Change of concanavalin A induced agglutinability during preimplantation mouse development

Mouse embryos during early cleavage (zygote to eight-cell stage) were agglutinable with a low concentration (10 μg/ml) of concanavalin A (ConA). This agglutinability was reduced during the first mitotic division. Morulae were agglutinable with a slightly higher concentration (100 μg/ml), whereas blastocysts were not agglutinable even with ConA at a concentration of 5000 μg/ml; however, isolated inner cell masses agglutinated readily at 10 μg/ml of ConA. Embryos grown in vitro behaved as did those isolated directly from the genital tract. Treatment with proteolytic enzymes did not induce agglutinability of mouse blastocyst. The change in agglutinability of trophoblastic cells reflects dramatic changes in the cell surface.     

Ultrastructural localization of cytoplasmic phosphatases in preimplantation mouse embryos.

The appearance and localization of the cytoplasmic phosphatases [acid phosphatase (AcPase) as a marker of lysosomes, TPPase as a marker of the Golgi apparatus, and NDPase (IDPase) as enzymatic marker of the endoplasmic reticulum (ER)] were cytochemically studied on the ultrastructural level in secondary oocytes and in preimplantation mouse embryos. The detectable AcPase activity, located on the inner surface of the membrane delimiting some cytoplasmic vacuoles (lysosomes and autophagic vacuoles), appears at the eight-cell stage and grows pregressively stronger up to the blastocyst stage. Golgi-associated reaction for TPPase was detectable in oocytes, dropped in one-cell embryos and became negative in the two-cell embryos. The reaction for TPPase and IDPase was present in plasma membranes of oocytes and early embryos and appeared in the delimiting membrane of some cytoplasmic vesicles in eight-cell embryos. Some activity of IDPase was found in small segments of the ER at the morula and blastocyst stage. The observed results suggest that the lysosomes are the first organelles in early embryos showing activity of the marker enzymes of the phosphatase type, while the activity of other marker enzymes is mainly concentrated in the plasma membrane of blastomeres. It cannot be excluded, however, that positive reaction for TPPase and IDPase in the plasma membrane results from nonspecific action of other phosphatases.     

Isocitrate dehydrogenase 1 R132C mutation occurs exclusively in microsatellite stable colorectal cancers with the CpG island methylator phenotype

The CpG Island Methylator Phenotype (CIMP) is fundamental to an important subset of colorectal cancer; however, its cause is unknown. CIMP is associated with microsatellite instability but is also found in BRAF mutant microsatellite stable cancers that are associated with poor prognosis. The isocitrate dehydrogenase 1 (IDH1) gene causes CIMP in glioma due to an activating mutation that produces the 2-hydroxyglutarate oncometabolite. We therefore examined IDH1 alteration as a potential cause of CIMP in colorectal cancer. The IDH1 mutational hotspot was screened in 86 CIMP-positive and 80 CIMP-negative cancers. The entire coding sequence was examined in 81 CIMP-positive colorectal cancers. Forty-seven cancers varying by CIMP-status and IDH1 mutation status were examined using Illumina 450K DNA methylation microarrays. The R132C IDH1 mutation was detected in 4/166 cancers. All IDH1 mutations were in CIMP cancers that were BRAF mutant and microsatellite stable (4/45, 8.9%). Unsupervised hierarchical cluster analysis identified an IDH1 mutation-like methylation signature in approximately half of the CIMP-positive cancers. IDH1 mutation appears to cause CIMP in a small proportion of BRAF mutant, microsatellite stable colorectal cancers. This study provides a precedent that a single gene mutation may cause CIMP in colorectal cancer, and that this will be associated with a specific epigenetic signature and clinicopathological features.     

奥美拉唑联合法莫替丁治疗反流性食管炎的临床效果分析

目的：观察并分析奥关拉唑联合法莫替丁治疗反流性食管炎的临床效果。方法：选取2008年5月至2012年5月在本院确诊并治疗的反流性食管炎患者45例,随机平均分为三组。联合用药组（15例）：每日早餐前口服20mg奥关拉唑,睡前口服20mg法莫替丁;奥关拉唑组（15例）：每日口服两次奥美拉唑,每次20mg;法莫替丁组（15例）：每日口服两次法莫替丁,每次20mg。每组的治疗时间均为8周。在内镜指导下观察并比较三组患者的胸痛、反酸和烧心等主要病征的改善情况,综合评价三种治疗方法的临床疗效。结果：联合用药组较其他两组获得的疗效更明显,患者的症状得到较好的改善,差异有统计学意义（P〈0．05）。结论：奥美拉唑联合法莫替丁能够有效地抑制胃酸的分泌,对于反流性食管炎的,临床治疗具有良好的效果。     

Infectivity of Four Species of Nematodes (Rhabditoidea: Steinernematidae, Heterorhabditidae) to the Asian Longhorn Beetle, Anoplophora glabripennis (Motchulsky) (Coleoptera: Cerambycidae)

Four species of entomopathogenic nematodes, Steinernema carpocapsae , Heterorhabditis bacteriophora , H. indica and H. marelatus , were tested for their ability to kill and reproduce in larvae of the Asian longhorn beetle, Anoplophora glabripennis (Motchulsky). The larvae were permissive to all four species but mortality was higher and production of infective juveniles was greater for S. carpocapsae and H. marelatus . The lethal dosage of H. marelatus was determined to be 19 infective juveniles for second and third instar larvae and 347 infective juveniles for fourth and fifth instar larvae. H. marelatus infective juveniles, applied via sponges to oviposition sites on cut logs, located and killed host larvae within 30 cm galleries and reproduced successfully in several of the larvae.     

Transgenic markers for mammalian chimeras

Summary We describe the construction of aggregation chimeras between normal and transgenic embryos containing multiple copies of mouse -globin genes. The transgenic component of the chimeras is then detected in tissue sections by a DNA-DNA in situ hybridization technique, using a biotinylated DNA -globin probe and an avidin-linked alkaline phosphatase detection system. The general advantages of transgenic markers for chimeras are discussed.     

Demonstrability of some oxidative enzymes in early rodent embryos with and without fixation

Several oxidative enzymes [NADH-TR (reduced nicotinamide-adenine dinucleotide-tetrazolium reductase), NADPH-TR (reduced nicotinamide-adenine dinucleotide phosphate-tetrazolium reductase), SDH (succinic dehydrogenase) and LDH (lactate dehydrogenase)] were studied by histochemical means during early development of rat and mouse. All investigated enzymes could be easily demonstrated in zygote and also to some extent in somitic stages without any pretreatment. However, in cleavage and early postimplantation stages enzyme activity could be revealed only after the embryos were pretreated in some way. This pretreatment can be fixation with formalin or acetone, freezing and thawing, slight mechanical damage or very prolonged incubation time. The formazan granules as a sign of enzymatic activity were present in all stages of embryonic development and were more abundant in reactions for NADH-TR and LDH than in reactions for NADPH-TR and SDH. Our results suggest that the investigated enzymes are present in all embryonic cells during early development. It seems that the permeability of embryonic cells for histochemical media must be increased otherwise the histochemical reactions cannot be accomplished.