OBJECTIVE To study the protective effects of Schwann cell derived neurotrophic factor (SDNF) on motoneurons of spinal anterior horn from spinal root avulsion induced cell death. METHODS Twenty SD rats were made the animal model of C6.7 spinal root avulsion induced motoneuron degeneration, and SDNF was applied at the lesion site of spinal cord once a week. After three weeks, the C6.7 spinal region was dissected out for motoneuron count, morphological analysis and nitric oxide synthase (NOS) enzyme histochemistry. RESULTS 68.6% motoneurons of spinal anterior horn death were occurred after 3 weeks following surgery, the size of survivors was significantly atrophy and NOS positive neurons increased. However, in animals which received SDNF treatment, the death of motoneurons was significantly decreased, the atrophy of surviving motoneurons was prevented, and expression of NOS was inhibited. CONCLUSION SDNF can prevent the death of motoneurons following spinal root avulsion. Nitric oxide may play a role in these injury induced motoneuron death.
Objective To evaluate the biocompatibility and safety of a novel orthopedics materials-graded zirconia(ZrO2)hydroxyapatite(HA) composite biomaterials. Methods First, ultrafine powers of ZrO2 and HA powder were prepared by chemical precipitation method, then graded ZrO2-HA composite was synthesized by dry-laying and sintering method. After the physiological saline and culture medium extracts of the composite were prepared, four experiments were conducted as follows:① The mouse acute toxic test consists of 2 groups(n=10). The extracts were intravenously injected to mice in the first group, and physiological saline to mice in the second group. The dose was 50 g/kg. Their toxicity manifestation, morality and the change of weight were recorded.② The standard curve of proliferation and metabolism of L929 cells was established. ③ The cytotoxinic test consists of 3 groups: materials group (extracts of the materials), positive control group (culture fluid with 0.64% phenol), and negative control group (RPMI-1640 culture fluid). Each of three was cultured with cell suspension, and then the morphology of the cells was observed, the relative proliferation rate (RGR) was calculated, and the toxicity was classified. ④ In vitrohemolytic test was divided into 3 groups: extracts, sterile distilled water (positive control) and 0.9% physiological saline. In each of three, 0.2 ml anticoagulant diluted fresh rabbit blood was added. The percentage of hemolysis was tested. ⑤ The muscle and implantation test were divided into 4 groups(n=3). The composite biomaterials were implanted into pygal muscleson either side and lateral condyles of femurs. After surgery, the rats of four groups were sacrificed at 12 and 24 weeks respectively.Tissue slice and scanning electronic microscopy were performed. Results General acute toxic test: no mouse died within 3 weeks; no toxicity symptom or adverse effects were shown within 3 days. The weight of materials group increased by 3.57±0.49 g, and the control group by 3.62±0.61 g, showing no statistically significant difference（Ρgt;0.05）.The standard curve of L929 cell perliferation and metabolism showed that their existed a positive correlation between the number of L929 cells and the perliferation. ③ Cytotoxinic test: cytosomes in the positive control group diminished and appeared round, there were pyknotic nucleus, the attached cells agglomerated; the toxicity was level Ⅳ. The morphology of cells in materials groupand negative control group was normal, and the number of them increased; the toxicity was level Ⅰand level 0, respectively. The MTT color experiments showed that positive control group was significantly lower than materials group and negative control group, showing statistically significant difference (Plt;0.01); there was no statistically significant difference between materials group and negative group.④ Hemolytic test: in vitrohemolytic rate of negative control group was0, of positive control group was 100%, and of materials group was 1.66%, which accords with the standard that hemolytic rate should be lower than 5% specified in ISO. ⑤ Implant test:No apparent rejection reaction took place after the composite was implanted; the composite bonded with the bones of the receptors firmly, which had good bonedinduced effect. Conclusion Graded ZrO2-HA composite bioceramic has good biocompatibility and is suitable for orthopedic biomaterials.
目的:研究缺氧预处理对老年大鼠子宫及双附件切除术后疲劳是否有改善作用,并通过对比观察超氧化物歧化酶及丙二醛水平的变化,初步探讨缺氧预处理的作用机制。方法:将老年大鼠分为空白对照组、对照组、缺氧预处理三组。空白对照组为假手术组,对照组为子宫及双附件切除术组, 缺氧预处理组为缺氧预处理加子宫及双附件切除术组。对比观察缺氧预处理对大鼠体力活动及血清超氧化物歧化酶和丙二醛水平的影响。结果:空白对照组、对照组、缺氧预处理三组大鼠悬尾不动时间分别为:(21±3)s,(83±10)s,(44±5)s,各组间比较Plt;0.05。三组SOD活性分别为:(131.23±5.31)U/L,(36.12±9.68)U/L,(73.01±9.82)U/L,各组间比较Plt;0.05。三组MDA水平分别为:(9.78±1.26)μmol/L,(29.87±3.13)μmol/L,(15.98±2.21)μmol/L,各组间比较Plt;0.05。结论:缺氧预处理可提高老年大鼠的抗氧化能力,对老年大鼠子宫及双附件切除术后疲劳综合征有明显的改善作用。
Objective To summarize the association between CYP1A1 rs4646903 polymorphisms and COPD risk. Methods Systematic literature search was conducted (up to January 2016) in five online databases, ie. PubMed, Embase, China National Knowledge Infrastructure (CNKI), VIP database, and WanFang databases. The strength of association was calculated by odds ratio (OR) and corresponding 95% confidence interval (CI). Results Six case-control studies with 1 050 cases and 1 202 controls were included. This study suggested a significant association between the CYP1A1 rs4646903 polymorphism and COPD risk (CC vs. TT: OR=1.63, 95%CI 1.17-2.27, P=0.004; CC vs. TC+TT: OR=1.62, 95%CI 1.19-2.20, P=0.002). However, there was no significant difference between allele model (C vs. T, OR=1.20, 95%CI 0.95-1.51, P=0.118) and dominant model (CC+TC vs. TT, OR=1.19, 95%CI 0.82-1.72, P=0.366). Conclusions The CYP1A1 rs4646903 polymorphisms might alter the susceptibility of COPD. More well-designed studies with larger sample size are warranted.
Age-related macular degeneration (AMD) is one of the leading irreversible causes of blindness in China. The pathogenesis of AMD is not fully understood at present. Under various stress conditions, cellular senescence is activated, characterized by telomere shortening, mitochondrial dysfunction, DNA damage, and the release of various senescence-related secretory phenotype factors. Senescence is implicated in the pathogenesis of AMD through multiple pathways, contributing to chronic inflammation and the onset and progression of AMD. Mechanisms such as oxidative stress, lipofuscin, β amyloid protein and the membrane attack complex have become hotspots of study in the pathogenesis of AMD. The cyclic guanosine phosphate - adenosine synthase - interferon stimulating factor synthase-stimulator of interferon gene pathway has emerged as a critical signaling pathway in the early development of AMD, providing direction for further research on AMD. Currently, senolytics, selective agents targeting the induction of senescent cell apoptosis, show significant potential in the treatment of AMD. The integration of new technologies with cellular senescence may offer a novel approach to AMD treatment, and intervening in the AMD treatment through anti-cellular senescence pathways holds promising prospects.
The experimental models of chronic hepatic lesion of 40 rabbits were made by intra-abdominal injection of thioacetamide.The chronic hepatic lesion was confirmed by pathological examination and hepatectomies were performed in accordance with different measurements on each rabbit.The observations included indocyanine green retention rate,hepatic resection volume,and the outcomes of operations.The results showed that the mortality was correlative with the change of hepatic functions in the background of chronic hepatic lesion.The indocyanine green retention and the level of serum albumin are important parameters to indicate hepatic impairment.When the former was over 40% or the latter below 2.8g% the operative danger was high and the mortality was over 50%.In accordance with the classification of hepatic function,the preoperative functional state of liver were classified:grade A,B and C.the mortality of posthepatectomy were respectively 16.7%,3O%,and 72%.The multiple progressive regression equation is employed for calculating the postoperative outcome.The equation predicted the postoperative outcome with 88.9% accuracy.