Role of acetylcholinesterase in the development of axon tracts within the embryonic vertebrate brain

In the developing vertebrate brain, acetylcholinesterase (AChE) expression coincides temporally with axon tract formation. Although AChE promotes neurite outgrowth in vitro, the role of this molecule in the development of axon tracts in vivo is unknown. To address this question, we examined the effects of the AChE inhibitor, BW284C51, on the formation of the early scaffold of axon tracts in the embryonic Xenopus brain. In exposed Xenopus brain preparations, axons elongate and establish a normal topography of axon tracts. However, when brains were exposed to BW284C51, the thickness of the major longitudinal axon tract, the tract of the post-optic commissure decreased in a dose-dependent manner. When BW284C51 was removed from the culture media axon tract development returned to normal within 5 h. These findings provide the first evidence for a non-classical role of AChE in the initial formation of axon tracts within the developing vertebrate brain.     

Putting the Patient in Patient Reported Outcomes: A Robust Methodology for Health Outcomes Assessment

When analyzing many health‐related quality‐of‐life (HRQoL) outcomes, statistical inference is often based on the summary score formed by combining the individual domains of the HRQoL profile into a single measure. Through a series of Monte Carlo simulations, this paper illustrates that reliance solely on the summary score may lead to biased estimates of incremental effects, and I propose a novel two‐stage approach that allows for unbiased estimation of incremental effects. The proposed methodology essentially reverses the order of the analysis, from one of ‘aggregate, then estimate’ to one of ‘estimate, then aggregate’. Compared to relying solely on the summary score, the approach also offers a more patient‐centered interpretation of results by estimating regression coefficients and incremental effects in each of the HRQoL domains, while still providing estimated effects in terms of the overall summary score. I provide an application to the estimation of incremental effects of demographic and clinical variables on HRQoL following surgical treatment for adult scoliosis and spinal deformity. Copyright © 2014 John Wiley & Sons, Ltd.     

Short-term recognition memory impairment is associated with decreased expression of FK506 binding protein 51 in the aged mouse brain

Evidence suggests that increased glucocorticoid receptor (GR) signaling may contribute to cognitive decline with age. We hypothesized that alterations in GR signaling pathway molecules, FK506 binding protein (FKBP) 51 and FKBP52, were associated with memory impairment in aged mice. We used the single-trial object recognition test to measure short-term memory in 18 aged mice compared to 22 young mice, and employed quantitative immunohistochemistry to assess cellular expression of those three proteins in the frontal cortex, hippocampal CA1, and dentate gyrus. Values of the discrimination ratio (DR, a measure of novelty preference) in aged mice were significantly lower than those in young mice (mean 0.54 vs. 0.67, p = 0.003, t test). Aged mice with DR below 0.54 were considered impaired (n = 9). In the three neuroanatomic regions studied, the immunoreactivity normalized to the area measured (IRn) for GR was significantly increased in aged mice regardless of their task performance compared to young mice (p < 0.005), as was the FKBP52 IRn (p < 0.007, U test). In the frontal cortex and CA1, the FKBP51 IRn was significantly lower in impaired aged mice than in unimpaired aged mice (p < 0.01 and <0.05, respectively) and in young mice (p < 0.05 and <0.01, respectively, Dunn’s post hoc test). In aged mice, the frontal cortex FKBP51 IRn correlated directly with DR (r _s = 0.68, p = 0.002, Spearman rank correlation). These observations suggest that recognition memory impairment in aged mice is associated with decreased FKBP51 expression that may promote GR-mediated glucocorticoid signaling to a greater extent than in unimpaired aged mice.     

Updated evaluation of the cost-effectiveness of lung volume reduction surgery

BACKGROUND: The National Emphysema Treatment Trial, a randomized clinical trial of lung volume reduction surgery (LVRS) vs medical therapy for severe emphysema, included a prospective economic analysis. We present an updated analysis of cost-effectiveness with 1-year additional follow-up data. METHODS: Following pulmonary rehabilitation, 1,218 patients at 17 medical centers were randomized to receive LVRS or continued medical treatment. The cost-effectiveness of LVRS vs medical therapy was calculated over the duration of the trial (January 1998 to December 2003) and estimated at 10 years using modeling based on observed trends in survival, cost, and quality of life. RESULTS: The cost-effectiveness of LVRS vs medical therapy was $140,000 per quality-adjusted life-year (QALY) gained (95% confidence interval, $40,155 to $239,359) at 5 years, and was projected to be $54,000 per QALY gained at 10 years. In subgroup analysis, the cost-effectiveness of LVRS in patients with upper-lobe emphysema and low exercise capacity was $77,000 per QALY gained at 5 years, and was projected to be $48,000 per QALY at 10 years. Compared to the initial results, the updated results are similar for the overall cohort but vary substantially for the subgroups. CONCLUSIONS: LVRS is costly relative to other health-care programs during the time horizon when costs and outcomes are known. The extended follow-up period offers more certainty regarding the long-term value and economic impact of this procedure.     

Plasma aldosterone is related to severity of obstructive sleep apnea in subjects with resistant hypertension

OBJECTIVE: Obstructive sleep apnea (OSA) and primary aldosteronism are common in subjects with resistant hypertension; it is unknown, however, if the two disorders are causally related. This study relates plasma aldosterone and renin levels to OSA severity in subjects with resistant hypertension, and in those with equally severe OSA but without resistant hypertension serving as control subjects. METHODS: Seventy-one consecutive subjects referred to the University of Alabama at Birmingham (UAB) for resistant hypertension (BP uncontrolled on three medications) and 29 control subjects referred to UAB Sleep Disorders Center for suspected OSA were prospectively evaluated by an early morning plasma aldosterone concentration (PAC) and renin level, and by overnight, attended polysomnography. RESULTS: OSA (apnea-hypopnea index [AHI] > or = 5/h) was present in 85% of subjects with resistant hypertension. In these subjects, PAC correlated with AHI (rho = 0.44, p = 0.0002) but not renin concentration. Median PAC was significantly lower in control subjects compared to subjects with resistant hypertension (5.5 ng/dL vs 11.0 ng/dL, p < 0.05) and not related to AHI. In male subjects compared to female subjects with resistant hypertension, OSA was more common (90% vs 77%) and more severe (median AHI, 20.8/h vs 10.8/h; p = 0.01), and median PAC was significantly higher (12.0 ng/dL vs 8.8 ng/dL, p = 0.006). CONCLUSION: OSA is extremely common in subjects with resistant hypertension. A significant correlation between PAC and OSA severity is observed in subjects with resistant hypertension but not in control subjects. While cause and effect cannot be inferred, the data suggest that aldosterone excess may contribute to OSA severity.     

Knockdown of DEAD-box 51 inhibits tumor growth of esophageal squamous cell carcinoma via the PI3K/AKT pathway

BACKGROUND Esophageal squamous cell carcinoma(ESCC)is one of the most prevalent malignancies that seriously threaten people’s health worldwide.DEAD-box helicase 51(DDX51)is a member of the DEAD-box(DDX)RNA helicase family,and drives or inhibits tumor progression in multiple cancer types.AIM To determine whether DDX51 affects the biological behavior of ESCC.METHODS The expression of DDX51 in ESCC tumor tissues and adjacent normal tissues was detected by Immunohistochemistry(IHC)analyses and quantitative PCR(qPCR).We knocked down DDX51 in ESCC cell lines by using a small interfering RNA(siRNA)transfection.The proliferation,apoptosis,and mobility of DDX51 siRNAtransfected cells were detected.The effect of DDX51 on the phosphoinositide 3-kinase(PI3K)/AKT pathway was investigated by western blot analysis.A mouse xenograft model was established to investigate the effects of DDX51 knockdown on ESCC tumor growth.RESULTS DDX51 exhibited high expression in ESCC tissues compared with normal tissues and represented a poor prognosis in patients with ESCC.Knockdown of DDX51 induced inhibition of ESCC cell proliferation and promoted apoptosis.Moreover,DDX51 siRNA-expressing cells also exhibited lower migration and invasion rates.Investigations into the underlying mechanisms suggested that DDX51 knock down induced inactivation of the PI3K/AKT pathway,including decreased phosphorylation levels of phosphate and tensin homolog,PI3K,AKT,and mammalian target of rapamycin.Rescue experiments demonstrated that the AKT activator insulin-like growth factor 1 could reverse the inhibitory effects of DDX51 on ESCC malignant development.Finally,we injected DDX51 siRNA-transfected TE-1 cells into an animal model,which resulted in slower tumor growth.CONCLUSION Our study suggests for the first time that DDX51 promotes cancer cell proliferation by regulating the PI3K/AKT pathway;thus,DDX51 might be a therapeutic target for ESCC.     

Human exonuclease 1 and BLM helicase interact to resect DNA and initiate DNA repair

The error-free repair of double-stranded DNA breaks by homologous recombination requires processing of broken ends. These processed ends are substrates for assembly of DNA strand exchange proteins that mediate DNA strand invasion. Here, we establish that human BLM helicase, a member of the RecQ family, stimulates the nucleolytic activity of human exonuclease 1 (hExo1), a 5′→3′ double-stranded DNA exonuclease. The stimulation is specific because other RecQ homologs fail to stimulate hExo1. Stimulation of DNA resection by hExo1 is independent of BLM helicase activity and is, instead, mediated by an interaction between the 2 proteins. Finally, we show that DNA ends resected by hExo1 and BLM are used by human Rad51, but not its yeast or bacterial counterparts, to promote homologous DNA pairing. This in vitro system recapitulates initial steps of homologous recombination and provides biochemical evidence for a role of BLM and Exo1 in the initiation of recombinational DNA repair.     

DNA修复基因Hrad51和转移抑制基因nm23在乳腺肿瘤中的表达及生物学意义

目的 探讨DNA 修复基因Hrad51和转移抑制基因nm23 在乳腺肿瘤中的表达及生物学意义.方法 应用S-P免疫组化法,分别检测了Hrad51 蛋白和nm23蛋白在乳腺癌、乳腺纤维腺瘤、乳腺小叶增生、导管上皮不典型增生、腺癌癌旁正常组织中的表达情况.结果 (1) Hrad51蛋白和nm23蛋白在乳腺癌组的表达与乳腺纤维腺瘤、乳腺小叶增生、导管上皮不典型增生、腺癌癌旁正常组织中的表达存在显著差异(均P＜0.01);(2) 乳腺癌中hrda51蛋白的阳性表达与肿瘤组织分级呈正相关(P＜0.01),与nm23、ER、PR的阳性表达呈负相关(均P＜0.01).(3) 乳腺癌中nm23的阳性表达与肿瘤组织分级呈负相关(P＜0.01),与ER的阳性表达呈正相关(P＜0.05),与PR的阳性表达无相关性(P＞0.05).(4) 乳腺癌发生淋巴结转移与nm23、ER的阳性表达呈负相关(均P＜0.01),与Hrad51的阳性表达呈正相关(P＜0.01),与PR的阳性表达无相关性(P＞0.05).结论 (1)Hrad51蛋白在不同病变乳腺组织中呈现不同表达,在乳腺癌组织中存在高度表达;(2)nm23蛋白也在不同病变乳腺组织中呈现不同表达,在乳腺癌组织中存在低表达;(3)检测Hrad51 蛋白和nm23蛋白的表达情况有望成为评价乳腺癌患者预后的一个新指标.     

RAD515’UTRG135C单核苷酸多态性与NSCLC铂类化疗疗效的关系

目的探讨DNA修复基因RAD515’UTRG135C单核苷酸多态性与晚期非小细胞肺癌（NSCLC）铂类药物化疗敏感性的关系。方法经病理学确诊的晚期NSCLC患者152例,均给予铂类为主的方案化疗,每2个周期后进行疗效评价。使用PCR—RFLP方法检测其外周血RAD515’UTRG135C单核苷酸多态性。分析不同基因型与化疗疗效的关系。结果152例患者化疗总有效率为46．7％,携带RAD51G／C或C／C等位基因患者是G／G纯合子患者化疗敏感性的1．94倍（OR=1．94,95％可信区间为1．01～3．76,P=0．047）;有吸烟史的患者中,携带RAD51G／C或C／C等位基因是G／G纯合子患者化疗敏感性的2．60倍（OR=2．60,95％可信区间为1．16～5．83,P=0．019）,但在不吸烟的患者中差异无统计学意义（P=0．676）。结论DNA修复基因RAD515’uTRG135C单核苷酸多态性与晚期NSCLC铂类化疗敏感性相关。携带RAD51G／G等位基因及有吸烟史的晚期非小细胞肺癌患者铂类化疗敏感性降低。