Formation of depurinating N3Adenine and N7Guanine adducts by MCF-10F cells cultured in the presence of 4-hydroxyestradiol

Metabolic conversion of endogenous estrogens, estradiol (E2) and estrone (E1), to the catechol estrogens 4-hydroxyE1(E2) [4-OHE1(E2)] has been implicated in the initiation of cancer in rodents and humans. Evidence collected in our laboratories has shown that 4-OHE1(E2) are enzymatically oxidized to E1(E2)-3,4-quinones [E1(E2)-3,4-Q], which have the potential to damage DNA by forming predominantly depurinating adducts, 4-OHE1(E2)-1-N3Ade and 4-OHE1(E2)-1-N7Gua, leading to the accumulation of mutations and probably cell transformation. The human breast epithelial cell line MCF-10F has been transformed by treatment with E2 or 4-OHE2. We have used MCF-10F cells to study the presence of adducts and conjugates after treatment with 4-OHE2. To mimic the intermittent exposure of breast cells to endogenous estrogens, MCF-10F cells were treated with 1 microM 4-OHE2 for a 24-h period at 72, 120, 192 and 240 h postplating. Culture media were collected at each point, extracted by solid-phase extraction and analyzed by HPLC connected with a multichannel electrochemical detector and/or ultraperformance liquid chromatography/tandem mass spectrometry. Media from successive treatments with 4-OHE2 showed the formation of methoxy and cysteine conjugates, and the depurinating adducts 4-OHE1(E2)-1-N3Ade. The amount of 4-OHE1(E2)-1-N3Ade adducts was higher after the third treatment; smaller amounts of the 4-OHE1(E2)-1-N7Gua adducts were detected after the second and third treatments. These results demonstrate that MCF-10F cells oxidize 4-OHE2 to E1(E2)-3,4-Q, which react with DNA to form the depurinating N3Ade and N7Gua adducts. This DNA damage can play an important role in the 4-OHE2-induced mutations and transformation of MCF-10F cells to malignant cells.     

B cells mediate chronic allograft rejection independently of antibody production

Chronic rejection is the primary cause of long-term failure of transplanted organs and is often viewed as an antibody-dependent process. Chronic rejection, however, is also observed in mice and humans with no detectable circulating alloantibodies, suggesting that antibody-independent pathways may also contribute to pathogenesis of transplant rejection. Here, we have provided direct evidence that chronic rejection of vascularized heart allografts occurs in the complete absence of antibodies, but requires the presence of B cells. Mice that were deficient for antibodies but not B cells experienced the same chronic allograft vasculopathy (CAV), which is a pathognomonic feature of chronic rejection, as WT mice; however, mice that were deficient for both B cells and antibodies were protected from CAV. B cells contributed to CAV by supporting splenic lymphoid architecture, T cell cytokine production, and infiltration of T cells into graft vessels. In chimeric mice, in which B cells were present but could not present antigen, both T cell responses and CAV were markedly reduced. These findings establish that chronic rejection can occur in the complete absence of antibodies and that B cells contribute to this process by supporting T cell responses through antigen presentation and maintenance of lymphoid architecture.     

硝基(芳亚胺基)二乙基硫代硫酸钠和硝基苯丙氮酸衍生物的合成和放射增敏作用

A series of compounds was synthesized, these compounds were tested for Hela-S₃cells in vitro for radiosensitizing activity. Five of them are 2,2′- (arylimino)-diethyl-sodium thio-sulfate and two of them are phenylalanine derivatives. Most of them showed various degrees of ra-diosensitizing activity. Among them, SER of L07 was 1.89 at 3 mmol, and had low cytotoxicity toHela-S₃ cells;ID₅₀ was 18.8 mmol. The relationship between radiosensitizing effects and chemicalstructure was discussed. It offers a base for further exploration of selectively hypoxic cell radiosens-itizers.     

Morbidity associated with heroin overdose presentations to an emergency department: A 10‐year record linkage study

Introduction: To examine hospitalizations in a cohort of 224 patients who presented with non‐fatal heroin overdose to an ED. Methods: A record linkage study, using the morbidity, mental health and mortality databases in the Data Linkage Unit of the Department of Health, Western Australia. The main outcome measures were hospital separations 5 years before and after entry into the cohort. Results: Before entry into the cohort, 199 (89%) patients had an admission to mental health services. These 199 had a combined total of 1367 separations, most commonly for a mental health condition, injury or poisoning. Women had more than twice the relative risk (RR) of men for all separations (RR 2.35, 95% confidence interval [CI] 1.96–2.82, P < 0.001) and for injury and poisoning separations (RR 2.04, 95% CI 1.56–2.66, P < 0.001). The highest concentrations of separations occurred within 1 year before and 1 year after entry into the cohort. There were 12 (5.4%, 95% CI 2.9–9.4%) deaths, most commonly from overdose. Conclusion: Non‐fatal heroin overdose ED presentations are associated with a cluster of hospitalizations around that episode, likely to be related to heroin availability. Presentation to hospital by heroin users represents an opportunity to counsel less risky behaviour.     

肾移植术后肾功能延迟恢复原因及术后血液净化的干预作用

目的：分析肾移植术后常见并发症肾功能延迟恢复的诱因，并观察术后血液净化干预所发挥的临床效应。方法：选择1996—12/2006—12在解放军第三军医大学大坪医院野战外科研究所泌尿外科明确诊断为肾移植术后肾功能延迟恢复的患者193例，其中接受尸肾移植192例，活体肾移植1例，均知情同意。根据患者的临床资料，分析术后肾功能延迟恢复的主要原因。除5例因术前安置腹膜透析管继续采用腹膜透析外，其余均选择血液透析治疗，其中35例穿插接受过连续性肾脏替代治疗或血液透析滤过，8例血浆置换2-5次。终止透析的标准为每日尿量〉1500mL，血肌酐〈300μmol／L。分析术后肾功能延迟恢复的原因，观察接受透析治疗后肾功能延迟恢复患者的临床疗效。结果：193例患者全部进入结果分析。①术后肾功能延迟恢复的病因：急性肾小管坏死89例（46．1％），术后早期低血压42例（21．8％），排斥反应37例（19．2％），动静脉吻合口狭窄9例（4-7％），尿路梗阻8例（4．1％），动脉过长扭曲5例（2．6％），环孢素A肾毒性2例（1．0％），髂内动脉粥样硬化斑块阻塞1例（0．5％）。（④术后肾功能转归：移植肾功能恢复正常者145例（75．1％）；术后3个月血肌酐135-300μmol／L29例（15．3％）；〉300μmol/L15例（7．8％）；因超急性排斥反应切除移植肾2例（1％），肺部重症感染死亡2例（1％）。③术后接受血液透析次数：术后接受血液透析189例，透析1—5次移植肾功能恢复正常20例（13．8％）；6-10次41例（28．3％）；11-20次82例（56．6％）；21-25次2例（1．4％）；〉25次44例，仅1例恢复正常（0．7％），其余43例患者带肾存活。结论：急性肾小管坏死、术后早期低血压和排斥反应是引起肾移植术后肾功能延迟恢复的主要原因。在肾功能延迟恢复患者确定以血液净化为主的方案后，绝大多数移植肾功能可以恢复。     

慢性移植肾失功356例危险因素分析

目的:慢性移植肾失功是导致后期移植肾丧失的重要原因之一,文章拟探讨慢性移植肾失功的相关因素及防治措施。方法:①选择1993-12/2006-12于解放军第三军医大学大坪医院行肾移植术后发生慢性移植肾失功患者356例,回顾性分析其临床资料。②调整免疫抑制剂方案,停服硫唑嘌呤、环孢素A或减少环孢素A30%￣50%剂量,改用他克莫司0.5￣1mg/(kg·d)、霉酚酸酯1￣2g/d、西罗莫司1￣2mL/d等药;控制血糖、血脂、血压,抗凝及补充鱼肝油丸;服用雷公藤、百令胶囊或尿毒清等中药,给予低蛋白、低磷及高维生素、氨基酸饮食;必要时手术切除移植肾。③分析肾移植术后发生慢性移植肾失功的危险因素并观察其治疗结果。结果:①慢性移植肾失功的危险因素:急性排斥反应254例(71.35%),巨细胞病毒感染65例(18.26%),移植肾肾小球肾炎21例(5.9%),药物中毒(环孢素A/他克莫司)9例(2.53%),高血压/高血脂/高血糖5例(1.41%),肾单位减少(高龄供肾/性别差异)2例(0.56%)。②治疗结果:切除移植肾194例(54.49%),带肾存活、恢复血液透析87例(24.44%),经治疗血肌酐维持在200￣300μmol/L63例(17.70%),死亡12例(3.37%)。结论:急性排斥反应是引起肾移植术后慢性移植肾失功的主要因素。提高供肾质量,严格组织配型,减少移植肾功能延迟恢复的发生,制定个体化免疫方案,定期监测药物浓度及肝肾功能,预防巨细胞病毒感染,可减少慢性移植肾失功的发生。     

Vacuum-assisted closure as a surgical assistant in life-threatening necrotizing fasciitis in children

Necrotizing fasciitis is a severe soft tissue infection that can involve skin, subcutaneous fat, fascia and muscle. It can result in devastating sequelae including tissue necrosis, sepsis, toxic shock syndrome, cardiopulmonary collapse and death. To control rapidly spreading necrosis, early diagnosis and aggressive surgical treatment with extensive radical debridement of the affected areas is necessary, as well as systemic administration of broad-spectrum antimicrobials and, very often, intensive care support.The subatmospheric negative pressure dressing has been previously used in acute and complex wounds management. The concept of using vacuum-assisted closure dressing as another management component is presented in the current article.