Reshaping of T-lymphocyte compartment in adult prepubertaly ovariectomised rats: A putative role for progesterone deficiency

This study explores the role of ovarian hormones in the phenotypic shaping of peripheral T-cell pool over the reproductive lifespan of rats. For this purpose, 2-month-old prepubertally ovariectomised (Ox) rats, showing oestrogen and progesterone deficiency, and 11-month-old Ox rats, exhibiting only progesterone deficiency, were examined for thymus output, and cellularity and composition of major TCRαβ+ peripheral blood lymphocyte (PBL) and splenocyte subsets. Although ovariectomy increased thymic output in both 2- and 11-month-old rats, the count of both CD4+ and CD8+ PBLs and splenocytes increased only in the former. In the blood and spleen of 11-month-old Ox rats only the count of CD8+ cells increased. Although ovariectomy affected the total CD4+ count in none of the examined compartments from the 11-month-old rats, it increased CD4+FoxP3+ PBL and splenocyte relative proportions over those in the age-matched controls. The age-related differences in the cellularity and the major subset composition in Ox rats were linked to the differences in the ovarian steroid hormone levels registered in 2- and 11-month-old rats. The administration of progesterone to Ox rats during the seven days before the sacrificing confirmed contribution of this hormone deficiency to the ovariectomy-induced changes in the TCRαβ+ PBL and splenocyte pool from 11-month-old rats. The expansion of the CD8+ splenocyte subset in the 11-month-old Ox rats reflected increases in cellularity of memory and, particularly, naïve cells. This was due to greater thymic output of CD8+ cells and homeostatic proliferation than apoptosis in 11-month-old Ox rats when compared with age-matched sham-Ox control rats. The homeostatic changes within CD8+ splenocyte pool from 11-month-old Ox rats, most likely, reflected the enhanced splenic IL-7 and TGF-β mRNA expression. Overall, in adult female rats, circulating oestrogen and progesterone provide maintenance of T-cell counts, a diversity of T-cell repertoire, and the main T-cell subset composition in the periphery. Progesterone deficiency affects mainly the CD8+ lymphocyte compartment through increasing thymic CD8+ cell export and upsetting homeostatic regulation within the CD8+ splenocyte pool. These alterations were reversible through progesterone supplementation.     

Myeloperoxidase gene polymorphism predicts fibrosis severity in women with hepatitis C

Oxidative stress plays an important role on liver fibrosis progression in the course of hepatitis C virus (HCV) infection. Myeloperoxidase (MPO) is an enzyme released by neutrophils and macrophages, responsible for generating hypochlorous acid and reactive oxygen species (ROS) that may lead to liver injury in HCV infection. On the other hand, antioxidant enzymes such as manganese superoxide dismutase (SOD) controls ROS-mediated damage. The aim of the present study was to investigate the influence of MPO G-463A and SOD2 Ala16Val polymorphisms in the severity of liver fibrosis in individuals with chronic HCV infection. The present study included 270 patients with chronic HCV recruited from the Gastrohepatology Service of the Oswaldo Cruz University Hospital/Liver Institute of Pernambuco (Recife, Northeastern Brazil). All patients underwent liver biopsy, which was classified according METAVIR score. The SNPs were determined by real-time PCR. After multivariate analysis adjustment, the GG genotype of MPO and the presence of metabolic syndrome were independently associated with fibrosis severity in women (P = 0.025 OR 2.25 CI 1.10–4.59 and P = 0.032 OR 2.32 CI 1.07–5.01, respectively). The presence of the GG genotype seems to be a risk factor for fibrosis severity in women with HCV.     

Increased fracture risk in patients with type 2 diabetes mellitus: An overview of the underlying mechanisms and the usefulness of imaging modalities and fracture risk assessment tools

Type 2 diabetes mellitus has recently been linked to an increased fracture risk. Since bone mass seems to be normal to elevated in patient with type 2 diabetes, the increased fracture risk is thought to be due to both an increased falling frequency and decreased bone quality. The increased falling frequency is mainly a result of complications of the disease such as a retinopathy and polyneuropathy. Bone quality is affected through changes in bone shape, bone micro-architecture, and in material properties such as bone mineralization and the quality of collagen. Commonly used methods for predicting fracture risk such as dual energy X-ray absorptiometry and fracture risk assessment tools are helpful in patients with type 2 diabetes mellitus, but underestimate the absolute fracture risk for a given score. New imaging modalities such as high resolution peripheral quantitative computed tomography are promising for giving insight in the complex etiology underlying the fragility of the diabetic bone, as they can give more insight into the microarchitecture and geometry of the bone. We present an overview of the contributing mechanisms to the increased fracture risk and the usefulness of imaging modalities and risk assessment tools in predicting fracture risk in patients with type 2 diabetes.     

Role of CD8 T-cell in immune response to tuberculosis-specific antigen in QuantiFERON-TB Gold Plus

Recent contacts with active TB (tuberculosis) patients were screened for latent tuberculosis infection (LTBI) because of their greater relative risk for developing active TB. QuantiFERON®-TB Gold Plus (QFT-Plus) offers two TB-specific antigen tubes (TB1 and TB2). TB1 elicits CD4 T-cell responses, and TB2 is designed to elicit both CD4 and CD8 T-cell responses. These mechanisms could be useful for estimating the role of CD8 T-cell immune responses to TB-specific antigens. To estimate the QFT-Plus capability to diagnose LTBI, a prospective cross-sectional study was conducted. A total of 412 TB contacts (median age 44 years) were enrolled. The positivity rates of QFT-Plus, TB1 and TB2 were 7.5%, 6.3% and 7.2%, respectively. TB2 showed a higher positivity rate compared to TB1, but without significant difference. The interferon (IFN)-γ productions of TB1 and TB2 were well correlated (r = 0.934, P < 0.001). The ratio of IFN-γ production between TB1 and TB2 showed a median (interquartile range) of IFN-γ_{[QFT-Plus TB2]}/IFN-γ_{[QFT-Plus TB1]} of 1.09 (0.91–1.36). CD8 T-cell immune response to TB-specific antigens varied among subjects. CD8 T-cell potentially boosts IFN-γ productions in QFT-Plus and results in the detection of more persons with LTBI. However, there was no significant difference in the positivity rates of QFT-Plus TB1 and TB2 in our TB contact investigation. The contribution of CD8 T-cells might be small for the diagnosis of LTBI. The analysis of IFN-γ production in both TB1 and TB2 would lead to further analysis of the TB immune response, and especially that caused by CD8 T-cells.     

深部电刺激伏隔核对吗啡成瘾大鼠复吸后伏隔核内γ-氨基丁酸含量变化的影响

目的研究深部电刺激(deep brain stimulation,DBS)双侧伏隔核对吗啡成瘾大鼠复吸后伏隔核内γ-氨基丁酸(γ-aminobutyric Acid,GABA)含量的影响。方法手术前使用条件性位置偏爱试验(conditionedplace preference,CPP)筛选无自然偏爱大鼠,随机分组后DBS组行电极植入术,术后10天采用固定剂量吗啡皮下注射(10mg.Kg-1)建立吗啡成瘾大鼠模型(使用CPP证实)。通过改进的DBS电路进行电刺激(频率130Hz,电流300uA,电压1V,1h.d-1),在不同的时间点使用CPP证实DBS组大鼠戒断成功后再皮下给予小剂量吗啡(3mg.Kg-1),24h后使用CPP验证吗啡成瘾大鼠复吸模型建立成功。CPP试验结束后于冰台上按大鼠脑立体定位图谱取伏隔核行高效液相色谱法(high performance liquid chromatography,HPLC)测定GABA含量。结果①皮下注射固定剂量吗啡能够使大鼠成瘾,DBS能够有效抑制吗啡复吸行为;②morphine+DBS组大鼠伏隔核内GABA含量与吗啡组,morphine+sham组差异明显。结论 DBS双侧伏隔核使吗啡成瘾大鼠复吸后伏隔核内GABA含量增加。     

肺结核患者支气管肺泡灌洗液细胞因子的水平及其动态变化

目的研究肺结核患者支气管肺泡灌洗液(BALF)中γ干扰素(IFN-γ)、白细胞介素12(IL-12)、白细胞介素4(IL-4)、白细胞介素10(IL-10)水平的变化及其临床意义。方法采用双抗体夹心ELISA法检测60例活动性肺结核患者、33例非活动性肺结核患者BALF中IFN-γ、IL-12、IL-4、IL-10的水平,对其中32例活动性肺结核患者抗结核治疗后的上述细胞因子水平进行随访。组间比较采用t检验。结果活动性肺结核病例BALF中IFN-γ、IL-12的水平要显著高于非活动性肺结核病例(P0.01),而IL-4、IL-10的水平两组间无明显差异(P0.05)。菌阳及重症肺结核的IFN-γ、IL-4、IL-12水平要明显高于菌阴及轻症(P0.05),IL-10值无明显差异(P0.05)。32例活动性肺结核的病例在抗痨治疗一个月后复查支气管镜,BALF中IFN-γ、IL-4、IL-12的水平均较治疗前有明显的下降(P0.01)。而IL-10值亦有所下降,但差异无统计学意义(P0.05)。结论肺结核患者BALF中IFN-γ、IL-4、IL-12水平的检测可作为了解病灶活动性、严重程度、监测疗效的参考。     

γH2AX在HPV16阳性宫颈鳞癌组织中的表达及意义

目的 探讨γH2AX在HPV16阳性宫颈鳞癌组织中的表达及意义.方法 对74例宫颈鳞癌组织通过DNA提取,PCR检测,分析HPV的感染情况并筛选HPV16阳性宫颈癌组织;进而对HPV16阳性的宫颈癌石蜡组织连续切片HE染色明确组织型别,进行HPV16 DNA原位杂交检测HPV定位、免疫组化检测γH2 AX和p16蛋白的表达;最后选取30例典型的包括从正常宫颈组织、宫颈上皮内瘤变到宫颈原位癌渐变的组织切片,对比HPV DNA定位与γH2 AX和p16蛋白的表达,分析γH2 AX作为HPV感染导致宫颈癌发生过程中生物标记物的可行性.结果 经PCR扩增证明HPV感染率为98.65％,HPV16是最常见的型别占74.32％;原位杂交结果显示正常宫颈组织和CIN Ⅰ检测不到HPV16 DNA的存在,CINⅡ中HPV主要为游离型存在,随着宫颈病变的加重,HPV16 DNA逐渐出现整合形式;p16和γH2AX的表达均随着宫颈上皮病变级别的增加其阳性表达率增高,HPVDNA和γH2AX的表达均以颗粒细胞层和棘细胞层为主,定位具有一致性,HPV DNA和p16的表达定位不具有一致性.结论 γH2AX作为DNA损伤激活的重要蛋白,可作为HPV16感染致宫颈癌发生过程中的生物标记物.     

γ-干扰素对过氧化氢诱导血管内皮氧化应激损伤的作用研究

目的 观察γ-干扰素(IFN-γ)对血管内皮氧化应激损伤的保护作用,并评价26S蛋白酶体在其中的作用.方法 建立由过氧化氢(H2O2)诱导的血管内皮氧化应激损伤细胞及离体器官模型,以细胞培养上清液中乳酸脱氢酶(LDH)及丙二醛(MDA)浓度评价血管内皮细胞(VEC)的损伤程度,以内皮依赖性血管松弛反应评价离体器官水平VEC的损伤程度.结果 H2O2可呈剂量依赖性和时间依赖性引起VEC损伤,表现为细胞培养上清液中LDH及MDA浓度增加(P<0.05或P<0.01),由乙酰胆碱(Ach)诱导的血管内皮依赖性松弛反应明显降低,表现为10-5 mol/L Ach引起血管最大舒张反应由(95.82±9.25)%降至(12.61±2.96)%(P<0.01);采用20 μg/L IFN-γ预孵育VEC 48 h后可明显降低由H2O2引起的LDH及MDA生成(P均<0.05),改善内皮依赖性血管松弛反应,由Ach诱导的血管最大舒张反应增至(72.68±18.82)%(P<0.01);26S蛋白酶体抑制剂lactacystin可取消由IFN-γ诱导的内皮抗氧化保护作用.结论 IFN-γ可诱导血管内皮对氧化应激的保护,其机制与26S蛋白酶体有关.