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The usefulness of exogenous nicotine as a factor in the induction of morphogenesis in a tobacco tissue culture medium has been demonstrated. Nicotiana rustica callus cell cultures were grown on a modified Murashige and Skoog medium with 2 mg/l indoleacetic acid (IAA) and 0.2 mg/l kinetin (MMS). Root morphogenesis was induced in roller tube callus cell cultures and solid callus cell cultures grown on MMS without kinetin supplemented with 10-100 mg/l nicotine. Optimal nicotine concentration for root induction was 50 mg/l. Other tests using varying combinations of IAA, kinetin and nicotine produced no obvious morphogenesis, although some changes in the amount of callus growth and endogenous protein concentration did correlate with nicotine concentration relative to the presence of IAA and/or kinetin. In liquid MMS medium, 14C-nicotine was primarily incorporated into the protein fraction of cultured cells while primarily incorporated into the cell wall and/or cell membrane fraction of cells cultured on MMS without kinetin in the medium. In MMS without IAA and MMS without both IAA and kinetin, there was incorporation, but to a lesser extent in both the protein and the cell wall and/or cell membrane fractions. [ABSTRACT FROM AUTHOR]

Full elastolytic activity in Pseudomonas aeruginosa is a result of the combined activities of elastase, alkaline proteinase, and the lasA gene product, LasA. The results of this study demonstrate that an active fragment of the LasA protein which is isolated from the culture supernatant fraction is capable of degrading elastin in the absence of elastase, thus showing that LasA Is a second elastase produced by this organism. In addition, it is shown that LasA-mediated enhancement of elastolysis results from the separate activities of LasA and elastase upon elastin. The LasA protein does not affect the secretion or activation of a proelastase as previously proposed in other studies. Furthermore, LasA has specific proteolytic capability, as demonstrated by its ability to cleave β-casein. Preliminary analysis of β-casein cleavage in the presence of various protease inhibitors suggests that LasA may be classified as a modified serine protease. [ABSTRACT FROM AUTHOR]

In clinical trials of potential pharmacotherapies for cocaine addiction, objective determination of subject relapse relies on qualitative urine analysis for benzoylecgonine, the major metabolite of cocaine. Unlike qualitative analysis, quantitative measurement allows differentiation between continued cocaine use and a single use, as well as identification of changes in the quantity of cocaine used at different times. The only quantitative technique that has been used is expensive and not generally feasible. This study was performed to modify an existing qualitative technique for use as a new simple and readily available quantitative method for identifying cocaine use among research subjects. Benzoylecgonine levels in 24-hour urine specimens collected from 11 cocaine-addicted subjects hospitalized in a research setting were measured semi-quantitatively by fluorescence polarization immunoassay. Accurate results required thorough mixing of urine specimens prior to analysis. At admission, eight subjects had urinary benzoylecgonine levels > or = 0.30 microgram/ml, the standard positive/negative cut-off used in qualitative analysis. The mean half-life of benzoylecgonine during initial elimination was 0.46 +/- 0.08 (SEM, n = 8) days. Benzoylecgonine (BE)/creatinine (C) levels remained > or = 0.30 microgramBE/mgC for 4.8 +/- 0.5 (n = 8) days and > or = 0.03 microgramBE/mgC for 10.5 +/- 1.5 (n = 8) days. Relapses in three subjects could be identified by quantitative analysis. This study indicates that quantitation of benzoylecgonine in daily urine specimens provides a sensitive, objective index to cocaine use.

Prenatal and perinatal correlates of abnormal auditory brainstem responses in neonates have been studied extensively. In contrast, vestibular function during the first year of life has received sparse attention. Using a specially modified vestibular test battery, 65 infants (17 low-risk, 48 high-risk) were initially evaluated during their first 6 months of life. Results revealed normal vestibular function in 46 infants (13 low-risk, 33 high-risk) and abnormal findings at either 3 or 6 months in 19 infants (4 low-risk, 15 high-risk). Correlations between vestibular results and variables such as auditory brainstem response results, birth history, and postnatal course in the neonatal intensive care unit were analyzed statistically. While some differences were mildly significant, none were highly significant. The lack of significant correlation between abnormal auditory brainstem response and vestibular results is of particular interest.