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1.
J Diet Suppl ; 17(5): 527-542, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32677489

RESUMEN

Manufacturers of hemp-based cannabidiol products have argued that their products should be federally regulated as dietary supplements in the U.S. The justifications offered for this suggestion often focus on a variety of assumptions that either are commonly invoked in marketing strategies of the cannabis/hemp industry or are codified in the 1994 Dietary Supplement Health Education Act. Three such assumptions are addressed herein and are characterized as: 1) the false dichotomy of herbs vs drugs, 2) the entourage fallacy, and 3) the false equivalence of incomparable evidence. An argument is presented which is intended to persuade that the legality or mere composition of phytochemical products do not speak to the reality of their pharmacological effects. It is further argued that non-prescription cannabidiol and hemp extracts should not be afforded regulatory protection by designation as dietary supplements.


Asunto(s)
Cannabidiol/normas , Cannabis , Suplementos Dietéticos/normas , Aprobación de Drogas/legislación & jurisprudencia , Extractos Vegetales/normas , Humanos , Medicamentos sin Prescripción/normas , Estados Unidos
2.
Eur J Clin Nutr ; 53(9): 711-5, 1999 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-10509767

RESUMEN

OBJECTIVES: To determine the levels of tocopherols, retinol and carotenoids in maternal and umbilical cord blood plasma and to investigate the relationships between them. DESIGN: Venous blood plasma concentrations of alpha, gamma and delta-tocopherol, retinol, lutein, lycopene, zeaxanthin, beta-cryptoxanthin, alpha and beta-carotene were determined by HPLC in healthy pregnant women and in pair-matched umbilical cords. Plasma levels of triglycerides and cholesterol were also measured. SUBJECTS: Sixty-six women, between 10 and 20 weeks gestation, were recruited randomly during their first antenatal appointment. From this group, 40 pair-matched umbilical cord blood samples were obtained. RESULTS: Tocopherols, retinol, carotenoids and lipids were present in significantly higher (P < 0.001) concentrations in maternal plasma than in cord plasma. There was a significant correlation (r = 0.45, P < 0.005) between maternal and cord levels of gamma-tocopherol, but not of alpha-tocopherol, retinol or carotenoids. Tocopherols and carotenoids were significantly correlated with each other (P < 0.05) in maternal and cord plasma. CONCLUSIONS: Plasma levels of tocopherols, carotenoids and lipids are substantially lower at birth than in adulthood. There is a clear relationship between gamma-tocopherol levels in maternal and cord plasma. The importance of gamma-tocopherol in human nutrition should be further investigated. There are no significant relationships between plasma alpha-tocopherol and carotenoids in pregnant mothers and cords. More research is needed to elucidate the maternal-foetal transfer of tocopherols and carotenoids, and to examine the impact of maternal antioxidant nutrient status on neonatal antioxidant capacity. It is important to determine if a low level of tocopherols and carotenoids at birth is a normal stage of human development or indicative of deficiency.


Asunto(s)
Carotenoides/sangre , Sangre Fetal/química , Embarazo/sangre , Vitamina E/sangre , Adolescente , Adulto , Colesterol/sangre , Cromatografía Líquida de Alta Presión , Femenino , Edad Gestacional , Humanos , Triglicéridos/sangre
3.
Eur J Clin Nutr ; 53(11): 861-4, 1999 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-10556998

RESUMEN

OBJECTIVE: To determine the concentrations of the low molecular weight antioxidants urate, bilirubin, albumin and sulphydryl groups and to measure lipid peroxidation levels in pair-matched maternal and cord blood plasma. DESIGN: Venous blood plasma concentrations of urate, bilirubin, albumin and sulphydryls were determined in healthy pregnant women and in pair matched umbilical cords. The ability of maternal and cord plasma to withstand Cu2+-induced lipid peroxidation was assessed by measuring the production of thiobarbituric acid reactive substances (TBARS) over time in plasma incubated with Cu2+. SUBJECTS: Forty healthy women, between 10 and 20 weeks gestation, were recruited randomly from an antenatal clinic. Venous blood samples were obtained from the mothers at the recruitment stage and from the umbilical cords of their newborn after delivery. RESULTS: Urate, bilirubin and sulphydryls were present in significantly higher concentrations (P<0.001) in cord plasma than in maternal plasma. Albumin levels were similar in mothers and cords. Significantly lower levels (P=0.018) of TBARS were produced in cord plasma compared with maternal plasma following incubation with Cu2+. There were significant correlations between albumin and sulphydryl concentrations in maternal plasma (r 0.43, P=0.007) and between urate concentrations in maternal and cord plasma (r 0.37, P=0.026). CONCLUSION: Urate, bilirubin and sulphydryls are present in significantly higher concentrations in cord blood than in maternal blood. The increased levels of these antioxidants in cord plasma may contribute to the increased resistance of cord plasma to Cu2+-induced lipid peroxidation.


Asunto(s)
Antioxidantes/análisis , Sangre Fetal/química , Peroxidación de Lípido , Adolescente , Adulto , Bilirrubina/sangre , Femenino , Humanos , Cinética , Peroxidación de Lípido/efectos de los fármacos , Peso Molecular , Embarazo , Valores de Referencia , Albúmina Sérica/análisis , Compuestos de Sulfhidrilo/sangre , Sustancias Reactivas al Ácido Tiobarbitúrico/metabolismo , Ácido Úrico/sangre
4.
Int J Vitam Nutr Res ; 69(4): 262-7, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10450531

RESUMEN

The concentrations of tocopherols and carotenoids are lowered in umbilical cord blood plasma, which may have a negative effect on antioxidant protection in neonates. Smoking may adversely affect dietary intakes and plasma concentrations of carotenoids. The dietary intakes of vitamin E and beta-carotene were assessed in 66 pregnant women (31 smokers and 35 non-smokers) between 10 and 20 weeks gestation using a food frequency questionnaire. The concentrations of alpha-tocopherol and beta-carotene were measured in maternal plasma at the time of the dietary assessment, and in the matched umbilical cords of their newborn after delivery. In smoking and non-smoking mothers, the mean intakes of vitamin E (9.3 [SD 5] and 8.2 [SD 5] mgd-1) and beta-carotene (3464 [SD 1885] and 2977 [SD 1503] micrograms d-1) were not significantly different. The plasma concentrations of alpha-tocopherol (20.8 [SD 4] and 20.5 [SD 4] mumol L-1), the alpha-tocopherol to lipid ratios (3.2 [SD 0.8] and 3.5 [SD 0.8]) and the plasma concentrations of beta-carotene (0.22 [SD 0.1] and 0.22 [SD 0.1] mumol L-1) were not significantly different in smoking and non-smoking mothers. There were no significant differences in plasma alpha-tocopherol (7.4 [SD 2] and 7.3 [SD 2] mumol L-1), in alpha-tocopherol to lipid ratios (3.2 [SD 0.6] and 2.8 [SD 0.6]) or in beta-carotene concentrations (0.05 [SD 0.04] and 0.03 [SD 0.02] mumol L-1) in cords from newborns of smoking and non-smoking mothers. There was a significant correlation (r = 0.41, P = 0.015) between dietary intakes and plasma concentrations of beta-carotene in non-smoking mothers. However, this relationship was not significant in smoking mothers (r = 0.28, P = 0.12). There were no relationships between dietary intakes and plasma concentrations of tocopherol. These results indicate that smoking during pregnancy does not appear to affect the dietary intakes or plasma concentrations of alpha-tocopherol and beta-carotene in pregnant women or their babies. However, smoking does influence the relationship between dietary intakes and plasma levels of beta-carotene.


Asunto(s)
Dieta , Sangre Fetal/química , Fumar , Vitamina E/sangre , beta Caroteno/sangre , Adolescente , Adulto , Femenino , Humanos , Embarazo , Trimestres del Embarazo
5.
Science ; 325(5939): 444-8, 2009 Jul 24.
Artículo en Inglés | MEDLINE | ID: mdl-19574351

RESUMEN

The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.

6.
Ann Neurol ; 13(6): 676-8, 1983 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-6136253

RESUMEN

A 31-year-old veterinarian developed seizures, left hemiparesis, loss of memory, and behavioral disorders 5 months after intensive antirabies vaccination, the longest incubation period yet recorded. Computed tomographic scan revealed a right frontal contrastenhanced mass that extended to the left frontal lobe through the corpus callosum. Brain biopsy showed foci of primary demyelination largely confined to the white matter. The lesions were characteristic of the demyelinating encephalomyelitis that follows treatment with certain vaccines against rabies. The hemiplegia improved, but seizures, memory impairment, and abnormal behavior persisted.


Asunto(s)
Enfermedades Desmielinizantes/etiología , Encefalomielitis Aguda Diseminada/etiología , Vacunas Antirrábicas/efectos adversos , Adulto , Encéfalo/patología , Enfermedades Desmielinizantes/diagnóstico , Encefalomielitis Aguda Diseminada/diagnóstico , Lóbulo Frontal/diagnóstico por imagen , Humanos , Masculino , Factores de Tiempo , Tomografía Computarizada por Rayos X
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