Direct detection of Borrelia burgdorferi in Ixodes scapularis (Acari: Ixodidae) nymphs by hybridization to ribosomal RNA.

A method for direct detection of Borrelia burgdorferi Johnson, Schmid, Hyde, Steigerwalt & Brenner has been developed. Cells are lysed to facilitate release of ribosomal RNA. Lysates are filtered onto nylon membranes that are hybridized with probes specific for sequences in B.

Induction of apoptosis and cell cycle-specific change in expression of p53 in normal lymphocytes and MOLT-4 leukemic cells by nitrogen mustard.

DNA damage in the cell activates expression of the p53 tumor suppressor gene, whose role is associated with cell arrest in G1 or apoptosis. The aim of this study was to examine the cell cycle position-related changes in expression of p53, as well as induction of apoptosis, in mitogen-stimulated normal human lymphocytes and in human leukemic MOLT-4 cells (which express mutated p53), following DNA damage by the alkylating agent nitrogen mustard. Measurement of p53 expression and DNA content by flow cytometry followed by bivariate analysis of the data made it possible to correlate the drug-induced changes in p53 expression in individual cells with their cell cycle position without the need for cell synchronization.

Functional analysis of a CArG-like promoter element in cardiac myosin light chain 2 gene.

We have examined the functional properties of a putative regulatory sequence, CCAAAAGTGG, (element A) in chicken cardiac myosin light chain 2 (MLC2) gene promoter by deletion/substitution mutagenesis and transcriptional analysis of RNA by S1 nuclease mapping. The results indicate that the element A sequence, which resembles the evolutionarily conserved A/T-rich CArG box, plays a role in defining the transcription initiation site in MLC2 gene. This is accomplished via repression of a potential transcription initiation at site -40 and promoting the initiation at +1.

Native low density lipoprotein. Endothelial cell recruitment of mononuclear cells.

The effect of native low density lipoprotein (LDL) on human umbilical vein endothelial cell (EC) recruitment of mononuclear cells (Monos) was investigated. ECs were exposed to LDL at atherogenic concentrations (240 mg cholesterol [Chol]/dl) for as long as 4 days (LDL-treated ECs). LDL-treated ECs bound substantially greater amounts of freshly isolated human monocytes and U937 cells than did control ECs.

Studies on the assembly and secretion of fibrinogen.

cDNAs of fibrinogen A alpha and gamma chains were individually subcloned into a eukaryotic expression vector by using the polymerase chain reaction. Triple cotransfection into COS cells of the two plasmids together with a B beta chain expression plasmid, constructed as described previously (Danishefsky, K.J.