Alpha‐phellandrene‐induced DNA damage and affect DNA repair protein expression in WEHI‐3 murine leukemia cells in vitro

Although there are few reports regarding α‐phellandrene (α‐PA), a natural compound from Schinus molle L. essential oil, there is no report to show that α‐PA induced DNA damage and affected DNA repair associated protein expression. Herein, we investigated the effects of α‐PA on DNA damage and repair associated protein expression in murine leukemia cells. Flow cytometric assay was used to measure the effects of α‐PA on total cell viability and the results indicated that α‐PA induced cell death. Comet assay and 4,6‐diamidino‐2‐phenylindole dihydrochloride staining were used for measuring DNA damage and condensation, respectively, and the results indicated that α‐PA induced DNA damage and condensation in a concentration‐dependent manner. DNA gel electrophoresis was used to examine the DNA damage and the results showed that α‐PA induced DNA damage in WEHI‐3 cells. Western blotting assay was used to measure the changes of DNA damage and repair associated protein expression and the results indicated that α‐PA increased p‐p53, p‐H2A.X, 14‐3‐3‐σ, and MDC1 protein expression but inhibited the protein of p53, MGMT, DNA‐PK, and BRCA‐1. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 1322–1330, 2015.     

Sealing of anodized magnesium alloy AZ31 with MgAl layered double hydroxides layers

In this work, anodized magnesium alloy AZ31 with and without boiling water sealing was pre-prepared, and then MgAl-layered double hydroxide (LDH) films were fabricated on it through hydrothermal chemical conversion of the pre-prepared anodic layer. The morphology, structure, and composition of the films were characterized by XRD, SEM, EDS, FT-IR, XPS and GDOES. It was found that the porosity of the films was reduced after in situ fabrication of the LDHs. The effects of boiling water sealing treatment on the anodized substrate were also discussed. Moreover, the polarization curve, EIS, and immersion tests showed that LDHs fabricated on the anodized substrate with boiling water sealing treatment exhibited a significant long period of protection for the substrate.

In this work anodized magnesium alloy AZ31 with and without boiling water sealing was pre-prepared, and then MgAl-layered double hydroxide (LDH) films were fabricated on it through hydrothermal chemical conversion of the pre-prepared anodic layer.     

Optimal treatment allocation for placebo‐treatment comparisons in trials with discrete‐time survival endpoints

In many randomized controlled trials, treatment groups are of equal size, but this is not necessarily the best choice. This paper provides a methodology to calculate optimal treatment allocations for longitudinal trials when we wish to compare multiple treatment groups with a placebo group, and the comparisons may have unequal importance. The focus is on trials with a survival endpoint measured in discrete time. We assume the underlying survival process is Weibull and show that values for the parameters in the Weibull distribution have an impact on the optimal treatment allocation scheme in an interesting way. Additionally, we incorporate different cost considerations at the subject and measurement levels and determine the optimal number of time periods. We also show that when many events occur at the beginning of the trial, fewer time periods are more efficient. As an application, we revisit a risperidone maintenance treatment trial in schizophrenia and use our proposed methodology to redesign it and compare merits of our optimal design. Copyright © 2015 John Wiley & Sons, Ltd.     

Fluorescence enhancement of carbon dots by graphene for highly sensitive detection of tetracycline hydrochloride

In this study, fluorescence of self-assembled multilayers (SAMs) of carbon dots (CDs) was found to be enhanced by graphene. The number of polyelectrolyte layers can be tuned to control the distance between CDs and graphene in SAMs. The enhanced fluorescence efficiency was found to be dependent on graphene concentration, degree of graphene reduction, and the distance between CDs and graphene surface. When graphene concentration and polyelectrolyte bilayer number were set to 0.005 mg mL⁻¹ and 3 layers, respectively, fluorescence intensity of CDs could be increased up to 3.2 times. Tetracycline hydrochloride (Tc) could be detected by the established SAMs in the presence of graphene as the sensitivity was 2 orders higher than that of SAMs in the absence of graphene. Limit of detection of this sensing system was 0.9284 nM, which is 1–3 orders of magnitude lower than those of most of reported fluorescence sensors. This method could be successfully applied to detect trace Tc in milk samples.

The fluorescence of carbon dots self-assembled multilayers (CDs SAMs) can be enhanced by graphene, the sensing sensitivity for tetracycline hydrochloride of CDs SAMs with graphene is two orders higher than that of SAMs without graphene.     

Effects of medroxyprogesterone and estradiol on the recovery of spermatogenesis in irradiated rats

Suppression of intratesticular testosterone (ITT) levels is required for spermatogenic recovery in rats after irradiation, but maintenance of peripheral testosterone (T) levels is important for many male functions. Considering the preservation of peripheral T while suppressing ITT, we tested the effects of a combination of a progestin, medroxyprogesterone acetate (MPA), plus T on spermatogenic recovery after irradiation, and compared its effects to those of T alone or T combined with estradiol (E2). Rats were given testicular irradiation (6 Gy) and treated during wk 3-7 after irradiation with MPA + T, or the individual steroids with or without GnRH antagonist (GnRH-ant), or GnRH-ant alone, or T + E2. Whereas GnRH-ant alone stimulated differentiation in 55% of tubules 13 wk after irradiation compared with 0% in irradiated-only rats, the addition of MPA reduced the percentage of tubules showing differentiation to 18%. However, T or MPA alone or the combination of the two induced germ cell differentiation in only 2-4% of tubules. In contrast, E2 stimulated differentiation in 88% of tubules, and T combined with E2 still resulted in differentiation in 30% of tubules. Although both MPA and E2 suppressed ITT levels to approximately 2% of control (2 ng/g testis), MPA was a less effective stimulator of spermatogenic recovery than E2 or GnRH-ant alone. MPA's function as a weak androgen was likely responsible for inhibiting spermatogenic recovery, as was the case for all other tested androgens. Thus, for clinical protection or restoration of spermatogenesis after radiation or chemotherapy by suppressing T production, MPA, at least in the doses used in the present study, is suboptimal. The combination of an estrogen with T appears to be most effective for stimulating such recovery.     

老年心肌缺血者QTc和QTcd变化及临床意义

测定了６４例老年心肌缺血（ＭＩＳ）患者和２１例心肌梗塞（ＭＩ）患者心电图的ＱＴｃ间期和ＱＴｃ离散度（ＱＴｃｄ），并与心血管神经官能症（ＣＶＮ）及正常老年人进行比较；探讨ＱＴｃ、ＱＴｃｄ与致命性室性心律失常（ＦＶＡ）、心原性猝死（ＣＳＤ）的关系；分析ＭＩ不同部位的ＱＴｃｄ变化以及稳定性心绞痛（ＳＡＰ）和不稳定性心绞痛（ＵＳＡＰ）的ＱＴｃｄ差异。结果：老年女性患者ＱＴｃ较男性长（Ｐ＜０．０５），而ＱＴｃｄ两者无差异；老年ＭＩＳ患者ＱＴｃ和ＱＴｃｄ较正常组明显延长（Ｐ＜０．０１）；ＭＩ前壁、下壁和后壁３组ＱＴｃｄ无明显差异（Ｐ＞０．０５）；ＵＳＡＰ患者ＱＴｃｄ较ＳＡＰ长（Ｐ＜０．０５）。     

Effect of interferon-gamma on hepatic fibrosis in chronic hepatitis B virus infection: a randomized controlled study.

BACKGROUND & AIMS: Hepatic fibrosis due to chronic HBV infection has enormous socioeconomic impact. Besides strategies targeting virus elimination, prevention or reversal of liver fibrosis is amenable. Given the antifibrotic activity of interferon-gamma (IFN-gamma), a randomized open-labeled multicenter trial was initiated to test IFN-gamma in HBV infection. METHODS: HBsAg-positive patients with biopsy proven hepatic fibrosis (n = 99, stages 2-4, Scheuer criterion) were treated with diammone-glycyrrhizinate and potassium-magnesium aspartate. Sixty-six randomly assigned patients were treated with 50 mug IFN-gamma intramuscularly on a daily basis for 3 months and on alternate days the subsequent 6 months. Efficacy was evaluated by liver biopsy and serologic markers. RESULTS: Fifty-four patients in the IFN-gamma group and 29 patients in the control group completed the study. The hepatic fibrosis score was significantly reduced in 63% of IFN-gamma treated patients compared with 24.1% in the control group by using a semiquantitative scoring system evaluating both liver architecture and fibrotic deposits. Mean values for the total fibrosis score decreased from 13.8 +/- 5.8 to 10.1 +/- 5.1 in the IFN-gamma group (P = .0001), whereas they were unchanged in control subjects (13.2 +/- 6.8 vs 12.6 +/- 4.8, P = .937). The Scheuer system showed 12 out of 54 patients improved >or=1 stage(s) in the IFN-gamma group compared with 1 of 29 in the control group. Antifibrotic activity might be attributed to decreased transforming growth factor-beta signaling via phosphorylated Smad2 and reduced number of activated, alpha-smooth muscle actin positive hepatic stellate cells. CONCLUSIONS: IFN-gamma treatment for 9 months improves fibrosis scores in patients with chronic HBV infection most likely by antagonizing profibrogenic transforming growth factor-beta effects.     

老年肺心病患者吸入一氧化氮后血流动力学与血管调节因子的变化

自的为探讨血管内皮细胞在慢性阻塞性肺疾病（ＣＯＰＤ）肺心病发生发展中的作用，对该病患者血浆内皮细胞释放的舒血管因子──一氧化氮（Ｎｏ）的含量与血管紧张素转换酶（ＡＣＥ）活性进行测定，并观察提供外源性ＮＯ对肺心病晚期患者肺血流动力学的影响。方法采用分光光度法测定９例老年ＣＯＰＤ肺心病晚期患者血浆ＮＯ的含量与ＡＣＥ活性，另有１２例健康老年人作为对照，并应用右心导管技术观察了吸入４０×１０－６ＮＯ２０分钟对晚期肺心病患者肺血流动力学的影响。结果老年肺心病患者血浆ＮＯ含量与ＡＣＥ活性显著降低；吸入ＮＯ后，血浆ＮＯ代谢产物显著增加的同时，肺动脉平均压（ＰＡＰｍ）从４．１±０．７ｋＰａ（１ｋＰａ＝７．５ｍｍＨｇ）降为３．３±０．５ｋＰａ（Ｐ值＜０．０１），肺血管阻力及其指数显著降低，输氧量（ＤＯ２）、心输出量（ＣＯ）增加，右室作功降低。全血谷胱甘肽过氧化物酶（ＧＳＨ－ｐｘ）活力显著降低（３７．３％）。结论老年慢性心病患者血管内皮依赖性舒张因子缺乏，其肺血管内皮可能存在一定的损伤，外源性补充ＮＯ可显著改善肺循环，增加输氧量，而副作用很少，对老年肺心病患者有益