Rapid sequencing of cloned DNA using a transposon for bidirectional priming: sequence of the Escherichia coli K-12 avtA gene.

A new approach to determining the sequence of cloned DNA is described. Unique regions near each end of the transposable element gamma-delta provide a pair of "portable" primer-specific sites for bidirectional sequencing by the dideoxy chain termination method. A set of gamma-delta insertions positioned about 200 bp apart over the entire cloned DNA allowed us to determine the sequence of both strands in a single parental plasmid without subcloning. The avtA (alanine-valine transaminase) gene of E. coli K-12 was sequenced by this approach. Surprisingly, gamma-delta insertions downstream of the coding region were found to significantly reduce avtA expression. We suggest that these nondisruptive insertions probably change the DNA topology and thereby alter gene expression.     

Evolutionarily conserved promoter motifs and enhancer organization in the mouse gene encoding the IIB myosin heavy chain isoform expressed in adult fast skeletal muscle.

We have isolated the mouse gene for the MHC isoform expressed in adult type IIB (fast-contracting, glycolytic) skeletal muscle fibers, and determined the DNA sequence of the promoter region. This sequence represents the first example of a promoter for a gene encoding an adult-specific isoform of a mammalian skeletal MHC. The proximal 200 bp of the promoter contains several sequence motifs which are identical or very similar to homologous motifs found in the promoters of a family of chicken skeletal MHC genes. Of these, two novel AT-rich sequences may be important for regulation of the promoter. A second feature of the mouse IIB MHC promoter sequence concerns a number of sequence motifs located at ca. -1,000 bp which are organized in a similar fashion in the IIB MHC promoter and a homologous region of promoter of the mouse muscle creatine kinase gene.     

RENOVASCULAR HYPERTENSION—A Review

Recognition of renal artery occlusion as a cause for hypertension is resulting in a systematic search for the patient with a potentially curable vascular lesion. Radioisotope renography, differential renal function studies and renal arteriography serve as screening studies to aid in the diagnostic evaluation. Vascular reconstructive operation was employed in 13 patients.     

Detection of tubulin and actin in various cell lines by an immunoperoxidase technique.

This paper reports on the preparation of immunsera against tubulin and actin, and the purification of anti-tubulin and anti-actin antibodies on immunoadsorbent columns. These purified antibodies were used in an indirect immunoperoxidase assay to visualize microtubules and microfilaments in various cell lines. The specificity of antibodies and the methods of cell fixation required are discussed, as well as some aspects of microtubule and microfilament organization, as visualized by this technique.     

Edible Myrciaria vexator fruits: bioactive phenolics for potential COPD therapy

The edible fruits of Myrciaria vexator McVaugh (Myrtaceae), from northern South America, are eaten in certain locales, either fresh or processed into jellies and drinks. Activity-guided fractionation of M. vexator resulted in identification of ellagic acid (1), cyanidin-3-O-glucoside (2), delphinidin-3-O-glucoside (3), 2-O-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxyphenylacetic acid (4), and jaboticabin (5), and latter two compounds are being reported for the first time in this species. Ellagic acid was further examined, and found to inhibit cigarette smoke extract induced MMP-1 expression in vitro, and may be of significance in the treatment of chronic obstructive pulmonary (COPD). Other compounds identified for the first time from M. vexator include cyanidin-3-O-galactoside (6), cyanidin-3-O-arabinoside (7), cyanidin-3-O-rutionoside (8), petunidin (9), peonidin-3-O-galactoside (10) malvidin (11), hyperoside (12), querecetin-3-O-glucoside (13), and guajaverin (14), methyl protocatechuate (15), and protocatechuic acid (16).