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1.
BMC Psychol ; 12(1): 242, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38685131

RESUMO

BACKGROUND: Eating disorders in children and adolescents can have serious medical and psychological consequences. The objective of this retrospective quantitative study is to gain insight in self-reported Health Related Quality of Life (HRQoL) of children and adolescents with a DSM-5 diagnosis of an eating disorder. METHOD: Collect and analyse data of patients aged 8-18 years, receiving treatment for an eating disorder. At the start and end of treatment patients completed the KIDSCREEN-52, a questionnaire measuring HRQoL. RESULTS: Data of 140 patients were analysed. Children diagnosed with Anorexia Nervosa, Bulimia Nervosa, and Other Specified Feeding or Eating Disorder all had lower HRQoL on multiple dimensions at the start of treatment, there is no statistically significant difference between these groups. In contrast, patients with Avoidant Restrictive Food Intake Disorder only had lower HRQoL for the dimension Physical Well-Being. HRQoL showed a significant improvement in many dimensions between start and end of treatment, but did not normalize compared to normative reference values of Dutch children. CONCLUSION: The current study showed that self-reported HRQoL is low in children with eating disorders, both at the beginning but also at the end of treatment. This confirms the importance of continuing to invest in the various HRQoL domains.


Assuntos
Transtornos da Alimentação e da Ingestão de Alimentos , Qualidade de Vida , Autorrelato , Humanos , Adolescente , Qualidade de Vida/psicologia , Criança , Feminino , Masculino , Transtornos da Alimentação e da Ingestão de Alimentos/psicologia , Estudos Retrospectivos , Inquéritos e Questionários , Nível de Saúde , Anorexia Nervosa/psicologia , Anorexia Nervosa/terapia
2.
Physiol Behav ; 198: 57-66, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30296404

RESUMO

Wavelength comparisons have indicated that circadian phase-shifting and enhancement of subjective and EEG-correlates of alertness have a higher sensitivity to short wavelength visible light. The aim of the current study was to test whether polychromatic light enriched in the blue portion of the spectrum (17,000 K) has increased efficacy for melatonin suppression, circadian phase-shifting, and alertness as compared to an equal photon density exposure to a standard white polychromatic light (4000 K). Twenty healthy participants were studied in a time-free environment for 7 days. The protocol included two baseline days followed by a 26-h constant routine (CR1) to assess initial circadian phase. Following CR1, participants were exposed to a full-field fluorescent light (1 × 1014 photons/cm2/s, 4000 K or 17,000 K, n = 10/condition) for 6.5 h during the biological night. Following an 8 h recovery sleep, a second 30-h CR was performed. Melatonin suppression was assessed from the difference during the light exposure and the corresponding clock time 24 h earlier during CR1. Phase-shifts were calculated from the clock time difference in dim light melatonin onset time (DLMO) between CR1 and CR2. Blue-enriched light caused significantly greater suppression of melatonin than standard light ((mean ±â€¯SD) 70.9 ±â€¯19.6% and 42.8 ±â€¯29.1%, respectively, p < 0.05). There was no significant difference in the magnitude of phase delay shifts. Blue-enriched light significantly improved subjective alertness (p < 0.05) but no differences were found for objective alertness. These data contribute to the optimization of the short wavelength-enriched spectra and intensities needed for circadian, neuroendocrine and neurobehavioral regulation.


Assuntos
Ritmo Circadiano/fisiologia , Luz , Melatonina/sangue , Vigília/fisiologia , Adulto , Atenção/fisiologia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Sonolência , Adulto Jovem
3.
Br J Cancer ; 108(3): 512-8, 2013 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-23340449

RESUMO

BACKGROUND: The polyamine-inhibitory regimen difluoromethylornithine (DFMO)+sulindac has marked efficacy in preventing metachronous colorectal adenomas. Polyamines are synthesised endogenously and obtained from dietary sources. Here we investigate dietary polyamine intake and outcomes in the DFMO+sulindac colorectal adenoma prevention trial. METHODS: Dietary polyamine data were available for 188 of 267 patients completing the study. Total dietary polyamine content was derived by the sum of dietary putrescine, spermine and spermidine values and categorised into two groups: highest (>75-100%) vs the lower three quartiles (0-25, 25-50 and 50-75%). Baseline tissue polyamine concentration and ODC1 genotype were determined. Logistic regression models were used for risk estimation. RESULTS: A significant interaction was detected between dietary polyamine group and treatment with regard to adenoma recurrence (P=0.012). Significant metachronous adenoma risk reduction was observed after DFMO+sulindac treatment in dietary polyamine quartiles 1-3 (risk ratio (RR) 0.19; 95% confidence interval (CI) 0.08-0.42; P<0.0001) but not in quartile 4 (RR 1.51; 95% CI 0.53-4.29; P=0.44). However, a lower number of events in the placebo group within dietary quartile 4 confound the aforementioned risk estimates. CONCLUSION: These preliminary findings reveal complex relationships between diet and therapeutic prevention, and they support further clinical trial-based investigations where the dietary intervention itself is controlled.


Assuntos
Adenoma/prevenção & controle , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Neoplasias Colorretais/prevenção & controle , Dieta , Recidiva Local de Neoplasia/prevenção & controle , Poliaminas/administração & dosagem , Adenoma/mortalidade , Adenoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Ensaios Clínicos Fase II como Assunto , Neoplasias Colorretais/mortalidade , Neoplasias Colorretais/patologia , Eflornitina/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/mortalidade , Recidiva Local de Neoplasia/patologia , Prognóstico , Sulindaco/administração & dosagem , Taxa de Sobrevida
4.
Amino Acids ; 33(2): 189-95, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17396214

RESUMO

Polyamine metabolic genes are downstream targets of several genes commonly mutated in colon adenomas and cancers. Inhibitors of ornithine decarboxylase, such as difluoromethylornithine (DFMO), and agents that stimulate polyamine acetylation and export, such as non-steroidal anti-inflammatory drugs (NSAIDS), act at least additively to arrest growth in human cell models and suppress intestinal carcinogenesis in mice. These preclinical studies provided the rationale for colon cancer prevention trials in humans. A Phase IIb clinical study comparing the combination of DFMO and the NSAID sulindac versus placebo was conducted. Endpoints were colorectal tissue polyamine and prostaglandin E2 contents and overall toxicity to participants. Participants in the Phase IIb study served as a vanguard for a randomized, placebo-controlled prospective Phase III trial of the combination of DFMO and sulindac with the primary study endpoint the prevention of colon polyps. Seventy percent of participants will have completed the three years of treatment in December 2006.


Assuntos
Neoplasias do Colo/metabolismo , Neoplasias do Colo/prevenção & controle , Poliaminas/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Anti-Inflamatórios não Esteroides/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Ensaios Clínicos como Assunto/métodos , Pólipos do Colo/prevenção & controle , Eflornitina/uso terapêutico , Feminino , Genes APC/efeitos dos fármacos , Genes ras/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Inibidores da Ornitina Descarboxilase
5.
Biochem Soc Trans ; 35(Pt 2): 322-5, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17371270

RESUMO

Colon cancer in humans is influenced by both genetic and dietary risk factors. The majority of colon cancers have somatic mutations in the APC (adenomatous polyposis coli) tumour-suppressor gene. Dietary arginine enhances the risk of APC-dependent colon carcinogenesis in mouse models by a mechanism involving NOS2 (nitric oxide synthase 2), as elimination of NOS2 alleles suppresses this phenotype. DFMO (difluoromethylornithine), a specific inhibitor of polyamine synthesis, also inhibits dietary arginine-induced colon carcinogenesis in C57BL/6J-Apc(Min)/J mice. The primary consequence of dietary arginine is to increase the adenoma grade in these mice. Either loss of NOS2 alleles or inhibition of polyamine synthesis suppresses the arginine-induced increase in adenoma grade. In addition to promoting intestinal carcinogenesis, polyamines can also reduce the efficacy of certain intestinal cancer chemopreventive agents. The NSAID (non-steroidal anti-inflammatory drug) sulindac is a potent inhibitor of intestinal carcinogenesis in the C57BL/6J-Apc(Min)/J mouse model and is used to treat humans with FAP (familial adenomatous polyposis). Dietary putrescine reduces the ability of sulindac to suppress intestinal tumorigenesis in the mouse model. These data suggest that reducing polyamine metabolism and dietary polyamine levels may enhance strategies for colon cancer chemoprevention.


Assuntos
Aminoácidos/farmacologia , Anticarcinógenos/farmacologia , Neoplasias do Colo/prevenção & controle , Dieta , Neoplasias Intestinais/prevenção & controle , Poliaminas/farmacologia , Animais , Antineoplásicos/uso terapêutico , Modelos Animais de Doenças , Eflornitina/uso terapêutico , Humanos , Camundongos
6.
Cell Mol Life Sci ; 60(7): 1394-406, 2003 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12943227

RESUMO

The polyamines spermidine and spermine along with the diamine putrescine are involved in many cellular processes, including chromatin condensation, maintenance of DNA structure, RNA processing, translation and protein activation. The polyamines influence the formation of compacted chromatin and have a well-established role in DNA aggregation. Polyamines are used in the posttranslational modification of eukaryotic initiation factor 5A, which regulates the transport and processing of specific RNA. The polyamines also participate in a novel RNA-decoding mechanism, a translational frame-shift, of at least two known genes, the TY1 transposon and mammalian antizyme. Polyamines are crucial for their own regulation and are involved in feedback mechanisms affecting both polyamine synthesis and catabolism. Recently, it has become apparent that the polyamines are able to influence the action of the protein kinase casein kinase 2. Here we address several roles of polyamines in gene expression.


Assuntos
Regulação da Expressão Gênica/fisiologia , Espermidina/fisiologia , Espermina/fisiologia , Animais , Caseína Quinase II , DNA/química , DNA/genética , Humanos , Conformação de Ácido Nucleico , Biossíntese de Proteínas , Processamento de Proteína Pós-Traducional , Proteínas Serina-Treonina Quinases/metabolismo , Putrescina/fisiologia , Transcrição Gênica
7.
Biochem Biophys Res Commun ; 306(2): 469-75, 2003 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-12804587

RESUMO

Spermidine/spermine N(1)-acetyltransferase (SSAT) regulates polyamine catabolism. Thioredoxin-1 (Trx-1) is a redox protein that is overexpressed in human cancer leading to increased cell proliferation, decreased apoptosis, and decreased patient survival. We report that SSAT mRNA expression is decreased in Trx-1 transfected MCF-7 human breast cancer cells. There is also a decrease in SSAT enzyme activity and lower putrescine levels but no change in spermine or spermidine levels. The expression of SSAT is regulated by the NF-E2-related factor 2 (Nrf-2) and polyamine modulated factor-1 (PMF-1) transcription factor complex. Trx-1 transfected MCF-7 cells showed decreased Nrf-2/PMF-1 DNA binding without a change in Nrf-2 or PMF-1 protein expression. The results suggest that Trx-1 may play a role in the redox regulation of SSAT expression and polyamine homeostasis that could contribute to the biological effects of Trx-1.


Assuntos
Acetiltransferases/metabolismo , Neoplasias da Mama/metabolismo , Proteínas de Membrana/metabolismo , Tiorredoxinas/metabolismo , Apoptose , Northern Blotting , Western Blotting , Divisão Celular , Núcleo Celular/metabolismo , DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Humanos , Fator 2 Relacionado a NF-E2 , Análise de Sequência com Séries de Oligonucleotídeos , Oxirredução , Poliaminas/química , Ligação Proteica , RNA Mensageiro/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Transfecção , Células Tumorais Cultivadas
8.
Biochem Soc Trans ; 31(2): 388-92, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12653645

RESUMO

Polyamines are downstream mediators of genetic risk factors in human intestinal cancers. The adenomatous polyposis coli (APC) tumour-suppressor gene, which is mutated in essentially all human colon cancers, regulates the expression of several e-box transcription factors. These factors, in turn, regulate the transcription of ornithine decarboxylase (ODC), the first enzyme in polyamine synthesis. The Kirsten ras ( K-ras ) oncogene regulates the expression of several genes, including suppressing the expression of peroxisomal proliferator-activated receptor gamma (PPARgamma). This PPAR, in turn, activates the expression of the spermidine/spermine-N(1)-acetyltransferase (SSAT), the first enzyme in polyamine catabolism. The non-steroidal anti-inflammatory drug (NSAID) sulindac induces the transcription of SSAT via activation of PPARgamma. Inactivation of the APC tumour-suppressor gene, and the activation of K-ras, have a combined effect on increasing tissue polyamine contents due to increased synthesis and decreased catabolism of the polyamines. Pharmacological strategies for suppressing ODC (e.g. the enzyme-activated inhibitor alpha-difluoromethylornithine) and activating SSAT (e.g. NSAIDs) are potent inhibitors of intestinal carcinogenesis in rodent models. Clinical trials combining these classes of agent in humans with risk factors for colon cancer are in progress.


Assuntos
Poliaminas Biogênicas/fisiologia , Neoplasias Intestinais/prevenção & controle , Antineoplásicos/farmacologia , Poliaminas Biogênicas/biossíntese , Poliaminas Biogênicas/metabolismo , Inibidores Enzimáticos/farmacologia , Regulação Enzimológica da Expressão Gênica , Humanos , Neoplasias Intestinais/genética , Fatores de Risco
9.
J Neurosci ; 21(16): 6405-12, 2001 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-11487664

RESUMO

The photopigment in the human eye that transduces light for circadian and neuroendocrine regulation, is unknown. The aim of this study was to establish an action spectrum for light-induced melatonin suppression that could help elucidate the ocular photoreceptor system for regulating the human pineal gland. Subjects (37 females, 35 males, mean age of 24.5 +/- 0.3 years) were healthy and had normal color vision. Full-field, monochromatic light exposures took place between 2:00 and 3:30 A.M. while subjects' pupils were dilated. Blood samples collected before and after light exposures were quantified for melatonin. Each subject was tested with at least seven different irradiances of one wavelength with a minimum of 1 week between each nighttime exposure. Nighttime melatonin suppression tests (n = 627) were completed with wavelengths from 420 to 600 nm. The data were fit to eight univariant, sigmoidal fluence-response curves (R(2) = 0.81-0.95). The action spectrum constructed from these data fit an opsin template (R(2) = 0.91), which identifies 446-477 nm as the most potent wavelength region providing circadian input for regulating melatonin secretion. The results suggest that, in humans, a single photopigment may be primarily responsible for melatonin suppression, and its peak absorbance appears to be distinct from that of rod and cone cell photopigments for vision. The data also suggest that this new photopigment is retinaldehyde based. These findings suggest that there is a novel opsin photopigment in the human eye that mediates circadian photoreception.


Assuntos
Ritmo Circadiano/fisiologia , Melatonina/sangue , Células Fotorreceptoras de Vertebrados/classificação , Adolescente , Adulto , Ritmo Circadiano/efeitos da radiação , Relação Dose-Resposta à Radiação , Olho/efeitos dos fármacos , Olho/metabolismo , Olho/efeitos da radiação , Feminino , Humanos , Luz , Masculino , Midriáticos/administração & dosagem , Estimulação Luminosa/instrumentação , Estimulação Luminosa/métodos , Células Fotorreceptoras de Vertebrados/metabolismo , Células Fotorreceptoras de Vertebrados/efeitos da radiação , Opsinas de Bastonetes/biossíntese , Opsinas de Bastonetes/classificação , Fatores de Tempo
10.
Anticancer Res ; 21(2A): 1163-5, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11396157

RESUMO

The efficacy of difluoromethylornithine (DFMO) as a chemopreventive agent has been tested in vitro using a human epidermal cell (HEC) assay with growth inhibition and involucrin induction as endpoints. Suppression of polyamine content is currently being utilized as a biomarker in clinical trials for the chemopreventive efficacy of DFMO against colon cancer formation. We have now examined the effects of DFMO on suppression of polyamine content in the HEC assay. The findings indicate 1) the % change in spermidine to spermine ratio and the depletion of putrescine show excellent correlation with chemopreventive efficacy in vitro; 2) the effective concentrations in vitro overlap the plasma concentrations in the clinical trial. These observations serve as further validation of the usefulness of the HEC assay as a screen for chemopreventive efficacy.


Assuntos
Antineoplásicos/farmacologia , Biomarcadores Tumorais/metabolismo , Eflornitina/farmacologia , Carcinógenos/farmacologia , Divisão Celular , Células Cultivadas , Quimioprevenção , Relação Dose-Resposta a Droga , Humanos , Queratinócitos/citologia , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Putrescina/metabolismo , Espermidina/metabolismo , Espermina/metabolismo , Tiofenos/farmacologia
11.
J Clin Endocrinol Metab ; 86(1): 433-6, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11232036

RESUMO

The aim of this study was to test if the three cone photopic visual system is the primary ocular photoreceptor input for human circadian regulation by determining the effects of different wavelengths on light-induced melatonin suppression. Healthy subjects with stable sleeping patterns (wake-up time 7:30 AM +/- 12 min) and normal color vision were exposed at night to full-field 505 nm or 555 nm monochromatic stimuli or darkness for 90 min. Plasma collected before and after exposures was quantified for melatonin. Subjects exposed to 10 irradiances at 505 nm showed no significant differences across mean pre-exposure melatonin values (F=0.505). A sigmoidal fluence-response curve fitted to the melatonin suppression data (R(2)=0.97) indicated that 9.34 x 10(12) photons/cm(2)/sec induced a half-saturation response (ED(50)) while 6.84 x 10(13) photons/cm(2)/sec induced a saturation melatonin suppression response. Further, a dose of 4.19 x 10(13) photon/cm(2)/sec at 505 nm was significantly stronger (P < 0.01) than an equal photon dose at 555 nm for melatonin suppression. These data demonstrate that the cone system that mediates human photopic vision is not the primary photoreceptor system to tranduce light stimuli for melatonin regulation.


Assuntos
Luz , Melatonina/metabolismo , Células Fotorreceptoras Retinianas Cones/fisiologia , Vias Visuais/fisiologia , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa , Fótons
13.
Cancer Res ; 60(23): 6607-10, 2000 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-11118042

RESUMO

Both the sulfide and sulfone metabolites of sulindac, a nonsteroidal anti-inflammatory drug, display anticarcinogenic effects in experimental models. Sulindac sulfide inhibits cyclooxygenase (COX) enzyme activities and has been reported to suppress ras-dependent signaling. However, the mechanisms by which sulindac sulfone suppresses cancer growth are not as defined. We studied the effects of these sulindac metabolites in human colon cancer-derived Caco-2 cells that have been transfected with an activated K-ras oncogene. Stable transfected clones expressed high levels of COX-2 mRNA and protein, compared with parental cells. K-ras-transfected cells formed tumors more quickly when injected into severe combined immunodeficiency disease mice than parental cells, and this tumorigenesis was suppressed by treatment with sulindac. Sulindac sulfone inhibited COX-2 protein expression, which resulted in a decrease in prostaglandin synthase E2 production. Sulindac sulfide had little effect on COX-2 in this model, but did suppress prostaglandin synthase E2 production, presumably by inhibiting COX enzyme activity. These data indicate that the sulfide and sulfone derivatives of sulindac exert COX-dependent effects by distinct mechanisms.


Assuntos
Anticarcinógenos/farmacologia , Neoplasias do Colo/enzimologia , Inibidores de Ciclo-Oxigenase/farmacologia , Genes ras/efeitos dos fármacos , Isoenzimas/antagonistas & inibidores , Sulindaco/farmacologia , Animais , Células CACO-2 , Células Clonais , Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/genética , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , Dinoprostona/biossíntese , Genes ras/fisiologia , Humanos , Isoenzimas/biossíntese , Proteínas de Membrana , Camundongos , Camundongos SCID , Prostaglandina-Endoperóxido Sintases/biossíntese , Sulindaco/análogos & derivados , Transfecção , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Cancer Epidemiol Biomarkers Prev ; 9(11): 1155-62, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11097222

RESUMO

The nonsteroidal anti-inflammatory drug sulindac and the ornithine decarboxylase inhibitor difluoromethylornithine (DFMO) are both potent inhibitors of colon carcinogenesis in experimental models of this disease. The combination of these two agents is undergoing evaluation as a strategy for colon cancer chemoprevention in humans with resected colon polyps. We evaluated the effects of the major sulfide and sulfone metabolites of sulindac and DFMO alone, or in combinations, on the growth and survival of Caco-2 colon cancer-derived cells and in clones of these cells transfected with an activated K-ras oncogene. Both the sulfide and sulfone metabolites of sulindac reduced cell viability, measured by colony-forming assays, primarily by inducing apoptosis. Expression of an activated K-ras oncogene caused cells treated with either sulindac sulfide or sulfone to undergo apoptosis earlier than nontransfected controls. However, clonogenic survival, measured 2 weeks after drug treatment, was the same in both Caco-2 and ras-transfected Caco-2 cells treated with sulindac metabolites. A 24-h treatment with DFMO caused a dose-dependent decrease in the colony-forming ability of cells expressing an activated K-ras but had no effect on the viability of the parental Caco-2 cells. The DFMO-dependent decrease in colony formation in K-ras-activated cells occurred in the absence of apoptosis. Assessment of cell survival by colony-forming assays indicated that these two agents acted in an additive manner when combined. These data indicate that K-ras can influence the kinetics of apoptosis induction by sulindac metabolites and cell survival in response to DFMO. However, cytotoxicity induced by these agents occurs via unique mechanisms. These studies suggest that the combination of DFMO and sulindac may be useful in human cancer prevention strategies.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Quimioprevenção , Eflornitina/farmacologia , Inibidores Enzimáticos/farmacologia , Sulindaco/farmacologia , Apoptose/efeitos dos fármacos , Células CACO-2 , Sobrevivência Celular , Transformação Celular Neoplásica , Eflornitina/análogos & derivados , Genes ras/genética , Humanos , Sulindaco/análogos & derivados
16.
Toxicol Lett ; 116(3): 199-207, 2000 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-10996481

RESUMO

The physiologic mode of cell death known as apoptosis has become a major focus of scientific research due to its biologic importance. Much of this research involves cells grown in culture, where induction of apoptosis is achieved through a variety of agents. We report that cell cultures in late log growth phase exhibit an increased susceptibility to apoptosis compared with cultures in early log growth phase when apoptosis is induced by sodium deoxycholate (NaDOC), anti-Fas antibody and cytosine-b-D-arabino-furanoside (Ara-C), three agents which induce apoptosis through different upstream mechanisms. We show that this phenomenon occurs in Jurkat lymphocytes, HT-29 and HCT-116 colon epithelial cells. We also present evidence that cell density alone does not affect NaDOC-induced apoptosis, but rather that the growth media plays a key role in increased susceptibility of cells in late log growth phase to NaDOC-induced apoptosis. These results indicate that growth phase is a variable that must be controlled in order to obtain reliable apoptosis data.


Assuntos
Apoptose , Apoptose/efeitos dos fármacos , Contagem de Células , Divisão Celular , Meios de Cultura , Citarabina/farmacologia , Ácido Desoxicólico/farmacologia , Humanos , Células Jurkat , Receptor fas/fisiologia
17.
Arch Dis Child Fetal Neonatal Ed ; 83(1): F1-6, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10873161

RESUMO

BACKGROUND: The increased incidence of neurological deviations in preterm infants with chronic lung disease (CLD) has been linked to severe brain haemorrhage (intraventricular haemorrhage (IVH)) and periventricular leucomalacia (PVL) rather than to CLD per se. AIM: To evaluate whether CLD without concomitant brain lesions constitutes a risk factor for adverse developmental outcome. METHOD: Forty three very low birthweight infants with CLD, but without IVH or PVL, and 43 very low birthweight infants without CLD, IVH, or PVL were evaluated at 5 and 10 months of corrected age using the movement assessment of infants (MAI) scale. The Griffiths' developmental test was carried out at 10 months of age. RESULTS: The overall motor assessments (MAI) in infants with CLD and controls were not significantly different. However, differences were observed in the execution of volitional movements (MAI), the total sum, hand and eye coordination, and perception and intelligence (measured by the performance scale of the Griffiths' test). CONCLUSIONS: CLD has a deleterious effect on the control of hand and eye coordination and on perception and intelligence. These results thus re-emphasise the necessity for careful neurodevelopmental follow up of infants with CLD whether or not they suffered IVH or PVL.


Assuntos
Desenvolvimento Infantil , Doenças do Prematuro/psicologia , Recém-Nascido de muito Baixo Peso , Pneumopatias/psicologia , Desempenho Psicomotor , Índice de Apgar , Doença Crônica , Seguimentos , Humanos , Recém-Nascido , Recém-Nascido Prematuro , Inteligência , Psicometria , Fatores de Risco
18.
Int J Hyperthermia ; 16(2): 171-81, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10763745

RESUMO

The objectives of this study were to quantity and compare the activities of a minimal heat shock (HS) promoter and other promoters used in gene therapy applications, and to identify strategies to amplify the heat inducibility of therapeutic genes. Human tumour cells were transiently or stably transfected with the HS promoter driving expression of reporter genes. HS promoter activity was induced transiently, with maximum activity 16-24 h after HS, and was dependent on temperature. The activity of the minimal HS promoter was similar, after 42 degrees C HS for 1 h, to that of the cytomegalovirus (CMV) promoter. To determine if the HS promoter could be used to activate a second conditional promoter, cells were transiently transfected with vectors containing both the HS and human immunodeficiency virus type 1 (HIV1) promoters. When the IL-2 gene was placed downstream of the HIV1 promoter. IL-2 production was temperature-independent. The addition of the HIV tat gene downstream of the HS promoter caused IL-2 to be induced more than 3 fold after a single 42 degrees C HS. These data indicate that the minimal HS promoter, following activation by clinically attainable temperatures (< or = 42 degrees C), can drive expression of therapeutic genes at levels comparable to the CMV promoter and be used in conjunction with a second conditional promoter to drive temperature-dependent, gene expression.


Assuntos
Terapia Genética , Vetores Genéticos , Hipertermia Induzida , Genes tat , Proteínas de Fluorescência Verde , HIV-1/genética , Proteínas de Choque Térmico HSP70/genética , Humanos , Interleucina-2/genética , Proteínas Luminescentes/genética , Regiões Promotoras Genéticas , Células Tumorais Cultivadas
19.
Carcinogenesis ; 20(9): 1709-13, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10469614

RESUMO

The colorectal mucosa of pre-symptomatic individuals with familial adenomatous polyposis (FAP) contains elevated levels of the proliferation-associated polyamines. The Min mouse, like humans with FAP, expresses an abnormal genotype for the APC tumor suppressor gene. In order to determine how APC mutation influences intestinal tissue polyamine content, we measured steady-state RNA levels of ornithine decarboxylase (ODC), the first enzyme in polyamine synthesis, antizyme (AZ), a protein which negatively regulates ODC, and the spermidine/spermine N(1)-acetyltransferase (SSAT), the first enzyme in polyamine catabolism. RNA content was increased 6- to 8-fold in both the small intestine and colon for ODC, decreased significantly in the small intestine but not the colon for AZ and was not statistically different in either intestinal tissue for SSAT in Min mice compared with normal littermates. Consistent with the changes in ODC and AZ gene expression, small intestinal, but not colonic, polyamine content was elevated in Min mice compared with normal littermates. Treatment of Min mice with the specific ODC inhibitor difluoromethylornithine (DFMO) suppressed small intestinal, but not colonic, polyamine content and tumor number. These data indicate that small intestinal tissue polyamine content is elevated in Min mice by a mechanism involving APC-dependent changes in ODC and AZ RNA. Further, ODC enzyme activity, which is influenced by both ODC and AZ RNA levels and inhibited by DFMO, is consequential for small intestinal tumorigenesis in this model. In the FAP population, DFMO may be of value in the chemoprevention of small intestinal adenocarcinoma that remains a risk following colectomy.


Assuntos
Colo/metabolismo , Neoplasias do Colo/genética , Regulação da Expressão Gênica , Genes APC , Neoplasias Intestinais/genética , Intestino Delgado/metabolismo , Ornitina Descarboxilase/biossíntese , Poliaminas/metabolismo , Biossíntese de Proteínas , Acetiltransferases/biossíntese , Acetiltransferases/genética , Animais , Anticarcinógenos/farmacologia , Colo/enzimologia , Neoplasias do Colo/metabolismo , Neoplasias do Colo/prevenção & controle , Eflornitina/farmacologia , Mucosa Intestinal/metabolismo , Neoplasias Intestinais/metabolismo , Neoplasias Intestinais/prevenção & controle , Intestino Delgado/enzimologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Mutantes , Especificidade de Órgãos , Ornitina Descarboxilase/genética , Proteínas/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética
20.
Clin Cancer Res ; 5(5): 945-51, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10353725

RESUMO

D,L-alpha-difluoromethylornithine (DFMO) was synthesized over 20 years ago. It was hoped that this enzyme-activated, irreversible inhibitor of ornithine decarboxylase, the first enzyme in polyamine synthesis, would be effective as a chemotherapy for hyperproliferative diseases, including cancer and/or infectious processes. DFMO was generally found to exert cytostatic effects on mammalian cells and tissues, and its effectiveness as a therapeutic agent has been modest. DFMO was also found to cause treatment-limiting (but reversible) ototoxicity at high doses. This side effect, along with its minimal therapeutic activity, contributed to the loss of interest by many clinicians in further developing DFMO as a cancer therapeutic agent. However, DFMO was subsequently shown to inhibit carcinogen-induced cancer development in a number of rodent models, and interest in developing this compound as a preventive agent has increased. The rationale for the inhibition of ornithine decarboxylase as a cancer chemopreventive agent has been strengthened in recent years because this enzyme has been shown to be transactivated by the c-myc oncogene in certain cell/tissue types and to cooperate with the ras oncogene in malignant transformation of epithelial tissues. Recent clinical cancer chemoprevention trials, using dose de-escalation designs, indicate that DFMO can be given over long periods of time at low doses that suppress polyamine contents in gastrointestinal and other epithelial tissues but cause no detectable hearing loss or other side effects. Current clinical chemoprevention trials are investigating the efficacy of DFMO to suppress surrogate end point biomarkers (e.g., colon polyp recurrence) of carcinogenesis in patient populations at elevated risk for the development of specific epithelial cancers, including colon, esophageal, breast, cutaneous, and prostate malignancies.


Assuntos
Anticarcinógenos/uso terapêutico , Eflornitina/uso terapêutico , Neoplasias/prevenção & controle , Animais , Anti-Inflamatórios não Esteroides/uso terapêutico , Anticarcinógenos/efeitos adversos , Anticarcinógenos/toxicidade , Divisão Celular/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Ensaios Clínicos Fase I como Assunto , Ensaios Clínicos Fase II como Assunto , Neoplasias do Colo/prevenção & controle , Ensaios de Seleção de Medicamentos Antitumorais , Sinergismo Farmacológico , Eflornitina/efeitos adversos , Eflornitina/toxicidade , Perda Auditiva/induzido quimicamente , Doenças Hematológicas/induzido quimicamente , Humanos , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/metabolismo , Neoplasias Experimentais/metabolismo , Neoplasias Experimentais/prevenção & controle , Inibidores da Ornitina Descarboxilase , Poliaminas/metabolismo , Lesões Pré-Cancerosas/tratamento farmacológico , Roedores , Células Tumorais Cultivadas/efeitos dos fármacos
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