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2.
Reprod Toxicol ; 91: 142-146, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31698003

RESUMEN

The aim of this study was to directly test and measure in vivo, if placental transfer of monoclonal antibodies takes place in pregnant Göttingen Minipigs to assess their suitability for reproductive assessment of therapeutic monoclonal antibodies. Simulect®, an approved anti CD25 (anti IL-2 receptor alpha) chimeric monoclonal IgG1 antibody, was used as a model monoclonal antibody. Maternal systemic exposure and potential placental transfer of Simulect® to fetuses were investigated following 4 weekly bolus intravenous administration of 5.0 mg/kg from gestation day (GD) 79 or 80 (e.g GD 79, 86, 93 and 100) and with terminal Caesarean section on GD 108 or GD 109 respectively. Results clearly showed exposure in maternal animals, detectable compound in the amniotic fluid from one out of 9 maternal animals, but no exposure in fetuses confirming absence of placental transfer of the selected model antibody Simulect® in minipigs. The absence of Simulect® in the fetuses further supports that the presence of Simulect® in the amniotic fluid in one maternal animal was likely due to contamination with maternal blood during sampling. The demonstrated absence of fetal exposure clearly indicates that, the minipig is not a suitable species for conduct of reproductive toxicity studies with monoclonal antibodies.


Asunto(s)
Basiliximab/farmacocinética , Inmunosupresores/farmacocinética , Intercambio Materno-Fetal , Líquido Amniótico/química , Animales , Basiliximab/sangre , Femenino , Sangre Fetal/química , Inmunosupresores/sangre , Embarazo , Porcinos , Porcinos Enanos
3.
Primate Biol ; 4(1): 93-100, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-32110696

RESUMEN

To safeguard patients, regulatory authorities require that new drugs that are to be given by the intravitreal (IVT) route are assessed for their safety in a laboratory species using the same route of administration. Due to the high similarity of ocular morphology and physiology between humans and nonhuman primates (NHPs) and due to the species specificity of many biotherapeutics, the monkey is often the only appropriate model. To this end, intravitreal administration and assessment of ocular toxicity are well established in cynomolgus monkeys (Macaca fascicularis). In contrast, the common marmoset monkey (Callithrix jacchus) is not a standard model for ocular toxicity studies due to its general sensitivity to laboratory investigations and small eye size. It was the purpose of the present work to study whether the marmoset is a useful alternative to the cynomolgus monkey for use in intravitreal toxicological studies. Six marmoset monkeys received repeated (every 2 weeks for a total of four doses) intravitreal injections of 10 or 20  µ L of a placebo. The animals were assessed for measurements of intraocular pressure (IOP), standard ophthalmological investigations and electroretinography (ERG). At the end of the dosing period, the animals were sacrificed and the eyes were evaluated histologically. ERG revealed similar results when comparing predose to end-of-study data, and there was no difference between the two dose volumes. A transient increase in the IOP was seen immediately after dosing, which was more pronounced after dosing of 20  µ L compared to 10  µ L. Ophthalmologic and microscopic observations did not show any significant changes. Therefore, it can be concluded that 10  µ L as well as 20  µ L intravitreal injections of a placebo are well tolerated in the marmoset. These results demonstrate that the common marmoset is an alternative to the cynomolgus monkey for intravitreal toxicity testing.

4.
Asian Pac J Cancer Prev ; 17(7): 3213-22, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27509954

RESUMEN

BACKGROUND: Methyl donor status influences DNA stability and DNA methylation although little is known about effects on DNA methyltransferases. The aim of this study was to determine whether methyldonor status influences DNA methyltransferase (Dnmt) gene expression in cervical cancer cells, and if so, whether there are associated effects on global DNA methylation. MATERIALS AND METHODS: The human cervical cancer cell line, C4 II, was grown in complete medium and medium depleted of folate (FM+) and folate and methionine (FM). Growth rate, intracellular folate, intracellular methionine and homocysteine in the extracellular medium were measured to validate the cancer cell model of methyl donor depletion. Dnmt expression was measured by qRT PCR using relative quantification and global DNA methylation was measured using a flow cytometric method. RESULTS: Intracellular folate and methionine concentrations were significantly reduced after growth in depleted media. Growth rate was also reduced in response to methyl donor depletion. Extracellular homocysteine was raised compared with controls, indicating disturbance to the methyl cycle. Combined folate and methionine depletion led to a significant downregulation of Dnmt3a and Dnmt3b; this was associated with an 18% reduction in global DNA methylation compared with controls. Effects of folate and methionine depletion on Dnmt3a and 3b expression were reversed by transferring depleted cells to complete medium. CONCLUSIONS: Methyl donor status can evidently influence expression of Dnmts in cervical cancer cells, which is associated with DNA global hypomethylation. Effects on Dnmt expression are reversible, suggesting reversible modulating effects of dietary methyl donor intake on gene expression, which may be relevant for cancer progression.


Asunto(s)
ADN (Citosina-5-)-Metiltransferasas/genética , Metilación de ADN , Ácido Fólico/metabolismo , Metionina/metabolismo , Neoplasias del Cuello Uterino/genética , Neoplasias del Cuello Uterino/metabolismo , Western Blotting , ADN (Citosina-5-)-Metiltransferasa 1 , Femenino , Humanos , Células Tumorales Cultivadas
5.
Nutr J ; 15(1): 69, 2016 07 14.
Artículo en Inglés | MEDLINE | ID: mdl-27418034

RESUMEN

BACKGROUND: Poor micronutrient status is reported among adolescents across Europe and USA. This may be related to the well-documented decline in the regular consumption of breakfast by this group. The regular consumption of a breakfast cereal offers a possible means to improve micronutrient status; fortified cereal is likely to have enhanced benefit. A study was conducted to determine the efficacy of the regular consumption of a fortified cereal with milk, compared with unfortified cereal, consumed either as a breakfast or a supper, in improving micronutrient intake and micronutrient status of adolescent girls. METHODS: A randomised, double-blind, placebo-controlled intervention trial was conducted in girls recruited at ages 16-19 years, from schools and colleges in Sheffield, UK. Girls were randomised to receive 50 g fortified or unfortified cereal, with 150 ml semi-skimmed milk, daily, for 12 weeks, as a breakfast or as a supper. Dietary intake was estimated using a 4-d food diary and blood collected for the assessment of nutritional status. Within-group changes were tested using a paired sample t test; two-way ANOVA was used to analyse effects of the intervention, with cereal type and time of consumption as factors, correcting for baseline values. The analysis was conducted on 71 girls who completed the study. RESULTS: Consumption of unfortified cereal elicited an increase in the intake of vitamins B1, B2 and B6; consumption of fortified cereal elicited increases in vitamins B1, B2, B6, B12, folate and iron (P < 0.001) and of vitamin D (P = 0.007), all increases were significantly greater than for unfortified cereal. Consumption of the fortified cereal also led to a significant improvement in biomarkers of status for vitamins B2, B12, folate and of iron, compared with girls receiving the unfortified cereal, and maintained vitamin D status, in contrast with the girls receiving the unfortified cereal (P < 0.001). CONCLUSIONS: The daily consumption of cereal with milk for 12 weeks by adolescent girls, increased intakes of micronutrients. The consumption of fortified cereal elicited greater increases than for unfortified cereal and improved biomarkers of micronutrient status. The findings justify strategies to encourage the consumption of fortified cereal with milk by adolescents, either as a breakfast or a supper. TRIAL REGISTRATION: Registered with Current Controlled Trials (Registration: ISRCTN55141306 ).


Asunto(s)
Grano Comestible , Alimentos Fortificados , Micronutrientes/sangre , Adolescente , Animales , Biomarcadores/sangre , Dieta , Método Doble Ciego , Femenino , Humanos , Micronutrientes/administración & dosificación , Leche , Evaluación Nutricional , Estado Nutricional , Cooperación del Paciente , Tamaño de la Muestra , Reino Unido , Adulto Joven
6.
Toxicol Pathol ; 44(3): 486-91, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26516163

RESUMEN

Developmental toxicity testing of therapeutic antibodies is most often conducted in nonhuman primates owing to lack of cross-reactivity in other species. Minipigs may show cross-reactivity for some humanized antibodies but have not been used for developmental toxicity testing due to an assumed lack of embryo-fetal exposure. Unlike in humans, maternal IgGs do not cross the porcine placenta to reach the fetus. Some humanized IgGs, however, have a higher affinity for the neonatal Fc receptor (FcRn) and are more likely than endogenous antibodies to cross the placenta of animals. The major site of prenatal IgG transfer is the placenta, though FcRn in fetal intestine could also uptake maternal IgGs from swallowed amniotic fluid. Using immunohistochemistry andin situhybridization in this experiment, FcRn was found in minipig placenta and fetal intestine during early, mid-, and late gestation. To date, however, fetal exposure to maternally administered IgGs has never been demonstrated in the minipig.


Asunto(s)
Feto , Antígenos de Histocompatibilidad Clase I/metabolismo , Yeyuno , Placenta , Receptores Fc/metabolismo , Porcinos Enanos/metabolismo , Animales , Femenino , Feto/química , Feto/inmunología , Feto/metabolismo , Antígenos de Histocompatibilidad Clase I/análisis , Yeyuno/química , Yeyuno/inmunología , Yeyuno/metabolismo , Placenta/química , Placenta/inmunología , Placenta/metabolismo , Embarazo , Receptores Fc/análisis , Porcinos
7.
Regul Toxicol Pharmacol ; 70(1): 413-29, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-25078890

RESUMEN

An international expert group which includes 30 organisations (pharmaceutical companies, contract research organisations, academic institutions and regulatory bodies) has shared data on the use of recovery animals in the assessment of pharmaceutical safety for early development. These data have been used as an evidence-base to make recommendations on the inclusion of recovery animals in toxicology studies to achieve scientific objectives, while reducing animal use. Recovery animals are used in pharmaceutical development to provide information on the potential for a toxic effect to translate into long-term human risk. They are included on toxicology studies to assess whether effects observed during dosing persist or reverse once treatment ends. The group devised a questionnaire to collect information on the use of recovery animals in general regulatory toxicology studies to support first-in-human studies. Questions focused on study design, the rationale behind inclusion or exclusion and the impact this had on internal and regulatory decisions. Data on 137 compounds (including 53 biologicals and 78 small molecules) from 259 studies showed wide variation in where, when and why recovery animals were included. An analysis of individual study and programme design shows that there are opportunities to reduce the use of recovery animals without impacting drug development.


Asunto(s)
Diseño de Fármacos , Evaluación Preclínica de Medicamentos/métodos , Modelos Animales , Toxicología/métodos , Animales , Humanos , Cooperación Internacional , Proyectos de Investigación , Encuestas y Cuestionarios , Factores de Tiempo
8.
Glob Adv Health Med ; 3(5): 37-44, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25568823

RESUMEN

BACKGROUND: Tobacco abuse is a well-recognized scourge on health and healthcare costs. Attempts to facilitate tobacco cessation are rarely better than marginally effective. PRIMARY OBJECTIVE: To describe an observational trial of an existing and highly successful tobacco cessation program featuring health coaching as the primary intervention. Core components of program design and data are presented and may serve as a model for other public health settings. METHODS: Health coaching and three complementary program components (auriculotherapy, alpha-electrical stimulation, and relaxation techniques) are presented. Quit rates at 6 months for 161 patients over 3 years are provided featuring 30-day point prevalence smoke free and intent-to-treat values. Comparisons for telephonic vs in-clinic health coaching, free choice vs mandated participation, and program costs are provided. RESULTS: Point prevalence quit rate was 88.7% while the more conservative intent-to-treat quit rate was 51.6%. Telephonic and in-clinic health coaching were not significantly different at any time point. Smoke-free rates at 6 and 12 months were 76.9% and 63.2%, respectively. CONCLUSIONS: Two cost-effective smoking cessation models featuring health coaching are presented. Point prevalence (30-day) above 80% and an enduring effect was seen. Personal and societal burdens (health and financial) of tobacco use might be greatly impacted if such programs were successfully implemented on a larger scale.

9.
J Nutr ; 143(2): 142-7, 2013 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-23236022

RESUMEN

Plasma vitamin B-12 is the most commonly used biomarker of vitamin B-12 status, but the predictive value for low vitamin B-12 status is poor. The urinary methylmalonic acid (uMMA) concentration has potential as a functional biomarker of vitamin B-12 status, but the response to supplemental vitamin B-12 is uncertain. A study was conducted to investigate the responsiveness of uMMA to supplemental vitamin B-12 in comparison with other biomarkers of vitamin B-12 status [plasma vitamin B-12, serum holotranscobalamin (holoTC), plasma MMA] in elderly people with moderately poor vitamin B-12 status. A double-blind, placebo-controlled, randomized 8-wk intervention study was carried out using vitamin B-12 supplements (500 µg/d, 100 µg/d, and 10 µg/d cyanocobalamin) in 100 elderly people with a combined plasma vitamin B-12 <250 pmol/L and uMMA ratio (µmol MMA/mmol creatinine) >1.5. All biomarkers had a dose response to supplemental vitamin B-12. Improvements in plasma vitamin B-12 and serum holoTC were achieved at cobalamin supplements of 10 µg/d, but even 500 µg/d for 8 wk did not normalize plasma vitamin B-12 in 8% and serum holoTC in 12% of people. The response in uMMA was comparable with plasma MMA; 15-25% of people still showed evidence of metabolic deficiency after 500 µg/d cobalamin for 8 wk. There was a differential response in urinary and plasma MMA according to smoking behavior; the response was enhanced in ex-smokers compared with never-smokers. uMMA offers an alternative marker of metabolic vitamin-B12 status, obviating the need for blood sampling.


Asunto(s)
Envejecimiento , Suplementos Dietéticos , Ácido Metilmalónico/orina , Estado Nutricional , Deficiencia de Vitamina B 12/dietoterapia , Vitamina B 12/administración & dosificación , Anciano , Anciano de 80 o más Años , Apoproteínas/sangre , Biomarcadores/sangre , Biomarcadores/orina , Creatinina/orina , Estudios Transversales , Método Doble Ciego , Femenino , Humanos , Masculino , Ácido Metilmalónico/sangre , Cooperación del Paciente , Fumar/efectos adversos , Factores de Tiempo , Transcobalaminas/análisis , Vitamina B 12/sangre , Vitamina B 12/uso terapéutico , Deficiencia de Vitamina B 12/sangre , Deficiencia de Vitamina B 12/fisiopatología , Deficiencia de Vitamina B 12/orina
10.
Eur J Nutr ; 52(7): 1801-10, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23271614

RESUMEN

BACKGROUND/OBJECTIVES: Folate has been strongly implicated in the aetiology of colorectal cancer. However, the relationship between dietary folate intake, rectal mucosal folate status and colorectal cancer risk is uncertain. The study aimed to estimate nutrient intakes and measure systemic folate status and rectal mucosal folate concentration in people at differential risk of developing colorectal cancer. METHODS: Two hundred and twenty-eight individuals were recruited from gastroenterology clinics and subdivided into three patient groups: untreated colorectal cancer (n = 43), adenomatous polyps (n = 90) or normal bowel (n = 95). Biopsies from macroscopically normal rectal mucosa and blood were collected and used for the measurement of rectal mucosal 5-methyltetrahydrofolate (5-MeTHF) and systemic markers of folate status, respectively. Nutrient intake was estimated using a validated food frequency questionnaire. RESULTS: Dietary intake variables, plasma 5-MeTHF and red cell folate and plasma homocysteine concentrations were similar in all three subject groups and 95% CI fell within normal range for each variable. Rectal mucosal 5-MeTHF concentration was higher in the normal mucosa of adenomatous polyp patients than in normal subjects (P = 0.055). Rectal mucosal 5-MeTHF was associated significantly with plasma folate (P < 0.001, r = 0.294), red cell folate (P = 0.014, r = 0.305), plasma homocysteine (P = 0.017, r = -0.163) and dietary folate intake (P = 0.036, r = 0.152). CONCLUSIONS: This study demonstrates adequate folate status of patients attending gastroenterology clinics for the investigation of bowel symptoms, with no significant difference in dietary intakes or systemic folate status indices according to diagnosis. Rectal mucosal 5-MeTHF concentrations were elevated in adenomatous polyp patients, but failed to reach significance. Further studies are required to determine the biological significance of this observation.


Asunto(s)
Neoplasias Colorrectales/sangre , Dieta , Ácido Fólico/administración & dosificación , Ácido Fólico/sangre , Tetrahidrofolatos/sangre , Estudios de Cohortes , Neoplasias Colorrectales/diagnóstico , Neoplasias Colorrectales/epidemiología , Eritrocitos/metabolismo , Femenino , Glutatión Reductasa/sangre , Homocisteína/sangre , Humanos , Mucosa Intestinal , Masculino , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Metilenotetrahidrofolato Reductasa (NADPH2)/metabolismo , Persona de Mediana Edad , Evaluación Nutricional , Estado Nutricional , Factores de Riesgo , Encuestas y Cuestionarios , Vitamina B 12/sangre
11.
Arthritis Care Res (Hoboken) ; 64(3): 340-50, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22076868

RESUMEN

OBJECTIVE: To assess 1) the rates of sexual activity and impairment, 2) clinical correlates of sexual activity/impairment, and 3) common sources of pain during and after sex in a large sample of female patients with systemic sclerosis (SSc; scleroderma). METHODS: We performed a cross-sectional multicenter study of female SSc patients from the Canadian Scleroderma Research Group Registry. Patients underwent medical examinations and clinical histories and were asked whether they had engaged in sexual activities with their partner in the past 4 weeks. Sexually active patients completed a 9-item version of the Female Sexual Function Index (FSFI) and items related to problems that may be linked to sexual dysfunction in SSc. Multivariate logistic regressions assessed independent predictors of activity/inactivity and sexual dysfunction. RESULTS: A total of 226 (41%) of 547 patients, including 215 (54%) of the 401 patients currently in relationships, reported having engaged in sexual activities with a partner in the past 4 weeks. Among 165 sexually active patients with complete data for all variables, 102 (62%) had FSFI total scores ≤22.5, indicating impaired function. Seventeen percent of the patients were sexually active and not impaired. Independent predictors (P < 0.05) of sexual activity were younger age, fewer gastrointestinal symptoms, and less severe Raynaud's phenomenon symptoms. Sexual impairment was independently associated with older age, higher skin scores, and more severe breathing problems. Vaginal pain was 8 times more likely among women with impairment. CONCLUSION: Research is needed to compare the extent of activity and impairment in SSc compared to women without SSc and to develop interventions to address impaired sexual function in women with SSc.


Asunto(s)
Esclerodermia Sistémica/fisiopatología , Conducta Sexual/estadística & datos numéricos , Disfunciones Sexuales Fisiológicas/fisiopatología , Adolescente , Adulto , Estudios Transversales , Femenino , Humanos , Persona de Mediana Edad , Sistema de Registros , Esclerodermia Sistémica/complicaciones , Conducta Sexual/fisiología , Disfunciones Sexuales Fisiológicas/etiología , Encuestas y Cuestionarios , Mujeres
12.
Am J Clin Nutr ; 93(6): 1274-84, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21525198

RESUMEN

BACKGROUND: Moderate riboflavin deficiency is prevalent in certain population groups in affluent countries, but the functional significance of this deficiency is not clear. Studies have indicated a role for riboflavin in the absorption and use of iron. OBJECTIVE: We investigated the effect of riboflavin supplementation on hematologic status in a group of moderately riboflavin-deficient women aged 19-25 y in the United Kingdom. DESIGN: One hundred twenty-three women with biochemical evidence of riboflavin deficiency [erythrocyte glutathione reductase activation coefficient (EGRAC) >1.40] were randomly assigned to receive 2 or 4 mg riboflavin or a placebo for 8 wk. Measurements of hematologic status were made pre- and postsupplementation, and dietary intakes were also assessed; iron absorption was measured in a subgroup of women. RESULTS: One hundred nineteen women completed the intervention. The use of a riboflavin supplement for 8 wk elicited a significant improvement in riboflavin status with a dose response (P < 0.0001). For women who received supplemental riboflavin, an increase in hemoglobin status correlated with improved riboflavin status (P < 0.02). Women in the lowest tertile of riboflavin status at baseline (EGRAC >1.65) showed a significantly greater increase in hemoglobin status in response to the supplement than did women in the first and second tertiles (P < 0.01). Dietary iron intake and iron absorption did not change during the study. CONCLUSIONS: Moderately poor riboflavin status can affect iron status: the lower the riboflavin status, the greater the hematologic benefits of improving status. The results also suggest that consideration should be given to raising the currently accepted EGRAC threshold for deficiency. This trial was registered at controlled-trials.com as ISRCTN35811298.


Asunto(s)
Hemoglobinas/metabolismo , Deficiencia de Riboflavina/sangre , Riboflavina/farmacología , Adulto , Suplementos Dietéticos , Relación Dosis-Respuesta a Droga , Índices de Eritrocitos/efectos de los fármacos , Femenino , Humanos , Absorción Intestinal , Hierro de la Dieta/farmacocinética , Riboflavina/sangre , Riboflavina/uso terapéutico , Deficiencia de Riboflavina/tratamiento farmacológico , Reino Unido , Adulto Joven
13.
Am J Clin Nutr ; 90(5): 1151-9, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19740970

RESUMEN

BACKGROUND: Riboflavin status is commonly measured by the in vitro stimulation of erythrocyte glutathione reductase with flavin adenine dinucleotide and expressed as an erythrocyte glutathione reductase activation coefficient (EGRAC). However, this assay is insensitive to poor riboflavin status in subjects with glucose-6-phosphate dehydrogenase (G6PD) deficiency. Because G6PD deficiency is common in parts of the world where ariboflavinosis is endemic, it is important to have a measure of riboflavin status that is unaffected by differences in G6PD status. OBJECTIVE: The objective was to further develop and validate a fluorometric assay for pyridoxamine phosphate oxidase (PPO) activity as a measure of riboflavin status. DESIGN: A fluorometric assay was optimized for the flavin-dependent enzyme PPO in erythrocytes. Hemolysates from a previous riboflavin intervention study (2- and 4-mg riboflavin supplements) were used to investigate the responsiveness of the method to changes in riboflavin intake. RESULTS: PPO activity and the PPO activation coefficient (PPOAC) were used to assess riboflavin status. Both PPO activity and PPOAC responded to riboflavin supplements (P < 0.01), but only PPO showed a dose response (P < 0.001). The change from baseline to after the intervention in PPOAC and PPO enzyme activity was significantly inversely correlated (P < 0.001). Both PPO activity and PPOAC were strongly correlated with EGRAC (P < 0.001). Additionally, both PPOAC and EGRAC showed a significant inverse correlation with dietary riboflavin intake (P < 0.01); PPO activity was positively correlated with riboflavin intake (P < 0.01). CONCLUSION: PPO activity could be used as a biomarker for measuring riboflavin status, especially in populations with a high prevalence of G6PD deficiency. This trial is registered at www.isrctn.org as ISRCTN35811298.


Asunto(s)
Eritrocitos/enzimología , Glutatión Reductasa/sangre , Piridoxaminafosfato Oxidasa/sangre , Riboflavina/sangre , Activación Enzimática , Flavina-Adenina Dinucleótido/sangre , Flavina-Adenina Dinucleótido/farmacología , Hemólisis , Humanos , Fosfato de Piridoxal/análogos & derivados , Fosfato de Piridoxal/metabolismo , Riboflavina/administración & dosificación
14.
BMC Public Health ; 9: 90, 2009 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-19323801

RESUMEN

BACKGROUND: The functional significance of moderate riboflavin deficiency as it is currently assessed is not well understood. Animal and human studies have suggested a role for riboflavin in the absorption and mobilisation of iron and as such may be important in maintaining haematological status. Recent National Diet and Nutrition Surveys in the United Kingdom have shown that young women in particular are at risk of moderate riboflavin deficiency and low iron status. METHODS/DESIGN: A randomised placebo controlled intervention trial was conducted to investigate the effect of riboflavin supplementation on various measures of haematological status in a group of moderately riboflavin deficient young women aged 19 to 25 years. Women who were low milk consumers were initially screened for riboflavin status as assessed by the erythrocyte glutathione reductase activation coefficient assay (EGRAC). One hundred and twenty three women with EGRAC values >1.40 were randomised to receive 2 mg, 4 mg riboflavin or placebo for 8 weeks. In addition 36 of these women were randomly allocated to an iron bioavailability study to investigate the effect of the intervention on the absorption or utilisation of iron using an established red cell incorporation technique. DISCUSSION: One hundred and nineteen women completed the intervention study, of whom 36 completed the bioavailability arm. Compliance was 96 +/- 6% (mean +/- SD). The most effective recruitment strategy for this gender and age group was e-communication (e-mail and website). The results of this study will clarify the functional significance of the current biochemical deficiency threshold for riboflavin status and will inform a re-evaluation of this biochemical threshold. TRIAL REGISTRATION: Current Controlled Trials Registration No. ISRCTN35811298.


Asunto(s)
Deficiencia de Riboflavina/tratamiento farmacológico , Riboflavina/administración & dosificación , Adulto , Disponibilidad Biológica , Registros de Dieta , Suplementos Dietéticos , Método Doble Ciego , Recuento de Eritrocitos , Índices de Eritrocitos , Femenino , Glutatión Reductasa/sangre , Humanos , Hierro/sangre , Hierro/metabolismo , Placebos , Riboflavina/sangre , Riboflavina/farmacocinética , Deficiencia de Riboflavina/sangre , Reino Unido , Adulto Joven
15.
Br J Nutr ; 102(2): 273-8, 2009 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-19102813

RESUMEN

Riboflavin status is usually measured as the in vitro stimulation with flavin adenine dinucleotide of the erythrocyte enzyme glutathione reductase, and expressed as an erythrocyte glutathione reductase activation coefficient (EGRAC). This method is used for the National Diet and Nutrition Surveys (NDNS) of the UK. In the period between the 1990 and 2003 surveys of UK adults, the estimated prevalence of riboflavin deficiency, expressed as an EGRAC value > or = 1.30, increased from 2 to 46 % in males and from 1 to 34 % in females. We hypothesised that subtle but important differences in the detail of the methodology between the two NDNS accounted for this difference. We carried out an evaluation of the performance of the methods used in the two NDNS and compared against an 'in-house' method, using blood samples collected from a riboflavin intervention study. Results indicated that the method used for the 1990 NDNS gave a significantly lower mean EGRAC value than both the 2003 NDNS method and the 'in-house' method (P < 0.0001). The key differences between the methods relate to the concentration of FAD used in the assay and the duration of the period of incubation of FAD with enzyme. The details of the EGRAC method should be standardised for use in different laboratories and over time. Additionally, it is proposed that consideration be given to re-evaluating the basis of the EGRAC threshold for riboflavin deficiency.


Asunto(s)
Pruebas Enzimáticas Clínicas/normas , Eritrocitos/enzimología , Glutatión Reductasa/metabolismo , Deficiencia de Riboflavina/diagnóstico , Riboflavina/sangre , Adulto , Pruebas Enzimáticas Clínicas/métodos , Dieta , Activación Enzimática , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas Nutricionales , Estado Nutricional , Valores de Referencia , Sensibilidad y Especificidad , Estadísticas no Paramétricas , Reino Unido , Adulto Joven
16.
Cancer Epidemiol Biomarkers Prev ; 16(10): 2128-35, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-17932361

RESUMEN

Epidemiologic data suggest that increasing folate intake may protect against colorectal cancer. Riboflavin may interact with folate to modulate the effect. A double-blind randomized placebo-controlled intervention study (the FAB2 Study) was carried out in healthy controls and patients with colorectal polyps (adenomatous and hyperplastic) to examine effects of folic acid and riboflavin supplements on biomarkers of nutrient status and on putative biomarkers of colorectal cancer risk (DNA methylation and DNA damage; to be reported elsewhere). Ninety-eight healthy controls and 106 patients with colorectal polyps were stratified for the thermolabile variant of methylene tetrahydrofolate reductase, MTHFR C677T, and were randomized to receive 400 microg of folic acid, 1,200 microg of folic acid, or 400 microg of folic acid plus 5 mg of riboflavin or placebo for 6 to 8 weeks. Blood samples and colon biopsy samples were collected for the measurement of biomarkers of folate and riboflavin status. Supplementation with folic acid elicited a significant increase in mucosal 5-methyl tetrahydrofolate, and a marked increase in RBC and plasma, with a dose-response. Measures of riboflavin status improved in response to riboflavin supplementation. Riboflavin supplement enhanced the response to low-dose folate in people carrying at least one T allele and having polyps. The magnitude of the response in mucosal folate was positively related to the increase in plasma 5-methyl tetrahydrofolate but was not different between the healthy group and polyp patients. Colorectal mucosal folate concentration responds to folic acid supplementation to an extent comparable to that seen in plasma, but with a suggestion of an upper limit.


Asunto(s)
Poliposis Adenomatosa del Colon/tratamiento farmacológico , Biomarcadores de Tumor/sangre , Ácido Fólico/administración & dosificación , Ácido Fólico/sangre , Riboflavina/administración & dosificación , Riboflavina/sangre , Poliposis Adenomatosa del Colon/sangre , Poliposis Adenomatosa del Colon/genética , Adulto , Anciano , Anciano de 80 o más Años , Alelos , Biopsia , Colonoscopía , Relación Dosis-Respuesta a Droga , Método Doble Ciego , Quimioterapia Combinada , Eritrocitos/efectos de los fármacos , Eritrocitos/metabolismo , Femenino , Estudios de Seguimiento , Tamización de Portadores Genéticos , Variación Genética/genética , Genotipo , Homocisteína/sangre , Humanos , Mucosa Intestinal/patología , Masculino , Metilenotetrahidrofolato Reductasa (NADPH2)/genética , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple , Sigmoidoscopía , Tetrahidrofolatos/sangre
17.
Clin J Pain ; 20(6): 415-22, 2004.
Artículo en Inglés | MEDLINE | ID: mdl-15502685

RESUMEN

Clinicians tend to assign greater weight to nonverbal expression than to patient self-report when judging the location and severity of pain. However, patients can be successful at dissimulating facial expressions of pain, as posed expressions resemble genuine expressions in the frequency and intensity of pain-related facial actions. The present research examined individual differences in the ability to discriminate genuine and deceptive facial pain displays and whether different models of training in cues to deception would improve detection skills. Judges (60 male, 60 female) were randomly assigned to 1 of 4 experimental groups: 1) control; 2) corrective feedback; 3) deception training; and 4) deception training plus feedback. Judges were shown 4 videotaped facial expressions for each chronic pain patient: neutral expressions, genuine pain instigated by physiotherapy range of motion assessment, masked pain, and faked pain. For each condition, the participants rated pain intensity and unpleasantness, decided which category each of the 4 video clips represented, and described cues they used to arrive at decisions. There were significant individual differences in accuracy, with females more accurate than males, but accuracy was unrelated to past pain experience, empathy, or the number or type of facial cues used. Immediate corrective feedback led to significant improvements in participants' detection accuracy, whereas there was no support for the use of an information-based training program.


Asunto(s)
Decepción , Expresión Facial , Dolor/diagnóstico , Adolescente , Adulto , Señales (Psicología) , Toma de Decisiones/fisiología , Empatía , Retroalimentación Psicológica/fisiología , Femenino , Humanos , Individualidad , Juicio/fisiología , Detección de Mentiras , Masculino , Simulación de Enfermedad , Análisis Multivariante , Variaciones Dependientes del Observador , Dolor/psicología , Dimensión del Dolor , Examen Físico , Factores Sexuales
18.
Pain ; 111(1-2): 84-95, 2004 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-15327812

RESUMEN

A patient's readiness to adopt a self-management approach to pain has been hypothesized to increase during multidisciplinary pain treatment and to impact pain coping responses. The Pain Stages of Change Questionnaire (PSOCQ; [J Pain (1997) 227]) was designed to assess four components of readiness to self-manage pain: pre-contemplation, contemplation, action, and maintenance. We tested three hypotheses concerning this construct in two different samples of patients with chronic pain: (1) readiness to self-manage pain, as assessed by the PSOCQ, would increase from pre-multidisciplinary pain treatment to post-treatment and follow-up; (2) changes in readiness to self-manage pain measured pre-treatment to post-treatment and follow-up would be associated with changes in the use of pain coping strategies; and (3) increases in readiness to self-manage pain would be associated with improvement in multidisciplinary pain treatment. The findings supported all three hypotheses. We discuss the implications of the findings for understanding motivational issues in the self-management of pain.


Asunto(s)
Adaptación Psicológica , Dolor/psicología , Autocuidado , Adulto , Enfermedad Crónica , Evaluación de la Discapacidad , Femenino , Fibromialgia/psicología , Fibromialgia/terapia , Humanos , Masculino , Persona de Mediana Edad , Clínicas de Dolor , Manejo del Dolor , Resultado del Tratamiento
19.
Cancer Epidemiol Biomarkers Prev ; 13(7): 1244-9, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15247137

RESUMEN

Folate deficiency may be associated with an increased risk of cancer at certain sites. There is a need to measure folate status and putative biomarkers of cancer risk in the same target tissue, or in surrogate tissues. A study was carried out to develop a method for the rapid measurement of folate in human buccal mucosa and lymphocytes and to evaluate the responsiveness of this measurement in both tissues to folic acid supplementation in healthy subjects, relative to conventional markers of folate status. Three hundred and twenty-three adults, ages between 20 and 60 years, were screened for RBC folate concentrations. Sixty-five subjects with red cell folate between 200 and 650 nmol/L participated in a randomized, double blind, placebo-controlled, folic acid (1.2 mg) intervention trial, lasting 12 weeks. As anticipated, a significant baseline correlation (r = 0.36, P < 0.01) was observed between red cell folate and plasma 5-methyltetrahydrofolate (5-MeTHF). Lymphocyte total folate was significantly associated with plasma 5-MeTHF (r = 0.28, P < 0.05) and plasma total homocysteine concentration (r = -0.34, P < 0.05). Buccal mucosa total folate showed no correlation with either red cell folate or 5-MeTHF, but was significantly associated with lymphocyte total folate (r = 0.35, P < 0.01). Supplementation elicited a significant increase in lymphocyte total folate (P < 0.01), and this was strongly associated with the increase in RBC total folate (P < 0.01) and plasma 5-MeTHF (P < 0.01). Buccal mucosa total folate was not influenced by folate supplementation. Methods have been developed for the rapid measurement of lymphocyte and buccal mucosal total folate. Lymphocyte folate is sensitive to folate intake and is reflected by plasma 5-MeTHF.


Asunto(s)
Suplementos Dietéticos , Eritrocitos/efectos de los fármacos , Ácido Fólico/sangre , Ácido Fólico/farmacología , Linfocitos/efectos de los fármacos , Mucosa Bucal/efectos de los fármacos , Adolescente , Adulto , Biomarcadores de Tumor/sangre , Cromatografía Líquida de Alta Presión , Daño del ADN , Femenino , Homocisteína/sangre , Homocisteína/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Tetrahidrofolatos/sangre
20.
J Pain ; 4(5): 267-77, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-14622696

RESUMEN

A study was conducted to clarify the nature of catastrophizing, a construct that is frequently referred to in the chronic pain literature. Information regarding 3 affective experience and 3 affect regulation dimensions was gathered from a heterogeneous sample of 104 chronic pain patients by using a semistructured clinical interview and the Affect Regulation and Experience Q-Sort (AREQ). Self-report questionnaires included visual analog pain scales, the Coping Strategies Questionnaire (CSQ), Multidimensional Pain Inventory (MPI), McGill Pain Questionnaire (MPQ), and Center for Epidemiological Studies Depression scale (CES-D). Hierarchical multiple regression was used to demonstrate the relative contributions of affective and cognitive appraisal components of catastrophizing. Thirty-one percent of the variance in CSQ-Catastrophizing scores was explained by a combination of cognitive appraisal variables (perceived ability to control pain; MPI Life Control) and AREQ scores, even after adjusting for pain severity and chronicity, age, and sex of participants. Results of the study strongly suggest that, rather than thinking of catastrophizing primarily as a cognitive coping construct, it should be described as an elaborate construct made up of both cognitive appraisal and affective components. Implications for tailoring interventions to match individual styles of affect regulation are discussed.


Asunto(s)
Afecto/fisiología , Cognición/fisiología , Hipocondriasis/psicología , Dolor/psicología , Adaptación Psicológica/fisiología , Adulto , Enfermedad Crónica , Estudios Transversales , Depresión/etiología , Depresión/psicología , Femenino , Humanos , Masculino , Variaciones Dependientes del Observador , Dimensión del Dolor , Pruebas Psicológicas , Reproducibilidad de los Resultados , Autoimagen , Encuestas y Cuestionarios
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