109 research outputs found
The optimal screening interval for gastric cancer using esophago-gastro-duodenoscopy in Japan
Molecular cloning of pertussis toxin genes.
We have cloned a 4.5 kb EcoRI/BamHI DNA fragment from Bordetella pertussis which contains at least two genes responsible for expression of pertussis toxin. The S4 subunit of the toxin was isolated by high pressure liquid chromatography and the NH2-terminal amino acid sequence determined. Using a mixed synthetic oligonucleotide probe designed by reverse translation of a portion of the protein sequence, a cloned DNA fragment was identified which contains the coding information for at least the S4 structural subunit of the toxin. Sequence analyses indicate that the mature protein is derived by proteolytic cleavage of a precursor molecule. Southern blot analyses of Tn5-induced B. pertussis toxin-deficient mutants show that the Tn5 DNA is inserted 1.3 kb downstream from the S4 subunit gene. This second gene could code for another subunit required for assembly of the mature toxin or a non-structural transport protein, possibly in the same polycistronic operon. The molecular cloning of pertussis toxin genes provides the basis for development of a safer recombinant "new generation" vaccine for whooping cough
Investigations on the correlation between abnormalities of neuromuscular transmission due to some organophosphates and activity of acetylcholinesterase in the skeletal muscle
Dynamical structures for southwesterly airflow over southern Norway: the role of dissipation
Has life satisfaction in Norway increased over a 20-year period? Exploring age and gender differences in a prospective longitudinal study, HUNT
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