低氧对培养的不同内径的肺动脉平滑肌细胞增殖的影响

目的和方法：分离培养三种不同内径的肺动脉平滑肌细胞（PASMCs）,用^3H－TdR掺入速率和细胞计数作为细胞增殖的指标,观察低氧对其增殖作用的影响。结果：低氧对三种不同内径的PASMCs（内径分别为＞1000μm、500－800μm、300-400μm）增殖促进作用显著不同,其^3H－TdR掺入速率和细胞计数分别增加23.5％和11.1％、60.0％和33.8％、141.4％和52.0％,选择对低氧最敏感的PASMCs（内径为300－400μm）,进一步探讨低氧促PASMCs增殖作用的细胞机制：钙拮抗剂verapail、蛋白激酶C抑制剂staurosporine(Stau)和细胞Na-H交换抑制剂amiloride可显著降低低氧情况下PASMCs^3H－TdR掺入速率和细胞计数。结论：低氧对三种不同内径的PASMCs增殖促进作用显著不同; Ca^2 、蛋白激酶C和Na^2 －H^ 交换的激活,可能是低氧促PASMCs增殖的重要胞内信息转导机制。     

An overview of epigenetics and chemoprevention

It is now appreciated that both genetic alteration, e.g. mutations, and aberrant epigenetic changes, e.g. DNA methylation, cause cancer. Epigenetic dysregulation is potentially reversible which makes it attractive as targets for cancer prevention. Synthetic drugs targeting enzymes, e.g. DNA methyltransferase and histone deacetylase, that regulate epigenetic patterns are active in clinical settings. In addition, dietary factors have been suggested to have potential to reverse aberrant epigenetic patterns. Uncovering the human epigenome can lead us to better understand the dynamics of DNA methylation in disease progression which can further assist in cancer prevention.     

A computer model of oxygen dynamics in human colon mucosa: implications in normal physiology and early tumor development

Based on the geometry of the colon mucosa, we built a model to compute the oxygen supply, the oxygen diffusion across the interstitial matrix, and the oxygen consumption by cryptal and stromal cells. By using an iterative algorithm, we have been able to solve a set of discretized (time and space) oxygen balance equations and determine the three-dimensional distribution of pO₂ in the mucosa. Although significant longitudinal and radial pO₂ variations were found, cells appeared to operate at their maximum respiratory capacity, regardless of their location in the tissue. The estimated oxygen extraction fraction was 47%, while the capillary oxygen permeability was 1.57×10⁻⁵ cm m s⁻¹. We concluded that cellular metabolism in normal colon mucosa is not limited by oxygen supply, thus prompting the idea that oxygenation does not determine the characteristic microenvironments occurring along the normal Lieberkhün crypts. In an extended model, simulation of an aberrant crypt focus (ACF)—the earliest stage in the adenomatous polyp-carcinoma sequence—showed instead that respiratory activity decreased when the capillary array symmetry is disrupted due to the ACF growth. A unified explanation about the alternative of a hypoxic-independent and/or a hypoxic-dependent early angiogenic response associated to the development of ACF is proposed.     

Cryopreservation does not alter the allogenicity and development of vasculopathy in post-transplant rat aortas

BACKGROUND: Cryopreservation is a valuable technique for storing heart valve and vascular allografts. However, the biological ramifications of cryopreservation are still unclear; therefore, using animal experiments we assessed how 'cryopreservation' influences graft allogenicity and cell viability. METHODS: Thoracic aortas of Lewis rats were prepared as fresh (F) or cryopreserved (CP) grafts, and implanted into the infrarenal aorta of Lewis or Brown Norway rats (BNs). The grafts and spleens were harvested at post-operative day 7 and 28 (POD7, POD28) for analyses. RESULTS: First, the systemic immune response to transplantation was estimated by mixed lymphocyte reaction analyses using spleen cells from na?ve or recipient BNs. The alloreactivity of the recipients increased to 1.5 times that of the na?ve BNs at POD7 and POD28, when stimulated by mitomycin C-treated Lewis spleen cells. Second, local immune response was estimated by TNFalpha, IFNgamma, and iNOS mRNA expression in the grafts by quantitative PCR, which revealed 20- to 40-fold increases at POD28 after allotransplantation. Third, endothelial cell viability was estimated by endothelial NOS mRNA expression level: it was similar and highest in F and CP grafts before transplantation then significantly decreased after both syngeneic and allogeneic transplantation. Finally, intimal hyperplasia, expressed by I/M ratio, developed over time after allotransplantation, reaching 2.5 times the thickness of F grafts before transplantation. The results of these experiments revealed no difference between F and CP grafts before and after transplantation. CONCLUSION: Cryopreservation did not modify the allogenicity of vascular allografts and had minimal adverse impacts on graft cell viability.     

Cryptic growth strategies of the Cambrian coral Cambroctoconus: flexible modes of budding and growth in immediate response to available space

The Cambrian coral Cambroctoconus occurs selectively in the crypts of calcimicrobe Epiphyton reefs of the Zhangxia Formation (Miaolingian) in Shandong Province, North China. These cryptobionts preferentially grow laterally and/or downward, in some cases showing pendent growth from the ceilings of the reef framework. The upside-down growth is clearly shown by the downward-oriented aperture and the presence of fork-like holdfasts at its base. The coral aggregations reveal two cryptic growth strategies: one involves the prevalence of far smaller individuals in vertically narrow spaces; the other involves the predominance of modular individuals in large cavernous spaces. Offset individuals frequently appear projecting downward and are connected to each other in a chain-like fashion. Individuals often undergo rejuvenescence laterally and downward, when the growth directions may change. Therefore, the size and modularity of individuals and the direction of budding depend largely upon the cryptic microenvironments available at the time. The cryptobionts make the best use of vacant spaces by modifying the location of budding and altering their growth directions through rejuvenescence. The cryptic growth strategies found in Cambroctoconus indicate a certain degree of morphological variability in the modules. More importantly, they indicate that the individuals flexibly and exquisitely utilized the microbial crypts that were still predominant even during the middle Cambrian. These modes of cryptic growth demonstrate the age-specific exploitation of niches by sessile skeletal organisms that was facilitated by the development of a firm attachment structure.     

Validation of a total testosterone assay using high-turbulence liquid chromatography tandem mass spectrometry: Total and free testosterone reference ranges

Accurate measurement of testosterone concentration is of critical importance when diagnosing and treating male hypogonadism, congenital adrenal hyperplasia, premature or delayed puberty, and androgen excess in polycystic ovary syndrome or other virilizing conditions. However, some assays have inherent limitations and biases that affect measurement of low-testosterone values. Therefore, we developed a highly specific online mass spectrometry method. Sera were extracted online using high-turbulence flow liquid chromatography coupled to analytical HPLC and atmospheric pressure chemical ionization tandem mass spectrometry (HTLC-APCI-MS/MS). Analyte ions were monitored by multiple reaction monitoring (MRM). Total analysis time was 1.15 min per sample when using the multiplexing system. Testosterone concentrations were measured directly from 150 μL of serum or plasma without derivatization or liquid-liquid extraction. The lower limit of quantification was 0.3 ng/dL, and the assay was linear up to 2000 ng/dL. The method compared very well with an established RIA: y = 1.02x + 1.5, r² = 0.994. Comparison with a platform immunoassay confirmed the previously reported ICMA positive bias at low concentrations. Male and female adult and pediatric reference ranges were developed for this very sensitive and accurate high-throughput LC-MS/MS method. This method is suitable for measuring the expected low-testosterone concentrations seen in women, children, and hypogonadal males and for monitoring testosterone suppressive therapy in prostate cancer patients.     

Zinc and cadmium analysis in human prostate neoplasms

The objective of this study was to test the hypothesis that prostatic cancer is associated with the changes of zinc (Zn) and cadmium (Cd) concentration. Normal prostate, benign prostatic hyperplasia (BPH), and prostatic carcinoma (PCA) were analyzed for Zn and Cd by atomic absorption spectrometry. Cd level was measured using a graphite furnace and Zn level was measured by flame mode. Metal content was assessed in whole tissues and in nuclear, plasma membrane, and cytosolic fractions. An increase of Zn content in BPH, but a decrease in PCA as compared to normal tissue, was observed. Cd concentration appeared to be higher in BPH and PCA than in normal tissue. No correlation between Zn and Cd level was found in BPH specimens obtained from the same patients. Probability values ofp ≤0.05 were considered to indicate significant differences. Obtained results seem to support the hypothesis of Cd carcinogenicity and preventing function of Zn in prostatic cancer. Plasma membrane fraction corresponding to lysosomal, mitochondrial, and microsomal subcellular compartments are probably critical in Zn and Cd participation in human prostate neoplasms.     

经尿道前列腺电切(TURP)联合输尿管镜钬激光碎石术治疗前列腺增生症(BPH)合并膀胱结石的疗效观察

目的:观察分析经尿道前列腺电切(TURP)联合输尿管镜钬激光碎石术治疗前列腺增生症(BPH)合并膀胱结石的效果。方法:本组61例患者先行膀胱结石钬激光碎石,然后采用经尿道前列腺电切术(TURP)治疗前列腺增生症。结果:61例一次性治疗成功,术后结石无残留,排尿情况较前明显改善,IPSS评分均分由24.4分降到9.4分,最大尿流率由7.2 mL/s上升到19.5 mL/s。结论:钬激光碎石及TURP同期治疗前列腺增生合并膀胱结石是安全有效的方法。     

BPH-1通过分泌PGE2上调前列腺间质细胞ERRα的表达

摘要 雌激素受体相关受体α（estrogen receptor-related receptor α,ERRα）是一类可以直接或间接参与雌激素应答反应的孤儿核受体,它与雌激素受体（estrogen receptor）在结构上有很强的同源性．雌激素效应在良性前列腺增生（benign prostatic hyperplasis,BPH）的发生和发展中起着重要的作用．通常,孤儿核受体的转录活性多受一些非经典激素如维生素A衍生物、前列腺素类、固醇的调控．本文研究前列腺上皮细胞分泌的活性因子对间质细胞ERRα表达调控的分子机制．收集前列腺增生上皮细胞系BPH-1和前列腺癌上皮细胞系DU-145的条件培养液（condition medium,CM）培养的间质细胞,采用实时定量RT-PCR和Western 印迹法检测前列腺间质细胞（prostate stromal cells,PrSCs）中ERRα的表达,筛选CM中影响ERRα表达的活性因子．研究结果显示,BPH-1的CM可以上调ERRα的表达,而DU-145的CM对ERRα的表达没有影响;BPH-1中合成前列腺素E2 (prostaglandin E2, PGE2)的限速酶——环氧合酶2（cyclooxygenase-2, COX-2）的mRNA表达水平和PGE2的分泌水平明显高于DU-145中COX-2表达水平和PGE2分泌水平;用经添加COX-2抑制剂NS-398的培养液处理BPH-1,其CM中PGE2的浓度明显下降,并失去了对ERRα表达的上调作用;添加PGE2可上调间质细胞中ERRα的表达．结果表明,BPH-1通过分泌PGE2促进间质细胞ERRa的表达,提示：在良性前列腺增生的发生和发展中,上皮细胞的旁分泌作用可促进间质细胞由ERRα介导的雌激素效应．     

TRPC3-mediated Ca2+ influx contributes to Rac1-mediated production of reactive oxygen species in MLP-deficient mouse hearts

Obesity-related metabolic abnormalities, including chronic inflammation and oxidative stress, increase the risk of colorectal cancer. Dysregulation of the renin–angiotensin system (RAS) also plays a critical role in obesity-related metabolic disorders and in several types of carcinogenesis. In the present study, we examined the effects of an angiotensin-converting enzyme (ACE) inhibitor and angiotensin-II type 1 receptor blocker (ARB), both of which inhibit the RAS, on the development of azoxymethane (AOM)-initiated colonic premalignant lesions in C57BL/KsJ-db/db (db/db) obese mice. Male db/db mice were given 4 weekly subcutaneous injections of AOM (15 mg/kg body weight), and then, they received drinking water containing captopril (ACE inhibitor, 5 mg/kg/day) or telmisartan (ARB, 5 mg/kg/day) for 7 weeks. At sacrifice, administration of either captopril or telmisartan significantly reduced the total number of colonic premalignant lesions, i.e., aberrant crypt foci and β-catenin accumulated crypts, compared to that observed in the control group. The expression levels of TNF-α mRNA in the colonic mucosa of AOM-treated db/db mice were decreased by captopril and telmisartan. Captopril lowered the expression levels of TNF-α, IL-1β, IL-6, and PAI-1 mRNAs, while telmisartan lowered the expression levels of COX-2, IL-1β, IL-6, and PAI-1 mRNAs in the white adipose tissues of these mice. In addition, these agents significantly reduced the levels of urinary 8-OHdG, a surrogate marker of oxidative damage to DNA, in the experimental mice. These findings suggested that both ACE inhibitor and ARB suppress chemically-induced colon carcinogenesis by attenuating chronic inflammation and reducing oxidative stress in obese mice. Therefore, targeting dysregulation of the RAS might be an effective strategy for chemoprevention of colorectal carcinogenesis in obese individuals.