Inhibition of normal human lung fibroblast growth by beryllium

Inhalation of particulate beryllium (Be) and its compounds causes chronic Be disease (CBD) in a relatively small subset (1–6%) of exposed individuals. Hallmarks of this pulmonary disease include increases in several cell types, including lung fibroblasts, that contribute to the fibrotic component of the disorder. In this regard, enhancements in cell proliferation appear to play a fundamental role in CBD development and progression. Paradoxically, however, some existing evidence suggests that Be actually has antiproliferative effects. In order to gain further information about the effects of Be on cell growth, we: (1) assessed cell proliferation and cell cycle effects of low concentrations of Be in normal human diploid fibroblasts, and (2) investigated the molecular pathway(s) by which the cell cycle disturbing effects of Be may be mediated. Treatment of human lung and skin fibroblasts with Be added in the soluble form of BeSO₄ (0.1–100 μM) caused inhibitions of their growth in culture in a concentration-dependent manner. Such growth inhibition was found to persist, even after cells were further cultured in Be²⁺-free medium. Flow cytometric analyses of cellular DNA labeled with the DNA-binding fluorochrome DAPI revealed that Be causes a G₀–G₁/pre-S phase arrest. Western blot analyses indicated that the Be-induced G₀–G₁/pre-S phase arrest involves elevations in TP53 (p53) and the cyclin-dependent kinase inhibitor CDKN1A (p21^Waf-1,Cip1). That Be at low concentrations inhibits the growth of normal human fibroblasts suggests the possibility of the existence of abnormal cell cycle inhibitory responses to Be in individuals who are sensitive to the metal and ultimately develop CBD.     

氧化铍致大鼠肺氧化损伤与枸杞多糖的保护作用

目的 探讨氧化铍(BeO)诱发的肺损伤及枸杞多糖(lycium barbarum polysaccharides,LBP)的保护作用.方法 选用SPF健康雄性大鼠128只,随机分为空白对照组(8只)、生理盐水组(24只)、BeO染毒组(32只,染毒剂量10 mg/kg)、BeO+LBP低剂量(10 mg/kg,32只)、BeO+LBP高剂量组(40 mg/kg,32只).动物染毒选用非暴露式气管一次注人法,LBP干预采用灌胃法.试剂盒检测大鼠肺组织中缺氧诱导因子-1(HIF-1)、血管内皮生长因子(VGEF)和血红素氧合酶(HO-1)的含量.制作肺组织病理切片观察病理改变,电子显微镜观察肺脏超微结构改变.结果 BeO染毒组大鼠肺组织出现炎性细胞浸润,间质增厚以及细胞、细胞器超微结构等病理学改变;经LBP干预后上述病理变化减轻.染毒40d,与对照组比较,BeO染毒组、BeO+LBP低剂量组HO-1的含量升高,差异有统计学意义(P＜0.05或P＜0.01);染毒80 d,BeO染毒组、BeO+LBP低剂量组HO-1的浓度与对照组比较降低,差异有统计学意义(P＜0.05或P＜0.01).染毒40 d,BeO染毒组、BeO+LBP干预组,染毒60、80 d,BeO染毒组HIF-1含量均高于对照组,差异有统计学意义(P＜0.05或P＜0.01);染毒40、80 d,BeO染毒组、BeO+LBP干预组,染毒60 d,BeO染毒组VEGF含量与对照组比较升高,差异有统计学意义(P＜0.05或P＜0.01).经LBP干预40d后,BeO+LBP高剂量组HO-1的含量低于BeO染毒组,差异有统计学意义(P＜0.05);干预80 d后,BeO+LBP高剂量组HO-1的含量高于BeO染毒组,差异有统计学意义(P＜0.05);干预60 d后,BeO+LBP高剂量组、干预80 d后,BeO+LBP干预组HIF-1含量低于BeO染毒组,差异有统计学意义(P＜0.01);干预40 d后,BeO+LBP干预组、干预60 d后,BeO+LBP高剂量组VEGF的含量与BeO染毒组比较降低,差异有统计学意义(P＜0.05或P＜0.01).结论 BeO可引起大鼠肺组织中氧化损伤相关基因表达异常,LBP具有保护作用.     

Toxicokinetic and toxicodynamic studies of beryllium

The question of dose-effect relations of berylliosis was examined by measuring the Be-concentration in blood and urine, as well as the immunological behaviour of T-lymphocytes for a group of occupationally exposed men (< 8 ng Be/m³,4–6 h daily) and a non-exposed control group. Normal values 1.0 ± 0.4 ng Be/g(n = 10) in blood and 0.9 ± 0.5 ng Be/g(n = 10)in urine were found by an optimized flameless atomic absorption spectrometry method. The corresponding values for the exposed group (n = 8) showed a mean increase of a factor of 4. The preferential enrichment of Be in the prealbumin and in the-globulin fractions was determined by a preparative isotachophoretic column with physiological pH conditions, especially developed for this application. The Be-specific stimulation of the T-lymphocytes of the exposed group was increased significantly.In blood and urine samples of exposed (2–40 mg Be/m³ as Be(NO₃)₂)Wistarrats and guinea pigs Be values up to 36 ng Be/g in serum and up to 300 ng Be/g in urine were determined. After Be exposure, guinea pig serum showed a significant increase in the-globulins after the isotachophoretical separation of the serum proteins, which could not be correlated with increased Be-levels in this fraction. 70% of the total Be (10–100 ng/g serum) were detected in the prealbumin, only about 1% in the-globulin fraction. The same results were found in serum samples with in vitro addition of He. The lymphocyte transformation rates for the exposed animals were increased. Skin tests were found to be positive in 70% for exposed rats and in 50–70% for guinea pigs.

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Zusammenfassung Zur Frage der Dosis-Wirkungs-Relation der Berylliose wurde sowohl der Verlauf der Be-Konzentration in Blut und Urin, als auch das immunologische Verhalten der T-Lymphozyten bei einer Gruppe beruflich exponierter Menschen (< 8 ng Be/m³, 4–6 h täglich) und einer nichtexponierten Kontrollgruppe geprüft. Mit Hilfe der optimierten flammenlosen Atomabsorptionsspektrometrie wurden als Normalwerte l,0 ± 0,4 ng Be/g (n = 10) in Blut und 0,9 ± 0,5 ng Be/g (n = 10) in Urin gefunden. Die exponierte Gruppe (n = 8) wies einen mittleren Anstieg um das 4fache auf. Die bevorzugte Anreicherung des Berylliums im Präalbumin- und-Globulinbereich wurde mit einer speziell entwickelten präparativen Isotachophoresesäule mit physiologischen Trenn-pH-Bedingungen nachgewiesen. Die Prüfung der spezifischen Stimulation der T-Lymphozyten ergab gegenüber der Kontrollgruppe eine signifikant erhöhte Transformationsrate.Die Untersuchung von Blut- und Urinproben Be exponierter Wistarratten und Meerschweinchen (2–40 mg Be/m³ als Be(NO₃)₂-Aerosol) ergab Be-Werte im Serum bis 36 ng Be/g, in Urin bis 300 ng Be/g. Die Menge der isotachophoretisch getrennten Fraktion der-Globuline von Meerschweinchen war nach der Exposition erhöht und nicht mit erhöhten Be-Gehalten in dieser Fraktion korrelierbar. Wie bei der in vitro-Zugabe von Be zu Vollblut befand sich das Be (10–100 ng/g Serum) zu 70% in der Präalbuminfraktion und nur zu etwa 1% im-Globulin. Die Lymphozytentransformationsrate war bei exponierten Tiergruppen erhöht, die zusätzlich durchgeführten Hautteste waren bei Ratten zu 70% und bei Meerschweinchen zu 50–70% positiv.

     

Occupational exposure to beryllium and cancer risk: A review of the epidemiologic evidence

There is controversy on whether occupational exposure to beryllium causes lung cancer. We conducted a systematic review of epidemiologic studies on cancer among workers exposed to beryllium, including a study of seven U.S. production plants which has been recently updated, a study of patients with beryllium disease (largely overlapping with the former study) and several smaller studies. A small excess mortality from lung cancer was detected in the large cohort, which was partially explained by confounding by tobacco smoking and urban residence. Other potential confounders have not been addressed. The excess mortality was mainly among workers employed (often for a short duration) in the early phase of the manufacturing industry. There was no relation with duration of employment or cumulative exposure, whereas average and maximum exposure were associated with lung cancer risk. The use of lagged exposure variables resulted in associations with lung cancer risk; however, these associations were due to confounding by year of birth and year of hire. The studies of beryllium disease patients do not provide independent evidence and the results from other studies do not support the hypothesis of an increased risk of lung cancer or any other cancer. Overall, the available evidence does not support a conclusion that a causal association has been established between occupational exposure to beryllium and the risk of cancer.     

铍病豚鼠BALF中纤维粘连蛋白,层粘连蛋白和磷脂的变化

以氧化铍（ＢｅＯ）气道染毒方法制备实验性豚鼠铍病模型。用间接酶免疫吸附法测定铍病豚鼠支气管肺泡灌洗液（ＢＡＬＦ）中纤维粘蛋白（ＦＮ）、层粘连蛋白（ＬＭ）水平的变化，结果表明染毒后１周豚鼠ＢＡＬＦ中ＦＮ明显升高，染毒后１０周ＬＭ有下降趋势。用高效液相色谱（ＨＰＬＣ）法测定染毒豚鼠ＢＡＬＦ中磷脂（ＰＬ）组分的变化，初期为ＰＩ和ＰＥ下降，尔后逐渐恢复。     

铍对口腔链球菌细胞膜元素含量及过氧化氢产量的影响

目的:研究铍离子(Be2+)对口腔链球菌细胞膜元素含量及抗菌性能的影响,探讨镍铬合金修复体对牙周损伤的微生物学机制.方法:含有不同浓度(5mg/L、10mg/L、20mg/L和40mg/L)Be2+的口腔链球菌培养液厌氧培养24h.X线能谱仪分析细胞膜元素含量变化,ABTS-HRP法检测细菌产生H2O2的能力.采用SPSS11.0软件包对数据进行单因素方差分析.结果:口腔链球菌细胞膜钙元素含量减少,钠元素先升高后降低,磷元素升高.Be2+浓度为40mg/L时,口腔链球菌H2O2产量显著下降(P＜0.05).结论:Be2+会改变口腔链球菌细胞膜元素含量,降低H2O2产量,从而导致修复体周围正常微生态环境失衡,引起牙周疾病.     

小鼠腹腔注射硫酸铍的病理形态学观察

目的研究腹腔注射硫酸铍(BeSO₄·4H₂O)对小鼠主要脏器的损害作用。方法将30只6周龄昆明(KM)雄性小鼠随机分为三组,分别予以不同剂量硫酸铍生理盐水溶液腹腔注射染毒,隔日一次,染毒两周。观察主要脏器的病理组织学变化并测定脏器系数。结果与对照组比较,染毒组心、脾、肾、睾丸脏器系数无显著差异,肝、肺脏器系数差异有统计学意义(P<0.05);对照组肺、肝病理学组织检查未见异常,低剂量组小鼠肺组织可见淤血、出血、支气管扩张出血,肺泡腔内有少量炎性渗出物、支气管周围炎、间质性肺炎、小叶性肺炎等;高剂量组小鼠肺组织可见支气管扩张出血,支气管腔内有大量炎性渗出物,支气管周围肺泡扩张,间质性肺炎、小叶性肺炎、融合性小叶性肺炎;低剂量组肝细胞水肿,可见点状坏死和小灶性坏死;高剂量组小鼠肝组织损伤严重,肝细胞排列紊乱,多数肝细胞呈细胞水肿, 肝细胞胞质成空泡状,可见明显的点状坏死和小灶性坏死, 并伴有炎细胞浸润,坏死区周围肝细胞细胞质呈嗜酸性变,轻度核固缩,并且肝细胞呈不同程度的胞质疏松,肝窦以及肝中央静脉扩张有广泛变性、坏死等病理改变。睾丸、心、脾、肾未见明显异常。结论小鼠腹腔注射本试验剂量的硫酸铍后主要引起肺组织和肝脏损伤,其它脏器未见明显异常。     

Characterization of the energy distribution of neutrons generated by 5 MeV protons on a thick beryllium target at different emission angles

Neutron energy spectra at different emission angles, between 0° and 120° from the Be(p,xn) reaction generated by a beryllium thick-target bombarded with 5 MeV protons, have been measured at the Legnaro Laboratories (LNL) of the Italian National Institute for Nuclear Physics research (INFN). A new and quite compact recoil-proton spectrometer, based on a monolithic silicon telescope, coupled to a polyethylene converter, was efficiently used with respect to the traditional Time-of-Flight (TOF) technique. The measured distributions of recoil-protons were processed through an iterative unfolding algorithm in order to determine the neutron energy spectra at all the angles accounted for. The neutron energy spectrum measured at 0° resulted to be in good agreement with the only one so far available at the requested energy and measured years ago with TOF technique. Moreover, the results obtained at different emission angles resulted to be consistent with detailed past measurements performed at 4 MeV protons at the same angles by TOF techniques.