Subsidised nicotine replacement therapy.
Explore the source record for details and available documents.
Adult↗
Biomedical subjects
H Glasgow
Publications and source records attributed to H Glasgow.
Identification of a P2X7 receptor in GH(4)C(1) rat pituitary cells: a potential target for a bioactive substance produced by Pfiesteria piscicida.
We examined the pharmacologic activity of a putative toxin (pPfTx) produced by Pfiesteria piscicida by characterizing the signaling pathways that induce the c-fos luciferase construct in GH(4)C(1) rat pituitary cells. Adenosine-5'-triphosphate (ATP) was determined to increase and, at higher concentrations, decrease luciferase activity in GH(4)C(1) rat pituitary cells that stably express c-fos luciferase. The inhibition of luciferase results from cytotoxicity, characteristic of the putative P. piscicida toxin (pPfTx). The actions of both pPfTx and ATP to induce c-fos luciferase were inhibited by the purinogenic receptor antagonist pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS). Further characterization of a P2X receptor on the GH(4)C(1) cell was determined by the analog selectivity of P2X agonists. The P2X1/P2X3 agonist alpha,beta-methylene ATP (alpha,beta-MeATP) failed to increase or decrease c-fos luciferase. However, the P2X7 agonist 2',3'-(4-benzoyl)benzoyl ATP (BzATP), which had a predominant cytotoxic effect, was more potent than ATP. Immunoblot analysis of GH(4)C(1) cell membranes confirmed the presence of a 70-kDa protein that was immunoreactive to an antibody directed against the carboxy-terminal domain unique to the P2X7 receptor. The P2X7 irreversible antagonist oxidized-ATP (oxATP) inhibited the action of ATP, BzATP, and pPfTx. These findings indicate that GH(4)C(1) cells express purinogenic receptors with selectivity consistent with the P2X7 subtype and that this receptor pathway mediates the induction of the c-fos luciferase reporter gene by ATP and the putative Pfiesteria toxin
Adenosine Triphosphate↗
Microfluorimetric analysis of a purinergic receptor (P2X7) in GH4C1 rat pituitary cells: effects of a bioactive substance produced by Pfiesteria piscicida.
Pfiesteria piscicida Steidinger & Burkholder is a toxic dinoflagellate that leads to fish and human toxicity. It produces a bioactive substance that leads to cytotoxicity of GH4C1 rat pituitary cells. Extracellular adenosine 5'-triphosphate (ATP) acting on P2X7 purinergic receptors induces the formation of a nonselective cation channel, causing elevation of the cytosolic free calcium followed by a characteristic permeabilization of the cell to progressively larger ions and subsequent cell lysis. We investigated whether GH4C1 rat pituitary cells express functional P2X7 receptors, and if so, are they activated by a bioactive substance isolated from toxic P. piscicida cultures. We tested the selective agonist 2'-3'-O-(benzoyl-4-benzoyl)-ATP (BzATP) and antagonists piridoxalphosphate-6-azophenyl-2'-4'-disulfonic acid (PPADS) and oxidized-ATP (oxATP) using elevated cytosolic free calcium in Fura-2 loaded cells, and induced permeability of these cells to the fluorescent dye YO-PRO-1 as end points. We demonstrated that in GH4C1 cells, BzATP induces both the elevation of cytosolic free calcium and the permeabilization of the cell membrane. ATP-induced membrane permeabilization was inhibited by PPADS reversibly and by oxATP irreversibly. The putative Pfiesteria toxin (pPfTx) also elevated cytosolic free calcium in Fura-2 in GH4C1 cells and increased the permeability to YO-PRO-1 in a manner inhibited fully by oxATP. This study indicates that GH4C1 cells express a purinoceptor with characteristics consistent with the P2X7 subtype, and that pPfTx mimics the kinetics of cell permeabilization by ATP.
Adenosine Triphosphate↗
Current progress in isolation and characterization of toxins isolated from Pfiesteria piscicida.
The isolation and partial purification of toxic substances derived from Pfiesteria piscicida Steidinger & Burkholder extracts is described. Four distinct bioassay systems were used to monitor bioactivity of the P. piscicida extracts, including a high throughput cell cytotoxicity assay and a reporter gene assay as well as assays using brine shrimp and fish. Using these bioassays to guide fractionation, we have isolated two distinct, active fractions from Pfiesteria culture medium and cell mass extracts on the basis of their solubility characteristics. We have identified and characterized a bioactive lipophilic substance from Pfiesteria-derived extracts as di(2-ethylhexyl)phthalate, a commonly used plasticizer. The source of this typically man-made substance has been identified as originating from Instant Ocean (Aquarium Systems, Mentor, OH, USA), a commercially available seawater salt mixture used to prepare our mass culture growth medium. We have developed chromatographic methodology to isolate a bioactive polar compound isolated from extracts of Pfiesteria culture and presently report the characterization of the activity of this substance. The molecular structural analysis of the polar active component(s) using mass spectrometry and nuclear magnetic resonance spectroscopy is currently under way.
Animals↗
Are New Zealand schools smoke-free? Results from a national survey of primary and intermediate school principals.
AIMS: To document policies and practices developed by primary and intermediate schools in response to the Smoke-free Environments Act 1990 and estimate levels of staff support for legislation requiring totally smoke-free schools. METHODS: Questionnaires were mailed to a random national sample of 10% of principals of all primary and intermediate schools. RESULTS: There were 209 questionnaires returned, a response rate of 87%. While 97% of principals reported that their school had a written policy for smoking, only 58% provided a copy. Only 49% of principals said that their school smoking policy was prominently displayed. Most (82 %) claimed that school buildings were smoke-free, but only 44% said that this applied to buildings and grounds. Overall, 62% considered that school staff would support legislation that required schools to be totally smoke-free in buildings and grounds. School policies ranged from total prohibition of smoking in school buildings and grounds to the provision of designated smoking areas for staff. CONCLUSIONS: Compliance with current smoke-free legislation appears to be variable. Consistency in the meaning of smoke-free status in schools is lacking. There appears to be good staff and parent support for making all schools totally smoke-free. The best way to achieve universal, permanent and totally smoke-free status for New Zealand schools would be to amend current legislation to include specific requirements for all school premises.
Child↗
Tobacco smoking among fourth form school students in Wellington, New Zealand, 1991-97.
OBJECTIVE: To investigate trends in smoking and associated demographic factors among fourth form (14-15 years) school students. METHOD: In 1991, all 35 secondary schools in Wellington, New Zealand, were invited to participate; 15 took part. Smoking behaviours were assessed biennially by self-report. Trends were examined among 5,834 students, using multilevel regression. RESULTS: When adjusted for sex, ethnicity and their interaction, the baseline (1991) prevalence of smoking within the past month was 18% (95% CI 10-29) rising to 28% (95% CI 15-46) in 1997. The comparable baseline prevalence of daily smoking was 8% (95% CI 3-21) rising to 15% (95% CI 4-40) in 1997. Smoking was more common among girls than boys and most common among Maori girls, for whom the adjusted odds of current and daily smoking were, respectively, 3.40 times (95% CI 2.56-4.52) and 5.00 times (95% CI 3.64-6.87) those of Europeans. School socio-economic status and sex composition added to the explanatory power of the model for daily smoking, but had negligible effect on the odds ratios for sex and ethnic group. CONCLUSIONS AND IMPLICATIONS: The suggested rise in the prevalence of smoking has implications for future adult smoking rates and health costs. Under-representation of socio-economically disadvantaged schools may have produced conservative estimates. The increased odds of smoking among girls and Maori confirm the need to develop interventions appropriate for these groups.
Adolescent↗
Reporter gene assay for fish-killing activity produced by Pfiesteria piscicida.
Collaborative studies were performed to develop a functional assay for fish-killing activity produced by Pfiesteria piscicida. Eight cell lines were used to screen organic fractions and residual water fraction by using a 3-[4, 5-dimethylthiazol-(2-4)]-diphenyltetrazolium bromide cytotoxicity assay. Diethyl ether and a residual water fraction were cytotoxic to several cell lines including rat pituitary (GH(4)C(1)) cells. Residual water as well as preextracted culture water containing P. piscicida cells induced c-fos-luciferase expressed in GH(4)C(1) cells with a rapid time course of induction and sensitive detection. The reporter gene assay detected activity in toxic isolates of P. piscicida from several North Carolina estuaries in 1997 and 1998 and may also be suitable for detecting toxic activity in human and animal serum.
Animals↗
Sunburn and sun protection among young children.
OBJECTIVE: To examine the extent of sun exposure, sun protection and experience of sunburn among young New Zealand children on summer weekends. METHODS: In a telephone survey of 1243 respondents, those with children in the household were asked about sun exposure and protection for the youngest child in the family. Information was obtained for 285 children aged from infancy to 10 years. RESULTS: Over 90% of the children were reported to be outside on the preceding Saturday and/or Sunday; 7% of those outside experienced some degree of sunburn. The worst burning was on the face, head, neck or ears. On either day about half the children were wearing sunscreen and 60% were wearing a hat. Parental use of sun protection was the strongest predictor of sun protection among the children. CONCLUSIONS: While reports of sun protection among young children were encouraging, many children in the community are still at high risk of sunburn. Efforts to promote sun protection as a family responsibility may reduce the experience of burning among the young.
Adolescent↗
Clinical leadership in control of melanoma.
Explore the source record for details and available documents.
Humans↗
Increased resistance to penicillin of pneumococci isolated from man.
Explore the source record for details and available documents.
Aged↗