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1.
Am J Hypertens ; 14(9 Pt 2): 280S-290S, 2001 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-11583141

RESUMEN

Circadian (24-h) rhythms are important to the practice of medicine. The phasing and amplitude of key physiologic and biochemical circadian rhythms contribute to predictable-in-time patterns in the manifestation and exacerbation of most medical conditions. Moreover, body rhythms can significantly affect responses of patients to diagnostic tests and medications. Rhythmicity in the pathophysiology of medical conditions is the rationale for chronotherapeutics--that is purposeful variance of the concentration of medicines in synchrony with biologic rhythm determinants of disease activity--to optimize treatment outcomes. This article discusses the concept of biologic time structure and its relevance to the practice of medicine, with a focus on hypertension and cardiovascular issues.


Asunto(s)
Ritmo Circadiano/fisiología , Hipertensión/fisiopatología , Antihipertensivos/administración & dosificación , Presión Sanguínea/fisiología , Cronoterapia/métodos , Homeostasis , Humanos , Hipertensión/tratamiento farmacológico , Sueño/fisiología
2.
Pathol Biol (Paris) ; 44(7): 654-65, 1996 Sep.
Artículo en Francés | MEDLINE | ID: mdl-8977922

RESUMEN

Biological rhythms spread over a wide range of frequencies: circadian, ultradian and infradian. Circannual rhythms belong to this latter domain as their period average one year +/- 2 months. The seasonal rhythms in man of melatonin, prolactin, hormones of bone metabolism, ACTH and HCG are here reviewed and the questions raised by their characterization - including methodological problems - their origin and their incidence on health and diseases.


Asunto(s)
Fenómenos Cronobiológicos , Hormonas/sangre , Hormona Adrenocorticotrópica/sangre , Adulto , Anciano , Calcitonina/sangre , Calcio/sangre , Gonadotropina Coriónica/sangre , Ritmo Circadiano , Femenino , Humanos , Masculino , Melatonina/sangre , Hormona Paratiroidea/sangre , Fósforo/sangre , Prolactina/sangre , Estaciones del Año , Vitamina D/sangre
6.
Chronobiologia ; 18(4): 141-52, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1687728

RESUMEN

In a patient with a debulked müllerian adenocarcinoma involving the ovary, an elevated serum concentration of macrophage-colony stimulating factor (M-CSF) (5.3 ng/ml) was lowered into the range of the age- and gender-matched controls by a 24-hour infusion of 135 mg/m2 of taxol, as was a Ca125 of 1480 U/ml by three such taxol courses given at 3-week intervals (to 14 U/ml). A downward trend of M-CSF in serum with an about-14-hour ultradian modulation during the first chemotherapy course resembles that of the concomitantly assessed Ca125. A decreasing trend modulated by an about-half-weekly component is found in M-CSF of fractionated urines collected at spontaneous voidings around the clock for 5 days. M-CSF may serve as a chronobiologic marker for optimizing, on an individualized basis, 1) the infradian scheduling of chemotherapy courses and 2) the ultradian-circadian within-course time patterns. Timing based on markers of the anticancer effect aims at teh as-yet unattained transfer from rodent to human of cancer cures that were not previously feasible without chronobiologic considerations. This goal can be pursued with M-CSF as well as Ca125 and UGP as possibly complementary chronobiologic markers in a chronotherapy trial with taxol in humans.


Asunto(s)
Biomarcadores de Tumor/sangre , Gonadotropina Coriónica Humana de Subunidad beta , Factor Estimulante de Colonias de Macrófagos/sangre , Periodicidad , Anciano , Alcaloides/uso terapéutico , Antígenos de Carbohidratos Asociados a Tumores/sangre , Antineoplásicos Fitogénicos/uso terapéutico , Biomarcadores de Tumor/orina , Gonadotropina Coriónica/orina , Femenino , Humanos , Factor Estimulante de Colonias de Macrófagos/orina , Neoplasias de Células Germinales y Embrionarias/sangre , Neoplasias de Células Germinales y Embrionarias/tratamiento farmacológico , Neoplasias de Células Germinales y Embrionarias/orina , Neoplasias Ováricas/sangre , Neoplasias Ováricas/tratamiento farmacológico , Neoplasias Ováricas/orina , Paclitaxel , Fragmentos de Péptidos/orina
8.
Endocrinologie ; 27(2): 73-86, 1989.
Artículo en Inglés | MEDLINE | ID: mdl-2799241

RESUMEN

The urinary iodine excretion was measured in 193 children 11 +/- 1.5 years of age living in the endemic goiter area of Dîmbovita, Romania. One hundred and thirty four of the children showed some degree of endemic goiter, 59 showed none. All children followed a diurnal activity pattern with rest during the night. They received their usual iodine supplement of 1 gm potassium iodide once a week during the school year (which included the time of all measurements made). Urine was collected in six 4-hour samples over a 24-hour span. The examinations were conducted during the months of March, June, September and December. Iodine was determined by an automated ceric ion arsenic acid method using a Technicon Autoanalyzer. Circadian and seasonal variations of urine volume and iodine excretion were statistically verified by the cosinor technique and the seasonal variations also by one way analysis of variance using the circadian means as input. A comparable circadian rhythm of iodine excretion was found in the children with and without endemic goiter, with an acrophase during the evening (20:16 with a 95% C.I., from 19:32 to 21:04). The circadian rhythm in iodine excretion has to be taken into account whenever an estimate of the 24-hour excretion is attempted from a sample covering less than the entire 24-hour span. There was a statistically significant seasonal variation of the 24-hour iodine excretion in the boys with and without endemic goiter and in the group as a whole. The 24-hour iodine excretion during March was 102 +/- 6 mcg, during June 81 +/- 4 mcg, during September 79 +/- 3 mcg and during December 102 +/- 7 mcg. The average 24-hour iodine excretion pooled over all seasons was 91 +/- 3 mcg/24 hrs in the children with and 91 +/- 5 mcg/24 hrs in the children without endemic goiter. During March and December the iodine excretion indicates an iodine intake not usually associated with a high prevalence of endemic goiter. However, during the months of June and September (and presumably even more during the months of July and August when during summer vacation no iodine supplementation was given in school) the 24-hour iodine excretion indicates some degree of iodine deficiency. The seasonal variation in urinary iodine excretion thus points to a time when increased iodine prophylaxis may be of value.


Asunto(s)
Ritmo Circadiano , Bocio Endémico/orina , Yodo/orina , Estaciones del Año , Niño , Reservorios de Enfermedades , Femenino , Bocio Endémico/tratamiento farmacológico , Humanos , Masculino , Yoduro de Potasio/administración & dosificación , Rumanía
9.
J Natl Cancer Inst ; 81(2): 135-45, 1989 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-2909754

RESUMEN

In anticipation of the development of clinical chronotherapy and in order to pick clinical test times for doxorubicin and cisplatin trials, two large studies were performed on rats bearing a transplanted plasmacytoma. The circadian timing of each of two anticancer drugs given at precisely equal dose intensities was expected to improve therapeutic benefit over conventionally given (time-unqualified) treatment. In each chronotherapeutic study, maximal benefit and minimal toxic effects were found when cisplatin was administered in the middle to latter part of the daily activity (dark) span, while doxorubicin was administered near the end of the daily resting (light) span for these nocturnally active rodents living on a 12-hour-12-hour or 8-hour-16-hour light-dark schedule. This was true whether doxorubicin or cisplatin was given first and whether there was a lag of only a few hours or a few days between the administration of these two agents.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Cisplatino/administración & dosificación , Doxorrubicina/administración & dosificación , Plasmacitoma/tratamiento farmacológico , Animales , Ritmo Circadiano , Esquema de Medicación , Femenino , Masculino , Plasmacitoma/mortalidad , Plasmacitoma/patología , Ratas , Ratas Endogámicas
10.
Chronobiol Int ; 3(4): 213-9, 1986.
Artículo en Inglés | MEDLINE | ID: mdl-3677205

RESUMEN

Cytoplasmic estrogen receptors were determined by the dextran-coated charcoal method in inguinal breast tissue of three groups of Balb/C female mice 6-8 weeks following subcutaneous implantation into the intact animals of three pituitary glands and three pieces of skeletal muscle (group I), three pituitary glands and three segments of hypothalamic tissue (group II), or three pieces of skeletal muscle (group III) obtained from animals of the same inbred strain as control. A circadian rhythm in estrogen receptor content was statistically quantified by cosinor analysis in the muscle implanted control and the pituitary and hypothalamic implant groups. In the pituitary and muscle implant group the circadian rhythm is of borderline significance with a P-value between 0.05 and 0.10. The timing (acrophase) and extent of change (amplitude) are similar in all three treatment groups. The average receptor content (MESOR) in the two pituitary-implanted groups, which in previous studies were shown to have an increased breast cancer incidence is about twice that of the control group. The reduction in the pituitary induced breast cancer rate by hypothalamic tissue addition to a cancer incidence between the animals with pituitary and muscle isograft and the mice carrying no pituitary at all has also been shown previously in this strain of mice and is not reflected in receptor content.


Asunto(s)
Ritmo Circadiano , Glándulas Mamarias Animales/metabolismo , Hipófisis/trasplante , Receptores de Estrógenos/metabolismo , Animales , Citoplasma/metabolismo , Femenino , Hipotálamo/fisiología , Hipotálamo/trasplante , Neoplasias Mamarias Experimentales/etiología , Ratones , Ratones Endogámicos BALB C , Hipófisis/fisiología , Trasplante Isogénico
12.
Chronobiologia ; 6(3): 203-11, 1979.
Artículo en Inglés | MEDLINE | ID: mdl-520097

RESUMEN

In cancer and other therapeutic research, an interpretation of median survival times can and should take cure into account. With this qualification, an analysis of recently published data provides further statistically significant evidence in favor of cancer chronotherapy as compared to homeostatic therapy.


Asunto(s)
Ritmo Circadiano , Ciclofosfamida/administración & dosificación , Citarabina/administración & dosificación , Leucemia L1210/tratamiento farmacológico , Animales , Ciclofosfamida/uso terapéutico , Citarabina/uso terapéutico , Esquema de Medicación , Ratones
14.
Chronobiologia ; 5(3): 263-76, 1978.
Artículo en Inglés | MEDLINE | ID: mdl-102501

RESUMEN

Under the conditions of disynchronization by the manipulation of both the alternation of light and darkness and the availability and unavailability of food, circadian rhythms characterize the excretion of several amino acids by inbred LOU rats bearing an immunocytoma. Large amplitude rhythms can be demonstrated for urinary beta-aminoisobutyric acid, beta-alanine, phenylalanine and tyrosine. Under the same conditions of disynchronization, control animals excrete the same compounds also with a marked circadian variation but at an invariably lower average rate. These excretory rhythms, along with those demonstrated earlier for polyamines and light-chains, are of interest as potential markers for the chronotherapy of cancer.


Asunto(s)
Aminoácidos/orina , Ritmo Circadiano , Linfoma/orina , Aminobutiratos/orina , Animales , Dieta , Luz , Neoplasias Experimentales/orina , Fenilalanina/orina , Ratas , Ratas Endogámicas , Tirosina/orina , beta-Alanina/orina
15.
Chronobiologia ; 3(4): 309-22, 1976.
Artículo en Inglés | MEDLINE | ID: mdl-828877

RESUMEN

Large-amplitude circadian rhythms were observed in the urinary excretion of polyamines by rats bearing an immunocytoma. Control animals excreted polyamines at a lower rate but also with marked circadian variation. In confirmation of earlier observations, light-chain excretion by the tumor-bearing rats also exhibited a circadian rhythm, superimposed on an increasing trend. The potential of these rhythms as markers for the chronotherapy of cancer is noted.


Asunto(s)
Ritmo Circadiano , Plasmacitoma/orina , Poliaminas/orina , Animales , Cadaverina/orina , Dieta , Cadenas Ligeras de Inmunoglobulina/orina , Masculino , Trasplante de Neoplasias , Neoplasias Experimentales/orina , Plasmacitoma/tratamiento farmacológico , Putrescina/orina , Ratas , Espermidina/orina , Espermina/orina
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