PDEA-coated magnetic nanoparticles for gene delivery to Hep G2 cells

Poly(2-(diethylamino)ethyl methacrylate) coated magnetic nanoparticles (PDEA-MNPs) were synthesized as a new gene nanocarrier to delivery plasmids (pEGFPN1 and pRL-TK) into human hepatoma (Hep G2) cells. The PDEA-MNPs shows the pH-sensitive property. These nanoparticles are positively charged at acidic pH and negatively charged at neutral or alkaline pH. The PDEAMNPs exhibited a low cytotoxicity in Hep G2 cells. PDEA-MNPs could bind and protect DNA from DNase I degradation. The transfection study demonstrated that the PDEA-MNPs could carry plasmid into Hep G2 cells and exhibited a high gene transfection efficiency. These results indicated that the novel magnetic nanoparticles could enhance gene transfection in vitro and hold the potential to be a promising non-viral nanodevice.     

Ultrastructural study of polyspermy during early embryo development in pigs, observed by scanning electron microscope and transmission electron microscope

Polyspermy is generally considered a pathological phenomenon in mammals. Incidence of polyspermy in porcine eggs in vivo is extremely high (30-40%) compared with other species, and polyspermy rate in the in vitro fertilized eggs in pigs can reach 65%. It is still unknown whether polyspermy to a certain degree is a physiological condition in pigs, and whether porcine eggs have any capability with which to remove the accessory sperm in the cytoplasm. The objectives in the present study are to observe the ultrastructural changes of accessory sperm during early embryonic development in pigs. A total of 58 normal, early embryos at one-, two, three-, and four-cell and morular stages were collected from gilts and were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The surface ultrastructure showed that sperm fusion with the zona pellucida was a continuous process during one-, two-, three-, and four-cell and morular stages, as observed by the SEM. Accessory sperm were present in the cytoplasm of cleaved embryos. The sperm heads in the cytoplasm of cleaved embryos did not decondense. TEM revealed the presence of a condensed sperm head within a lysosome (or phagolysosome) in a three-cell embryo. These observations suggest that polyspermy may be a physiological condition in pigs and that early embryos may develop to term if accessory sperm do not interrupt the embryo genome. Furthermore, lysosome activity could be another physiological mechanism for removing accessory sperm in the cytoplasm of fertilized eggs and cleaved embryos after fertilization in pigs.     

Flow‐injection chemiluminescent determination of estrogen benzoate using the tris(1,10‐phenanthroline) ruthenium(II)–permanganate system

Chemiluminescence (CL) detection for the determination of estrogen benzoate, using the reaction of tris(1,10–phenanthroline)ruthenium(II)–Na₂SO₃–permanganate, is described. This method is based on the CL reaction of estrogen benzoate (EB) with acidic potassium permanganate and tris(1,10–phenanthroline)ruthenium(II). The CL intensity is greatly enhanced when Na₂SO₃ is added. After optimization of the different experimental parameters, a calibration graph for estrogen benzoate is linear in the range 0.05–10 µg/mL. The 3 s limit of detection is 0.024 µg/mL and the relative standard deviation was 1.3% for 1.0 µg/mL estrogen benzoate (n = 11). This proposed method was successfully applied to commercial injection samples and emulsion cosmetics. The mechanism of CL reaction was also studied. Copyright © 2011 John Wiley & Sons, Ltd.     

马科在中国的分布与现状

蒙古野驴(Asinus h．hemionus)分布于内蒙和甘肃西北角、新疆东北部至准噶尔盆地西部。1982年航调,卡拉麦里山保护区内有356头,O.02头／平方公里;1986年调查为O.03头／平方公里。估计目前我国境内不超过2000头。西藏野驴(Asinus k.kiang)分布于西藏西部、新疆南缘山地;A.k.holdereri分布于除湟水河谷外青海全境、四川西北角、甘肃祁连山。1984年调查,阿尔金山保护区内有41,262头,0.917头／平方公里。估计我国境内种群约在20万头上。多年考察未发现野马(Equus przewalskii),目前可能在北塔山以东尚有少数残存。     

ACE2 and FZD1 are prognosis markers in squamous cell/adenosquamous carcinoma and adenocarcinoma of gallbladder

The clinicopathological characteristics of squamous cell/adenosquamous carcinoma (SC/ASC) of the gallbladder have not been well documented, and no prognosis marker has been identified because of the rare occurrence of this gallbladder cancer subtype. In this study, we examined ACE2 and FZD1 expression in 46 SC/ASCs and 80 adenocarcinomas using immunohistochemistry and further analyzed their correlations with clinicopathological characteristics. We demonstrated that positive FZD1 and negative ACE2 expression were significantly associated with large tumor size, high TNM stage, lymph node metastasis and invasion of SC/ASC and AC. Univariate Kaplan–Meier analysis showed that positive FZD1 and negative ACE2 expression as well as differentiation, tumor size, TNM stage, lymph node metastasis, invasion, and surgical curability were closely associated with decreased overall survival in both SC/ASC (p < 0.001) and AC (p < 0.001) patients. The average survival time in SC/ASC and AC patients with FZD1^?ACE2⁺ expression was significantly longer than that in patients with FZD1⁺ACE2^? or FZD1⁺ACE2⁺ (p < 0.01). Multivariate Cox regression analysis showed that positive FZD1 and negative ACE2 expression are independent poor-prognostic factors for both SC/ASC and AC patients. In addition, FZD1 expression positively, but ACE2 expression negatively correlated with the expression of CA19-9 in SC/ASC and AC. Our study suggested that positive FZD1 and negative ACE2 expression are closely related to the expression of CA19-9; clinical, pathological, and biological behaviors; as well as poor-prognosis of gallbladder cancer.     

哺乳动物克隆及其应用前景

细胞核移植一词最早出现于Ｓｐｅｍａｎｎ(1938)所著《胚胎发育与诱导》一书中,他建议把发育后期的细胞核移植到去核的卵中,以研究细胞核的发育能力,但由于当时实验条件的限制而未能够实施。直到1952年,Ｂｒｉｇｇｓ和Ｋｉｎｇ才第一次报道了蛙的胚胎细胞核移植成功。Ｇｕｒｄｏｎ(1962)将爪蟾蝌蚪期肠上皮细胞核移植到去核的卵母细胞中,重构胚胎发育成正常的个体;而将成体爪蟾的肠上皮细胞核移入去核卵母细胞中时....     

Study on the interaction between protein and Eu(III)-chlorotetracycline complex and the determination of protein using the fluorimetric method.

Chlorotetracycline (CTC) can react with europium ions Eu3+, and the complex emits the intrinsic fluorescence of Eu3+. The intensity is greatly enhanced by proteins and this forms the basis of a new fluorimetric method for determination of protein. Further research indicates that under optimum conditions, the enhanced intensity of fluorescence is in proportion to the concentration of proteins, in the range 2.0 x 10(-7)-1.0 x 10(-5) g/mL for bovine serum albumin (BSA) (linear equation, I(f) = 34.35933 + 11.54467 x 10(6)C)(r = 0.99895) and 8.0 x 10(-7)-1.0 x 10(-5) g/mL for human serum albumin (HSA) (linear equation, I(f) = 76.58881 + 5.3569 x 10(6)C) (r = 0.99283). Detection limits (S/N = 3) were 8.9 x 10(-9) g/mL for BSA and 3.3 x 10(-8) g/mL for HSA. In an assay for BSA in calf serum, this method gave a value close to that determined by the UV spectrophotometric method.