Reliability and significance of DNA measurements in interphase nuclei and division figures in histological sections

DNA contents from single cells at interphase and division were analysed in histological sections and in imprints from 73 breast cancer specimens. Fetal livers from 18 terminations of normal pregnancies provided the standard for truly mitotic prophases, metaphases and telophases. The reliability of DNA quantities from image microphotometry was improved using paraffin-embedded tissue samples from which 4, 8 and 15 μm slices were Feulgen stained. Imprinted replicas from the mirror surface of each freshly cut specimen provided matching domains and represent the crucial approach in this project. A close positive relationship was observed between interphase nuclei in 8 μm sections and their imprinted counterparts (r=0.992; n=73). Interphase nuclei in 4 μm sections yielded insufficient DNA contents when compared with the imprints (r=0.815; n=21) and with endogenous lymphocyte nuclei. This 2 c DNA standard also calibrated 232 mitotic figures to 3.91±0.01 c in 15 μm sections from fetal liver. Prophases, metaphases and telophases were slightly scattered (coefficient of variation=0.04 each). The 0.09 c deficiency to plain 4.0 c was read as an artifact from sectioning. However, the methodical bias did not challenge the most irregular DNA distribution profiles recorded from chromosome division figures (CDFs) in 15 μm sections of breast cancers. Poorly differentiated and aggressive breast cancer (Auer type IV, Zetterberg type A) exhibited a 4.5 c exceeding rate of 82.24% from a total of 752 CDFs in 10 randomly selected cases. Well differentiated, slowly growing cancer with diploid interphase nuclei (Auer I, Zetterberg D) surprisingly showed a 4.5 c exceeding rate of 29.26% from a total of 173 mitoses and CDFs in 10 randomly selected cases. The bulk of data beyond the mitotic 4.0 c level discriminates biological bias from methodical impairment. We concluded that 8 μm sections are sufficient for human interphase nuclei, whereas a depth of 15 μm preserves intact mitoses and CDFs.     

颐年降压饮含药血清对自发性高血压大鼠内皮细胞增殖及PPAR-γ mRNA表达的影响

目的观察颐年降压饮含药血清对体外原代培养的自发性高血压大鼠(spontaneously hypertensiverats,SHR)内皮细胞增殖及PPAR-γmRNA表达的影响。方法取SHR主动脉内皮细胞进行原代培养,取3代后内皮细胞用于实验,SD大鼠40只随机分为正常血清对照组和颐年降压饮高、中、低剂量组,给与高脂饮食喂养,分别灌服生理盐水和高、中、低剂量颐年降压饮(分别含生药5.2 g/mL、2.6 g/mL、1.3 g/mL),给药20天麻醉后开始收集血清,经灭活后作用各组内皮细胞。MTT法检测不同浓度血清作用各组2、4、8、16、24、48 h细胞活性;RT-PCR法检测作用4、8、16、24 h内皮细胞PPAR-γmRNA表达情况。结果MTT检测OD值发现,4、8 h颐年降压饮高、中、低剂量组OD值均高于正常血清对照组,差异有统计学意义(P0.05),而颐年降压饮3剂量组间差异无统计学意义(P0.05);16 h颐年降压饮中剂量组OD值上升低于其他组,差异有统计学意义(P0.05);24 h各组OD值均下降,但颐年降压饮高、中剂量组下降比低剂量、正常血清对照组明显,差异有统计学意义(P0.05);48 h各组OD值继续下降,颐年降压饮高剂量组比正常血清对照组下降更明显(P0.05)。RT-PCR检测不同血清作用内皮细胞4 h时,各组PPAR-γmRNA表达差异无统计学意义(P0.05);8 h时颐年降压饮高剂量组PPARγmRNA表达明显低于其他各组(P0.05);16 h颐年降压饮各剂量组PPAR-γmR NA表达比正常血清对照组高(P0.05),其中颐年降压饮高剂量组PPARγmR NA表达最高,与其他组比较,差异有统计学意义(P0.01);24 h各组PPAR-γmR NA表达有所下降,但颐年降压饮低剂量组PPAR-γmRNA表达仍高于正常血清对照组(P0.05)。结论颐年降压饮对内皮细胞增殖呈双向调节作用,或许与调节PPAR-γmR NA表达有关。颐年降压饮所具有的上调及维持PPAR-γmRNA表达作用,可能是该方药具有保护血管内皮功能,降低血压的机制之一。     

A nanocleaner specifically penetrates the blood‒brain barrier at lesions to clean toxic proteins and regulate inflammation in Alzheimer's disease

Insurmountable blood‒brain barrier (BBB) and complex pathological features are the key factors affecting the treatment of Alzheimer''s disease (AD). Poor accumulation of drugs in lesion sites and undesired effectiveness of simply reducing Aβ deposition or TAU protein need to be resolved urgently. Herein, a nanocleaner is designed with a rapamycin-loaded ROS-responsive PLGA core and surface modification with KLVFF peptide and acid-cleavable DAG peptide [R@(ox-PLGA)-KcD]. DAG can enhance the targeting and internalization effect of nanocleaner towards neurovascular unit endothelial cells in AD lesions, and subsequently detach from nanocleaner in response to acidic microenvironment of endosomes to promote the transcytosis of nanocleaner from endothelial cells into brain parenchyma. Then exposed KLVFF can capture and carry Aβ to microglia, attenuating Aβ-induced neurotoxicity. Strikingly, rapamycin, an autophagy promoter, is rapidly liberated from nanocleaner in the high ROS level of lesions to improve Aβ degradation and normalize inflammatory condition. This design altogether accelerates Aβ degradation and alleviates oxidative stress and excessive inflammatory response. Collectively, our finding offers a strategy to target the AD lesions precisely and multi-pronged therapies for clearing the toxic proteins and modulating lesion microenvironment, to achieve efficient AD therapy.KEY WORDS: Alzheimer''s disease, Aβ-capturing, Autophagy, ROS-responsive, Anti-inflammatory, Blood‒brain barrier transcytosis, Microenvironment modulation, Lesion targeting     

青藤碱免疫抑制作用机制的研究进展

青藤碱是青藤Sinomenium acutum藤茎中的主要活性生物碱,具有显著的镇痛、抗炎、免疫抑制等药效作用,是一种应用前景良好的天然免疫抑制剂.大量研究表明青藤碱对众多免疫细胞(T细胞、单核/巨噬细胞、树突状细胞、肥大细胞)和免疫应答相关因子(细胞因子、活性氧、核因子-κB、细胞黏附分子)均具有免疫调节作用.通过综...     

Chronic Trypanosoma cruzi infection in the rat: Cyclophosphamide-induced recovery of adjuvant arthritis correlates with changes in the levels of lymph node T-lymphocytes and class II+ cells

We have previously reported that treatment with cyclophosphamide (Cy) reversed the partial resistance of chronically Trypanosoma cruzi-infected rats to adjuvant-induced arthritis (AA) and caused a slight enhancement of arthritis in controls, when given 48 h before induction. To ascertain whether this Cy effect could be associated with regional changes of immunocompetent cells, popliteal lymph nodes were studied for their T-cell subsets and cells carrying class II major histocompatibility (MHC) antigens (I-A and I-E molecules). Analysis at the time of arthritis induction revealed that infected rats receiving Cy 48 h earlier appeared to have recovered from the inverse balance of major T-cell subsets and showed I-E⁺ cells lowered to normal, whereas values from control rats remained unchanged by Cy treatment. Establishment of AA was associated with substantial changes in the phenotype of lymph node cells that drained the affected limb. Changes were equally recorded in control and infected arthritic rats, and consisted of a significant raise of CD4⁺ and I-A⁺ cells along with lowered numbers of CD8⁺ and I-E⁺ cells. Treatment with Cy lowered even further the levels of CD8⁺ cells, while causing no affectation in the number of CD4⁺ cells that remained increased as in the arthritic counterparts receiving no Cy. Comparative analysis of class II MHC⁺ cells in Cy-treated rats revealed an additional decrease of I-E⁺ cells in draining lymph nodes from infected and control rats, which coincided with a simultaneous increase in I-A⁺ cells in the uninfected group. It is suggested that a deletion of a regulatory T-cell subset as well as an improved presentation of arthritogenic peptides may at least underlie the Cy-induced enhancement of the arthritic response.     

Purine and pyrimidine nucleotide metabolism of vascular smooth muscle cells in culture

• 1.1. Cultures of vascular smooth muscle cells accumulate extracellular breakdown products of purine and pyrimidine nucleotides that, over 9 hr, represent 60±7 and 78±17%, respectively, of the intracellular nucleotide content.
• 2.2. The accumulation is stimulated during contracture with 20 mM KCl or 70 μM carbachol, consistent with the notion that both pyrimidine and purine nucleotides are involved in the energetics of smooth muscle contracture.
• 3.3. Because the intracellular levels of pyrimidine and purine nucleotides remain constant, it appears likely that rates of synthesis match the rates of release.
• 4.4. Ectonucleotidases are present that can degrade ATP, UTP, and CTP. High-energy nucleotides may be the primary products released.