RESUMO
Wide rejection of conventional hormone therapy (HT) after the initial publication of the Women's Health Initiative (WHI) led to unjustified use of custom-compounded bioidentical hormones. In the USA, it became an unregulated drug manufacturer industry in disguise, without proper control and making false claims and misleading advertisements. Manufacturing quality is not ensured. Unspecific harm from compounding has occurred on a large scale, such as deaths from infected products and end-stage renal failure plus carcinoma due to confusion between different Chinese herbs. Oral estrogens increase venous thromboembolic and ischemic stroke events, even more when overdosed; these excess risks can be avoided by non-oral administration, readily accessible in custom-compounded HT by administering estradiol through diverse routes (of which transdermal is the best documented). Another risk specific to custom-compounded HT, resulting from estrogen/progestogen imbalance, might be excess endometrial carcinomas. HT can be optimized by continuously combining transdermal estradiol with progesterone (when required). Registered preparations do exist for such a more physiological treatment and therefore must be preferred. Custom compounding is only seldom legitimate, for example in case of allergy (such as to peanut oil) or to prescribe different combinations, doses or components (e.g. estriol, dehydroepiandrosterone or testosterone), even when not approved by local regulatory authorities despite being scientifically acceptable.
Assuntos
Terapia de Reposição de Estrogênios/efeitos adversos , Menopausa , Composição de Medicamentos , Feminino , Humanos , Saúde da MulherRESUMO
The many advantages of registered bioidentical sex hormones over registered, conventional, non-bioidentical menopausal hormone therapy (MHT) are considered. The transdermal route of estrogen administration avoids excess venous thromboembolic and ischemic stroke events. There is some indication that conjugated equine estrogens are more thrombogenic and most likely induce some hypertensive responses; estradiol might also be superior to conjugated equine estrogens (CEE) in terms of global cardiovascular health. The most valid evidence presently suggests that CEE-only treatment does not increase the risk of breast cancer and even may reduce it. But its combination with a synthetic progestogen (mainly medroxyprogesterone acetate) is a critical issue since it seems to be primarily associated with an increased incidence of breast cancer, however similar to or lower than that associated with some common lifestyle factors. Though not yet proven in a randomized, controlled trial, MHT continuously combining oral micronized progesterone with transdermal estradiol can presently be considered as the optimal MHT. It is not only safer than custom-compounded bioidentical hormones but also than oral conventional MHT and has the best breast profile; registered products for such optimal MHT are available around the world and must be preferred.
Assuntos
Terapia de Reposição de Estrogênios/métodos , Estrogênios/administração & dosagem , Menopausa/fisiologia , Progesterona/administração & dosagem , Administração Cutânea , Neoplasias da Mama/induzido quimicamente , Estradiol/administração & dosagem , Estradiol/efeitos adversos , Estrogênios/efeitos adversos , Estrogênios Conjugados (USP)/administração & dosagem , Estrogênios Conjugados (USP)/efeitos adversos , Feminino , Humanos , Células MCF-7 , Menopausa/efeitos dos fármacos , Medicina de Precisão , Progesterona/efeitos adversos , Progestinas/administração & dosagem , Progestinas/efeitos adversos , Fatores de Risco , Especificidade da Espécie , Acidente Vascular Cerebral/induzido quimicamente , Tromboembolia Venosa/induzido quimicamenteRESUMO
The 24th annual symposium of the International Isotope Society's United Kingdom Group took place at the Møller Centre, Churchill College, Cambridge, UK on Friday 6th November 2015. The meeting was attended by 77 delegates from academia and industry, the life sciences, chemical, radiochemical and scientific instrument suppliers. Delegates were welcomed by Dr Ken Lawrie (GlaxoSmithKline, UK, chair of the IIS UK group). The subsequent scientific programme consisted of oral presentations, short 'flash' presentations in association with particular posters and poster presentations. The scientific areas covered included isotopic synthesis, regulatory issues, applications of labelled compounds in imaging, isotopic separation and novel chemistry with potential implications for isotopic synthesis. Both short-lived and long-lived isotopes were represented, as were stable isotopes. The symposium was divided into a morning session chaired by Dr Rebekka Hueting (University of Oxford, UK) and afternoon sessions chaired by Dr Sofia Pascu (University of Bath, UK) and by Dr Alan Dowling (Syngenta, UK). The UK meeting concluded with remarks from Dr Ken Lawrie (GlaxoSmithKline, UK).
RESUMO
Hormone replacement therapy (HRT) remains the gold standard for treatment of climacteric symptoms in menopausal women; it is relatively safe in healthy subjects for at least 5 years, provided it had been initiated before the age of 60 years and/or within 10 years from menopause. Estrogen probably adds some cardioprotection, that can, however, be obscured by progestogens, especially medroxyprogesterone acetate (MPA). Oral HRT is associated with an increased risk of venous thromboembolism (VTE), gallbladder disease and possibly stroke. The increased occurrence of all these events can be prevented by the use of the transdermal route of estradiol administration; this route seems also advantageous for women with diabetes, hypertension and other cardiovascular risk factors, and also especially with advancing age. Endometrial protection by any progestogen is insufficient in the mid to long term when cyclical, sequential regimens are used; full protection can be secured only by continuous combined estrogen + progestogen. Natural, 'body-identical' progesterone, devoid of any androgenic as well as glucocorticoid activities but being slightly hypotensive due to its antimineralocorticoid activity, appears to be the optimal progestogen in terms of cardiovascular effects, blood pressure, VTE, probably stroke and even breast cancer (contrary to synthetic progestogens and particularly MPA, which appear to be mitogenic on breast cells, in synergism with estrogen). HRT optimization can thus be achieved by combining low doses of estrogen given transdermally with micronized oral progesterone; such optimized HRT will allow us to treat symptomatic women for as long as required. Asymptomatic women at risk of (osteoporotic) fractures can also be treated with this optimized HRT as long as their individual risk/benefit ratio remains favorable (thanks to the absence of increased risks of VTE, stroke and breast cancer).
Assuntos
Estradiol/administração & dosagem , Terapia de Reposição de Estrogênios/métodos , Menopausa , Progesterona/administração & dosagem , Administração Cutânea , Fatores Etários , Idoso , Neoplasias da Mama/induzido quimicamente , Neoplasias do Endométrio/induzido quimicamente , Neoplasias do Endométrio/prevenção & controle , Terapia de Reposição de Estrogênios/efeitos adversos , Feminino , Fogachos/tratamento farmacológico , Humanos , Pessoa de Meia-Idade , Fatores de Risco , Acidente Vascular Cerebral/induzido quimicamente , Tromboembolia Venosa/induzido quimicamenteRESUMO
Well aligned, long and dense multi-walled carbon nanotubes (CNT) can be grown on both carbon fibres and any metal substrates compatible with the CNT synthesis temperature. The injection-CVD process developed involves two stages, including fibre pretreatment by depositing a SiO(2)-based sub-layer from an organometallic precursor followed by CNT growth from toluene/ferrocene precursor mixture. Carbon substrates, as well as metals, can easily be treated with this process, which takes place in the same reactor and does not need any handling in between the two stages. The aligned CNT carpets obtained are similar to the ones grown on reference quartz substrates. The CNT growth rate is fairly high (ca. 30 µm min(-1)) and it is possible to control CNT length by varying the CNT synthesis duration. The thickness of the SiO(2)-based sub-layer can be varied and is shown to have an influence on the CNT growth. This layer is assumed to play a diffusion barrier layer role between the substrate and the iron based catalyst nanoparticles producing CNT. The CNT anchorage to the carbon fibres has been checked and good overall adhesion proved, which is in favour of a good transfer of electrical charge and heat between the nanotubes and fibre.
RESUMO
This work reports the design of a resistive gas sensor based on 2D mats of multi-walled carbon nanotubes (MWCNTs) grown by aerosol-assisted chemical vapour deposition. The sensor sensitivity was optimized using chlorine as analyte by tuning both CNT network morphology and CNT electronic properties. Optimized devices, operating at room temperature, have been calibrated over a large range of concentration and are shown to be sensitive down to 27 ppb of chlorine. The as-grown MWCNT response is compared with responses of 2000 °C annealed CNTs, as well as of nitrogen-doped CNTs and CNTs functionalized with polyethyleneimine (PEI). Under chlorine exposure, the resistance decrease of as-grown and annealed CNTs is attributed to charge transfer from chlorine to CNTs and demonstrates their p-type semiconductor behaviour. XPS analysis of CNTs exposed to chlorine shows the presence of chloride species that confirms electron charge transfer from chlorine to CNTs. By contrast, the resistance of nitrogen-doped and PEI functionalized CNTs exposed to chlorine increases, in agreement with their n-type semiconductor nature. The best response is obtained using annealed CNTs and is attributed to their higher degree of crystallinity.
RESUMO
If released in the environment, nanomaterials might be inhaled by populations and cause damage to the deepest regions of the respiratory tract, i.e., the alveolar compartment. To model this situation, we studied the response of A549 human pneumocytes after exposure to aluminium oxide or titanium oxide nanoparticles, and to multi-walled carbon nanotubes. The influence of size, crystalline structure and chemical composition was investigated. After a detailed identification of nanomaterial physico-chemical characteristics, cells were exposed in vitro and viability and intracellular accumulation were assessed. In our conditions, carbon nanotubes were more toxic than metal oxide nanoparticles. Our results confirmed that both nanotubes and nanoparticles are able to rapidly enter into cells, and distribute in the cytoplasm and intracellular vesicles. Among nanoparticles, we demonstrate significant difference in biological response as a function of size, crystalline phase and chemical composition. Their toxicity was globally lower than nanotubes toxicity. Among nanotubes, the length did not influence cytotoxicity, neither the presence of metal catalyst impurities.
Assuntos
Citoplasma/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Nanopartículas Metálicas/toxicidade , Nanotubos de Carbono/toxicidade , Mucosa Respiratória/efeitos dos fármacos , Óxido de Alumínio/toxicidade , Apoptose/efeitos dos fármacos , Linhagem Celular Tumoral , Citoplasma/ultraestrutura , Células Epiteliais/química , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/ultraestrutura , Humanos , Pulmão/química , Pulmão/ultraestrutura , Nanopartículas Metálicas/análise , Nanopartículas Metálicas/química , Microscopia Eletrônica de Transmissão , Nanotubos de Carbono/análise , Nanotubos de Carbono/química , Mucosa Respiratória/química , Mucosa Respiratória/citologia , Mucosa Respiratória/ultraestrutura , Titânio/toxicidadeRESUMO
UNLABELLED: Small cell ovarian tumors are rare and highly malignant, occurring mainly in young patients. Early mortality is high due to the lack of an effective treatment. The first adjuvant therapy is usually chemotherapy. CASE: During laparotomy for renal transplant in a 17-year-old girl, the right ovary exhibited a suspicious mass, whose pathological diagnosis was Stage 1A small cell ovarian tumor. Prognosis was poor (young age, hypercalcemia, tumor >10 cm, and presence of large cells). Since chemotherapy is contraindicated for dialysed patients, only radiotherapy was given. The patient is still alive and disease-free ten years after diagnosis. CONCLUSION: This is the first case with a poor prognosis reported in the literature that has been successfully cured by surgery plus adjuvant radiotherapy only.
Assuntos
Carcinoma de Células Pequenas/terapia , Neoplasias Ovarianas/terapia , Adolescente , Intervalo Livre de Doença , Feminino , Humanos , Radioterapia AdjuvanteRESUMO
Dispersion of nanotubes is a crucial step for many applications. The properties of the final nanotube-based material are strongly dependent on the quality of nanotube suspensions. In this study, long and aligned multi-walled carbon nanotubes obtained by catalytic chemical vapour deposition were dispersed in water with different dispersing agents using high intensity ultrasounds. Among different additives, we selected sodium dodecyl sulfate (SDS) as dispersing agent to prepare suspensions of nanotubes. UV-Visible spectrometry method was used to measure the influence of dispersion parameters (power and duration of sonication) on dispersion state and suspension stability. Therefore, we demonstrated that, even if high intensity ultra-sounds are breaking nanotubes, it is possible to obtain stable water-based suspensions containing MWNTs which exhibit length up to 20 microm.
Assuntos
Coloides/química , Cristalização/métodos , Nanotecnologia/métodos , Nanotubos de Carbono/química , Nanotubos de Carbono/ultraestrutura , Água/química , Coloides/efeitos da radiação , Substâncias Macromoleculares/química , Teste de Materiais , Conformação Molecular , Nanotubos de Carbono/efeitos da radiação , Tamanho da Partícula , Soluções , Sonicação , Propriedades de SuperfícieRESUMO
With the use of an in vivo tritiated thymidine [( 3H]dThd) nuclear labeling followed by autoradiography, the effects at different times before sacrifice of prolactin (PRL) and/or 17 beta-estradiol (E2) were studied in C57BL X DBA/2f)F1 mice given transplants of the MXT hormone-sensitive mammary tumor whose growth was previously shown to be influenced by E2 and/or progesterone. Uteri were chosen as controls for the methodology. Experiments were conducted on ovariectomized mice submitted to endocrine manipulation to achieve plasma PRL modifications. In addition to E2, the proliferation of cancer cells, assessed by the measurement of thymidine labeling indices (TLIs), was demonstrated to be enhanced by ovine prolactin (oPRL) and Sulpiride and strongly slowed down by castration and 2-bromo-alpha-ergokryptin treatment, thus emphasizing the great importance of PRL in mammary cancer development. Moreover, a pulse of 1 mg oPRL/animal produced a marked TLI rise in tumors, lasting from the 6th to the 48th hour after its injection and reaching a maximum at 24 hours. PRL had no proliferative effect on the uterine luminal epithelium. When PRL and E2 were injected concomitantly, the profile of stimulation was quite similar to that obtained with E2 alone; i.e., a maximum stimulation was observed at the 24th and 36th hours after hormonal pulse. From these data it is concluded that, in spayed mice, not only E2 but also PRL is of major importance leading to enhanced proliferation of MXT mammary neoplastic cells. Further investigations are needed to throw light on the cellular events presiding over the action of PRL and E2 at the cancer cell level.
Assuntos
Estradiol/farmacologia , Neoplasias Mamárias Experimentais/patologia , Prolactina/farmacologia , Útero/efeitos dos fármacos , Animais , Bromocriptina/farmacologia , Divisão Celular/efeitos dos fármacos , Feminino , Camundongos , Camundongos Endogâmicos , Prolactina/sangue , Sulpirida/farmacologia , Útero/patologiaRESUMO
Plasma prolactin (PRL) levels were measured at 15-minute intervals for 24 hours in 18 men suffering from major endogenous depressive illness and in 7 age-matched healthy men. Eleven of the 18 depressed patients were restudied during clinical remission following either electroconvulsive therapy or treatment with amitriptyline hydrochloride. During the acute phase of the illness, the unipolar depressed patients had fragmented patterns of PRL secretion with an early timing of the nocturnal secretory phase of PRL, which started, on the average, 2 hours earlier than in healthy subjects. Moreover, the amplitude of the circadian variation of PRL was reduced in these patients, with subnormal PRL levels occurring during the midsleep period. This latter abnormality was also observed in bipolar patients, who had otherwise normal PRL profiles. These lower midsleep PRL concentrations were associated with a significant increase in the amount of time spent awake during the same period. Antidepressant treatment did not consistently correct the abnormalities in the patterns of PRL release observed during the acute phase of the illness. These results indicate that early timing of nocturnal PRL secretion and damping of the nighttime PRL elevation may be found in men with endogenous depressive disorders. In contrast to disturbances of the corticotropic and somatotropic axes, these abnormalities of PRL secretion may still be present during clinical remission following antidepressant treatment.
Assuntos
Ritmo Circadiano , Transtorno Depressivo/sangue , Prolactina/sangue , Adulto , Amitriptilina/uso terapêutico , Transtorno Bipolar/sangue , Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/fisiopatologia , Transtorno Depressivo/tratamento farmacológico , Transtorno Depressivo/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Prolactina/metabolismo , Sono/fisiologiaRESUMO
Four normally cycling women received an iv injection of 20 mg Premarin (conjugated estrogens equivalent to 20 mg estrone sulfate) on the seventh day of two consecutive cycles; the second experiment was performed under sulpiride-induced hyperprolactinemia (mean PRL level = 906 microU MRC standard 71/222 per ml; significantly 7.8 times greater than mean control level of 115 microU MRC standard 71/222 per ml, P less than 0.001). In comparison to the control experiment, sulpiride-induced hyperprolactinemia prevented the occurrence of any gonadotropin peak within the 84 h of estrogen administration; the negative feedback effect of estrogen on gonadotropin secretion was maintained and was even potentiated. These alterations of feedback mechanisms of estrogen were considered to be related to hyperprolactinemia itself rather than to sulpiride. Five other normally cycling women received iv injections of 100 microgram LRH on the 22nd day of a cycle under sulpiride-induced hyperprolactinemia since the onset of menstruation. Their mean LH response was somewhat greater (although not statistically significant) and their mean FSH response was considerably greater (P less than 0.001 at all times) than those of a control group of 10 women tested in their luteal phase. The results of these LRH tests under sulpiride-induced hyperprolactinemia give some support to the concept that hyperprolactinemia interferes at the hypothalamic or higher level with cyclic release of indogenous LRH.
Assuntos
Estrogênios Conjugados (USP)/farmacologia , Hormônio Foliculoestimulante/metabolismo , Hormônio Luteinizante/metabolismo , Prolactina/sangue , Sulpirida , Adolescente , Adulto , Retroalimentação , Feminino , Hormônio Liberador de Gonadotropina , Humanos , MenstruaçãoRESUMO
Serum prolactin has been measured in blood samples collected daily during 51 menstrual cycles using an homologous human radioimmunoassay for 17 cycles and an homologous ovine radioimmunoassay for 34 cycles. There was a progressive and significant increase in serum prolactin during the late follicular phase, with a maximal value concomitant to the LH peak. Serum prolactin levels were also significantly higher during the luteal phase than during early follicular phase. In some 70% of the individual cycles, the highest serum prolactin level was found at mid-cycle. Similar patterns were obtained with both radioimmunoassays. However, when using the same laboratory serum standard, the average serum prolactin level calculated for the entire cycle was 1.6 times higher with the homologous ovine assay than with the homologous human assay. The overall pattern of serum prolactin during the menstrual cycle resembles that reported for circulating 17beta-estradiol.
Assuntos
Menstruação , Prolactina/sangue , Animais , Feminino , Humanos , Radioimunoensaio , Ovinos , Especificidade da EspécieRESUMO
The characteristics of pituitary hormonal responses to insulin-induced hypoglycemia were investigated in 16 normal men. In all subjects, levels of blood sugar fell below 35 mg/100 ml. A statistically significant increase in mean plasma levels of prolactin, ACTH, cortisol and growth hormone was observed. Prolactin levels increased in all subjects but one; individual peak values were 1.4 minus 8.4 times greater than base levels. The kinetics of prolactin, GH and ACTH responses were similar; in particular, the onset of release (25 min) of prolactin, GH and ACTH was similar. After dexamethasone administration, insulin tolerance tests wererepeated in a number of subjects using adequate amounts of insulin to achieve hypoglycemia equivalent to that obtained in the control experiments. The administration of 1 mg of dexamethasone the evening before the test suppressed basal levels of ACTH and cortisol and the ACTH-but not the cortisol-response to hypoglycemia. Both basal levels of prolactin and prolactin response to hypoglycemia were significantly lowered but growth hormone response was not modified by administration of 1 mg of dexamethasone. The administration of larger doses of dexamethasone (1 mg every 6 h for 2 days) almost completely suppressed basal levels of ACTH, cortisol and prolactin, as well as the hypoglycemia-induced release of these hormones. In contrast, the growth hormone response to hypoglycemia was only partially inhibited. These findings demonstrate that both basal secretion and hypoglycemia-induced release of prolactin, ACTH, cortisol and growth hormone are suppressible by glucocorticoids.
Assuntos
Glicemia , Dexametasona/farmacologia , Prolactina/metabolismo , Adolescente , Hormônio Adrenocorticotrópico/metabolismo , Adulto , Hormônio do Crescimento/metabolismo , Humanos , Hidrocortisona/metabolismo , Insulina , Masculino , Pessoa de Meia-Idade , Estimulação Química , Fatores de TempoRESUMO
The response of plasma PRL to exercise, as performed on a bicycle ergometer under conditions below and above the anaerobic threshold, was studied in 10 normal young men. One hour of submaximal work against a workload at which blood lactic acid remained below 4 mmol/liter (anaerobic threshold) was accompanied by a slight decrease in plasma PRL levels, similar to the changes occurring under control conditions in the same subjects. However, during graded maximal ergometric exercise until exhaustion, plasma PRL rose promptly and significantly (P less than 0.05) when the anaerobic threshold was reached. These data suggest that PRL levels increase provided that the intensity of exercise is such that the anaerobic threshold is reached.
Assuntos
Anaerobiose , Metabolismo , Esforço Físico , Prolactina/sangue , Adulto , Fenômenos Químicos , Química , Humanos , Masculino , Resistência FísicaRESUMO
The endocrine response to prolonged dexamethasone treatment was investigated in six postmenopausal women with generalized mammary carcinoma. Plasma cortisol levels decreased rapidly and became undetectable whereas significant concentrations of plasma dehydroepiandrosterone and androstenedione persisted throughout the study, even in two ovariectomized patients, indicating a certain degree of autonomy or a greater resistance of adrenal 'androgens' to the inhibition of ACTH secretion. Except in the ovariectomized patients, plasma testosterone did not fall significantly whereas the plasma oestrogens tended progressively towards undetectable concentrations. A similar response was found in six normal postmenopausal women although the disappearance of their oestrogens was relatively rapid. This indicates that much of the testosterone present after the menopause could still be produced by the ovaries whereas the ovarian production of oestrogens becomes negligible. The delayed disappearance of oestrogens in the patients with mammary carcinoma indicates that the persisting adrenal 'androgens' remained efficient precursors of oestrogen synthesis within the peripheral tissues and presumably within the mammary tumour itself. Plasma dihydrotestosterone behaved like the plasma oestrogens. Despite the fall in plasma oestrogens, plasma gonadotrophins did not increase further but plasma prolactin rose progressively. The persistance of steroid sex hormones and the rise of plasma prolactin might explain the poor response to dexamethasone treatment in mammary carcinoma.
PIP: A prolonged suppression of the adrenal cortex was produced by giving dexamethasone to 6 postmenopausal women with generalized mammary carcinoma. Plasma cortisol levels decreased rapidly while plasma dehydroepiandrosterone and androstenedione persisted. Plasma testosterone did not fall, except in ovariectomized patients. Plasma estrogens gradually decreased. This slow disappearance of estrogen indicated that persisting adrenal androgens continued to be precursors of estrogen synthesis in peripheral tissues, and possibly within the tumor tissue also. Plasma dihydrotestosterone estimations were similar to those of plasma estrogens. Plasma gonadotropins remained the same. Prolactin increased gradually. Since the growth of mammary carcinoma in postmenopausal women may be partially under endocrine control and the hormones involved are the sex hormones, and possibly prolactin, the persistence of sex hormones and rise of plasma prolactin may be why dexamethasone produces only a minimal response.
Assuntos
Androgênios/sangue , Neoplasias da Mama/sangue , Dexametasona/uso terapêutico , Estrogênios/sangue , Menopausa , Prolactina/sangue , Idoso , Androstenodiona/sangue , Neoplasias da Mama/tratamento farmacológico , Castração , Desidroepiandrosterona/sangue , Feminino , Gonadotropinas Hipofisárias/sangue , Humanos , Hidrocortisona/sangue , Pessoa de Meia-Idade , Testosterona/sangueRESUMO
Studies in rodents have shown that triazolam, a commonly used hypnotic, may shift circadian rhythms, with the direction and magnitude of the phase-shifts being dependent on the time of drug administration. To determine whether benzodiazepine, taken at standard bedtime, modifies the amount and/or temporal organization of hormonal secretion, six normal men were studied during basal conditions and on the first and third days of treatment with 0.5 mg triazolam. In each study, sleep was polygraphically monitored and plasma cortisol, growth hormone (GH), melatonin, and prolactin (PRL) (i.e., hormones influenced by circadian rhythmicity and/or sleep) were measured at 20-min intervals for 24 h. The sleep latency and the number and duration of awakenings were reduced during triazolam treatment as compared to baseline conditions. The only alteration of sleep architecture was a partial suppression of stages III + IV (SW) in late sleep. Triazolam did not affect the mean cortisol and melatonin levels or the total amount of GH secreted over the 24-h span. The circadian timings of the onsets of cortisol and melatonin secretions were essentially unaltered. The nocturnal rise of melatonin was prolonged by 45 to 60 minutes. Sleep-associated GH release was not modified by triazolam. Sleep-associated PRL secretion persisted, but in half of the nights studied was enhanced almost threefold. This effect of the drug on nocturnal PRL secretion was not specific to either the first or the third night of treatment, nor was it specific to certain subjects. Irrespective of the magnitude of the nocturnal elevation, morning PRL levels were slightly but consistently higher after triazolam treatment than under basal conditions. Normal PRL levels resumed around noon. In conclusion, administration of 0.5 mg triazolam at normal bedtime (2230) for three consecutive days may induce a transient hyperprolactinemia, but does not abolish sleep-related hormone secretion and does not affect the timing of endocrine events controlled by the circadian clock. These findings are consistent with studies in hamsters where treatment with triazolam in the early subjective night was also without effect on the rodent circadian clock.
Assuntos
Ritmo Circadiano/efeitos dos fármacos , Hormônios/metabolismo , Sono , Triazolam/farmacologia , Animais , Cricetinae , Hormônio do Crescimento/metabolismo , Humanos , Hidrocortisona/metabolismo , Masculino , Melatonina/metabolismo , Mesocricetus , Prolactina/metabolismo , Sono/efeitos dos fármacosRESUMO
The effects of Pergolide, a potent dopamine agonist, on exercise-induced plasma prolactin (PRL) changes were studied in normal men. Exercises consisted of a graded bicycle ergometer test and of a 20-km endurance run. In both circumstances, treatment with Pergolide, when compared with placebo or control values, resulted in a significant suppression of basal PRL (P less than 0.001) as well as of exercise-induced PRL increase (P less than 0.01). From these experiments it was concluded that augmented levels of PRL in plasma, as seen during or after muscular exercise, are caused by increased pituitary secretion, rather than decreased elimination.
Assuntos
Antagonistas de Dopamina , Ergolinas/farmacologia , Esforço Físico , Prolactina/metabolismo , Adulto , Hematócrito , Humanos , Masculino , Pessoa de Meia-Idade , Pergolida , Adeno-Hipófise/metabolismo , CorridaRESUMO
PIP: The risks and benefits of specific types of postmenopausal estrogens and progestogens are explored: those affecting serum lipids, clotting elements, hepatic proteins synthesis, blood pressure, glucose tolerance, endometrial, breast and cervical cancer. Ethinyl estradiol taken orally is the only estrogen likely to cause gall bladder disease. It also induces liver protein synthesis when taken orally or vaginally. Natural estrogens do not heighten coagulation factors, and may shift towards fibrinolysis. Both ethinyl estradiol and equine estrogens may increase blood pressure, while natural estrogens may decrease it. Similarly natural estrogens induce prostacyclin synthesis, while ethinyl estradiol activates both prostacyclin and thromboxanes. Progestagens, especially so the norprogestins, disturb carbohydrate metabolism and tend to reverse the beneficial effects of estrogens on serum lipids, a 40-70% reduction in risk of mortality from coronary heart disease. A meta- analysis of 23 studies concluded that menopausal estrogens do not increase the risk of breast cancer by a measurable degree, except in high doses and in those predisposed by family history. There is an increased risk of endometrial carcinoma for those taking unopposed estrogens for more than 3-6 years. This can be attenuated by taking combined estrogen-progestins, which will eventually result in absence of bleeding, or a 12-day progestogen course every 4-6 cycles. Oral micronized progesterone decreases blood pressure. The relative androgenic effects of progestins other than the norprogesterone derivatives are less significant. As an alternative to taking a progestogen, a woman could have regular endometrial sampling or abdominal or vaginal sonograms to detect endometrial cancer.^ieng
Assuntos
Terapia de Reposição de Estrogênios/efeitos adversos , Progestinas/efeitos adversos , Congêneres do Estradiol/efeitos adversos , Congêneres do Estradiol/farmacologia , Estrogênios Conjugados (USP)/efeitos adversos , Estrogênios Conjugados (USP)/farmacologia , Feminino , Humanos , Progestinas/farmacologia , RiscoRESUMO
PIP: On the basis of available evidence, it is reasonable to conclude that at this time women between 35-45 years should not be denied the benefit of oral contraception (OC) if they do not smoke. As Upton recently reported, the risk of death due to pregnancy and childbirth, even in a developed country such as the US, is greater than the risk of OC, including the risk for OC users who smoke. Low-dose, or very low-dose, ethinyl-estradiol combined OCs most likely can be prescribed safely for most women up to the time of menopause in the absence of cardiovascular risk factors. The alternative treatments that might be initiated before and then continued during and after the climacteric include: cyclic or continuous combined estrogen-progestogen preparations containing estradiol (in valerate or micronized form); "transdermal therapeutic systems" delivering both estrogen and progestogen, for cyclic or even continuous use; and other newly-developed means of delivering fairly constant doses of steroids, such as pellet implants and microspheres. The combination of estradiol pellet implants with the cyclic or continuous administration of progesterone or a progestogen also might prove to be a promising approach if estrogen accumulation could be avoided. Substantial effort still needs to be made to improve the available preparations and provide the clinician and the women concerned with the best possible formulations for use in the perimenopause, and possibly indefinitely afterwards as true substitution therapy.^ieng