The EbpA-RpoN Regulatory Pathway of the Pathogen Leptospira interrogans Is Essential for Survival in the Environment.

Leptospira interrogans is the agent of leptospirosis, a reemerging zoonotic disease. It is transmitted to humans through environmental surface waters contaminated by the urine of mammals chronically infected by pathogenic strains able to survive in water for long periods. Little is known about the regulatory pathways underlying environmental sensing and host adaptation of L.

[Spectrum-Effect Relationship of GualouXiebai Dropping Pills on Myocardial Ischemia].

Objective: To study the relationship between HPLC characteristic spectrum and pharmacodynamics on anti-myocardial ischemia of GualouXiebai dropping pills.

Methods: HPLC characteristic spectrum of GualouXiebai dropping pills was established, dropping pills were divided into five dose groups (3.75, 11.

[Study on HPLC Fingerprint of Trichosanthes Fruit and Its Processed Products].

Objective: To study the correlation on chemical fingerprint features between Trichosanthis Fructus and its processed products.

Methods: The chemical fingerprints were established by HPLC for the ethyl acetate extraction and the n-butanol extraction in Trichosanthis Fructus and its processed products,the common pattern was established by the mean and the median, and the similarity degree between Trichosanthis Fructus and its processed products was calculated by the correlation coefficient method and the included angle cosine method.

Results: There were 24 common peaks in the fingerprints of ethyl acetate extraction of Trichosanthis Fructus and its processed products,the average similarity degree was calculated separately by the correlation coefficient method and the included angle cosine method:the former as the value was 0.

Function and Identification of a Novel Silencer in 5' Flanking Distal Region of Human beta Globin Gene.

In order to inquire into the possible function of the sequence in the 5' flanking distal region and/or delta-beta intergene of human beta-globin gene several recombinant retrovirus vectors containing beta-globin gene with different length of 5' flanking sequences were constructed and transfected into Hela cells. The levels of beta-globin gene expression determined quantitatively by Northern blotting and RT-cPCR revealed that there is a strong silencer activity in a DNA sequence(723 bp) between-2282 bp and -1559 bp upstream from the cap site of beta-globin gene. The silencer activity was further identified to be possibly located mainly on a 310bp DNA restriction fragment by using the competitive gel retardation assay(cGRA) and many known regulatory elements were found present in it as well.

Structure and Function of a Novel Silencer in 5' Flanking Distal Region of Human beta Globin Gene.

A novel silencer fragment(310 bp) was recently discovered and identified to locate between -2 132 bp and -1 822 bp upstream from the cap site of beta-globin gene by gel retardation assay and luciferase reporter gene expression analysis. DNA footprinting assays were performed to determine the interaction between its DNA sequence and binding proteins from the nuclear extract of Hela cells. The results showed that there were two nuclear protein binding sites in thissilencer, one was the -2 017--2 011 bp sequence CTTCCGC" and the other was the -2 006--1 997 bp sequence "CACTTTATTT".