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Biomedical subjects

S M Andersen

Publications and source records attributed to S M Andersen.

At least 19 recordsLinked to original sources
PubMed2001

Development and utilisation of a medium to isolate phenanthrene-degrading Pseudomonas spp.

In this study, we isolated phenanthrene degraders belonging to Pseudomonas spp. by combining the selective force of two previously described media. The two compounds, sodium lauryl sarcosine and trimethoprim, from the Gould S1 medium, were added to minimal agar plates sprayed with phenanthrene. Pseudomonas spp. that could produce clearing zones were isolated in one step from the rhizosphere without first selecting for Pseudomonas spp. and subsequently screening for degraders or vice versa. Enumeration and isolation of Pseudomonas spp. attached to the rhizosphere showed clear differences between two types of soil. Rhizosphere-attached phenanthrene degraders (from Pseudomonas spp.) were isolated from a former coal gasification site, but were absent in an agricultural soil subjected to organic farming. We isolated 23 phenanthrene degraders producing clearing zones from the rhizosphere of barley roots. All of these 23 isolates (of which 16 were fluorescent in UV light) proved to be members of the Pseudomonas RNA homology group I, on the basis of results of the analytical profile index (API) test system and classic taxonomic tests.

Bacteriological Techniques↗
PubMed2001

Mineralisation studies of 14C-labelled metsulfuron-methyl, tribenuron-methyl, chlorsulfuron and thifensulfuron-methyl in one Danish soil and groundwater sediment profile.

Bacterial mineralisation of four sulfonylurea herbicides at 20 microg kg(-1) in a sandy soil from nine different depths in a sandy soil horizon (5-780 cm) was investigated in laboratory studies. Metsulfuron-methyl, chlorsulfuron, and tribenuron-methyl were 14C-labelled in the sulfonamide ring, while thifensulfuron-methyl was labelled in the thiophene ring. The highest mineralised amount in 126 days was observed for metsulfuron-methyl (40%) followed by tribenuron-methyl (25%), and thifensulfuron-methyl (11%). Chlorsulfuron showed low mineralisation in all the soils tested (<4%). Mineralisation of the herbicides metsulfuron-methyl and tribenuron-methyl varied according to soil depth (upper profile: 5-70 cm, and lower profile: 165-780 cm) and were proven faster in soil taken from depths 5-7 and 30-35 cm, and slower in depths 45-50 and 70-75 cm. Mineralisation was absent in the lower profile (165-780 cm). As an indicator of microbial activity bacterial counts were taken at the experimental start; these counts grouped in three levels: highest in the surface layer (5-7 cm), slightly lower in the depths 30-75 cm, and lowest in the lower profile (165-780 cm). Residual concentrations of metsulfuron-methyl correlated to the accumulated amount mineralised, with high residual concentrations in soil showing low mineralisation. Also chlorsulfuron showed high residual concentrations with increasing depth in the upper profile, but the relatively high dissipation at 30-35 cm and lower one at 45-50 cm could not be related with the lack of mineralisation. This shows that hydrolysis occurs, but mineralisation of the chloro-substituted sulfonamide is restricted. Tribenuron-methyl and thifensulfuron-methyl could not be detected due to interference with other compounds.

Arylsulfonates↗
PubMed2001

Isolation and characterisation of Rhodococcus erythropolis TA57 able to degrade the triazine amine product from hydrolysis of sulfonylurea pesticides in soils.

We isolated a bacterium capable of metabolising a methylated and methoxylated s-triazine ring as the only nitrogen source. On a weight basis, the s-triazine, commonly named triazine amine (TAM), constitutes approx. half of several sulfonylurea herbicides and is formed after hydrolysis of these herbicides. The isolate, strain TA57 was identified using multi-phasic taxonomy as a gram-positive Rhodococcus erythropolis. Strain TA57 mineralised over 50% 14C-labelled TAM within 4 days in growing cultures using all of the nitrogen for growth. The degradation capacity was found stable in cells grown on either tryptic soy broth agar plates or in minimal medium with NH4+. Among other s-triazines tested, only one other methylated, but de-methoxylated s-triazine amine supported growth. Inoculating 10(6) cells of TA57 per gram of soil (d.w.) resulted in 50% mineralisation of 14C labelled TAM (1 mg kg(-1)) within 25 days, in contrary to the indigenous population that mineralised only 6% in 50 days.

Biodegradation, Environmental↗
PubMed2000

Syntheses of sugar-related trihydroxyazepanes from simple carbohydrates and their activities as reversible glycosidase inhibitors.

Five diastereomeric trideoxy-1,6-iminohexitols were synthesised, and their inhibitory activities were determined against selected glycosidases. For comparison, 1,4,5-trideoxy-1,5-imino-D-lyxo-hexitol, the 4-deoxy derivative of 1-deoxymannojirimicin, was prepared by enzymatic isomerisation of 6-azido-3,6-dideoxy-D-ribo-hexose into the corresponding 2-ulose and subsequent hydrogenation accompanied by intramolecular reductive amination.

Animals↗
PubMed2000

Pseudomonas frederiksbergensis sp. nov., isolated from soil at a coal gasification site.

Phenotypic and genotypic characterization indicated that a group of 29 closely related phenanthrene-degrading bacteria from a coal gasification site in Frederiksberg, Copenhagen, Denmark, belonged to the genus Pseudomonas. The strains were isolated at two sampling occasions 2 years apart. The isolates were phenotypically different from any known species of the genus Pseudomonas and were therefore subject to further identification. Colonies were smooth and pale yellowish and did not produce pigments fluorescent in UV light when grown on King's B agar. Cells were rod-shaped, approximately 0.5-0.8 x 1.5-3.0 microm, and grew at 4 and 30 degrees C, but not 37 degrees C. The bacteria were oxidase- and catalase-positive, accumulated poly-beta-hydroxybutyrate and denitrified, but did not utilize D-xylose. The mean G+C content was 59.6 mol%. Phenotypic data and 16S rDNA sequence data information for Pseudomonas amygdali and Pseudomonas corrugata, and 16S rDNA sequence data for Pseudomonas chlororaphis and Pseudomonas syringae showed close relationships to these strains. However, DNA-DNA hybridization data showed that the isolates belong to a new species, for which the name Pseudomonas frederiksbergensis sp. nov. is proposed. The type strain is JAJ28T (DSM 13022T).

Bacterial Typing Techniques↗
PubMed2000

The impact of past relationships on interpersonal behavior: behavioral confirmation in the social-cognitive process of transference.

This study extended research on transference in social perception (e.g., S. M. Andersen, I. Reznik, & L. M. Manzella, 1996) into the realm of social behavior by examining behavioral confirmation (e.g., M. Snyder, 1992) in transference. Each perceiver participated in a brief conversation with a naive target participant, who either did or did not appear to resemble the perceiver's own positively or negatively regarded significant other. Trained judges rated positive affect expressed in targets' behavior. As predicted, targets expressed more positive affect in their behavior when they allegedly resembled the perceiver's own positively versus negatively toned significant other, an effect not found in the control condition. This evidence demonstrates behavioral confirmation in transference, suggesting a means by which present relationships may resemble past ones.

Cognition↗
PubMed1999

Analysis of metsulfuron-methyl in soil by liquid chromatography/tandem mass spectrometry. Application to a field dissipation study.

An analytical method is described for the extraction of metsulfuron-methyl from soil at sub-parts per billion levels (LOQ = 0.2 microgram kg(-1)). The herbicide was quantitatively determined and identified by ESI LC/MS/MS. The method has been applied to a field dissipation study in which metsulfuron-methyl was applied to spring barley at three dosage rates: 4, 8, and 16 g of active ingredient ha(-)(1). The results of 2 years are presented. The dissipation rate of metsulfuron-methyl in topsoil was very rapid, with a calculated half-life of 6.5 days. Laboratory mineralization studies with native soils in contrast to autoclaved soils indicated that microbial degradation of (14)C-labeled metsulfuron-methyl and (14)C-labeled 2-amino-4-methoxy-6-methyl-1,3,5-triazine in soil microcosms is an important factor for the complete degradation of metsulfuron-methyl in the field. However, the mineralization rate of the sulfonamide was much higher.

Arylsulfonates↗
PubMed1999

Activating transference without consciousness: using significant-other representations to go beyond what is subliminally given.

Two studies examined nonconscious transference in social perception, defined as inferences about a new person based on a subliminally triggered significant-other representation (e.g., S. M. Andersen & S. W. Cole, 1990). In a nomothetic experimental paradigm involving idiographic stimuli, participants believed they were playing a computer game with another participant while exposed to subliminal descriptors from either their own, or a yoked participant's, significant other. In an impression-rating task, participants were more likely to infer that their "game partner" had significant-other features not subliminally presented when the subliminal cues described their own, rather than a yoked participant's, significant other. Another control condition in Study 1 ruled out self-generation effects. A subliminality check confirmed that stimuli were nonconscious. Hence, subliminal activation of significant-other representations and nonconscious transference occur.

Consciousness↗
PubMed1998

Mental representations of the self, significant others, and nonsignificant others: structure and processing of private and public aspects.

Using prior research on self and social inference (e.g., S. M. Andersen, 1984) and significant-other representations in social perception (S. M. Andersen & S. W. Cole, 1990), the present study examined a dual-factor conceptualization of self-other differences based on perspective differences and emotional-motivational relevance. Both factors were assumed to contribute to how private versus public aspects of the self, significant others, and nonsignificant others are structured in memory. In an idiographic-nomothetic design, participants' response latencies in completing sentences to characterize private and public aspects of each person were measured, and participants rated how well a pooled, randomized set of these predicates described each aspect of each person. Evidence showed differences in featural richness (availability), distinctiveness, and free-retrieval latency (accessibility) supporting the dual-factor conceptualization of self-other differences.

Adult↗
PubMed1996

The working self-concept in transference: significant-other activation and self change.

This research tested the hypothesis that changes in the working self-concept emerge in transference, defined as the activation and application of a significant-other representation to a new person and indexed by relevant inferences and memory (e.g., S. M. Andersen & A. Baum, 1994; S. M. Andersen, N. S. Glassman, S. Chen, & S. Cole, 1995). In an idiographic-nomothetic design, participants learned of a target person who resembled their own or a yoked participant's positively or negatively toned significant other. Results replicated the basic memory effect verifying transference. As predicted, the working self-concept changed in the transference condition. After learning about the new person, participants' freely listed self features shifted; the working self-concept became more infused with aspects of the self reflecting the self when with this significant other. Relevant changes in self evaluation were observed. Hence, changes in the working self-concept occurred in transference.

Analysis of Variance↗
PubMed1996

Eliciting facial affect, motivation, and expectancies in transference: significant-other representations in social relations.

Recent research has demonstrated transference in social perception, defined in terms of memory and schema-triggered evaluation in relation to a new person (S. M. Andersen & A. B. Baum, 1994; S. M. Andersen & S. W. Cole, 1990; S. M. Andersen, N. S. Glassman, S. Chen, & S. W. Cole, 1995). The authors examined schema-triggered facial affect in transference, along with motivations and expectancies. In a nomothetic experimental design, participants encountered stimulus descriptors of a new target person that were derived either from their own idiographic descriptions of a positively toned or a negatively toned significant other or from a yoked control participant's descriptors. Equal numbers of positive and negative target descriptors were presented, regardless of the overall tone of the representation. The results verified the memory effect and schema-triggered evaluation in transference, on the basis of significant-other resemblance in the target person. Of importance, participants' nonverbal expression of facial affect when learning about the target person (i.e., at encoding) reflected the overall tone of their significant-other representation under the condition of significant-other resemblance, providing strong support for schema-triggered affect in transference, through the use of this unobtrusive, nonverbal measure. Parallel effects on interpersonal closeness motivation and expectancies for acceptance/rejection in transference also emerged.

Affect↗
PubMed1995

Substance P mediated stimulation of cytokine levels in cultured murine bone marrow stromal cells.

Substance P (SP) is a neuropeptide which has been reported to have immunomodulatory activity. Most studies on SP have been performed on cells of the peripheral immune system. More recently, SP has been reported to have stimulatory activity on human bone marrow cells in vitro, and this activity was dependent on the presence of an adherent layer of cells. The in vitro adherent layer represents the stromal cells of the marrow. In this study, we directly addressed the effect of SP on cultured bone marrow stromal cells. Since stromal cells play an important role in the regulation of hematopoiesis, interactions of neuropeptides such as SP with this cell population could lead to an alteration of stem cell development within the bone marrow. Previously we have shown that SP stimulates protein synthesis in this cell population with two waves of protein synthesis activation, after 2 hr and 48 hr of SP incubation. In this study, we asked whether levels of known stromal cell cytokines were altered in response to SP incubation. We assayed the levels of Interleukin-7 (IL-7) and Stem Cell Factor (SCF) associated with the stromal cell surface following 2 hr and 48 hr of SP incubation. Cells were stimulated with SP for 2 hr or 48 hr. Following SP incubation, cells were washed and the levels of cell associated cytokine was determined by ELISA. Following 2 hr of treatment, 0.1 nM of SP significantly increased (p = 0.05) the level of IL-7 as compared to untreated controls. After 48 hr of treatment, 1, 10, and 100 nM SP significantly increased the levels of IL-7 in this cell population. When SCF levels were assayed, SP at all concentrations tested was found to increase significantly the levels of SCF following 2 hr of incubation. Following 48 hr of incubation, 10 and 100 nM of SP significantly increased the levels of SCF. The ability of SP to affect cytokine levels varied with time. Following 2 hr of SP incubation, cytokine levels were enhanced at the lower end of the concentration range as compared to 48 hr of SP treatment. A 48 hr incubation with SP yielded the highest levels of cytokine at the higher end of the concentration range. Taken together, the results of these studies suggest that SP has an immunoregulatory effect on bone marrow stromal cells leading to alteration in the production and/or secretion of regulatory cytokines such as IL-7 and SCF.

Adjuvants, Immunologic↗
PubMed1995

Transference in social perception: the role of chronic accessibility in significant-other representations.

Research has shown that the activation and application of a significant-other representation to a new person, or transference, occurs in everyday social perception (S. M. Andersen & A. Baum, 1994; S. M. Andersen & S. W. Cole, 1990). Using a combined idiographic and nomothetic experimental paradigm, two studies examined the role of chronic accessibility of significant-other representations in transference. After learning about 4 fictional people, 1 of whom resembled a significant other, participants' recognition memory was assessed. Both studies showed greater false-positive memory in the significant-other condition, relative to control, even in the absence of priming. Study 2 showed that although the effect was greater when the significant-other representation was concretely applicable to the target information, it occurred even when no such applicability was present. Results implicate the chronic accessibility of significant-other representations in transference.

Adolescent↗
PubMed1994

Transference in interpersonal relations: inferences and affect based on significant-other representations.

Based on an information-processing model of transference and a recent experimental demonstration of transference, defined in terms of "biased inference and memory" (Andersen & Cole, 1990), the present research examined the transfer of affective responses to a new individual, as in schema-triggered affect (Fiske, 1982). Using idiographic stimulus-generation procedures and a nomothetic experimental design, we exposed subjects to a description of a new, unknown person, allegedly seated next door. The description resembled either a positively or negatively toned significant other from the subject's own life or from another subject's life. As predicted, and replicating previous work, subjects misremembered the target person as having more representation-consistent features when the target resembled their own significant other rather than someone else's. Moreover, and also as predicted, subjects transferred more representation-consistent affect to this same target person. The data are discussed in terms of conceptions of transference and basic aspects of social cognition.

Affect↗
PubMed1992

Future-event schemas and certainty about the future: automaticity in depressives' future-event predictions.

The proposition was tested that depressives make predictions about the future based on a pessimistic future-event schema. Participants varying in depression predicted whether positive and negative events would happen to them (or to an average person) in the future by pressing yes or no at a computer terminal as quickly as possible, either under a concurrent attentional load or under no such load. As hypothesized, depressives predicted more negative events and fewer positive events than did mild depressives or nondepressives and showed greater automaticity in their predictions. That is, the attentional load did not increase depressives' response latencies for either negative or positive events, even though it did so reliably for both mildly depressed and nondepressed individuals. Depressives may thus possess a highly developed future-event schema that operates efficiently in enabling future-event predictions.

Adult↗