Hydrolytic and depolymerising enzyme activity of Prevotella intermedia and Prevotella nigrescens

OBJECTIVE: Prevotella intermedia has been reported to be associated with periodontal disease whilst P. nigrescens has predominantly been isolated from more specific conditions and healthy sites. The aim of the present study was to compare the enzyme activity of these species.
MATERIALS AND METHODS Nine strains of P. intermedio and 12 strains of P. nigrescens were studied. Lipolytic. saccharolytic, nucleolytic and proteolytic activity was determined by traditional microbiological and chromo-genic substrate methods.
RESULTS: All strains hydrolysed gelatine, casein. DNA and RNA. Lipase activity was produced by all strains except P. nigrescens ATCC 33563^T. Lipolytic activity of P. nigrescens strains decreased as the environmental glucose concentration was increased. Only two strains, both P. intermedia , hydrolysed benzyl-arg-p-nitroanilide. All strains hydrolysed alkaline pnitrophenolphosphate (except P. intermedia DAL 100). produced glycylprolyl dipeptidase activity and demonstrated elastase-like activity. All but three strains (2 P. intermedia and I P. nigrescens) hydrolysed suc-ala-ala-pro-phe-p-nitroanilide. Overall, no qualitatively analysed enzyme activity was exclusive to all strains of either species. Quantitatively analysed activity exhibited a high degree of variability both within and between species.
CONCLUSIONS: P. intermedia and P. nigrescens degrade natural and synthetic substrates, but intra- and interspec-ies activity is variable.     

Reactive oxygen species scavenging activity during periodontal mucoperiosteal healing: an experimental study in dogs

Excessive release of reactive oxygen species (ROS) in wounded tissue due to inflammation and ischaemia is a deleterious and destructive phenomenon for the healing process. Hence, scavenging of ROS is one of the essential steps in normal wound repair. In this study, we presented a profile of free radical scavenging enzyme (FRSE) activity of periodontal mucoperiosteal wounds in order to investigate ROS activity during periodontal wound healing. Mucoperiosteal periodontal flaps were elevated in the mandibular buccal region of seven dogs between the first premolar and first molar teeth, creating acute incisional wounds in the inner side of the flaps and they were replaced 30 min after elevation. Gingival samples taken from certain biopsy regions at baseline (before flap elevation), day 3, 12, 21 and 30 were processed for detection of active amounts of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX). All enzyme activities had increased by more than 100% of their baseline levels by day 3. SOD activity decreased gradually from days 3 to 30 and reached a level lower than the baseline value. The increase in CAT activity continued until day 21, and decreased to a level higher than the baseline value by day 30. GPX also decreased from day 3, and reached a level less than its baseline value by day 30. Our results suggest that FRSEs may contribute to the detoxification of ROS during periodontal mucoperiosteal healing. This relationship may be utilized to facilitate soft tissue and/or flap management in periodontal or intra-oral treatments.     

In vivo host interactions with mineral trioxide aggregate and calcium hydroxide: inflammatory molecular signaling assessment

Introduction

Mineral trioxide aggregate (MTA) and calcium hydroxide [Ca(OH)₂] are promising biomaterials for stimulating dentinogenesis and cementogenesis. This research was undertaken to understand how MTA and CA(OH)₂ participate in the inflammatory, healing, and biomineralization processes. In this part of the study, we evaluated inflammatory signaling molecules promoted by in vivo host interaction with MTA and Ca(OH)₂.

Methods

Human dentin tubes were filled with ProRoot MTA (Dentsply Tulsa Dental, Tulsa, OK), Ca(OH)₂, or kept empty. After 12 hours and 1, 3, 7, 15, 30, and 60 days of implantation in subcutaneous tissues in the backs of mice, the tubes and surrounding tissues were retrieved for cytokine level quantification and histological and immunohistochemical analysis.

Results

MTA and Ca(OH)₂ induced proinflammatory cytokine up-regulation for up to 3 days. Moreover, interleukin-10 overexpression was noted on the tissue in contact with the biomaterials during the acute phase of the inflammatory reaction. Immunohistochemical analyses showed an increased expression of myeloperoxidase, nuclear factor kappa B (NF-κB), cyclooxygenase-2, inducible nitric oxide synthase enzymes, and vascular endothelial growth factor on day 1 for all groups.

Conclusions

MTA and Ca(OH)₂ increased the activation of the NF-κB signaling system on day 1 for all groups. This finding can be associated with a proinflammatory and pro-wound healing environment, which was promoted earlier by MTA.     

17种中药多糖提取物的理化性质研究

[目的] 探究中药多糖的一般理化性质,为中药多糖成分的研究及应用提供参考依据。[方法] 通过比色法、光谱法等多种方法研究17种中药多糖粉末的基本理化性质,包括含量测定、黏度测定、吸湿性与抗氧化能力测定。[结果] 市售的17种中药多糖粉末中多糖含量均较高,且蛋白质含量非常低,具有较好的吸湿性及抗氧化活性。多糖黏度随溶液浓度升高而增大,随温度升高而降低。[结论] 实验所采用的方法可以对17种中药多糖的理化性质进行测定,为多糖的研究提供理论性支持。     

胸椎旁神经阻滞联合全麻对肺癌切除术后患者血清心肌酶水平的影响

目的 探讨胸椎旁神经阻滞联合全麻对肺癌切除术后患者血清心肌酶水平的影响。方法 选择2017 年2 月至2019 年12 月在本院进行胸腔镜下肺癌切除术患者86 例,分为观察组与对照组,每组各43 例。对照组给予双腔支气管插管全身麻醉,观察组在对照组麻醉的基础上给予胸椎旁神经阻滞,记录麻醉效果与血清心肌酶水平变化情况。结果 观察组使用量丙泊酚为（822.14±15.29）mg、舒芬太尼为（0.92±0.11）mg,与对照组丙泊酚（824.09±18.22）mg、舒芬太尼（0.98±0.08）mg 比较,差异无统计学意义（P>0.05）。观察组疼痛VAS 评分术后24 h 为（1.89±0.38）分、36 h（1.65±0.22）分与72 h（1.34±0.17）分,均显著低于对照组24 h 的（3.42±0.32）分、36 h（3.18±0.17）分与72 h（3.00±0.16）分（P<0.05）。观察组术后72 h 的恶心、躁动、眩晕、胸闷等不良反应发生率（4.7%）显著低于对照组（27.9%）（P<0.05）。对照组术后72 h 的血清LDH 为（204.77±21.04）U/L 与CK-MB（22.72±1.84）U/L 均高于术前12 h 与观察组（P<0.05）,观察组术前血清LDH（198.38±12.47）U/L、CK-MB（12.49±1.48）U/L 与术后LDH（168.29±17.76）U/L、CK-MB（13.01±1.74）U/L 比较,差异无统计学意义（P>0.05）。结论 胸椎旁神经阻滞联合全麻在肺癌切除术患者的应用不会增加全麻剂量,且能抑制血清心肌酶的释放,可减少术后不良反应的发生,提高术后镇痛效果。     

Chk2敲除可通过增强抗氧化能力改善由Bmi⁃1缺失所致的小鼠脑衰老表型

目的：探索细胞周期检测点激酶2（cell?cycle checkpoint kinase 2,Chk2）敲除是否能改善由B淋巴瘤Mo?MLV插入区1（B cell?specific MLV integration site?1,Bmi?1）缺失所致的小鼠脑衰老表型。方法：取2月龄Bmi?1基因敲除（Bmi?1-/-）小鼠、Chk2基因敲除（Chk2-/-）小鼠、Bmi?1和Chk2双敲（Bmi?1-/-Chk2-/-）小鼠以及同窝野生型（wild type,WT）小鼠脑组织,通过免疫组织化学染色检测不同组小鼠脑组织皮层、海马、下丘脑中NeuN、GFAP、Iba1、p16等指标的变化,通过Western blot检测不同组小鼠脑皮质中p16、SOD1、SOD2蛋白表达量的差异。结果：与同窝WT小鼠相比,Bmi?1?/?小鼠在上述脑区中NeuN、Iba1阳性细胞百分率明显减少,GFAP与p16的阳性细胞百分率明显增加,SOD1、SOD2蛋白表达量明显降低,p16蛋白表达量明显上升,而在Chk2-/-小鼠中NeuN、Iba1阳性细胞百分率则增加,GFAP与p16的阳性细胞百分率明显减少,SOD1、SOD2蛋白表达量明显上调,p16蛋白表达量明显下降;与Bmi?1-/-小鼠相比,Bmi?1-/-Chk2-/-小鼠在上述脑区中NeuN、Iba1阳性细胞百分率明显增加,GFAP与p16的阳性细胞百分率明显减少,SOD1和SOD2蛋白表达量明显上升,p16蛋白表达量明显下降。结论：Chk2敲除可通过增强抗氧化能力,从而改善由Bmi?1缺失所致的小鼠脑衰老表型。     

丁苯酞软胶囊对急性脑梗死患者氧化损伤及抗氧化能力的影响

目的研究丁苯酞对急性脑梗死患者氧化损伤及抗氧化能力的影响。方法选择急性脑梗死患者62例,分为实验组(添加丁苯酞软胶囊)和对照组(未添加丁苯酞软胶囊),所有患者均采用Fenton法测定血清活性氧(ROS)水平和ELISA法检测患者的血清总抗氧化能力(T-AOC)水平,并比较两组的差异。结果治疗后1周实验组患者的血清ROS水平低于对照组,差异有统计学意义(P0.05);治疗后1周实验组患者的血清T-AOC水平较对照组明显升高,差异有统计学意义(P0.05);实验组患者的血清T-AOC水平治疗后较治疗前升高明显,差异有统计学意义(P0.05);实验组2周后NHISS评分低于对照组,差异有统计学意义(P0.05)。结论丁苯酞可能通过减少ROS,提高机体总抗氧化能力,达到对神经元的保护,从而有效改善神经功能缺损症状。     

Low plasma antioxidant status in patients with epilepsy and the role of antiepileptic drugs on oxidative stress

Background:

Oxidative stress has been implicated in various disorders including epilepsy. We studied the antioxidant status in patients with epilepsy and aimed at determining whether there was any difference in the antioxidant levels between patients and controls, patients who are not on antiepileptic drugs (AEDs), and on treatment, between individual AEDs and patients on monotherapy and polytherapy.

Materials and Methods:

Antioxidant levels like catalase, glutathione peroxidase (GPx), vitamin E, glutathione (GSH), thiol group (SH), uric acid, and total antioxidant capacity (TAC) were compared between 100 patients with epilepsy and equal number of controls. Twenty-five patients who were not on AEDs were compared with patients on AEDs and the control group. Patients were divided into monotherapy and polytherapy group and antioxidant status was compared between the two groups and between individual drugs.

Results:

Catalase, SH, vitamin E, and TAC were significantly low in patients with epilepsy than those in the control group (P < 0.001). GSH and uric acid did not show any difference; GPx in patients was significantly higher than those in the control group There were no differences in the antioxidant levels between the treated and the untreated groups; however, it was lower in untreated patients than controls (P < 0.001), suggesting that AEDs do not modify the oxidative stress. Patients on Valproate (VPA) showed higher catalase and GPx levels. Catalase was higher in the monotherapy than polytherapy group (P < 0.04).

Conclusion:

Our study found significantly low levels of antioxidant in patients as compared to controls. AED did not influence the antioxidant status suggesting that seizures induce oxidative stress.     

【原创论文】同侧和对侧大鼠睾丸缺血再灌注损伤的生化效应和褪黑激素对此的保护作用

睾丸扭转（TT）,是一个多发于青春期男性的泌尿急症,如果不及时治疗,可致不孕不育。睾丸扭转所致缺血再灌注（I／R）损伤在睾丸损伤的病理生理过程中起一定作用。我们研究了褪黑激素在单侧睾丸扭转大鼠中同侧和对侧睾丸的氧化损伤效应：将21只青春期雄性Wistar大鼠分成三组,每组七只,处理如下：第1组（假手术组）：行左睾丸和双边睾丸假切除术;第2组（I/R组）：通过以下方式诱发缺血再灌注损伤（顺时针720°旋转左侧睾丸2小时,2小时后复位）：第3组（I／R＋MEL组）：大鼠经诱导缺血再灌注损伤和一次性褪黑激素注射（50mgkg-1,i．p）。处理后离体分离各组大鼠双侧睾丸,用于检测睾丸组织中抗氧化过氧化氢酶、超氧化物歧化酶和谷胱甘肽过氧化物酶的活性,丙二醛、蛋白质羰基和一氧化氮的组织水平。较对照组,褪黑激素注射组同侧睾丸的脂质过氧化水平,相关酶活性降低,具有显著性（P〈0．05）,而在对侧的睾丸中相关酶活性变化无统计学意义（P〉0．05）。在对侧睾丸中,丙二醛水平改变具有明显统计学意义（P=0．009）。应用褪黑素能减轻老鼠同侧睾丸扭转所致缺血再灌注损伤的不利影响,而对于对侧睾丸,睾丸扭转影响不大。     

美洲大蠊粪便提取物抗氧化活性及其化学成分研究

[目的] 探究美洲大蠊粪便提取物的抗氧化活性和化学成分。[方法] 采用1,1-二苯基-2-三硝基苯肼（DPPH）自由基清除法测定美洲大蠊粪便提取物的抗氧化能力。综合利用溶剂提取法、大孔吸附树脂、制备高效液相色谱等分离纯化方法,对美洲大蠊粪便提取物中的化学成分进行提取分离,通过核磁共振波谱、质谱法鉴定化合物结构。[结果] DPPH法测试结果表明美洲大蠊粪便提取物具有明显的抗氧化活性,其半抑制浓度（IC₅₀）为44.53 μg/mL。从中分离得到12个化合物,依据物理性质及波谱数据鉴定结构分别为：邻苯二酚（1）、苯甲酸（2）、羟吲哚（3）、5-羟基吲哚啉-2-酮（4）、8-羟基喹啉-2-羧酸（5）、6-羟基-2-喹啉酮（6）、8-羟基-2-喹啉酮（7）、2-喹啉酮（8）、6-羟基-3,4-二氢-2-喹啉酮（9）、5-羟基-3,4-二氢-2-喹啉酮（10）、8-羟基-3,4二氢-2-喹啉酮（11）、3,4-二氢-2-喹啉酮（12）。[结论] 美洲大蠊粪便提取物具有明显的抗氧化活性,分离得到的化合物主要为喹啉酮类化合物。