BACKGROUND Microcinephotography was used to study a model of persistent truncus arteriosus created in chick embryos by ablation of premigratory neural crest destined for the third and fourth aortic arch arteries as well as the septum of the cardiac outflow tract. METHODS AND RESULTS Twenty-five control embryos and 105 of 202 experimental embryos were filmed on day 3 of incubation and then rei...

Background. Microcinephotography was used to study a model of persistent truncus arteriosus created in chick embryos by ablation of premigratory neural crest destined for the third and fourth aortic arch arteries as well as the septum of the cardiac outflow tract. Methods and Results. Twenty-five control embryos and 105 of 202 experimental embryos were filmed on day 3 of incubation and then rei...

in English..........................................................................................................................223 Abstract in Danish ..........................................................................................................................225

Vkry variable incubation periods have been given by different observers, making it most difficult to make any definite, authoritative statement on the subject. Thus Ralph Hopkins of Lousiana places it at six to eight years, Besnier says it is usually four years, Iveravel in the Caucasus found it to be three to four years in a few cases where it could be definitely fixed, while Munch of South Ru...

Recent findings revealed that the commonly used (15)N2 tracer assay for the determination of dinitrogen (N2) fixation can underestimate the activity of aquatic N2-fixing organisms. Therefore, a modification to the method using pre-prepared (15-15)N2-enriched water was proposed. Here, we present a rigorous assessment and outline a simple procedure for the preparation of (15-15)N2-enriched water....

Previous studies have suggested a role for glucocorticoids in the differentiation of the acinar pancreas. We have now used the rat tumor cell line AR42J, derived from the acinar pancreas, to directly study this effect of glucocorticoids in vitro. The steroid hormones dexamethasone, corticosterone, aldosterone, and progesterone, but not estrogen, increased both the amylase content and the number...

Sterility testing as described in the pharmacopoeia compendia requires a 14-day incubation period to obtain an analytical result. Alternative methods that could be applied to evaluating product sterility are especially interesting due to the possibility of reducing this incubation period and thus the associated costs. The aims of this study were to evaluate the performance of the BacT/ALERT(R) ...

The effects of volume of blood, number of consecutive cultures, and incubation time on pathogen recovery were evaluated for 37,568 blood cultures tested with the automated BACTEC 9240 instrument (Becton Dickinson Diagnostic Instrument Systems) at a tertiary care center over the period of 12 June 1996 through 12 October 1997. When the results for this study were compared with previous data publi...