Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 175
Filtrar
2.
Pharmacol Biochem Behav ; 73(4): 951-61, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12213542

RESUMO

Levonorgestrel (LNG), a contraceptive progestin, exhibits, besides its progestational activity, other hormone-like effects at the peripheral level. To assess whether LNG and its metabolites exert androgenic and/or estrogenic actions at the central nervous system (CNS), their effects on male sexual behavior in castrated rats were examined. LNG, 5alpha-dihydro LNG (5alphaLNG), and the 3alpha,5alpha- and 3beta,5alpha-tetrahydro derivatives of LNG (3alphaLNG and 3betaLNG, respectively) were administered for 3 weeks either alone (1000 microg/day) or in combination (300 microg/day) with 5alpha-dihydrotestosterone (DHT, 300 microg/day) or with estradiol-17beta (E(2), 5 microg/day). Copulatory behavior was assessed twice per week and sex accessory organs weights recorded at the end of treatments. LNG restored full copulatory behavior comparable to that of testosterone treated animals, although with a slight delay, whereas 5alphaLNG induced male sexual behavior in a significantly lower number of subjects. 3betaLNG and 3alphaLNG induced mounting but failed to restore intromission and ejaculation. Combined LNG+E(2) treatment fully activated mounting and intromission, but ejaculation was only partially restored. Combined 5alphaLNG+E(2) treatment and the combinations of 3alphaLNG or 3betaLNG with E(2) were significantly less effective, activating fewer intromissions and ejaculations. 3alphaLNG and 5alphaLNG, in combination with DHT, restored male sexual behavior. LNG, but not its metabolites, induced a significant increase on the weight of sex accessory organs. The overall results demonstrated that high doses of LNG induce a potent androgen agonistic behavioral effect and that its A-ring reduction diminishes this potency and enables a shift towards a weak estrogen-like effect.


Assuntos
Hormônios Esteroides Gonadais/metabolismo , Hormônios Esteroides Gonadais/farmacologia , Levanogestrel/metabolismo , Levanogestrel/farmacologia , Comportamento Sexual Animal/efeitos dos fármacos , Androgênios/metabolismo , Androgênios/farmacologia , Animais , Estrogênios/metabolismo , Estrogênios/farmacologia , Feminino , Masculino , Ratos , Ratos Wistar , Comportamento Sexual Animal/fisiologia
3.
Eur J Pharmacol ; 427(2): 167-74, 2001 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-11557270

RESUMO

Levonorgestrel (13beta-ethyl-17alpha-ethynyl-17beta-hydroxy-4-gonen-3-one), a potent contraceptive progestin stimulates growth and proliferation of cultured breast cancer cells through a receptor-mediated mechanism, even though levonorgestrel does not bind to the oestrogen receptor (ER). To assess whether the oestrogen-like effects induced by this synthetic progestin are exerted via its metabolic conversion products, we studied the binding affinity of three A-ring levonorgestrel derivatives to the ER and their capability to transactivate an oestrogen-dependent yeast system co-transfected with the human ER gene and oestrogen responsive elements fused to a beta-galactosidase reporter vector. The results demonstrated that the 3beta,5alpha reduced levonorgestrel derivative and to a lesser extent its 3alpha isomer interact with the oestrogen receptor, with a significantly lower relative binding affinity (2.4% and 0.4%, respectively) than that of oestradiol (100%), while levonorgestrel does not. Both levonorgestrel metabolites were able to activate, in a dose-dependent manner, the beta-galactosidase reporter gene in the yeast expression system, an effect that was precluded by a steroidal antioestrogen. The oestrogenic potency of levonorgestrel metabolites was significantly lower (750-fold) than that of oestradiol. Furthermore, high doses of 3beta,5alpha levonorgestrel (2.5 mg/day/6 days) induced an increase of oestrogen-dependent progestin receptor in the anterior pituitary of castrated rats. The overall data offer a plausible explanation for the weak oestrogenic effects induced by high, non-pharmacological doses of levonorgestrel.


Assuntos
Anticoncepcionais Femininos/farmacologia , Estrogênios/farmacologia , Levanogestrel/farmacologia , Animais , Ligação Competitiva , Anticoncepcionais Femininos/metabolismo , Relação Dose-Resposta a Droga , Estradiol/análogos & derivados , Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Estrogênios/metabolismo , Feminino , Fulvestranto , Humanos , Levanogestrel/análogos & derivados , Levanogestrel/metabolismo , Adeno-Hipófise/efeitos dos fármacos , Adeno-Hipófise/metabolismo , Ratos , Ratos Wistar , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/efeitos dos fármacos , Receptores de Progesterona/metabolismo , Proteínas Recombinantes de Fusão/efeitos dos fármacos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae/genética , beta-Galactosidase/efeitos dos fármacos , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
4.
Endocrinology ; 142(9): 3791-9, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11517155

RESUMO

It has previously been demonstrated that 19-nor contraceptive progestins undergo in vivo and in vitro enzyme-mediated A-ring double bond hydrogenation. Bioconversion of 19-nor progestins to their corresponding tetrahydro derivatives results in the loss of progestational activity and acquisition of estrogenic activities and binding to the ER. Herein, we report subtype-selective differences in ligand binding and transcriptional potency of nonphenolic synthetic 19-nor derivatives between ER alpha and ER beta. In this study, we have examined both ER- and PR-mediated transcriptional activity of a number of A-ring chemically reduced derivatives of norethisterone and Gestodene. Double bond hydrogenation decreased the transcriptional potency of norethisterone and Gestodene through both PR isoforms with a 100- to 1,000-fold difference, respectively. In terms of the effects of norethisterone and Gestodene and their corresponding 5 alpha-dihydro (5 alpha-norethisterone and 5 alpha-Gestodene), or 3 alpha,5 alpha-tetrahydro or 3 beta,5 alpha-tetrahydro derivatives (3 alpha,5 alpha-norethisterone/3 alpha,5 alpha-Gestodene and 3 beta,5 alpha-norethisterone/3beta,5 alpha-Gestodene, respectively) on estrogen-mediated transcriptional regulation, the 3 beta,5 alpha-tetrahydro derivatives of both norethisterone and Gestodene showed the highest induction when HeLa cells were transiently transfected with an expression vector for ER alpha. This activity could be inhibited with tamoxifen. These compounds did not activate gene transcription via ER beta, and none of them showed antagonistic activities through either ER subtype. The 3 beta,5 alpha-tetrahydro derivatives of both norethisterone and Gestodene were active in other cells in addition to HeLa cells and activated reporter expression through the oxytocin promoter. In summary, two ER alpha selective agonists have been identified. These compounds, with ER alpha vs. ER beta selective agonist activity, may be useful in evaluating the distinct role of these receptors as well as in providing useful insights into ER action.


Assuntos
Progestinas/metabolismo , Receptores de Estrogênio/agonistas , Animais , Células CHO , Cricetinae , Receptor alfa de Estrogênio , Células HeLa , Humanos , Estrutura Molecular , Noretindrona/metabolismo , Noretindrona/farmacologia , Norpregnenos/metabolismo , Norpregnenos/farmacologia , Oxirredução , Receptores de Estrogênio/classificação , Receptores de Estrogênio/efeitos dos fármacos , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Receptores de Progesterona/fisiologia , Ativação Transcricional/fisiologia
5.
Eur J Pharmacol ; 417(3): 249-56, 2001 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-11334857

RESUMO

Gestodene (13beta-ethyl-17alpha-ethynyl-17beta-hydroxy-4,5-gonadien-3-one), the most potent progestin ever synthesized, stimulates breast cancer cell growth through an oestrogen receptor-mediated mechanism, and its use in hormonal contraception has been associated with side effects attributable to oestrogenic actions. These observations have remained controversial, since gestodene does not bind to the oestrogen receptor or exert oestrogen-like activities. Recently, we have demonstrated that non-phenolic gestodene derivatives interact with oestrogen receptors and induce oestrogenic effects in cell expression systems. To assess whether gestodene is biotransformed to metabolites with intrinsic oestrogenic potency, [3H]- and [14C]-labelled gestodene were incubated in vitro with rat anterior pituitary, hypothalamus and ventral prostate homogenates under different experimental conditions. The most remarkable finding was the isolation and identification of 3beta,5alpha-tetrahydrogestodene and 3alpha,5alpha-tetrahydrogestodene as metabolic conversion products of gestodene, presumably with 5alpha-dihydrogestodene as intermediate. The overall results seem to indicate that the weak oestrogenic effects attributable to gestodene could be mediated by its tetrahydro metabolites.


Assuntos
Hipotálamo/metabolismo , Norpregnenos/química , Norpregnenos/metabolismo , Adeno-Hipófise/metabolismo , Próstata/metabolismo , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/metabolismo , Animais , Biotransformação , Anticoncepcionais Orais Sintéticos/química , Anticoncepcionais Orais Sintéticos/metabolismo , Anticoncepcionais Orais Sintéticos/farmacocinética , Feminino , Concentração de Íons de Hidrogênio , Hipotálamo/enzimologia , Masculino , NADP/metabolismo , Norpregnenos/farmacocinética , Adeno-Hipófise/enzimologia , Congêneres da Progesterona/química , Congêneres da Progesterona/metabolismo , Congêneres da Progesterona/farmacocinética , Próstata/enzimologia , Ratos , Ratos Wistar , Testosterona/metabolismo
6.
J Endocrinol ; 165(3): 693-702, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10828854

RESUMO

Gestodene (17 alpha-ethynyl-13 beta-ethyl-17 beta-hydroxy-4, 15-gonadien-3-one) is the most potent synthetic progestin currently available and it is widely used as a fertility regulating agent in a number of contraceptive formulations because of its high effectiveness, safety and acceptability. The observation that contraceptive synthetic progestins exert hormone-like effects other than their progestational activities, prompted us to investigate whether gestodene (GSD) administration may induce oestrogenic effects, even though the GSD molecule does not interact with intracellular oestrogen receptors (ER). To assess whether GSD may exert oestrogenic effects through some of its neutral metabolites, a series of experimental studies were undertaken using GSD and three of its A-ring reduced metabolites. Receptor binding studies by displacement analysis confirmed that indeed GSD does not bind to the ER, whereas its 3 beta,5 alpha-tetrahydro reduced derivative (3 beta GSD) interacts with a relative high affinity with the ER. The 3 alpha,5 alpha GSD isomer (3 alpha GSD) also binds to the ER, though to a lesser extent. The ability of the A-ring reduced GSD derivatives to induce oestrogenic actions was evaluated by the use of two different molecular bioassays: (a) transactivation of a yeast system co-transfected with the human ER alpha (hER alpha) gene and oestrogen responsive elements fused to the beta-galactosidase reporter vector and (b) transactivation of the hER alpha-mediated transcription of the chloramphenicol acetyl transferase (CAT) reporter gene in a HeLa cells expression system. The oestrogenic potency of 3 beta GSD was also assessed by its capability to induce oestrogen-dependent progestin receptors (PR) in the anterior pituitary of castrated female rats. The results demonstrated that 3 beta GSD and 3 alpha GSD were able to activate, in a dose-dependent manner, the hER alpha-mediated transcription of both the beta-galactosidase and the CAT reporter genes in the yeast and HeLa cells expression systems respectively. In both assays the 3 beta derivative of GSD exhibited a significantly greater oestrogenic effect than its 3 alpha isomer, while unchanged GSD and 5 alpha GSD were completely ineffective. Neither 3 beta GSD nor 3 alpha GSD exhibited oestrogen synergistic actions. Interestingly, the pure steroidal anti-oestrogen ICI-182,780 diminished the transactivation induced by 3 beta GSD and 3 alpha GSD in the yeast expression system. Furthermore, administration of 3 beta GSD resulted in a significant increase of oestrogen-dependent PR in the anterior pituitaries of castrated rats in comparison with vehicle-treated animals. The characteristics of the 3 beta GSD-induced PR were identical to those induced by oestradio benzoate. The overall results demonstrate that 3 beta GSD and its 3 alpha isomeric alcohol specifically bind to the ER and possess a weak intrinsic oestrogenic activity, whereas unmodified GSD does not. The data contribute to a better understanding of the GSD mechanism of action and allow the hypothesis to be advanced that the slight oestrogenlike effects attributable to GSD are mediated by its non-phenolic, tetrahydro reduced metabolites.


Assuntos
Anticoncepcionais Orais Sintéticos/farmacologia , Norpregnenos/farmacologia , Congêneres da Progesterona/farmacologia , Animais , Ligação Competitiva , Anticoncepcionais Orais Sintéticos/metabolismo , Feminino , Células HeLa , Humanos , Norpregnenos/metabolismo , Oxirredução , Adeno-Hipófise/efeitos dos fármacos , Adeno-Hipófise/metabolismo , Congêneres da Progesterona/metabolismo , Ratos , Ratos Wistar , Receptores de Estradiol/metabolismo , Receptores de Progesterona/biossíntese , Saccharomyces cerevisiae/genética , Ativação Transcricional/efeitos dos fármacos
7.
Gac Med Mex ; 136(1): 42-4, 2000 Jan.
Artigo em Espanhol | MEDLINE | ID: mdl-10721601
9.
Ginecol Obstet Mex ; 67: 308-18, 1999 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-10496052

RESUMO

In the last decades has been a worldwide trend to increase the number of cesarean sections as an alternative of obstetric resolution, phenomenon for which it was proposed a variety of explanation, this fact remains practically unknown in the institutions of the National Health System (NHS) in Mexico. To identify the trend of the pregnancy to end for cesarean sections during the years of 1991-1995 in the 32 states of de country, as well as of all the institutions of the National Health System. Descriptive, cross sectional and retrospective. We use the data of the Bureau of Statistics and Informatics of de Health Ministry of each one of the 32 states of the country, of the years 1991 to 1995, and of the number of cesarean sections made in the hospitals of the different institutions of the NHS. We started off with a data-base, to calculate frequency tables, and the specific rate of the cesarean section for each year, for each one of the states and institutions of the NHS. We calculate the secular trends using the annual rates of cesarean section, for each one of the states and institutions of the NHS. We also made bivariate analysis and estimated the odds ratio (OR) and 95% Confidence Interval (95% IC); and the statistic X2 for trend, setting the two tailed statistic significance level of 0.05. During the study period, there was 7,503,817 births in all hospitals of the NHS, of these births 1,929,865 (25.72%) was resolved by cesarean section. For the whole period it there was a clear trend to increment of the cesarean section, the rate for 1991 was 20.44%, and by 1995 was 28.58%, the raise for the period was 39.82%, with values of the OR for trend of 1.56; 95% IC (1.55-1.57). "P" < 0.05. The rate for institutions attending open population had an increment of 35.08% [OR trend 1.45; 95% IC (1.43-1.46), "p" < 0.05], of them the highest rate was for the State System of Health in 1995 with 29.78%, the rates for the remaining institutions varied from 16.57% for the IMSS/SOLIDARIDAD and 21.7% for the Health Ministry, all trends were statistically significant. In relation to the institutes attending closed population the raise was of 53.27% [OR trend 1.82; 95% IC (1.81-1.83), "p" < 0.05], with the highest rate for the National Defense Ministry which had a rate of 51-15%, the rates for the remaining institutions varied from 33.52% for the Mexican Institute of Social Security (IMSS) to 43.89% for the Institute of Safety and Social Services for the State Workers (ISSSTE), with exception of the Management of the Medical Services of the Mexican Oils (PEMEX) and the Marine Ministry (SECMAR), all trends were statistically significant. When the analysis of the cesarean section rates for the 32 states of the Mexican Republic was carried out, we found that in 1995, the national average rate was 28.58%, the lowest rate corresponded to the state of Zacatecas with 19.82% and the highest to the state of Nuevo León with 42.14%. There was a tendency to increment for all states which varied from 23.55% for the state Chiapas and 67.97% for the states of Querétaro, all increments were statistically significant. We conclude, that rates of cesarean section for both, institutions of NHS and states of the Mexican Republic, are of the highest in the world, no matter what big the interinstitutional and interstate variation are. The highest rates occurred in institutions attending closed population, and the states with a higher degree of socioeconomic development.


Assuntos
Cesárea/tendências , Cesárea/estatística & dados numéricos , Distribuição de Qui-Quadrado , Intervalos de Confiança , Estudos Transversais , Feminino , Humanos , Modelos Lineares , México , Programas Nacionais de Saúde/estatística & dados numéricos , Razão de Chances , Gravidez , Estudos Retrospectivos
10.
J Med Screen ; 6(2): 77-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10444724

RESUMO

OBJECTIVE: To report the experience, obstacles, and strategies of screening for congenital hypothyroidism. SETTING: Newborns in Mexico. METHODS: Thyroid stimulating hormone (TSH) was measured by enzyme immunoassay using commercial kits in 1,140,364 newborns. RESULTS: There were 464 positive cases, of whom 299 (64.4%) were girls. 236 (50.9% showed ectopic nodules, 202 (43.5%) thyroid agenesis, 21 (4.5%) dyshormonogenesis, and 5 (1.1%) an unclassified goitre. The false positive rate was 0.024% and there were 11 false negative results. Currently, 600,000 (26%) of the 2,300,000 newborns are screened. This percentage has been increased in recent years by taking samples from cord blood and will be increased further by starting congenital hypothyroidism screening at social security units and by midwives screening infants born at home. CONCLUSIONS: Mental retardation in infants in developing countries can be reduced by neonatal screening, and carefully planned strategies can steadily extend the benefits of screening.


Assuntos
Hipotireoidismo Congênito , Hipotireoidismo/diagnóstico , Triagem Neonatal , Coleta de Amostras Sanguíneas/métodos , Reações Falso-Positivas , Feminino , Sangue Fetal/química , Humanos , Hipotireoidismo/epidemiologia , Recém-Nascido , Estudos Longitudinais , Masculino , México/epidemiologia , Triagem Neonatal/métodos , Triagem Neonatal/organização & administração , Triagem Neonatal/normas , Prevalência , Distribuição por Sexo , Glândula Tireoide/anormalidades , Tireotropina/sangue
11.
Contraception ; 58(1): 7-12, 1998 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-9743890

RESUMO

A large introductory study of Cyclofem, a once-a-month injectable contraceptive, was conducted in three Mexican provinces. A total of 3457 healthy women participated: 640 women from rural areas (community-based component) and 2817 women from urban and suburban areas (health center-based component). A total of 20,316 women-months of treatment experience were accumulated during a one year period. Cyclofem proved its use-effectiveness (pregnancy rate of 0.03%) and its safety under routine service conditions of family planning facilities in Mexico. The overall life table continuation rate at 1 year was 26.1%. Higher continuation rates were observed in the community-based component (36.6%) as compared to the health center component (23.7%). The most common reason for method discontinuation was change of address. Only 15% of the discontinuations were attributable to the injectable contraceptive method, with the overall 1 year discontinuation rate for bleeding problems (including amenorrhea) was < 11%. These observations underscore the importance of appropriate counseling and follow-up measures, providing convenient access to repeat injections, and other service delivery issues related to continuation of Cyclofem. The results of this trial have once again demonstrated that Cyclofem is a highly effective method with an acceptable side effect profile. In addition, the study provided the elements for its approval by local health authorities and its inclusion into the Ministry of Health Family Planning Program.


PIP: The effectiveness and continuation rates associated with the once-a-month injectable contraceptive Cyclofem were investigated in an introductory trial conducted in three Mexican provinces (Sinaloa, Guanajuato, and Veracruz). Cyclofem contains 25 mg of medroxyprogesterone acetate and 5 mg of estradiol cypionate. A total of 3457 women (640 women from rural communities and 2817 from urban and suburban family planning centers) were enrolled and 20,316 woman-months of treatment experience were accumulated during the 12-month study period. The mean age of study participants was 23.6 years; 70% had previously used at least one contraceptive method. There was only one pregnancy (rate, 0.03%). The overall life-table continuation rate at 1 year was 26.1%, but this rate was higher in the community-based group (36.9%) than in the health center group (22.4%). This discrepancy is presumed to reflect the greater access of clinic clients to other contraception options. Continuation was highest among women 30-34 years of age, those with low levels of education, women with five or more children, and those who did not want more children. Only 14% of discontinuations were method-related. The 1-year discontinuation rate for bleeding problems, including amenorrhea, was 10.2%. These findings indicate Cyclofem is a safe, effective method appropriate for inclusion in Mexico's Ministry of Health Family Planning Program.


Assuntos
Anticoncepcionais Femininos , Estradiol/análogos & derivados , Acetato de Medroxiprogesterona/administração & dosagem , Adolescente , Adulto , Anticoncepcionais Orais Combinados/administração & dosagem , Anticoncepcionais Orais Combinados/efeitos adversos , Combinação de Medicamentos , Escolaridade , Estradiol/administração & dosagem , Estradiol/efeitos adversos , Feminino , Humanos , Injeções Intramusculares , Acetato de Medroxiprogesterona/efeitos adversos , México , Satisfação do Paciente , Estudos Prospectivos
12.
Ginecol Obstet Mex ; 66: 335-8, 1998 Aug.
Artigo em Espanhol | MEDLINE | ID: mdl-9745195

RESUMO

This is an analysis of the characteristics of cesarean section operations within the Ministry of Health (SSA) and the implications in relation to maternal and perinatal mortality during the five year period from 1990 to 1995. A descriptive study was undertaken based on cesarean section information obtained from the Statewide (Reporting) System of Basic Information (SEIR) and based on maternal and perinatal mortality information provided by the Ministry's Internal Hospital Committees from 1990 to 1995. This information was analyzed as a chronological series in order to compare the changes in the annual cesarean rates at both national and statewide levels. The Pearson test was used to determine the correlation between the frequency of cesarean sections and maternal and perinatal mortality rates during the same period within a 95 percent confidence interval (p < 0.05). The frequency of cesarean sections was shown to have increased within the SSA hospital system as whole and when considering each state separately. A positive and statistically significant correlation was observed between the frequency of cesarean sections and maternal mortality rates, while the increase in cesarean rates demonstrated no relationship with perinatal mortality rates. The increase in cesarean section rates in the Ministry of Health during the period analyzed exceeded any potential benefits and could have contributed to the increase in maternal morbidity and morbility as well as hospital cost. This increase is worrisome due to the projected tendency for the rates to continue to increase in the next few years if quick and concrete actions are not taken in order to decrease these rates.


Assuntos
Cesárea/classificação , Cesárea/normas , Feminino , Humanos , México , Gravidez , Garantia da Qualidade dos Cuidados de Saúde
13.
Ginecol Obstet Mex ; 66: 65-8, 1998 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-9586390

RESUMO

In Mexico, as in almost all the Latin American countries, abortion represents an important maternal morbidity-mortality reason. It has been pointed out that those women who had an abortion, are in greater risk to repeat this condition than those women who have not had the episode. For this reason, it is a transcendental matter, the use of modern contraceptive technology for fertility regulation with the aim to avoid not planned pregnancies and their devastating consequences. This document reviews-according to the Family Planning Official Norm of the Ministry of Health-those different contractive alternatives, that can be used in the postabortion.


Assuntos
Anticoncepção , Aborto Induzido , Anticoncepcionais Orais Combinados/administração & dosagem , Anticoncepcionais Orais Sintéticos/administração & dosagem , Serviços de Planejamento Familiar , Feminino , Humanos , Dispositivos Intrauterinos , Levanogestrel/administração & dosagem , Congêneres da Progesterona/administração & dosagem , Progestinas/administração & dosagem
15.
Contraception ; 55(6): 359-67, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9262932

RESUMO

In order to assess efficacy, safety, and acceptability of the contraceptive subdermal implants Norplant and Norplant-II in Mexican women, a comparative phase III clinical trial was undertaken in eight clinics across the country. The study involved 1052 women who were followed-up trimonthly for three years. Cumulative pregnancy rates were 0.29% and 0.34% for Norplant and Norplant-II implants, respectively. Similar overall cumulative discontinuation rates were observed at three years: 50.38% for Norplant capsules, and 50.44% for Norplant-II rods. The main method-related reason for termination was endometrial bleeding irregularity which led to discontinuation rates of 11.94% and 11.62% for Norplant and Norplant-II contraceptive systems, respectively. In 15,279 woman-months of experience accumulated with Norplant implants and 14,092 with Norplant-II implants, there were few adverse events reported. No difference was found between the two groups in either difficulty for implants placement and removal or women's discomfort, even though the time required for insertion and removal of Norplant capsules was longer than for Norplant-II rods. It is concluded that during the first three years of use, both implants systems are equally effective, safe, and acceptable.


Assuntos
Anticoncepção/métodos , Anticoncepcionais Femininos/administração & dosagem , Levanogestrel/administração & dosagem , Adulto , Cápsulas , Estudos de Coortes , Anticoncepção/normas , Anticoncepção/estatística & dados numéricos , Anticoncepcionais Femininos/efeitos adversos , Anticoncepcionais Femininos/normas , Implantes de Medicamento , Feminino , Seguimentos , Humanos , Levanogestrel/efeitos adversos , Levanogestrel/normas , Pacientes Desistentes do Tratamento/estatística & dados numéricos , Satisfação do Paciente/estatística & dados numéricos , Taxa de Gravidez , Segurança , Fatores de Tempo
16.
Clin Endocrinol (Oxf) ; 46(2): 155-60, 1997 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9135696

RESUMO

BACKGROUND AND OBJECTIVE: Male pseudohermaphroditism due to 5 alpha-reductase deficiency was originally described in 1974. Recently, 5 alpha-reductase Type 2 gene defects have been found generally to be due to point mutations within the 5 exons of the 5 alpha-reductase-2 gene. In this report, we describe the molecular study of patients with 5 alpha-reductase deficiency. DESIGN: Previously diagnosed patients with 5 alpha-reductase deficiency were sampled in order to perform molecular studies. PATIENTS: Eight 5 alpha-reductase deficient individuals from 6 unrelated families. MEASUREMENTS: Single-strand conformational polymorphism and DNA sequencing were performed after polymerase chain reaction amplification of each of the 5 exons of the gene. RESULTS: Five different missense mutations were found. In 4 patients a cytosine to guanine substitution was observed at codon 212 in exon 4. Two siblings presented a cytosine to adenine substitution at codon 207 in exon 4. Another patient exhibited a guanine to adenine substitution at codon 34 in exon 1, whilst one individual presented 2 mutations: a guanine to adenine substitution at codon 115 in exon 2 and a guanine to adenine substitution at codon 203 in exon 4 (previously undescribed mutation). CONCLUSIONS: The presence of the same mutation in 4 patients from 3 families indicates the increased prevalence of this mutation in a particular ethnic group, suggesting a common ancestry for the gene defect in these patients. The existence of hot spots is supported by the mutations in codons 34 and 207 which have also been found in other ethnic groups. Interestingly, the patient who presented 2 different mutations, one of them previously undescribed, was reared as a male and exhibited a more masculine phenotype. Further studies in patients with this and other mutations will be needed to verify genotype-phenotype correlation.


Assuntos
3-Oxo-5-alfa-Esteroide 4-Desidrogenase/deficiência , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Transtornos do Desenvolvimento Sexual/genética , Mutação Puntual , Adolescente , Adulto , Transtornos do Desenvolvimento Sexual/etnologia , Éxons/genética , Humanos , Masculino , México/etnologia , Linhagem , Reação em Cadeia da Polimerase , Polimorfismo Conformacional de Fita Simples , Análise de Sequência de DNA
17.
J Steroid Biochem Mol Biol ; 60(1-2): 121-9, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9182866

RESUMO

Norethisterone (NET), a 19-nor synthetic progestin, undergoes enzyme-mediated 5alpha-reduction and exerts potent androgenic effects in target organs. To investigate its mode of androgenic action we examined, in a comparative manner, the in vitro metabolism of NET and testosterone (T), as well as the binding affinities to androgen receptors (AR) and the androgenic potency of NET, T, and their 5alpha-reduced derivatives. Bioconversion of [3H]-NET and [3H]-T was studied in rat prostate homogenates, AR binding affinity was assessed in rat ventral prostates using [3H]-mibolerone as the radioligand, and the androgenic potency was evaluated by the increase of beta-glucuronidase activity in the mouse kidney, and by the growth of accessory sex organs in castrated male rats. The results demonstrated that 5alpha-NET displayed a higher AR binding affinity but a significantly lower androgenic potency than unchanged NET. The bioconversion studies indicated that the metabolism of NET was similar to that of T, although to a lesser extent, thus ruling out the possibility that the synthetic progestin metabolizes rapidly into less active derivatives. To investigate the nature of the paradoxical effect of 5alpha-reduction upon the NET molecule, the interaction with AR and the androgenic potency of T, 19-nortestosterone (19norT), 17alpha-ethynyl testosterone (ET) and their 5alpha-reduced derivatives were examined. The results of AR binding studies revealed that 5alpha-reduction of T and ET significantly enhanced their affinities, and that the 5alpha-derivative of 19norT displayed a similar binding affinity to that exhibited by 19norT. In terms of biological activity, the results showed that 5alpha-reduction of T and 19norT significantly increased their androgenic potency, whereas 5alpha-reduction of ET resulted in a significant diminution of its androgenicity in a manner similar to that observed with the 5alpha-reduction of NET. When NET and 19norT were simultaneously administered with 5alpha-dihydrotestosterone they exhibited a potent synandrogenic activity, an effect that was cancelled by their 5alpha-reduction. Interestingly, ET displayed an antiandrogenic activity, an effect that was also suppressed by its 5alpha-reduction. The overall results demonstrated a distinctive, paradoxical effect of 5alpha-reduction upon the NET molecule, which was different from that seen in naturally occurring androgens, and which suggests that the presence of the 17alpha-ethynyl group plays a key role in this phenomenon. The data provided further evidence that the metabolism of synthetic contraceptive progestins modulates the expression of their hormone-like actions.


Assuntos
Glucuronidase/metabolismo , Noretindrona/metabolismo , Noretindrona/farmacologia , Receptores Androgênicos/metabolismo , Androgênios/fisiologia , Animais , Ligação Competitiva , Relação Dose-Resposta a Droga , Sinergismo Farmacológico , Etisterona/metabolismo , Etisterona/farmacologia , Glucuronidase/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Nandrolona/análogos & derivados , Nandrolona/metabolismo , Nandrolona/farmacologia , Noretindrona/análogos & derivados , Orquiectomia , Tamanho do Órgão/efeitos dos fármacos , Oxirredução , Congêneres da Progesterona/metabolismo , Próstata/efeitos dos fármacos , Próstata/crescimento & desenvolvimento , Próstata/metabolismo , Ratos , Ratos Wistar , Glândulas Seminais/efeitos dos fármacos , Glândulas Seminais/crescimento & desenvolvimento , Relação Estrutura-Atividade , Testosterona/análogos & derivados , Testosterona/metabolismo , Testosterona/farmacologia , Trítio
18.
Life Sci ; 61(12): 1159-67, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9315506

RESUMO

The reproductive function of male and female rats with induced nephrotic syndrome was examined by assessing hormonal levels, the estrous cycle pattern and fertility. Measurements were carried out on day 10 (nephrotic stage) and on day 30 (remission stage) after treatment (a single s.c. dose of puromycin aminonucleoside 15 mg/100 g body wt.). Serum concentrations of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and progesterone (P4) from both sexes as well as 17beta-estradiol (E2) in females and total testosterone (tT) in males were assayed at both phases of the illness by specific radioimmunoassays; free and urine testosterone (fT, uT) was also determined in male rats on day 10. The estrous cycle was followed alongside the study through vaginal smears, while fertility was estimated by the rate of pregnancies (females) or pregnancy induction (males), and by the litter size. The results showed that most serum hormone levels, except FSH in females, were significantly reduced at the nephrotic stage of the illness, returning to their normal values after 30 days. Besides, on day 10, fT was found reduced in nephrotic males, while uT concentrations remained unmodified. The ovulatory cycle of nephrotic rats was disrupted on day 3 and not restored until day 23; nevertheless, the reproductive function, measured as a fertility index, was fully reinstalled at the remission stage. Interestingly, the capacity of fertilization of the nephrotic males was not entirely abolished during the acute phase, since 37% of the animals were fertile. Moreover, on day 30 the reproductive function in nephrotic males was totally recovered. The data from this study show the existence of reversible endocrine disorders in rats bearing nephrotic syndrome; such changes are manifested during the acute phase of the illness as a temporary cessation of the reproductive processes.


Assuntos
Hormônios Esteroides Gonadais/sangue , Síndrome Nefrótica/fisiopatologia , Reprodução/fisiologia , Animais , Estradiol/sangue , Estro , Feminino , Fertilização , Hormônio Foliculoestimulante/sangue , Tamanho da Ninhada de Vivíparos , Hormônio Luteinizante/sangue , Masculino , Ovulação , Gravidez , Progesterona/sangue , Puromicina Aminonucleosídeo/farmacologia , Ratos , Ratos Wistar , Caracteres Sexuais , Testosterona/sangue , Testosterona/urina , Fatores de Tempo
20.
Arch Androl ; 37(1): 19-26, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8827344

RESUMO

The 46,XX male syndrome is characterized by the presence of testicular development in subjects who lack a Y chromosome. The majority of patients have male external genitalia without ambiguity; however, 10-15% show diverse degrees of hypospadias. Testicular function is normal at birth but deteriorates thereafter. However, it has not been clarified why some cases exhibit genital ambiguity. This study examined 10 affected patients, including 4 prepubertal (< 1 year old) with hypospadias (1 glandular, 1 penile, and 2 penoscrotal). In all subjects, testicular function was evaluated by performing a stimulation with choriogonadotropin. In the postpubertal individuals, basal and poststimuli testosterone were below the reference values. Prepubertal patients had age-appropriate basal test-osterone concentrations. All responded to the choriogonadotropin challenge; however, the most significant response was observed in the patient with the glandular hypospadias, the second highest response was presented by the patient with the penile hypospadias, while both patients with the penoscrotal hypospadias had the poorest responses. These results suggest that the degree of genital ambiguity is correlated with the impairment in testosterone response to choriogonadotropin in early infancy, indicating a defect in testosterone production in XX males with genital ambiguity.


Assuntos
Gonadotropina Coriônica/farmacologia , Aberrações Cromossômicas , Transtornos Cromossômicos , Cromossomos Sexuais , Testículo/efeitos dos fármacos , Adolescente , Adulto , Criança , Pré-Escolar , Estradiol/metabolismo , Hormônio Foliculoestimulante/metabolismo , Humanos , Lactente , Hormônio Luteinizante/metabolismo , Masculino , Fenótipo , Testículo/metabolismo , Testosterona/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...