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1.
Pilot Feasibility Stud ; 9(1): 87, 2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37221614

RESUMO

BACKGROUND: There has been a growing focus on functional communication interventions for primary progressive aphasia (PPA). These interventions aim to support individuals to participate in life situations. One such intervention, communication partner training (CPT) aims to change conversation behaviours in both the person with PPA and their communication partner (CP). CPT has a growing evidence base in stroke aphasia; however, these programmes are not designed to meet the needs of people with progressive communication difficulties. To address this, the authors developed a CPT program entitled Better Conversations with PPA (BCPPA) and undertook a pilot trial to establish for a future full trial; predicted recruitment rates, acceptability, an assessment of treatment fidelity and an appropriate primary outcome measure. METHODOLOGY: This was a single-blind, randomised controlled pilot study comparing BCPPA to no treatment, delivered across 11 National Health Service Trusts in the UK. A random sample of eight recordings of local collaborators delivering the intervention were analysed to examine fidelity. Participants completed feedback forms reporting on acceptability. Pre- and post-intervention measures targeted conversation behaviours, communication goals and quality of life. RESULTS: Eighteen people with PPA and their CPs (9 randomised to BCPPA, 9 randomised to no treatment) completed the study. Participants in the intervention group rated BCPPA positively. Treatment fidelity was 87.2%. Twenty-nine of 30 intervention goals were achieved or over-achieved and 16 of 30 coded conversation behaviours demonstrated change in the intended direction. The Aphasia Impact Questionnaire was identified as the preferred outcome measure. CONCLUSION: The first randomised controlled UK pilot study of a CPT program for people with PPA and their families demonstrates BCPPA is a promising intervention. The intervention was acceptable, treatment fidelity high and an appropriate measure identified. Results of this study indicate a future RCT of BCPPA is feasible. TRIAL REGISTRATION: Registered 28/02/2018 ISRCTN10148247 .

2.
BMJ Open ; 6(2): e009493, 2016 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-26908518

RESUMO

OBJECTIVES: While there is good evidence for associations between short-term exposure to ozone and a range of adverse health outcomes, the evidence from narrative reviews for long-term exposure is suggestive of associations with respiratory mortality only. We conducted a systematic, quantitative evaluation of the evidence from cohort studies, reporting associations between long-term exposure to ozone and mortality. METHODS: Cohort studies published in peer-reviewed journals indexed in EMBASE and MEDLINE to September 2015 and PubMed to October 2015 and cited in reviews/key publications were identified via search strings using terms relating to study design, pollutant and health outcome. Study details and estimate information were extracted and used to calculate standardised effect estimates expressed as HRs per 10 ppb increment in long-term ozone concentrations. RESULTS: 14 publications from 8 cohorts presented results for ozone and all-cause and cause-specific mortality. We found no evidence of associations between long-term annual O3 concentrations and the risk of death from all causes, cardiovascular or respiratory diseases, or lung cancer. 4 cohorts assessed ozone concentrations measured during the warm season. Summary HRs for cardiovascular and respiratory causes of death derived from 3 cohorts were 1.01 (95% CI 1.00 to 1.02) and 1.03 (95% CI 1.01 to 1.05) per 10 ppb, respectively. CONCLUSIONS: Our quantitative review revealed a paucity of independent studies regarding the associations between long-term exposure to ozone and mortality. The potential impact of climate change and increasing anthropogenic emissions of ozone precursors on ozone levels worldwide suggests further studies of the long-term effects of exposure to high ozone levels are warranted.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/efeitos adversos , Mortalidade , Ozônio/efeitos adversos , Doenças Cardiovasculares/mortalidade , Causas de Morte , Estudos de Coortes , Humanos , Doenças Respiratórias/mortalidade , Fatores de Risco , Estações do Ano , Fatores de Tempo
3.
BMJ Open ; 5(5): e006946, 2015 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-25967992

RESUMO

BACKGROUND: Short-term exposure to NO2 has been associated with adverse health effects and there is increasing concern that NO2 is causally related to health effects, not merely a marker of traffic-generated pollution. No comprehensive meta-analysis of the time-series evidence on NO2 has been published since 2007. OBJECTIVE: To quantitatively assess the evidence from epidemiological time-series studies published worldwide to determine whether and to what extent short-term exposure to NO2 is associated with increased numbers of daily deaths and hospital admissions. DESIGN: We conducted a quantitative systematic review of 204 time-series studies of NO2 and daily mortality and hospital admissions for several diagnoses and ages, which were indexed in three bibliographic databases up to May 2011. We calculated random-effects estimates by different geographic regions and globally, and also tested for heterogeneity and small study bias. RESULTS: Sufficient estimates for meta-analysis were available for 43 cause-specific and age-specific combinations of mortality or hospital admissions (25 for 24 h NO2 and 18 of the same combinations for 1 h measures). For the all-age group, a 10 µg/m(3) increase in 24 h NO2 was associated with increases in all-cause, cardiovascular and respiratory mortality (0.71% (95% CI 0.43% to 1.00%), 0.88% (0.63% to 1.13%) and 1.09% (0.75% to 1.42%), respectively), and with hospital admissions for respiratory (0.57% (0.33% to 0.82%)) and cardiovascular (0.66% (0.32% to 1.01%)) diseases. Evidence of heterogeneity between geographical region-specific estimates was identified in more than half of the combinations analysed. CONCLUSIONS: Our review provides clear evidence of health effects associated with short-term exposure to NO2 although further work is required to understand reasons for the regional heterogeneity observed. The growing literature, incorporating large multicentre studies and new evidence from less well-studied regions of the world, supports further quantitative review to assess the independence of NO2 health effects from other air pollutants.


Assuntos
Poluentes Atmosféricos/efeitos adversos , Poluição do Ar/prevenção & controle , Doenças Cardiovasculares/mortalidade , Hospitalização/estatística & dados numéricos , Pneumopatias/mortalidade , Dióxido de Nitrogênio/efeitos adversos , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Doenças Cardiovasculares/epidemiologia , Doenças Cardiovasculares/etiologia , Monitoramento Ambiental , Estudos de Avaliação como Assunto , Humanos , Pneumopatias/epidemiologia , Pneumopatias/etiologia , Estudos Multicêntricos como Assunto , Dióxido de Nitrogênio/análise , Material Particulado , Fatores de Tempo
4.
Thorax ; 69(7): 660-5, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24706041

RESUMO

BACKGROUND: Short-term exposure to outdoor fine particulate matter (particles with a median aerodynamic diameter <2.5 µm (PM2.5)) air pollution has been associated with adverse health effects. Existing literature reviews have been limited in size and scope. METHODS: We conducted a comprehensive, systematic review and meta-analysis of 110 peer-reviewed time series studies indexed in medical databases to May 2011 to assess the evidence for associations between PM2.5 and daily mortality and hospital admissions for a range of diseases and ages. We stratified our analyses by geographical region to determine the consistency of the evidence worldwide and investigated small study bias. RESULTS: Based upon 23 estimates for all-cause mortality, a 10 µg/m(3) increment in PM2.5 was associated with a 1.04% (95% CI 0.52% to 1.56%) increase in the risk of death. Worldwide, there was substantial regional variation (0.25% to 2.08%). Associations for respiratory causes of death were larger than for cardiovascular causes, 1.51% (1.01% to 2.01%) vs 0.84% (0.41% to 1.28%). Positive associations with mortality for most other causes of death and for cardiovascular and respiratory hospital admissions were also observed. We found evidence for small study bias in single-city mortality studies and in multicity studies of cardiovascular disease. CONCLUSIONS: The consistency of the evidence for adverse health effects of short-term exposure to PM2.5 across a range of important health outcomes and diseases supports policy measures to control PM2.5 concentrations. However, reasons for heterogeneity in effect estimates in different regions of the world require further investigation. Small study bias should also be considered in assessing and quantifying health risks from PM2.5.


Assuntos
Poluentes Atmosféricos/toxicidade , Exposição Ambiental/efeitos adversos , Hospitalização/estatística & dados numéricos , Mortalidade/tendências , Material Particulado/toxicidade , Poluentes Atmosféricos/análise , Doenças Cardiovasculares/mortalidade , Exposição Ambiental/análise , Humanos , Pneumopatias/mortalidade , Tamanho da Partícula , Material Particulado/análise
5.
Scott Med J ; 58(4): 217-22, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24215040

RESUMO

BACKGROUND AND AIMS: Chronic liver disease affects 855 people per million in the UK. Previous studies have reported that coffee appears protective against the development of abnormal liver enzymes, hepatic fibrosis and cirrhosis. The aim of this study, the first in a Scottish population, was to compare coffee consumption in patients with liver disease and that of control populations to determine correlations between coffee intake and the incidence of non-cancerous liver disease and with Child's-Pugh and model for end-stage liver disease (MELD) scores. METHODS AND RESULTS: Two hundred and eighty-six patients attending the liver outpatient department at the Royal Infirmary of Edinburgh completed a questionnaire regarding coffee consumption and lifestyle factors. Control questionnaires were also completed by 100 orthopaedic outpatients and 120 medical students. Patients with cirrhosis (n = 95) drank significantly less coffee than those without cirrhosis (p = <0.001). There was no correlation between Child's-Pugh (-0.018) and MELD scores (-0.132) with coffee consumption. CONCLUSION: Coffee drinking is associated with a reduced prevalence of cirrhosis in patients with chronic liver disease. However, there was no significant difference in the amount of coffee drunk by liver patients and the control groups. It is possible that by changing the amount of coffee drunk, the development of cirrhosis in liver disease could be postponed.


Assuntos
Cafeína/farmacologia , Café , Diterpenos/farmacologia , Doença Hepática Terminal/prevenção & controle , Cirrose Hepática/prevenção & controle , Substâncias Protetoras/farmacologia , Cafeína/administração & dosagem , Estudos de Casos e Controles , Diterpenos/administração & dosagem , Doença Hepática Terminal/epidemiologia , Doença Hepática Terminal/patologia , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prevalência , Substâncias Protetoras/administração & dosagem , Reprodutibilidade dos Testes , Escócia/epidemiologia , Inquéritos e Questionários
6.
Hum Reprod ; 26(2): 369-75, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21127355

RESUMO

BACKGROUND: First-line treatments for unexplained infertility traditionally include clomifene citrate (CC) or unstimulated intrauterine insemination (IUI). A recently published randomized controlled trial considered the effectiveness of CC and IUI in patients with unexplained infertility and found that neither treatment offered a superior live birth rate when compared with expectant management (EM). This paper reports the economic evaluation conducted alongside this trial in order to assess whether health care providers are gaining value for money in this clinical area. METHODS: Five hundred and eighty women across five Scottish hospitals were randomized to either EM, CC or IUI for 6 months. The primary outcome measure was live births. Resource-use data were collected during the trial and costs were calculated from a UK National Health Service (NHS) perspective. Incremental cost-effectiveness ratios were calculated, expressed as cost per live birth, in order to compare the cost-effectiveness of CC and IUI with that of EM to treat unexplained infertility. RESULTS: Live birth rates in the three randomized groups were: EM = 32/193 (17%), CC = 26/194 (13%) and IUI = 43/193 (22%). The mean (standard deviation) costs per treatment cycle were £0 for EM, £83 (£17) for CC and £98 (£31) for IUI. The mean treatment costs per patient for EM, CC and IUI were £12 (£117), £350 (£220) and £331 (£222), respectively. The cost per live birth for EM, CC and IUI was £72 (95% confidence interval £0-£206), £2611 (£1870-£4166) and £1487 (£1116-£2155), respectively. The incremental cost-effectiveness ratio for IUI versus EM was £5604 (-£12204 to £2227), with CC dominated by IUI. CONCLUSIONS: Despite being more expensive, existing treatments such as empirical CC and unstimulated IUI do not offer superior live birth rates compared with EM of unexplained infertility. They are unlikely to be a cost-effective use of limited NHS resources. The study's main limitation is that it did not consider the psychological effects on couples. ISRCT Number: 71762042.


Assuntos
Coeficiente de Natalidade , Clomifeno/uso terapêutico , Infertilidade/terapia , Clomifeno/economia , Análise Custo-Benefício , Feminino , Humanos , Infertilidade/tratamento farmacológico , Infertilidade/economia , Inseminação , Masculino , Gravidez , Escócia , Conduta Expectante/economia
7.
BMJ ; 337: a716, 2008 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-18687718

RESUMO

OBJECTIVE: To compare the effectiveness of clomifene citrate and unstimulated intrauterine insemination with expectant management for the treatment of unexplained infertility. DESIGN: Three arm parallel group, pragmatic randomised controlled trial. SETTING: Four teaching hospitals and a district general hospital in Scotland. PARTICIPANTS: Couples with infertility for over two years, confirmed ovulation, patent fallopian tubes, and motile sperm. INTERVENTION: Expectant management, oral clomifene citrate, and unstimulated intrauterine insemination. MAIN OUTCOME MEASURES: The primary outcome was live birth. Secondary outcome measures included clinical pregnancy, multiple pregnancy, miscarriage, and acceptability. RESULTS: 580 women were randomised to expectant management (n=193), oral clomifene citrate (n=194), or unstimulated intrauterine insemination (n=193) for six months. The three randomised groups were comparable in terms of age, body mass index, duration of infertility, sperm concentration, and motility. Live birth rates were 32/193 (17%), 26/192 (14%), and 43/191 (23%), respectively. Compared with expectant management, the odds ratio for a live birth was 0.79 (95% confidence interval 0.45 to 1.38) after clomifene citrate and 1.46 (0.88 to 2.43) after unstimulated intrauterine insemination. More women randomised to clomifene citrate (159/170, 94%) and unstimulated intrauterine insemination (155/162, 96%) found the process of treatment acceptable than those randomised to expectant management (123/153, 80%) (P=0.001 and P<0.001, respectively). CONCLUSION: In couples with unexplained infertility existing treatments such as empirical clomifene and unstimulated intrauterine insemination are unlikely to offer superior live birth rates compared with expectant management. TRIAL REGISTRATION: ISRCT No: 71762042.


Assuntos
Clomifeno/administração & dosagem , Fármacos para a Fertilidade Feminina/administração & dosagem , Infertilidade Feminina/tratamento farmacológico , Inseminação Artificial Homóloga/métodos , Administração Oral , Adulto , Clomifeno/efeitos adversos , Clomifeno/economia , Custos e Análise de Custo , Feminino , Fármacos para a Fertilidade Feminina/efeitos adversos , Fármacos para a Fertilidade Feminina/economia , Humanos , Infertilidade Feminina/economia , Masculino , Gravidez , Resultado da Gravidez , Fatores de Tempo
8.
Euro Surveill ; 10(7): 168-71, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-16088043

RESUMO

This paper describes a retrospective analysis of the impact of the 2003 heat wave on mortality in England and Wales, and compares this with rapid estimates based on the Office for National Statistics routine weekly deaths reporting system. Daily mortality data for 4 to 13 August 2003, when temperatures were much hotter than normally seen in England, were compared with averages for the same period in years 1998 to 2002. The August 2003 heat wave was associated with a large short-term increase in mortality, particularly in London. Ozone and particulate matter concentrations were also elevated during the heat wave. Overall, there were 2139 (16%) excess deaths in England and Wales. Worst affected were people over the age of 75 years. The impact was greatest in the London region where deaths in those over the age of 75 increased by 59%. Estimated excess mortality was greater than for other recent heat waves in the United Kingdom. The estimated number of deaths registered each week is reported by the Office for National Statistics. The first clear indication of a substantial increase in deaths was published on 21 August 2003. This provided a quick first estimate of the number of deaths attributable to the heat wave and reflected the pattern of daily deaths in relation to the hottest days, but underestimated the excess when compared with the later analysis.


Assuntos
Transtornos de Estresse por Calor/mortalidade , Temperatura Alta/efeitos adversos , Idoso , Poluição do Ar/efeitos adversos , Atestado de Óbito , Inglaterra/epidemiologia , Métodos Epidemiológicos , Humanos , Mortalidade/tendências , Ozônio , Estudos Retrospectivos , População Urbana , País de Gales/epidemiologia
9.
J Hazard Mater ; 84(2-3): 163-74, 2001 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-11406304

RESUMO

Hexavalent and trivalent chromium are released into the environment from a number of different industrial activities. It is known that Cr(VI) can be reduced and subsequently complexed by humic acids to produce Cr(III) humic acid complexes in the soil and aquatic environments. The metabolic fate of Cr(III) humic acid complexes and other Cr(III) organic complexes in mammalian systems is unknown. Therefore, Cr(III) picolinate was chosen as a model complex for Cr(III) humic acid complexes and other environmentally relevant Cr(III) complexes. Both human hepatocyte microsomes and primary cultures of chick hepatocytes were used to generate metabolites of Cr(III) picolinate. The results from both of these treatments show that a significant amount of Cr(III) is released (66 and 100%, respectively) and that N-1-methylpicotinamide is the primary organic metabolite from this compound. These data suggest that the populations of humans who are exposed Cr(III) picolinate or other environmentally relevant organic Cr(III) complexes, such as Cr(III) humic acid complexes, are potentially accumulating high levels of Cr(III) intracellularly. This intracellular accumulation of Cr(III) can result in the formation of covalent bonds between Cr(III) and DNA and/or other macromolecules, causing genotoxic effects. These data should be considered when assessing the risk of an area contaminated with chromium.


Assuntos
Compostos de Cromo/metabolismo , Hepatócitos/fisiologia , Quelantes de Ferro/metabolismo , Ácidos Picolínicos/metabolismo , Animais , Técnicas de Cultura de Células , Galinhas , Compostos de Cromo/análise , Humanos , Substâncias Húmicas/química , Microssomos , Medição de Risco
10.
Hepatology ; 33(2): 406-12, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11172342

RESUMO

Porphyria cutanea tarda (PCT), a liver disease with skin lesions caused by excess liver production of uroporphyrin (URO), is associated with consumption of alcoholic beverages or estrogens, and moderate iron overload. Recently, it has been shown that many PCT patients carry mutations in the HFE gene, which is responsible for hereditary hemochromatosis. Mice homozygous for either the null mutation in the Hfe gene or the C282Y missense mutation rapidly accumulate hepatic parenchymal iron similar to patients with hemochromatosis. Here we investigated whether disruption of the murine Hfe gene would result in hepatic uroporphyria. Mice homozygous for the Hfe-null mutation accumulated high levels of hepatic URO when fed 5-aminolevulinate (ALA). Hfe (+/-) mice also accumulated hepatic URO when fed ALA, but at a much slower rate. The amount of accumulated URO in the null mutant mice was similar to that in wild-type mice treated with iron carbonyl in the diet, or injected with iron dextran. Iron in both wild-type and Hfe (+/-) mice was mostly in Kupffer cells. In contrast, Hfe (-/-) mice had considerable parenchymal iron deposition as well, in a pattern similar to that observed in wild-type mice treated with iron carbonyl. URO accumulation was accompanied by 84% and 33% decreases in hepatic uroporphyrinogen decarboxylase activities in Hfe (-/-) and Hfe (+/-) mice, respectively. No increases in CYP1A2 or other cytochrome P450s were detected in the Hfe-null mutant mice. We conclude that this experimental model of uroporphyria is a valid model for further investigations into the mechanism of PCT.


Assuntos
Ácido Aminolevulínico , Hemocromatose/genética , Ferro/fisiologia , Mutação/fisiologia , Porfiria Cutânea Tardia/genética , Uroporfirinas/metabolismo , Ácido Aminolevulínico/farmacologia , Animais , Citocromo P-450 CYP1A2/metabolismo , Modelos Animais de Doenças , Ferro/metabolismo , Compostos Carbonílicos de Ferro , Complexo Ferro-Dextran/farmacologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Camundongos , Compostos Organometálicos/farmacologia , Porfiria Cutânea Tardia/metabolismo , Valores de Referência , Uroporfirinogênio Descarboxilase/metabolismo
11.
Toxicol Appl Pharmacol ; 168(2): 114-22, 2000 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-11032766

RESUMO

CYP2E1 has been reported to have an essential role in alcohol-mediated increases in hepatic steatosis and acetaminophen hepatotoxicity. We found that pretreatment of Cyp2e1(-/-) mice with ethanol plus isopentanol, the predominant alcohols in alcoholic beverages, for 7 days resulted in micro- and macrovesicular steatosis in the livers of all mice, as well as a dramatic increase in acetaminophen hepatotoxicity. In Cyp2e1(-/-) mice administered up to 600 mg acetaminophen/kg alone and euthanized 7 h later, there was no increase in serum levels of ALT. In Cyp2e1(-/-) mice pretreated with ethanol and isopentanol, subsequent exposure to 400 or 600 mg acetaminophen/kg resulted in centrilobular necrosis in all mice with maximal elevation in serum levels of ALT. Acetaminophen-mediated liver damage was similar in males and females. Hepatic microsomal levels of APAP activation in untreated females were similar to those in males treated with the alcohols. However, the females, like the males, required pretreatment with the alcohols in order to increase APAP hepatotoxicity. These findings suggest that, in the Cyp2e1(-/-) mice, the alcohol-mediated increase in acetaminophen hepatotoxicity involves the contribution of other factors, in addition to induction of CYP(s) that activate acetaminophen. Alternatively, CYP-mediated activation of acetaminophen measured in vitro may not reflect the actual activity in vivo. Our findings that a 7-day treatment with ethanol and isopentanol causes extensive hepatic steatosis and increases acetaminophen hepatotoxicity in Cyp2e(-/-) mice indicate that CYP2E1 is not essential for either response.


Assuntos
Acetaminofen/toxicidade , Analgésicos não Narcóticos/toxicidade , Doença Hepática Induzida por Substâncias e Drogas , Citocromo P-450 CYP2E1/metabolismo , Etanol/toxicidade , Fígado Gorduroso Alcoólico/etiologia , Pentanóis/toxicidade , Acetaminofen/farmacocinética , Analgésicos não Narcóticos/farmacocinética , Animais , Benzoquinonas/metabolismo , Biotransformação/efeitos dos fármacos , Citocromo P-450 CYP2E1/genética , Sinergismo Farmacológico , Fígado Gorduroso Alcoólico/enzimologia , Feminino , Iminas/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/patologia , Hepatopatias/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fatores Sexuais
12.
Toxicol Appl Pharmacol ; 168(3): 177-82, 2000 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11042089

RESUMO

We had reported previously that 2.5-5 microM sodium arsenite decreased the phenobarbital-mediated induction of CYP2H activity and protein but not CYP2H1 mRNA in chick-embryo hepatocyte cultures. Induction of a CYP1A activity and protein by 3-methylcholanthrene was also decreased by low arsenite concentrations; however, CYP1A mRNAs were not measured in those studies. We report here that low concentrations of arsenite decreased induction of activities and mRNAs of two chicken cytochromes P450, CYP1A (1A4 and 1A5), by 3-methylcholanthrene in chick-embryo hepatocyte cultures. Arsenite treatment did not affect the turnover of either mRNA, nor did it decrease the superinduction of each mRNA caused by treatment with cycloheximide in addition to 3-methylcholanthrene. Glutathione depletion enhanced the effect of arsenite to decrease induction of CYP1A4. These results indicate the induction of CYP1A4 and 1A5 is inhibited by sodium arsenite at the level of transcription, suggesting that the Ah receptor complex may be involved.


Assuntos
Arsenitos/toxicidade , Hidrocarboneto de Aril Hidroxilases , Proteínas Aviárias , Sistema Enzimático do Citocromo P-450/biossíntese , Hepatócitos/enzimologia , Oxirredutases/biossíntese , Animais , Células Cultivadas , Embrião de Galinha , Cicloeximida/farmacologia , Sistema Enzimático do Citocromo P-450/metabolismo , Indução Enzimática/efeitos dos fármacos , Glutationa/fisiologia , Hepatócitos/efeitos dos fármacos , Indicadores e Reagentes , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Oxirredução , Oxirredutases/metabolismo , Inibidores da Síntese de Proteínas/farmacologia , RNA Mensageiro/biossíntese , Uroporfirinogênios/biossíntese
13.
J Cell Biochem ; 78(4): 674-80, 2000 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-10861864

RESUMO

The integrins alpha(vbeta3) and alpha(vbeta5) have been implicated in playing a key role in the process of angiogenesis. In this study, we examined the effects of hypoxia, an important stimulus of angiogenesis, on the differential expression of the integrin subunits beta(3) and beta(5). beta(3) and beta(5) messenger RNA (mRNA), protein levels, and alpha(v)beta(3) function were measured in human umbilical vein endothelial cells (HUVECs) cultured under normoxic and hypoxic (1% O(2)) conditions. Cells exposed to hypoxic conditions for up to 72 h showed gradually increased mRNA levels of alpha(V) and beta(3), peaking at 24 h, in comparison with cells cultured under normoxic conditions. However, beta(5) mRNA levels, under the same hypoxic conditions, remained at a constant level. Results from Western blot analysis of HUVECs, cultured under hypoxic conditions, paralleled those of the Northern analysis with an increased expression in alpha(v)beta(3) protein levels, measured by blotting with LM609, evident by 24 h. alpha(v)beta(5) protein levels, measured by blotting with P1F6, did not change for up to 72 h. HUVECs cultured under hypoxic conditions for 72 h showed increased attachment to fibrinogen, an alpha(v)beta(3) mediated process. These results indicate that hypoxia can increase expression of alpha(v)beta(3) in HUVECs, and that hypoxic regulation of alpha(v)beta(3) may be an important regulator of angiogenesis.


Assuntos
Hipóxia , Integrinas/biossíntese , Receptores de Vitronectina/biossíntese , Northern Blotting , Western Blotting , Adesão Celular , Células Cultivadas , Fatores de Crescimento Endotelial/metabolismo , Endotélio Vascular/metabolismo , Fibrinogênio/metabolismo , Humanos , Linfocinas/metabolismo , Neovascularização Fisiológica , Oxigênio/metabolismo , Testes de Precipitina , RNA Mensageiro/metabolismo , Fatores de Tempo , Cordão Umbilical/metabolismo , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
14.
Toxicol Appl Pharmacol ; 162(1): 60-7, 2000 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-10631128

RESUMO

Using Cyp1a2(-/-) mice we previously showed that CYP1A2 is absolutely required for hepatic uroporphyrin accumulation caused by iron and 5-aminolevulinate (ALA) treatment, both in the presence and absence of an inducer of CYP1A2. In this study we have used these mice to investigate whether CYP1A2 has an obligatory role in hepatic uroporphyria caused by hexachlorobenzene (HCBZ), an inducer of CYP2B and CYP3A, as well as CYP1A2. Here we treated mice with HCBZ and iron, with and without the porphyrin precursor, ALA, in the drinking water. In iron-loaded wild-type mice given a single dose of HCBZ and ALA, hepatic uroporphyrin (URO) accumulated to 300 nmol/g liver after 37 days, whereas in Cyp1a2(-/-) mice, there was no hepatic URO, even after an additional dose of HCBZ, and a further 29 days of ALA treatment. A similar requirement for CYP1A2 was found in uroporphyria produced in HCBZ and iron-treated mice in the absence of ALA. As detected by Western immunoblotting, HCBZ induced small increases in CYP2B and CYP3A in the livers of all animals. In the wild-type animals, HCBZ also induced CYP1A2 and associated enzyme activities, including uroporphyrinogen oxidation, by about 2-3-fold. In the Cyp1a2(-/-) mice, HCBZ did not increase hepatic microsomal uroporphyrinogen oxidation. These results indicate that, in mice, CYP1A2 is essential in the process leading to HCBZ-induced uroporphyria. Contributions by other CYP forms induced by HCBZ appear to be minimal.


Assuntos
Citocromo P-450 CYP1A2/fisiologia , Indução Enzimática/efeitos dos fármacos , Imidazóis/toxicidade , Ferro/toxicidade , Microssomos Hepáticos/metabolismo , Uroporfirinas/metabolismo , Ácido Aminolevulínico/farmacologia , Animais , Anticorpos/imunologia , Western Blotting , Doença Hepática Induzida por Substâncias e Drogas , Citocromo P-450 CYP1A2/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Interações Medicamentosas , Fígado/química , Masculino , Metilcolantreno/toxicidade , Camundongos , Camundongos Endogâmicos C57BL , Oxazinas/metabolismo , Oxirredução , Fenobarbital/toxicidade , Fatores de Tempo , Uroporfirinogênios/metabolismo
15.
Arch Biochem Biophys ; 384(2): 383-90, 2000 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-11368328

RESUMO

Porphyria cutanea tarda is a liver disease characterized by excess production of uroporphyrin. We previously reported that acetone, an inducer of CYP2E1, enhances hepatic uroporphyrin accumulation in mice treated with iron dextran (Fe) and 5-aminolevulinic acid (ALA). Cyp2e1(-/-) mice treated with Fe and ALA were used to investigate whether CYP2E1 is required for the acetone effect. Hepatic uroporphyrin accumulation was stimulated by acetone in Cyp2e1(-/-) mice to the same extent as in wild-type mice. In the absence of acetone, uroporphyrin accumulated in Cyp2e1(-/-) mice treated with Fe and ALA, but less than in wildtype mice. However, in Cypla2(-/-) mice, uroporphyrin accumulation caused by Fe and ALA, with or without acetone, was completely prevented. Acetone was not an inducer of hepatic CYP1A2 in the wild-type mice. Although acetone is an inducer of CYP2E1, CYP1A2 appears to have the essential role in acetone-enhancement of uroporphyria.


Assuntos
Acetona/farmacologia , Citocromo P-450 CYP1A2/fisiologia , Citocromo P-450 CYP2E1/fisiologia , Uroporfirinas/biossíntese , Ácido Aminolevulínico/farmacologia , Animais , Citocromo P-450 CYP1A2/genética , Citocromo P-450 CYP2E1/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Ferro/metabolismo , Ferro/farmacologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologia , Oxirredutases/metabolismo , Porfiria Cutânea Tardia/enzimologia , Uroporfirinogênios/metabolismo
16.
Arch Biochem Biophys ; 371(1): 8-14, 1999 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-10525283

RESUMO

We had previously reported that low concentrations of sodium arsenite (1-5 microM) decreased the induction of cytochrome P450 CYP1A and CYP2H in cultured chick embryo hepatocytes in parallel with increases in heme oxygenase. However, in those studies exogenous heme did not prevent the decrease in CYPs. In this study, we investigated the effect of arsenite on the synthesis and degradation of heme. Arsenite had no effect on induction of 5-aminolevulinic acid synthase mRNA or activity. Arsenite, at concentrations from 1 to 25 microM, had no effect on protoporphyrin synthesis from 5-aminolevulinic acid and did not increase the accumulation of other porphyrins, indicating that the enzymes in the pathway between 5-aminolevulinic acid synthase and ferrochelatase were unaffected by arsenite. Synthesis of heme from radioactive 5-aminolevulinic acid was slightly decreased (less than 20%) by 2.5 microM arsenite, a concentration that decreased induction of CYP1A and CYP2H by greater than 50%. Rates of biliverdin formation and degradation of exogenous heme were not different in cultures treated simultaneously with arsenite and heme or with heme alone. However, arsenite treatment increased biliverdin formation from heme synthesized from added 5-aminolevulinic acid by 60% and decreased the endogenous heme content of the cells by 30%. Our results suggest that although 2.5 microM arsenite induced heme oxygenase four- to sixfold, this had no effect on degradation of exogenous heme. Degradation of heme synthesized from 5-aminolevulinic acid was increased but this did not affect the regulatory heme pool.


Assuntos
Arsenitos/farmacologia , Sistema Enzimático do Citocromo P-450/genética , Regulação Enzimológica da Expressão Gênica , Heme/metabolismo , Fígado/metabolismo , Compostos de Sódio/farmacologia , 5-Aminolevulinato Sintetase/biossíntese , 5-Aminolevulinato Sintetase/genética , Animais , Células Cultivadas , Embrião de Galinha , Sistema Enzimático do Citocromo P-450/biossíntese , Indução Enzimática/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Cinética , Fígado/efeitos dos fármacos , Porfirinas/metabolismo , Transcrição Gênica/efeitos dos fármacos
17.
Biochem Pharmacol ; 58(2): 375-82, 1999 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-10423181

RESUMO

Previous work has implicated CYP1A2 in experimental uroporphyria caused by polyhalogenated aromatic compounds, and in uroporphyria caused by iron and 5-aminolevulinate (ALA) in the absence of inducers of CYP1A2. Here we examined whether the different susceptibilities of SWR and C57BL/6 strains of mice to uroporphyria in the absence of inducers of CYP1A2 are related to different levels of CYP1A2. Enzymological assays (ethoxy- and methoxyresorufin dealkylases, and uroporphyrinogen oxidation) and immunoblots indicated that there was about twice the amount of hepatic CYP1A2 in SWR mice compared with C57BL/6 mice. Immunohistochemistry revealed that CYP1A2 was located centrilobularly in the liver, and the staining was more intense in SWR mice than in C57BL/6 mice. Hepatic non-heme iron was about double in SWR compared with C57BL/6 mice. In SWR mice given iron dextran, hepatic iron was 1.7-fold that of C57BL/6 mice given iron dextran. SWR mice administered ALA in the drinking water accumulated much less hepatic protoporphyrin than did C57BL/6 mice. To confirm the importance of small increases in CYP1A2, C57BL/6 mice were given a low dose of 3-methylcholanthrene (MC) (15 mg/kg), as well as iron and ALA. There was about a 5- to 6-fold increase in hepatic uroporphyrin accumulation after 32 days on ALA compared with animals not given MC. In these animals, CYP1A2 was increased by 10-fold at 2 days, but returned to basal levels by 14 days. We conclude that small and transient differences in CYP1A2 may be important in the development of uroporphyria.


Assuntos
Ácido Aminolevulínico/farmacologia , Citocromo P-450 CYP1A2/metabolismo , Ferro/farmacologia , Fígado/enzimologia , Uroporfirinas/urina , Animais , Citocromo P-450 CYP1A2/análise , Imuno-Histoquímica , Fígado/efeitos dos fármacos , Fígado/patologia , Camundongos , Camundongos Endogâmicos C57BL , Especificidade da Espécie , Uroporfirinas/metabolismo
19.
J Extra Corpor Technol ; 31(2): 80-3, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10724647

RESUMO

This study was undertaken to evaluate the accuracy, reliability, consistency and biases of the CDI-100 saturation monitor when compared with a blood gas analyzer. The advantage of continuous in-line monitoring is that the perfusionist has continuous updates as to the patient's changing physiologic state. During this study, if the sample readout of the CDI-100 was off by greater than 10% from that of the Gem-Premier, the CDI-100 parameter was recalibrated. The accuracy of the CDI-100 was fair (greater than 10% of the samples needed recalibration) with regards to the initial sample comparisons. Recalibration was needed 67% of the time for the hematocrit and 35% for the saturation. The reliability of the CDI-100 was good (no equipment failure). The CDI-100 was consistent. It consistently overestimated both the hematocrit and saturation. This overestimation is the bias of the monitor. We recommend recalibration of the CDI-100 during clinical use to insure greater accuracy.


Assuntos
Gasometria/instrumentação , Hematócrito/instrumentação , Monitorização Intraoperatória/instrumentação , Idoso , Viés , Calibragem , Procedimentos Cirúrgicos Cardíacos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Fatores de Tempo
20.
Arch Biochem Biophys ; 360(2): 239-47, 1998 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-9851836

RESUMO

We had previously found that combined treatment with isopentanol and ethanol synergistically induced CYP2H protein and activity in cultured chick nepatoytes. Here we investigated the mechanism of induction of CYP2H by the alcohols and whether they caused a coordinate induction of 5-aminolevulinate synthase (ALAS) mRNA. Treatment with isopentanol alone or in combination with ethanol resulted in coordinate increases in CYP2H1 and ALAS mRNAs. With isopentanol alone, the amounts of CYP2H1 and ALAS mRNAs at 4 to 6 h were similar to those observed after treatment with the alcohol combination, but declined by 11 h. Readdition of isopentanol at 11 h again increased the expression of both mRNAs, indicating that the decreases at 11 h were due to limiting amounts of inducer. Similar results were observed in cells exposed to low concentrations of glutethimide. In the combined alcohol treatment, increases in CYP2H1 and ALAS mRNAs were sustained from 4 h to 11 h after addition of the alcohols, but decreased to control levels by 24 h. Using pulse labeling to measure de novo synthesis of CYP2H1/2 protein, we found that the increases in CYP2H1/2 protein reflected the increases in CYP2H1 mRNA. The half-life of CYP2H1/2 protein, measured from pulse-chase experiments, was approximately twofold greater than the half-life of CYP2H1 mRNA. Our results indicate that the alcohols and glutethimide coordinately increase ALAS and CYP2H1 mRNA, and that increases in CYP2H1/2 protein arise from increases in its mRNA.


Assuntos
5-Aminolevulinato Sintetase/genética , Sistema Enzimático do Citocromo P-450/genética , Etanol/farmacologia , Glutetimida/farmacologia , Pentanóis/farmacologia , 5-Aminolevulinato Sintetase/biossíntese , Animais , Células Cultivadas , Embrião de Galinha , Sistema Enzimático do Citocromo P-450/biossíntese , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Indução Enzimática/efeitos dos fármacos , Estabilidade Enzimática/efeitos dos fármacos , Glutetimida/metabolismo , Meia-Vida , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/enzimologia , Pentanóis/metabolismo , Biossíntese de Proteínas/efeitos dos fármacos , Fatores de Tempo
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