Formation of quinone methide in the self-cure of quinoid phenol formaldehyde resin

The study of the reaction of some methylenebisphenols with chloranil in ethanol and also of a phenol formaldehyde condensate prepared by acid catalysis, reveals that quinone methide is formed in the self-cure of quinoid phenol formaldehyde resin. The quinone methide reacts with ethanol to give an adduct. The structure of the alcohol adduct is identified by NMR and IR data and by means of pyrolysis.     

一种用ICA去除瞬态诱发耳声发射伪迹的新方法

如何去除伪迹是瞬态诱发耳声发射检测中一个关键的问题。本研究提出了一种用ICA去除伪迹的新方法。首先用四组线性增长的刺激声在耳道内录音 ,得到的波形是瞬态诱发耳声发射和伪迹的混叠。因为伪迹和瞬态诱发耳声发射是统计独立的 ,而且伪迹随刺激声的变化线性增长 ,而瞬态诱发耳声发射随刺激声的变化非线性增长 ,逐渐趋于饱和 ,所以它们在混叠信号中具有不同的混叠系数。用ICA算法可以将各独立分量及混叠矩阵估计出来 ,伪迹是其中的一个独立分量。然后将伪迹的波形置零后再进行一次混叠 ,便达到了去除伪迹的目的。最后通过与传统的DNLR方法比较 ,证明这种方法是有效的     

Wg3h细胞系转染PSV_2-neo质粒前后生长特性及表面超微结构改变的研究

本文对转染PSV_2-neo质粒后的Wg3h细胞系(Wg3h-neo)在长期传代中的生长特性和表面超微结构与母系Wg3h细胞进行了比较研究。结果发现:转染后Wg3h细胞的DNA合成及生长速度明显高于母系Wg3h细胞,生长饱和密度增大。在软琼脂培养中不形成集落,接种在裸鼠不长肿瘤。在扫描电镜下,细胞表面的微绒毛较母系Wg3h细胞丰富。Southern印迹杂交实验证明PSV_2-neo质粒已整合到宿主细胞的基因组中。转染后Wg3h细胞的生长特性和表面超微结构均发生了某些转化特征。     

Fos oncoprotein expression in the rat forebrain following muscimol-induced absence seizures

Fos oncoprotein expression is a marker of neuronal activation following seizures. Here, using this method we examined the anatomical locations of muscimol-induced absence seizures in the rat forebrain. Six hours after a systemic injection of muscimol a massive Fos immunoreactivity appeared in the olfactory system, retrosplenial cortex and paraventricular thalamic nucleus, whereas other cortical areas contained low level of Fos expression. These results provide the first functional morphological evidence suggesting that these forebrain structures with Fos expression may play an important role in the pathophysiology of muscimol-induced absence seizures.     

Use of enzyme-linked immunosorbent assays with chimeric fusion proteins to titrate antibodies against Epstein-Barr virus nuclear antigen 1.

Two new enzyme-linked immunosorbent assays (ELISAs) with chimeric fusion polypeptides for the detection of human antibodies specific to Epstein-Barr virus nuclear antigen 1 (EBNA-1) are described. One is an indirect ELISA with affinity-purified beta-galactosidase-EBNA-1 fusion protein as the antigen. The other is a "sandwich" assay based on the use of anti-beta-galactosidase antibody to capture beta-galactosidase-EBNA-1 fusion proteins in bacterial extracts. A good correlation was shown between antibody titers determined by the ELISA with the EBNA-1 fusion proteins and those determined by a conventional anticomplement immunofluorescence test which is being widely performed with Raji cells for the purpose of research and clinical diagnosis. The advantage of the ELISAs for seroepidemiologic studies on Epstein-Barr virus was demonstrated by sensitive detection of marginal immunoglobulin G antibody to the EBNA-1 domain in serum samples from patients with infectious mononucleosis.     

Digital detection of genetic mutations using SPC-sequencing

Deletion or insertion mutations lead to a frameshift that causes misalignment between wild-type and mutated allele sequences, making it difficult to identify such mutations unambiguously by using electrophoresis-based DNA sequencing. We have previously established the feasibility of an accurate DNA sequencing method using solid-phase capturable (SPC) dideoxynucleotides and MALDI-TOF mass spectrometry on synthetic templates, an approach we refer to as SPC-sequencing. Here, we report the application of SPC-sequencing in characterizing frameshift mutations by using the detection of the BRCA1 gene mutations 185delAG and 5382insC as examples. In this method, Sanger DNA sequencing fragments are generated in one tube by using biotinylated dideoxynucleotides. The sequencing fragments carrying a biotin moiety at the 3' end are captured on a streptavidin-coated solid phase to eliminate excess primer, primer dimers, and false stops. Only correctly terminated DNA fragments are captured, subsequently released, and analyzed by mass spectrometry to obtain digital DNA sequencing data. This method produces distinct doublet mass peaks at each point in the mass spectrum beyond the mutation site, facilitating the accurate characterization of the mutation. We have compared SPC-sequencing with electrophoresis-based sequencing in characterizing the above BRCA1 mutations, demonstrating the significant advantage offered by SPC-sequencing for the accurate identification of frameshift mutations.     

Molecular characterization of the full-length genome of the Japanese encephalitis viral strain K87P39

We have determined the complete nucleotide and deduced amino acid sequences of the Japanese encephalitis virus (JEV) strain K87P39, isolated from a pool of circulating Culex tritaeniorhynchus mosquitoes in Korea. In comparison with 27 fully sequenced JEV genomes currently available, we found that the 10968-nucleotide RNA genome of K87P39 has a nine-nucleotide deletion in the 3' nontranslated variable region and that its single open reading frame has a total of eight amino acid substitutions. The K87P39 isolate is highly similar to other JEV isolates, and homology ranges from 97.9 to 89.0% at the nucleotide level, and 99.1 to 96.7% at the deduced amino acid level. Phylogenetic analyses using the full-length sequence of the 27 available JEV genomes showed that the K87P39 strain is most closely related to six Chinese SA14 derivatives and that it is distantly related to the Australian FU, Korean K94P05 and Japanese Ishikawa strains. In addition, we also found that phylogenetic relationships based on the full-length genome are highly similar to those based on the E gene, indicating that phylogenetic analysis of the E gene will be useful for studying the genetic relationships among JEV isolates. We therefore performed a more extensive E gene-based phylogenetic analysis on a selection of 70 JEV isolates available from GenBank, which represent a temporally and geographically wide variety of JEV strains.     

白细胞介素—1对大鼠下丘脑室旁核Fos癌蛋白和CRF的诱导作用

将白细胞介素-1(IL)注入大鼠侧脑室,用Fos癌蛋白抗体免疫组化法检测了下丘脑室旁核的激活神经元:大量位于含促肾上腺皮质激素释放因子(CRF)相应区域的室旁核小细胞部神经元呈Fos免疫强阳性。Fos和CRF的免疫双染色显示了许多Fos免疫阳性神经元也呈CRF免疫阳性。此外,在IL-1注射动物中,CRF的免疫阳性显著加强,提示CRF合成增加。