[Relationships between children and dogs, prevention of bites].
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Aggression↗
Biomedical subjects
L Kern
Publications and source records attributed to L Kern.
Analysis of the estrogen regulation of the zebrafish estrogen receptor (ER) reveals distinct effects of ERalpha, ERbeta1 and ERbeta2.
We have previously cloned and characterized three estrogen receptors (ER) in the zebrafish (zfERalpha, zfERbeta1 and zfERbeta2). We have also shown that they are functional in vitro and exhibit a distinct expression pattern, although partially overlapping, in the brain of zebrafish. In this paper, we have shown that the hepatic expression of these zfER genes responds differently to estradiol (E2). In fact, a 48-h direct exposure of zebrafish to E2 resulted in a strong stimulation of zfERalpha gene expression while zfERbeta1 gene expression was markedly reduced and zfERbeta2 remained virtually unchanged. To establish the potential implication of each zfER in the E2 upregulation of the zfERalpha gene, the promoter region of this gene was isolated and characterized. Transfection experiments with promoter-luciferase reporter constructs together with different zfER expression vectors were carried out in different cell contexts. The data showed that in vivo E2 upregulation of the zfERalpha gene requires ERalpha itself and a conserved transcription unit sequence including at least an imperfect estrogen-responsive element (ERE) and an AP-1/ERE half site at the proximal transcription initiation site. Interestingly, although in the presence of E2 zfERalpha was the most potent at inducing the expression of its own gene, the effect of E2 mediated by zfERbeta2 represented 50% of the zfERalpha activity. In contrast, zfERbeta1 was unable to upregulate the zfERalpha gene whereas this receptor form was able to tightly bind E2 and activate a reporter plasmid containing a consensus ERE. Altogether, these results indicated that the two ERbeta forms recently characterized in teleost fish could have partially distinct and not redundant functions.
Animals↗
Peptide insertion in the DNA-binding domain of fish glucocorticoid receptor is encoded by an additional exon and confers particular functional properties.
The trout glucocorticoid receptor (rtGR) contains an additional sequence of nine amino acids located between the two zinc fingers of the DNA-binding domain (DBD) (Endocrinology 136 (1995) 3774). Polymerase chain reaction on trout genomic DNA and sequencing were performed in the DBD region, demonstrating that this peptide is encoded by an additional exon of 27 nucleotides between the two exons encoding the two zinc fingers of other nuclear receptors. This additional sequence in the rtGR confers a better binding affinity of the receptor to a single GRE, as shown by gel shift experiments with GST-DBDrtGR fusion proteins, deleted or not of the nine amino acids (Delta9). This higher affinity is correlated with a higher constitutive transcriptional activity of the receptor on a reporter gene driven by a single GRE, but not with the ligand-induced transcriptional activity. Nevertheless, on a double GRE, the wild type and rtGR-Delta9 are equally active on both constitutive or dexamethasone-induced transcriptional activity. This original DBD structure could have emerged during evolution such as to allow better regulation of glucocorticoid dependent genes in relation to the large spectrum of cortisol physiological functions in fish.
Amino Acid Sequence↗
Classroom-based functional and adjunctive assessments: proactive approaches to intervention selection for adolescents with attention deficit hyperactivity disorder.
The present investigation evaluated the utility of classroom-based functional and adjunctive assessments of problem behaviors for 2 adolescents who met diagnostic criteria for attention deficit hyperactivity disorder (ADHD) and comorbid oppositional defiant disorder (ODD). For children with ADHD-ODD, environmental classroom variables, when systematically manipulated by teachers, were related to the occurrence and nonoccurrence of problem behaviors. Classroom interventions derived from information that was obtained during functional and adjunctive assessments and from subsequent analyses resulted in substantial reductions in problem behaviors. Teacher and student consumer satisfaction ratings indicated that the interventions were effective and feasible in the classroom setting.
Adolescent↗
The nuclear orphan receptors COUP-TF and ARP-1 positively regulate the trout estrogen receptor gene through enhancing autoregulation.
The rainbow trout estrogen receptor (rtER) is a positively autoregulated gene in liver cells. In a previous report, we showed that upregulation is mediated by an estrogen response element (ERE) located in the proximal promoter of the gene and that a half binding site for nuclear receptors (5'-TGACCT-3') located 15 bp upstream of the ERE is involved in the magnitude of the estrogen response. We now report that the human orphan receptor COUP-TF and a COUP-TF-like protein from trout liver are able to bind to the consensus half-site. When cotransfected with the rtER gene proximal promoter, COUP-TF had no regulatory functions on its own. Interestingly, COUP-TF enhanced rtER transactivation properties in the presence of estradiol in a dose-dependent manner when cotransfected with the rtER gene promoter. Unliganded retinoid receptor heterodimers had the same helper function as COUP-TF in the presence of estradiol but were switched to repressors when the ligand all-trans-retinoic acid was added. Mutation of the consensus half-site only slightly reduced COUP-TF helper function, suggesting that it actually results from a complex mechanism that probably involves both DNA binding of COUP-TF to the promoter and protein-protein interaction with another transcription factor bound to the promoter. Nevertheless, a DNA-binding-defective mutant of COUP-TF was also defective in ER helper function. Competition footprinting analysis suggested that COUP-TF actually establishes contacts with the consensus upstream half-site and the downstream ERE half-site that would form a DR-24-like response element. Interaction of COUP-TF with the DR-24 element was confirmed in footprinting assays by using nuclear extracts from Saccharomyces cerevisiae expressing COUP-TF. Finally, interaction of COUP-TF with mutants of the rtER gene promoter showed that COUP-TF recognizes the ERE when the upstream half-site is mutated. These data show that COUP-TF may activate transcription through interaction with other nuclear receptors. This cross-talk between liganded nuclear receptors and orphan receptors is likely to modulate the spectrum of action of a particular ligand-receptor complex and may participate in the cell-type specificity of the ligand effect.
Animals↗
Cooperation between the human estrogen receptor (ER) and MCF-7 cell-specific transcription factors elicits high activity of an estrogen-inducible enhancer from the trout ER gene promoter.
The human estrogen receptor (hER) is expressed in breast cancer MCF-7 cells and plays a major role in tumorigenic processes. In this report, we demonstrate that MCF-7-specific factors can cooperate with the hER to increase its transactivation activity. We previously demonstrated that the rainbow trout ER (rtER) gene is up-regulated by the rtER protein itself, through an enhancer that contains an imperfect estrogen-responsive element (FP1 area). By performing footprinting experiments, we have delineated two other regulatory regions (FP2 and FP3 areas) in the 0.2-kb enhancer. We show, by transient transfections, that hER poorly transactivates this enhancer in CHO-K1 and Ishikawa cells whereas, in MCF-7 cells, transcriptional activation occurs at a level about 20-fold higher than when the enhancer estrogen-responsive element (FP1) is the only regulatory region included in the reporter gene. These results indicate that areas other than FP1 are important regulatory sites of this enhancer. Site-directed mutagenesis demonstrated that the FP1 area is absolutely necessary for induction by estradiol as well as for basal activity of this enhancer in MCF-7 cells. Gel shift experiments showed that MCF-7 cells contain a factor that binds to the FP3 area and is poorly expressed in all other tested cell lines. As suggested by site-directed mutagenesis and deletion experiments, this FP3-binding protein may enhance the hER transactivation ability in MCF-7 cells. These data reinforce the idea that cell-specific transcription factors cooperate with steroid receptors to achieve maximal induction of hormone-responsive genes.
Animals↗
A comparison of simultaneous and delayed reinforcement as treatments for food selectivity.
This study compared the relative efficacy of providing simultaneous or delayed reinforcement on food acceptance during meals. The participant was a 7 year-old boy with pervasive developmental disorder and a history of food selectivity. Results indicated that both procedures were effective in increasing acceptance; however, the simultaneous reinforcement procedure produced more rapid behavior change and a higher overall percentage of food acceptance.
Child↗
Characterization of the transcription start point of the trout estrogen receptor-encoding gene: evidence for alternative splicing in the 5' untranslated region.
The estrogen receptor (ER)-encoding gene (ER) regulates many genes implicated in the reproductive functions. Moreover, rainbow trout ER (rtER) is itself up-regulated by its own product. We have used Northern blot, RNase protection, primer extension and reverse transcription-polymerase chain reaction (RT-PCR) to study the position of the rtER mRNA transcription start point (tsp) in liver. This analysis has revealed the presence of a tsp positioned at the beginning of the cloned rtER cDNA. Functionality of this tsp was tested in transient transfections in CHO-K1 cells. The characterization of the rtER 5' untranslated region (UTR) showed that two transcripts exist in liver which differ in their 5'-UTR. The first one is 100% homologous to the cloned rtER cDNA sequence. The other one contains a 41-bp insertion. The isolation and sequencing of the first intron showed that this insertion arises from alternative splicing, due to the use of a splicing site internal to the first intron.
Alternative Splicing↗
Rainbow trout estrogen receptor presents an equal specificity but a differential sensitivity for estrogens than human estrogen receptor.
The estrogen receptor is a transcription factor that mediates the actions of estrogens which plays a major role in salmonid vitellogenesis. Previously, we cloned and described the estradiol receptor in rainbow trout. To study the transactivation characteristics, the full length cDNA was inserted in an expression vector and tested by transfection on an estrogen-dependent promoter (pERE-TK-CAT). For the first time, direct comparison between the trout receptor (rtER) and human receptor (hER) in an analogous system has been possible. We demonstrate that rtER can, like hER, transactivate transcription in a strictly hormone-dependent manner. The specificity and sensitivity of the rtER response to different steroids have been studied. With rtER, the E2 concentration needed for half maximal activation is 10 times higher than with hER. In addition, we show that rtER has a weak affinity for androgens and transactivation could be induced using high testosterone concentration. Experiments show that both rtER and hER have an equal specificity for estrogens but that the rtER binds its ligand with a lower sensitivity than hER. Several hypotheses concerning the role of main amino acids within the receptor protein are proposed based on the different properties of the receptors and comparison of sequences.
Animals↗
Characterization of an estrogen-responsive element implicated in regulation of the rainbow trout estrogen receptor gene.
We previously reported that the expression of the rainbow trout estrogen receptor (rtER) gene is markedly increased by estradiol (E2). In this paper, we have used transient transfection assays with reporter plasmids expressing chloramphenicol acetyl transferase (CAT), linked to 5' flanking regions of the rtER gene promoter, to identify cis-elements responsible for E2 inducibility. Deletion analysis localized an estrogen-responsive element (ERE), at position +242, with one mutation on the first base compared with the consensus sequence. This element confers estrogen responsiveness to CAT reporter linked to both the herpes simplex virus thymidine kinase promoter and the homologous rtER promoter. Moreover, using a 0.2 kb fragment of the rtER promoter encompassing the ERE and the rtER DNA binding domain obtained from a bacterial expression system, DNase I footprinting experiments demonstrated a specific protection covering 20 bp (+240/+260) containing the ERE sequence. Based on these studies, we believe that this ERE sequence, identified in the rtER gene promoter, may be a major cis-acting element involved in the regulation of the gene by estrogen.
Animals↗
Functional analysis and intervention for breath holding.
We conducted a functional analysis of breath-holding episodes in a 7-year-old girl with severe mental retardation and Cornelia-de-Lange syndrome. The results showed that breath holding served an operant function, primarily to gain access to attention. The intervention, consisting of extinction, scheduled attention, and use of a picture card communication system, resulted in decreased breath holding.
Behavior Therapy↗
Improving the peer interactions of students with emotional and behavioral disorders through self-evaluation procedures: a component analysis and group application.
We conducted two experiments examining the effects of a self-evaluation package on the peer interactions of students described as emotionally or behaviorally disordered. Experiment 1 assessed the additive effects of various components of a self-evaluation package on the frequency of inappropriate and appropriate peer interactions. The components assessed were rewards alone, rewards plus discussion, and self-evaluation plus rewards. Results showed limited effectiveness when rewards alone and rewards plus discussion were implemented. However, substantial improvements in peer interactions were observed when the self-evaluation component was added. Experiment 2 examined the efficacy and feasibility of the procedures when implemented in a group setting. Students in three classrooms served as participants. Direct observation data collected for 8 of the participants showed the procedures to be effective in improving peer interactions when implemented in a group context.
Affective Symptoms↗
Using assessment-based curricular intervention to improve the classroom behavior of a student with emotional and behavioral challenges.
We evaluated a process of descriptive assessment, functional assessment, and assessment-based intervention with an elementary-school child who was described as having emotional and behavioral challenges, but who also exhibited above-average intelligence and communication skills. During a hypothesis-development phase, information was gathered from several sources including an interview that was conducted directly with the participant. Descriptive information collected during this phase produced five hypotheses about variables maintaining the problem behavior that were then tested experimentally in the classroom environment. The resulting functional assessment data supported the hypotheses. Intervention packages based on the hypotheses were implemented sequentially across English, spelling, and math classes. The interventions were successful in increasing on-task behavior, and the improvements were maintained for the remainder of the school year.
Affective Symptoms↗
Reviews and summaries of research related to AACN 1980 research priorities: contextual topics.
This article reviews and summarizes the research conducted following publication of the 1980s American Association of Critical-Care Nurses' contextual research priorities. Reports of original research conducted on the contextual priority topics between 1981 and 1991 were included. Review articles, doctoral dissertations, theses, and abstracts were excluded unless judged to provide important information on the topic. Following the statement of each priority, progress in the area is summarized. Limitations and measurement issues are discussed as appropriate. Recommendations for future research are provided, and progress in the area is summarized.
Academic Dissertations as Topic↗
Reviews and summaries of research related to AACN 1980 research priorities: clinical topics.
This article reviews and summarizes the research conducted following publication of the 1980s American Association of Critical-Care Nurses' clinical research priorities. Original research conducted on the clinical priority topics between 1981 and 1991 was included. Review articles, doctoral dissertations, theses and abstracts were excluded unless judged to provide important information on the topic. Following the statement of each priority, progress in the area is summarized. Limitations and measurement issues are discussed as appropriate. Recommendations for future research are provided, and progress in the area is summarized.
Clinical Nursing Research↗
Regulation of the pyrimidine salvage pathway by the FUR1 gene product of Saccharomyces cerevisiae.
In Saccharomyces cerevisiae, the protein encoded by the FUR1 gene is absolutely required for the expression of uracil phosphoribosyl transferase activity. The occurrence of semi-dominant mutations for 5-fluorouracil-(5FU)-resistance at this locus led us to clone and sequence the semi-dominant fur1-5 allele. A single point mutation, resulting in the substitution of arginine 134 for serine, is responsible for this mutant phenotype. The fur1-5 allele is transcribed and expressed at the same level as the wild-type allele. But, in contrast with the wild-type, the UPRTase activity of the fur1-5 mutant strain is stimulated in vitro by UTP and does not, therefore, correspond to a loss of feedback of UPRTase activity. We found that uracil, as a free base, induces a significative increase in transcription and UPRTase activity in a wild-type strain as well as in uracil-overproducing mutants which principally explains the high efficiency of the pyrimidine salvage pathway in S. cerevisiae.
Alleles↗
Calcium-independent phospholipid/diolein-dependent phosphorylation of a soluble ovarian Mr 80,000 substrate protein: biochemical characteristics.
Soluble ovarian extracts were incubated with protein kinase effectors in the presence of [gamma 32P]ATP and proteins were separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis. Autoradiograms revealed phosphorylation of an ovarian Mr = 80,000 substrate in the presence of EGTA ([ethylenebis(oxyethylenenitrilo)]tetraacetic acid), phosphatidylserine and 1,2-diolein. In contrast to a classical response pattern to C-kinase effectors, the ovarian Mr = 80,000 phosphorylation was inhibited by 2 x 10(-7) M or greater free Ca2+. The ovarian Mr = 80,000 substrate was distinguished from the myristoylated acidic Mr = 80,000 C-kinase substrate of brain tissue on the basis of heat stability and phosphorylative response to effectors. Phosphorylation of the exogenous substrate myelin basic protein by DEAE-resolved ovarian kinase showed the variant effector dependence, maximal in the presence of EGTA, phosphatidylserine and 1,2-diolein. Finally, the effect of Ca2+ on ovarian Mr = 80,000 [32P]phosphate content could not be accounted for by post-phosphorylation activities, or by DEAE-resolvable or hydroxylapatite-resolvable inhibitory activities.
Animals↗
The URK1 gene of Saccharomyces cerevisiae encoding uridine kinase.
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Amino Acid Sequence↗