A Case of Nonalcoholic Steatohepatitis and Small Intestinal Bacterial Overgrowth with Peripheral Edema Caused by Intestinal Bypass Surgery and Relieved by Repair

Intestinal bypass surgery, particularly jejuno-ileal bypass surgery, performed for the purpose of weight reduction may cause an unexpected exacerbation of nonalcoholic steatohepatitis (NASH). Here, we report a case of NASH caused by small intestinal bacterial overgrowth, which developed after jejuno-colic bypass surgery and resolved dramatically after surgical correction.     

慢性肾功能不全颈动脉波强值的临床意义研究

目的：研究慢性肾功能不全（CRI）患者颈动脉波强值的变化及其临床意义,探讨波强技术对CRI患者心血管功能变化早期诊断的价值。材料和方法：对32例CRI患者及与之相匹配的无心血管疾病的志愿者进行波强检查,并对波强检查结果进行统计比较和相关性分析。结果：CRI患者波强值与患者年龄、血压呈正相关,相关系数有统计学意义（P<0.05）,CRI患者颈动脉窦部及窦下2 cm处中内膜厚度高于正常组,差异有显著统计学意义（P<0.01）。CRI患者瞬时加速波强（W1）、瞬时减速波强（W2）、负向波面积（NA）、硬化参数（β）、应变弹性模量（Ep）及脉搏波传导速度（PWVβ）均显著高于正常组,差异有统计学意义（P<0.05）。结论：波强作为一种无创性心血管检查的新方法,能在血管壁出现器质性改变之前反映CRI患者心脏以及血管功能的变化,值得在临床上推广应用。     

Hydrogen peroxide detoxification is a key mechanism for growth of ammonia-oxidizing archaea

Ammonia-oxidizing archaea (AOA), that is, members of the Thaumarchaeota phylum, occur ubiquitously in the environment and are of major significance for global nitrogen cycling. However, controls on cell growth and organic carbon assimilation by AOA are poorly understood. We isolated an ammonia-oxidizing archaeon (designated strain DDS1) from seawater and used this organism to study the physiology of ammonia oxidation. These findings were confirmed using four additional Thaumarchaeota strains from both marine and terrestrial habitats. Ammonia oxidation by strain DDS1 was enhanced in coculture with other bacteria, as well as in artificial seawater media supplemented with α-keto acids (e.g., pyruvate, oxaloacetate). α-Keto acid-enhanced activity of AOA has previously been interpreted as evidence of mixotrophy. However, assays for heterotrophic growth indicated that incorporation of pyruvate into archaeal membrane lipids was negligible. Lipid carbon atoms were, instead, derived from dissolved inorganic carbon, indicating strict autotrophic growth. α-Keto acids spontaneously detoxify H₂O₂ via a nonenzymatic decarboxylation reaction, suggesting a role of α-keto acids as H₂O₂ scavengers. Indeed, agents that also scavenge H₂O₂, such as dimethylthiourea and catalase, replaced the α-keto acid requirement, enhancing growth of strain DDS1. In fact, in the absence of α-keto acids, strain DDS1 and other AOA isolates were shown to endogenously produce H₂O₂ (up to ∼4.5 μM), which was inhibitory to growth. Genomic analyses indicated catalase genes are largely absent in the AOA. Our results indicate that AOA broadly feature strict autotrophic nutrition and implicate H₂O₂ as an important factor determining the activity, evolution, and community ecology of AOA ecotypes.Refining knowledge about the intricacies of the global nitrogen cycle is critical for improving efforts to manage the biosphere (1, 2). Nitrogenous compounds are ubiquitous in aquatic and terrestrial habitats, occurring in both living and deceased biomass (e.g., as amino acids) and in inorganic pools (e.g., ammonia, nitrite, nitrate). They are the naturally occurring microbial communities native to soils and waters that catalyze the cascade of biochemical transformations that constitute the global N cycle [e.g., ammonification, nitrification, denitrification, anaerobic ammonia oxidation, dissimilatory nitrate reduction to ammonia, nitrogen fixation; Canfield et al. (1)].Ammonia is a key nitrogen-containing compound that occurs in waters and soils. Physiologically, ammonia can act directly as a plant nutrient and is also an energy-rich substrate that is oxidized by naturally occurring chemoautotrophic microorganisms [a physiological group that derives ATP from oxidation of an inorganic compound (in this case, ammonia) and derives cellular carbon from carbon dioxide] that carry out nitrification, a two-step process that oxidizes ammonia to nitrate. Recently, however, Bacteria that are capable of complete nitrification (ammonia to nitrate in one step; comammox) were cultivated from an oil exploration well and an anammox reactor (3, 4). The powerful greenhouse gas nitrous oxide (N₂O) is produced as a byproduct of nitrification via intermediary metabolites that include hydroxylamine (NH₂OH), nitroxyl hydride (HNO), and nitrite (NO₂⁻) [for details, see Hu et al. (5)].Traditionally, Bacteria have been considered the key agents in ammonia oxidation in terrestrial and aquatic habitats (6, 7). This view has been drastically altered in the last decade with the discovery that Archaea are often far more abundant and more active in performing ammonia oxidation (8–11). Understanding the physiological foundations of ammonia oxidation and N-cycle biogeochemistry is essential for making predictions about when and in which habitats the process will occur. The traditional view about ammonia oxidation is that it is catalyzed by chemoautotrophs. Originally, AOA were also presumed to be chemolithoautotrophs, similar to their long-characterized bacterial counterparts (12). However, recent reports have suggested that some AOA may use (or even require) organic carbon substrates to achieve ammonia oxidation (13, 14). Mussmann et al. (15) reported the lack of CO₂ fixation by a clade of Thaumarchaeota abundant in refinery nitrifying sludges. The controversy surrounding chemoautotrophic versus mixotrophic (autotrophy and heterotrophy combined) paradigms for ammonia oxidation needs to be resolved.Here we advance fundamental knowledge about the physiology of AOA. We isolated the thaumarchaeotal ammonia-oxidizing strains and show that their growth is stimulated by α-keto organic acids such as pyruvate. Surprisingly, however, pyruvate was not assimilated as a carbon source during ammonia oxidation. Instead, we found that α-keto organic acids served to nonenzymatically detoxify H₂O₂. Our results reveal that previously reported “nutritional requirements” by marine microorganisms for α-keto acids have likely been misinterpreted as indicating “mixotrophic growth.” Acceleration of ammonia oxidation by catalase and catalase-positive cocultures grown with strain DDS1 supports the principle that the in situ metabolic activities of many biogeochemically critical microbial populations (involved in the cycling of C and N and other elements) may be regulated by fellow adjacent populations that produce enzymes able to detoxify toxic reactive oxygen species in ocean water, particularly H₂O₂.     

姜黄素抗血吸虫病肝纤维化作用机制的研究

目的探讨姜黄素（CUR）在血吸虫病肝纤维化治疗中的作用。方法将60只小鼠随机分为6组，分别为对照组，感染组，溶剂组，CUR组（分低、中、高3个剂量）。CUR组于感染后第4周末开始通过灌胃给予CUR，感染后第10周末处死各组小鼠，剖取肝脏测定肝组织羟脯氨酸（Hyp），并检测肝脏基质金属蛋白酶-1（MMP-1）mRNA和组织金属蛋白酶抑制因子-1（TIMP-1）mRNA的表达水平。结果与感染组比较，肝组织中Hyp、胶原在CUR（低、中、高）组降低显著（tHyp=4．52、3，16、2．52，P〈0．05、P〈0，01；t胶原=33．72、23．54、18．80，P〈0．05、P〈0．01）；反转录PCR结果显示，随着CUR剂量的增加，MMP-1mRNA的表达逐渐升高。TIMP-1mRNA的表达逐渐降低，与感染组相比差异有统计学意义（tMMP-1=16．98、21．43、25．49，P〈0．05、P〈0．01；hTDMP-1=40．20、37．59、34．23．P〈0．05、P〈0．01）。结论CUR有减轻肝组织损伤程度，延缓和阻止肝纤维化发生发展的作用，此作用可能与上调MMP-1，阻止TIMP-1的产生有关。     

双源CT诊断痛风性关节炎临床分析

目的 采用非侵入性双源CT观察关节及周围组织的尿酸盐结晶,以探索临床诊断痛风或鉴别诊断其他关节疾病。方法 选择近2周发作过单关节肿或（和）痛患者17例,均行病变关节双源CT检查。部分患者在B超下穿刺取关节液镜检。结果 13例痛风患者发现33处有尿酸盐结晶,最常沉积的关节部位为双侧足趾关节(7/33)、近端指关节(5/33)、远端指间关节周围(4/33)、跖关节(4/33)、胫骨下端(3/33)。发现尿酸盐结晶易沉积在近关节骨表面,肌肉、韧带等关节周边软组织。关节肿痛部位与尿酸盐结晶沉积部位一致。尿酸盐结晶大小可以测量。结论 双源CT可以清晰显示尿酸盐结晶,为无创检测手段。在鉴别诊断不明原因单关节肿痛方面有很好的价值。     

Measuring the Complexity of Atrial Fibrillation Electrograms

AF Electrogram Complexity. Introduction: Complex fractionated atrial electrograms (CFAE) have been identified as targets for atrial fibrillation (AF) ablation. Robust automatic algorithms to objectively classify these signals would be useful. The aim of this study was to evaluate Shannon's entropy (ShEn) and the Kolmogorov‐Smirnov (K‐S) test as a measure of signal complexity and to compare these measures with fractional intervals (FI) in distinguishing CFAE from non‐CFAE signals. Methods and Results: Electrogram recordings of 5 seconds obtained from multiple atrial sites in 13 patients (11 M, 58 ± 10 years old) undergoing AF ablation were visually examined by 4 independent reviewers. Electrograms were classified as CFAE if they met Nademanee criteria. Agreement of 3 or more reviewers was considered consensus and the resulting classification was used as the gold standard. A total of 297 recordings were examined. Of these, 107 were consensus CFAE, 111 were non‐CFAE, and 79 were equivocal or noninterpretable. FIs less than 120 ms identified CFAEs with sensitivity of 87% and specificity of 79%. ShEn, with optimal parameters using receiver‐operator characteristic curves, resulted in a sensitivity of 87% and specificity of 81% in identifying CFAE. The K‐S test resulted in an optimal sensitivity of 100% and specificity of 95% in classifying uninterpretable electrogram from all other electrograms. Conclusions: ShEn showed comparable results to FI in distinguishing CFAE from non‐CFAE without requiring user input for threshold levels. Thus, measuring electrogram complexity using ShEn may have utility in objectively and automatically identifying CFAE sites for AF ablation. (J Cardiovasc Electrophysiol, Vol. 21, pp. 649‐655, June 2010)     

减低预处理剂量的异基因造血干细胞移植治疗骨髓增生异常综合征

目的:评估10例骨髓增生异常综合征(MDS)患者进行非清髓异基因造血干细胞移植的效果。方法:10例MDS患者中位年龄44岁,MDS-难治性贫血(RA)1例[国际预后积分系统(IPSS)中危-Ⅰ],MDS-难治性血细胞减少伴有多系增生异常(RCMD)5例(IPSS中危-Ⅰ4例,中危-Ⅱ1例),MDS转变为急性髓系白血病4例(均为IPSS高危)。人类白细胞抗原(HLA)完全相合同胞移植7例,HLA匹配无关供者移植3例。预处理方案以白消安8～10mg/kg、氟达拉滨90～150mg/m2及全身照射2～3Gy为主,移植物抗宿主病(GVHD)预防方案为环孢素、短程甲氨蝶呤和麦考酚酸酯。移植后供受者嵌合体检测采用PCR扩增短串联重复序列方法,对流式细胞仪分选出的T淋巴细胞、自然杀伤(NK)细胞和粒细胞进行动态定量检测。结果:移植后异基因造血干细胞都成功植入,中性粒细胞>0.5×109/L的中位时间为12(10～14)d,血小板>50×109/L的中位时间为13(0～29)d。10例患者中8例发生急性GVHD,其中仅1例患者发生Ⅳ度急性GVHD,其余患者为Ⅰ度。中位随访22(3.6～70)个月,5例发生慢性GVHD。2例患者死亡,均在移植前转变为急性髓系白血病,其余8例患者均无病生存至今,血细胞数恢复正常,中位生存时间为27(15～70)个月,预期5年总生存率为79%。结论:减低预处理剂量的异基因造血干细胞移植是治疗MDS或MDS继发急性髓系白血病的有效方法。移植后需要进行嵌合体的密切监测,根据供受者嵌合比例,尤其是T淋巴细胞嵌合比例给予个体化免疫抑制剂治疗,避免复发。     

Society stress and peptic ulcer perforation

To examine the relationship between society stress and peptic ulcer perforation, time-trend analysis was performed on the annual incidence of perforated peptic ulcer per 100 000 population in Hong Kong during the years 1962–85, when Hong Kong, as a developing city, went through significant socio-economic and political changes, and the trend was correlated with specially designed and validated society stress scores estimated annually during the same period. The society stress scores were derived independently by two expert panels blinded to the purpose of the study, one selecting and categorizing negative news events for Hong Kong during this period, and the other weighing the categories and scoring the impact of the news on Hong Kong. The incidence of perforation increased significantly during the years and manifested three distinct peaks, which coincided with the worst economic recession in Hong Kong, the influx of mainlander Chinese and Vietnamese boat people, and the Sino-British negotiation on the sovereignty of Hong Kong after 1997. Both linear and autoregression analysis, the latter taking into consideration point fluctuations in rates, showed that perforation rates correlated significantly with the society stress scores (r= 0.57, P < 0.002). The peak effects and the significant correlations indicate that an association exists between society stress and peptic ulcer perforation, and suggest that chronic society stress plays an important role in the aetiology of this condition, although the relatively low r value also suggests the presence of other aetiological factors.     

High-Risk Esophageal Varices in Patients Treated with Locoregional Therapies for Hepatocellular Carcinoma: Evaluation with Regular Follow-Up Liver CT

We evaluated the diagnostic performance of radiologists for the detection of high-risk esophageal varices on regular follow-up liver multi-detector row CT (MDCT) examinations in patients treated with locoregional therapies for hepatocellular carcinoma (HCC). A total of 110 cirrhotic patients that had undergone liver MDCT at 4 weeks or sooner before an upper endoscopy were evaluated. Three abdominal radiologists independently interpreted the CT images with the shortest interval of endoscopy in order to detect the presence of high-risk (grade 2 or 3) esophageal varices. With endoscopic grading as the reference standard, the diagnostic performances (areas under the ROC curves) of the three radiologists were 0.977 ± 0.018, 0.957 ± 0.024, and 0.939 ± 0.028, respectively. The mean sensitivity and specificity of the three radiologists were 91.9% and 92.2%, respectively. Our results showed excellent diagnostic performances of radiologists to detect high-risk esophageal varices on regular follow-up liver MDCT in patients treated with locoregional therapies for HCC.     

颈总动脉粥样硬化斑块形成对心脑血管预后的影响

目的:评价颈总动脉粥样硬化斑块形成对心脑血管预后的影响。方法:198例有冠状动脉(冠脉)粥样硬化性心脏病(冠心病)危险因素并行冠脉造影的患者,依据颈动脉超声检测将有无颈总动脉粥样硬化斑块分为动脉粥样硬化组(AS组)(120例)和对照组(78例),随访、比较2组心脑血管不良事件发生率,应用Cox回归分析与心脑血管预后相关的独立因素。结果:基线时,AS组平均年龄大(P<0.001)、慢性肾病患者多(P<0.05)、冠心病患者多(P<0.001)、血清肌酐(Scr)水平高(P<0.05)、颈总动脉内膜中膜厚度(IMT)平均值大(P<0.001)、颈总动脉内径(C-Di)较高(P<0.05)、服用他汀类药物患者较多(P