a promising method for treating long nerve defects.     

Nano ferrites (AFe2O4, A = Zn,Co, Mn,Cu) as efficient catalysts for catalytic ozonation of toluene

Nano ferrites (AFe₂O₄, A = Zn, Co, Mn, Cu) were supported on the surface of γ-Al₂O₃ support by hydrothermal synthesis to prepare a series of novel composite catalysts (AFe₂O₄/γ-Al₂O₃) for catalytic ozonation for elimination of high concentration toluene at ambient temperature. The characterization results showed that the high-purity nano-AFe₂O₄ particles were uniformly loaded on mesoporous γ-Al₂O₃. Further, it was confirmed that among the several catalysts prepared, the amount of oxygen vacancies (O_vs), Lewis acid sites (LAS), and Brønsted acid sites (BAS) of the ZnFe₂O₄/γ-Al₂O₃ catalyst were the highest. This meant that the ZnFe₂O₄/γ-Al₂O₃ catalyst had a strong adsorption capacity for toluene and ozone (O₃), and had a strong catalytic activity. When the temperature was 293 K and the space velocity was 1500 h⁻¹, the mol ratio of O₃ to toluene was 6, the degradation rate of toluene (600 mg m⁻³) can reach an optimum of 99.8%. The results of electron paramagnetic resonance (EPR) and Fourier infrared (FT-IR) proved superoxide radicals and hydroxyl radicals by catalytic ozonation. Moreover, the GC-MS analysis results indicated that the toluene degradation began with the oxidation of methyl groups on the benzene ring, eventually producing CO₂ and H₂O. After repeated experiments, the toluene degradation rate remained stable, and the residual content of O₃ in each litre of produced gas was less than 1 mg L⁻¹, thereby indicating that the ZnFe₂O₄/γ-Al₂O₃ catalyst had excellent reusability and showed great potential for the treatment of toluene waste gas.

Nano ferrites (AFe₂O₄, A = Zn, Co, Mn, Cu) were supported on the surface of γ-Al₂O₃ by hydrothermal synthesis to prepare a series of novel catalysts (AFe₂O₄/γ-Al₂O₃) for catalytic ozonation of high concentration toluene at ambient temperature.     

Large leiomyoma of lower esophagus diagnosed by endoscopic ultrasonography–fine needle aspiration: A case report

BACKGROUNDBenign esophageal tumors are rare accounting for < 1% of esophageal tumors; two-thirds of which are leiomyomas. Esophageal leiomyoma is a benign tumor derived from mesenchymal tissue that is completely muscularly differentiated. Most esophageal leiomyomas are < 5 cm. Esophageal leiomyomas > 5 cm are rare. We describe a case of a large esophageal leiomyoma involving the cardia and diaphragm.CASE SUMMARYA 35-year-old woman presented to the doctor because of a choking sensation after eating. Physical examination showed no positive signs. Gastroscopy indicated an uplifted change in the cardia. Enhanced computed tomography revealed space-occupying lesions in the lower part of the esophagus and cardia, which were likely to be malignant. Positron emission tomography–computed tomography showed increased metabolism of soft tissue masses in the lower esophagus and near the cardia. Malignant lesions were considered, and mesenchymal tumors were not excluded. Endoscopic ultrasonography was performed to examine a hypoechoic mass in the lower esophagus, which was unclear from the esophageal wall. Clinical evaluation suggested diagnosis of esophageal and cardiac stromal tumors. Finally, histological specimens obtained by endoscopic ultrasonography– fine needle aspiration suggested leiomyoma. The patient underwent laparoscopic local resection of the tumor. The postoperative pathological diagnosis was leiomyoma.CONCLUSIONEndoscopic ultrasonography-fine needle aspiration is necessary for the diagnosis of gastrointestinal leiomyomas. It provides a strong basis for diagnosis of gastrointestinal tumors of unknown nature and origin.     

AN INVESTIGATION OF THE DOSE PROPORTIONALITY OF DEFLAZACORT PHARMACOKINETICS

The dose proportionality of deflazacort was assessed following single-dose oral administration at doses of 3, 6, and 36 mg to 24 healthy young adult volunteers. The active metabolite of deflazacort (21-desacetyl deflazacort) was monitored in plasma using a sensitive, semi-microbore liquid chromatographic method. C_max averaged 10·4±5·0, 19·8±7·5, and 132·6±52·5 ng mL⁻¹ for the 3, 6, and 36 mg doses, respectively. AUC(0–∞) averaged 38·5±37·1, 64·9±20·8, and 411·7±148·5 ng h mL⁻¹ for the same three doses, respectively. Elimination half-life ranged from 1·9±0·5 h at the 6 mg dose to 2·4±1·5 h at the 36 mg dose. Regression analyses of dose versus C_max and AUC(0–∞) yielded intercepts which were not significantly different from zero (p>0·05) and slopes which were significant (p<0·05). Regression analysis of dose versus apparent oral clearance yielded a slope which was not significantly different from zero (p>0·05). These data indicate that deflazacort exhibits dose-proportional pharmacokinetics.     

右美托咪定复合丙泊酚在小儿磁共振检查镇静中的应用观察

目的:观察经鼻给予右美托咪定（dexmedetomidine, Dex）复合小剂量丙泊酚静脉推注应用于小儿两部位MRI检查的安全性和有效性。方法:60例ASA分级Ⅰ、Ⅱ级择期行两个部位（中途需搬动患儿1次,时间>45 min）MRI检查的儿童,按照随机数字表法分为两组（每组30例）：右美托咪定2 μg/kg组（D2组）...     

交通事故致下颌骨骨折的流行病学分析

目的对南方医院近10年交通事故造成下颌骨骨折进行流行病学分析。方法回顾性调查南方医院交通事故致下颌骨骨折患者247例,分析其人员年龄、性别、致伤原因、骨折部位、伴发伤、治疗及预后等指标。结果在交通事故造成的下颌骨骨折中,20~40岁男性占72.9%;与摩托车相关的占77%;单发骨折66%,有合并损伤的占79.3%;未配用安全设备的占87.9%;采用坚强内固定术占73.4%;96.8%患者一期愈合;治疗费用3000元~5000元占78%。结论青壮年男性为交通事故致下颌骨骨折的高发人群。预防和控制车祸的发生必须加强交通安全宣传。颏部位为骨折首发区;撞击力较小、速度低时下颌骨薄弱区为易骨折部位;撞击力较大、速度较高时易发生粉碎性骨折或多发性骨折,并伴有颅脑损伤等严重并发症。配备安全设备是预防骨折的重要手段。坚强内固定为主要治疗措施,其预后良好。     

复制缺陷的重组腺病毒经心包腔转染急性心肌梗死猪观察

目的:评价重组腺病毒经心包腔转染的效率及持续时间.方法:应用磷酸钙沉淀方法制备携带大肠杆菌LacZ基因复制缺陷的重组腺病毒(Ad-LacZ).12头中国小型猪随机等分为实验组和对照组,采用球囊堵塞前降支第一对角支远端,心肌梗死模型建立后即刻采用经皮剑突下穿刺中心静脉导管心包腔内注射转染,28 d后处死.实验组胶原酶1 200 u及透明质酸酶3 000 u预处理心包后,在心包腔内注射Ad-LacZ基因2.0×109噬斑集落形成单位;对照组:同样方法预处理心包后,在心包腔内注射生理盐水1 ml.于注射后3 d、7 d及28 d分别对缺血心肌进行HE、HBFP及X-gal染色.结果:冠状动脉造影证实前降支远端完全闭塞,病理学检查显示心肌有缺血和梗死.实验组注射Ad-LacZ基因后第3 d、7 d及28 d后X-gal染色有阳性细胞,以7 d最明显,对照组28 d内均未发现阳性细胞.结论:应用球囊堵塞法可成功建立猪急性心肌梗死模型,胶原酶及透明质酸酶预处理心包后,腺病毒载体可转染缺血心肌,并持续表达4周.