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Biomedical subjects

J A Best

Publications and source records attributed to J A Best.

At least 19 recordsLinked to original sources
PubMed2001

The cAMP responsive element and CREB partially mediate the response of the tyrosine hydroxylase gene to phorbol ester.

Tyrosine hydroxylase (TH) gene promoter activity is increased in PC12 cells that are treated with the phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA). Mutagenesis of either the cAMP responsive element (CRE) or the activator protein-1 element (AP1) within the TH gene proximal promoter leads to a dramatic inhibition of the TPA response. The TH CRE and TH AP1 sites are also independently responsive to TPA in minimal promoter constructs. TPA treatment results in phosphorylation of cAMP responsive element binding protein (CREB) and activation of cAMP-dependent protein kinase (PKA) in PC12 cells; hence, we tested whether CREB and/or PKA are essential for the TPA response. In CREB-deficient cells, the response of the full TH gene proximal promoter or the independent response of the TH CRE by itself to TPA is inhibited. The TPA-inducibility of TH mRNA is also blocked in CREB-deficient cells. Expression of the PKA inhibitor protein, PKI, also inhibits the independent response of the TH CRE to TPA. Our results support the hypothesis that TPA stimulates the TH gene promoter via signaling pathways that activate either the TH AP1 or TH CRE sites. Both signaling pathways are dependent on CREB and the TH CRE-mediated pathway is dependent on PKA.

Animals↗
PubMed1999

A dentoalveolar abscess in a pediatric patient with ketoacidosis caused by occult diabetes mellitus: a case report.

Oral health professionals are frequently asked to evaluate patients with routine odontogenic infections. These patients can sometimes present with systemic signs and symptoms, including fever, malaise, tachycardia, and dehydration. It is important for the astute clinician to understand the possible associated systemic diseases that may be contributing to odontogenic infections. We present here an interesting case of a pediatric patient with a routine canine space infection who exhibited classic clinical signs and symptoms of diabetic ketoacidosis.

Child, Preschool↗
PubMed1999

Effectiveness of a social influences smoking prevention program as a function of provider type, training method, and school risk.

OBJECTIVES: This study determined the effect of provider (nurse or teacher) and training method (workshop or self-preparation) on outcomes of a social influences smoking prevention program. METHODS: One hundred elementary schools were stratified by school risk score (high risk = high smoking rate among senior students) and assigned randomly to conditions: (1) teacher/self-preparation, (2) teacher/workshop, (3) nurse/self-preparation, (4) nurse/workshop, and (5) control. Intervention occurred in grades 6 to 8. Smoking status at the end of grade 8 was the primary endpoint variable. RESULTS: Intervention reduced grade 8 smoking rates in high-risk schools (smoking rates of 26.9% in control vs 16.0% in intervention schools) but not in low-risk schools. There were no significant differences in outcome as a function of training method and no significant differences in outcome between teacher-provided and nurse-provided interventions in high- and medium-risk schools. Although nurses achieved better outcomes than did teachers in low-risk schools, neither provider type achieved outcomes superior to the control condition in those schools. CONCLUSIONS: Workshop training did not affect outcomes. Teachers and nurses were equally effective providers. Results suggest that programming should target high-risk schools.

Adolescent↗
PubMed1998

The THCRE2 site in the rat tyrosine hydroxylase gene promoter is responsive to phorbol ester.

Recently, our laboratory has identified a tyrosine hydroxylase (TH) gene promoter element, THCRE2 (located at -97 to -90), that is required for maximal response to cyclic AMP. In this study we test whether the THCRE2 is responsive to phorbol ester. Rat PC12 cells were transfected with a reporter gene construct, TH(-272/+27)-CAT, which is driven by the first 272 bp of the rat TH gene 5' flanking region. Treatment of transfected cells with 0.1 microM 12-O-tetradecanoylphorbol 13-acetate (TPA) elicited a 5-6-fold increase in TH gene proximal promoter activity. Mutagenesis of the THCRE2 sequence diminished TPA-responsiveness of the TH gene promoter by approximately 50%. Minimal promoter constructs driven by a single copy of the region of the TH gene that encodes the THCRE2 (from -117 to -59) were also responsive to TPA. Our results suggest that the THCRE2 is a phorbol ester-responsive element, as well as a cyclic AMP-responsive element.

Animals↗
PubMed1997

Tyrosine hydroxylase gene promoter activity is regulated by both cyclic AMP-responsive element and AP1 sites following calcium influx. Evidence for cyclic amp-responsive element binding protein-independent regulation.

Membrane depolarization of PC12 cells using 50 mM KCl leads to induction of tyrosine hydroxylase (TH) mRNA. This induction of TH mRNA is apparently due to increased TH gene promoter activity mediated by the influx of Ca2+. In PC12 cells transiently transfected with a chimeric gene expressing chloramphenicol acetyltransferase (CAT) driven by the proximal TH gene 5'-flanking region, 50 mM KCl increases TH gene promoter activity 3-4-fold. Promoter analysis utilizing TH-CAT constructs containing mutagenized sequences indicates that this response to the depolarization-mediated influx of Ca2+ is primarily dependent on both the TH cAMP-responsive element (CRE) and TH activating protein-1 (AP1) site. Minimal promoter constructs that contain a single copy of either the TH CRE or TH AP1 site fused upstream of the TH gene basal promoter are only modestly responsive or nonresponsive, respectively, to depolarization. However, both these constructs are strongly responsive to the calcium ionophore, A23187. Gel shift assays indicate that TH AP1 complex formation is dramatically increased after treatment with either 50 mM KCl or A23187. Using antibodies to transcription factors of the Fos and Jun families, we show that the nuclear proteins comprising the inducible TH AP1 complex include c-Fos, c-Jun, JunB, and JunD. In cAMP-responsive element binding protein (CREB)-deficient cell lines that express antisense RNA complementary to CREB mRNA, the response of the TH gene promoter to cyclic AMP is dramatically inhibited, but the response to A23187 remains robust. This result indicates that transcription factors other than CREB can participate in the Ca2+-mediated regulation of the TH gene. In summary, our results support the hypothesis that regulation of the TH gene by Ca2+ is mediated by mechanisms involving both the TH CRE and TH AP1 sites and that transcription factors other than or in addition to CREB participate in this response.

Adaptor Protein Complex 1↗
PubMed1997

Healthy hospital: toward a better tomorrow. A demonstration project to promote culture change through participatory decision making.

The three-year "Healthy Hospital" project was designed to increase participatory decision making, thereby decreasing job stress and increasing job satisfaction. Evaluation methods included employee surveys, focus groups and key informant interviews. Overall stress levels, job satisfaction and self-esteem generally improved. The diverse types of evaluation converge on a conclusion that the project achieved modest but significant gains throughout the organization. Lessons for future research and applications are discussed.

British Columbia↗
PubMed1996

Regulation of tyrosine hydroxylase gene expression by the m1 muscarinic acetylcholine receptor in rat pheochromocytoma cells.

Tyrosine hydroxylase (TH) gene transcription rate is increased in rat adrenal medulla after administration of muscarinic agonists. In order to study this muscarinic regulation of TH gene expression in more detail, we have generated a rat pheochromocytoma PC18 cell line that stably expresses the mouse m1 muscarinic acetylcholine receptor. Treatment of this cell line, designated PC18/m1-13, with carbachol leads to rapid increases in phosphatidylinositol turnover and intracellular [Ca2+]i; these increases are totally blocked by the muscarinic antagonist atropine. Carbachol produces no changes in cAMP levels or protein kinase A activity in PC18/m1-13 cells. TH mRNA levels in PC18/m1-13 cells increase approximately 3-fold after 6 h of treatment with carbachol. This induction of TH mRNA is also completely inhibited by simultaneous treatment with atropine. Transient transfection assays using a TH gene promoter-chloramphenicol acetyltransferase (TH-CAT) construct demonstrate that sequences within the most proximal 272 bp of the TH gene 5'-flanking region are responsive to carbachol in PC18/m1-13 cells. Studies using TH-CAT constructs with site-directed mutations within the TH gene promoter indicate that the responsiveness of the promoter to carbachol is mediated primarily by the cAMP response element; however, the AP1 site also participates to a lesser extent in this response. The carbachol-mediated stimulation of TH gene promoter activity is partially inhibited by down-regulation of protein kinase C (PKC) or by treatment with the Ca2+/calmodulin-dependent protein kinase inhibitor, KN62. These results are consistent with the hypothesis that agonist occupation of m1 muscarinic receptors stimulates the TH gene via signal transduction pathways that are initiated by activation of PKC and Ca2+/calmodulin-dependent protein kinase, leading to activation of transcription factors that interact with the TH CRE and AP1 sites.

Adenosine↗
PubMed1995

The response of the tyrosine hydroxylase gene to cyclic AMP is mediated by two cyclic AMP-response elements.

Tyrosine hydroxylase (TH) gene transcription rate is stimulated by cyclic AMP in cultured rat pheochromocytoma cells. This effect is at least partially due to the interaction of transcription factors with the canonical cyclic AMP-response element (CRE) at position -45 to -38 within the TH gene promoter. In this study we test whether a region of the TH gene promoter, which is adjacent to and upstream of the canonical TH CRE, also participates in the response of the promoter to cyclic AMP. Using electrophoretic mobility shift assays, we demonstrate that nuclear proteins from rat pheochromocytoma cell lines bind to the region of the TH gene from -102 to -73. A comparison of promoter sequences indicates that sequences within this region of the TH gene are highly homologous to proenkephalin promoter sequences (between -110 and -80) designated ENKCRE-1 and ENKCRE-2. We designated the TH gene sequence homologous to ENKCRE-1 as TH E1 and the sequence homologous to ENKCRE-2 as TH E2. Competition displacement binding assays suggest that protein binding to the -102/-73 region of the TH gene is critically dependent on the TH E1 sequence. Transient transfection assays using minimal promoter constructs demonstrate that this region acts as a cyclic AMP-responsive element. Mutagenesis of the TH E1 sequence within the normal context of the TH gene proximal promoter leads to a 50% decrease in the cyclic AMP inducibility of the promoter. These results support the hypothesis that the full response of the TH gene to cyclic AMP requires both the canonical TH CRE and this newly discovered element, which we term TH CRE2.

Adrenal Gland Neoplasms↗
PubMed1995

The future of wellness care.

The current restructuring of the US healthcare system will result in a new emphasis on wellness services. Hospitals are challenged to define the wellness role they will play within managed care. This article reports on interviews with wellness experts and hospital CEOs, who reflect on these challenges and define strategic priorities. The interviews highlight the need to understand that this challenge requires a powerful paradigm shift from illness to preventive services, and a major rethinking of how hospitals operate to offer cost-effective preventive services. The interviewees see great opportunity, but also great need for thorough planning, careful design, and implementation. Hospital leaders must understand clearly what wellness means, and how best to position their hospital for strategic advantage. In the final analysis, wellness emerges as an integral strategy in the overall process of managing change.

Canada↗
PubMed1990

Mediation of nitrous oxide analgesia in mice by spinal and supraspinal kappa-opioid receptors.

Exposure to nitrous oxide produced concentration-dependent analgesia in the mouse abdominal constriction test. Intracerebroventricular or intrathecal pretreatment with naltrexone or nor-binaltorphimine significantly reduced nitrous oxide analgesia. However, similar pretreatment with beta-funaltrexamine had no appreciable effect. These findings suggest that nitrous oxide analgesia involves spinal and supraspinal kappa-opioid receptors.

Analgesics↗
PubMed1989

Tracking and attrition in longitudinal school-based smoking prevention research.

Research in the development of school-based smoking prevention programs has resulted in a set of approaches of known short-term efficacy. Further evaluation of these approaches now requires long-term follow-up of participants. To minimize the problems caused by attrition in these longitudinal studies, investigators have developed techniques for tracking study participants. Based primarily on the use of the telephone, mail, and public documents, these methods require good background information on both the study participants and their parents. This article summarizes the experience of three teams of researchers engaged in such follow-up studies. These investigators have identified the types of background information most useful in long-term follow-up of participants, have developed a set of strategies to obtain such background information, and have developed methods for successfully tracking participants after a lapse of several years.

Adolescent↗