Optimal transcription of the lac operon in a defined purified in vitro system is dependent upon the concentrations of cyclic adenosine 3’,5’-monophosphate (cyclic AMP), the cyclic AMP-binding protein (CRP) and RNA polymerase. The concentration of CRP required for maximal Zac transcription varies proportionately with the concentration of lac DNA used as template. Maximal Zac transcription is obt...

Bigio et al. (1) report that oral administration of acetyl-Lcarnitine (LAC) results in antidepressant-like effects along with an improvement of energy metabolism in the ventral dentate gyrus in endogenously depressed Flinders Sensitive Line rats (FSL). FSL also show a significant reduction of LAC in the hippocampus and prefrontal cortex compared with Flinders Resistant Line rats (2). However, i...

Among antiphospholipid antibodies, Lupus Anticoagulant (LAC) is recognized as the strongest risk factor for thromboembolic events or pregnancy morbidity.1 The presence of LAC in a subject with previously documented thromboembolism or a significant history of pregnancy loss defines the Antiphospholipid Syndrome (APS). Some patients, however, are diagnosed with LAC without ever having experienced...

The suicide plasmid pVA838 carrying the operon fusion transposon Tn5-lac was used as a delivery system to introduce Tn5-lac into Pseudomonas sp. strain M114. Random, in vivo lac gene fusions were successfully isolated in a one-step conjugation approach with this vector system. Tn5-lac-containing exconjugants were recovered at a frequency of approximately 10(-7) per recipient. However, when the ...

An assay system for the in vitro transcription of the lac operon is described. A protein factor (CAP) and cyclic AMP, which are essential for the lac expression in vivo, also stimulate lac transcription in vitro.

The origin of mutations under selection has been intensively studied using the Cairns-Foster system, in which cells of an Escherichia coli lac mutant are plated on lactose and give rise to 100 Lac+ revertants over several days. These revertants have been attributed variously to stress-induced mutagenesis of nongrowing cells or to selective improvement of preexisting weakly Lac+ cells with no mu...

INTRODUCTION Decreases in oxygen saturation (SO2) and lactate concentration [Lac] from superior vena cava (SVC) to pulmonary artery have been reported. These gradients (Delta SO2 and Delta[Lac]) are probably created by diluting SVC blood with blood of lower SO2 and [Lac]. We tested the hypothesis that Delta SO2 and Delta[Lac] result from mixing SVC and inferior vena cava (IVC) blood streams. ...

The molecular mechanism of down-regulated microRNA-145 (miR-145) expression in lung adenocarcinoma (LAC) remains largely unknown. We hypothesized that aberrant hyper-methylation of the CpG sites silenced the expression of miR-145 in LAC. In consideration of its pivotal role in LAC development and progression, we also evaluated the clinical utility of miR-145 as a prognostic marker. We assessed ...