Mycobacterial DNA gyrase: enzyme purification and characterization of supercoiling activity.

Putative structural genes encoding Mycobacterium bovis BCG gyrase A and gyrase B subunits were expressed in Escherichia coli under the control of a regulated promoter. Upon induction, high levels of proteins of M(r) 92,000 and 75,000 were generated. Purification and reconstitution of these proteins yielded an enzyme with bacterial DNA gyrase activity.

Expression and characterization of the trans-activating protein Tax of human T-cell leukemia virus type I in Saccharomyces cerevisiae.

The trans-activator protein Tax of human T-cell leukemia virus type I (HTLV-I) stimulates transcription of the viral genome from the long terminal repeat. With a reporter HIS4TATA::lacZ fusion gene, the transcriptional activity of the Tax-responsive element in the long terminal repeat was tested in Saccharomyces cerevisiae. We found that fragments containing the 21-bp repeat of the HTLV-I enhancer stimulate synthesis of beta-galactosidase activity 15- to 20-fold.

Premarital HIV-1 testing in New Jersey.

To answer questions related to the usefulness of premarital testing for human immunodeficiency virus type 1 (HIV-1), two "blinded" or "nonlinked" HIV-1 serosurveys were done in New Jersey, a state with a high incidence of AIDS, on blood specimens submitted for a premarital serologic test for syphilis. The first survey involved premarital blood specimens submitted to the New Jersey Department of Health laboratory for the year starting September 1987. The second survey involved premarital specimens submitted to five private or hospital clinical laboratories in the spring of 1989, of which approximately 1,000 consecutive premarital specimens from each laboratory were sent to the Department of Health laboratory for HIV-1 testing.

Antibody testing in Lyme disease. A comparison of results in four laboratories.

To evaluate the interlaboratory and intralaboratory agreement in the performance of Lyme disease serological testing, we sent serum specimens from 132 outdoor workers in New Jersey to as many as four independent laboratories. These included one state department of health laboratory, one large commercial laboratory, and two research laboratories. The measurement of agreement employed, the kappa statistic, ranged from .