Biomedical subjects

V Brache

Publications and source records attributed to V Brache.

At least 55 records · Page 3Linked to original sources

PubMed1996

Functional life-span of the dominant follicle in pharmacologically induced anovulatory cycles.

With the purpose of measuring the duration of the functional life-span (FLS) of the anovulatory follicle in women under continuous low-dose progestogen treatment, the oestradiol curve of Norplant implant users was retrospectively analysed. From all the data collected during the previous 5 years at the Department of Biomedical Research at the Family Planning Clinic of Profamilia, Santo Domingo, Dominican Republic, data from all 29 Norplant implant users showing follicular activity without luteal activity were selected for this retrospective analysis. Serial blood sampling twice or three times a week for 5 or 6 consecutive weeks had been taken in all subjects. The duration of the FLS of the dominant follicle in anovulatory cycles was defined at the period from the first day of ascending oestradiol curve until the day preceding onset of menses. The mean FLS of the dominant follicle in anovulatory cycles under continuous low-dose progestogen administration was 21.1 +/- 4.2 days, independently of the length of the menstrual cycle. The duration of the FLS of the anovulatory dominant follicle appears not to be different from the duration of a normal follicle/corpus luteum unit.

Anovulation↗

PubMed1993

Four-year experience in a randomized study of the Gyne T 380 Slimline and the Standard Gyne T 380 intrauterine copper devices.

Performance of the Slimline and Standard models of the Gyne T 380 were measured through four years in a comparative study initially involving 996 women, seventy percent of whom were randomized to the Slimline device. Cumulative pregnancy rates of Slimline users were 0.3 +/- 0.2 per 100 both at three and at four years, as compared with rates of 1.5 +/- 0.9 and 3.8 +/- 1.7 at the same intervals for users of the Standard model (P > .05). The four-year explusion rate of the Slimline, 8.6 +/- 1.3 per 100, was significantly higher than the comparable rate of the Standard model, 4.4 +/- 1.6 (P < .05). The two Gyne T* models did not differ in continuation rates. First time IUD users, however, had substantially lower continuation rates than did former users (P < .001), in consequence of their relative youth and desire to have additional children. Other performance measures did not differ importantly by device.

Adolescent↗

PubMed1993

Comparative study on the efficacy and acceptability of two contraceptive pills administered by the vaginal route: an international multicenter clinical trial.

The efficacy and acceptability of two widely used oral contraceptive tablets, one containing 250 mg levonorgestrel and 50 micrograms ethinyl estradiol and the other containing 150 micrograms desogestrel and 30 micrograms ethinyl estradiol, administered by the vaginal route were compared in 1055 women studied over 12,630 woman-months of vaginal contraceptive pill use. This multicenter clinical trial was performed in nine countries of the developing world by the "South to South Cooperation in Reproductive Health," an organization founded by scientists from the Third World working in the area of reproductive health, and the study was developed and coordinated by one of these centers. The findings of this study confirm the efficacy of both these tablets when administered by the vaginal route. Involuntary pregnancy rates at 1 year of 2.78 for subjects in the levonorgestrel group and 4.54 for subjects the desogestrel group showed no statistically significant difference between the two groups. However, total discontinuation rates of 47.01 for subjects in the levonorgestrel group and 56.33 for subjects in the desogestrel group showed a statistically significant difference between the two groups, and discontinuation rates attributable to prolonged bleeding of 0.6 for subjects in the levonorgestrel group and 3.2 for subjects in the desogestrel group were also significantly higher in the group of subjects using the desogestrel vaginal contraceptive pill. Blood pressure remained at admission values throughout treatment. A statistically significant weight increase from admission values occurred in both groups of subjects.

Administration, Intravaginal↗

PubMed1993

Recent experience with and future directions of contraceptive implants and injectable contraceptives.

Subdermal implantable contraception has been the most important addition to contraceptive technology in the past 2 decades. The Norplant system is only the first of a new family of long acting methods of high effectiveness, high acceptability, and prompt reversibility. The main advantage of the second generation implant systems, to be available soon, is the reduction in the number of implants, which greatly facilitates insertion and removal. However, great improvement in bleeding control is not to be expected. Large and carefully designed epidemiological studies have contributed to clear the main objections to the US Food and Drug Administration (FDA) approval of depot medroxyprogesterone acetate (DMPA) as an injectable contraceptive. New progestin-only, long acting injectables are being tested, but significant improvements over existing methods are difficult to foresee, although every alternative is welcome. Monthly combined injectables have been in great demand, at least in China and Latin America, because of better bleeding control. Improved combined monthly injectables, less estrogenic and more progestin dominated, have been developed and are being introduced in several countries and should soon replace the old monthly injectables. Contraceptive implants and injectables have shown to be an important addition to the contraceptive options available to women throughout both the developing and developed world.

Clinical Trials as Topic↗

PubMed1993

Differences in serum potassium concentrations in normal men in different geographic locations.

Hypokalemia has been associated with the taking of gossypol, a potential oral antifertility drug for men. Because the frequency of this response differed in different parts of the world, this study was done to learn if "normal" serum [K+] also differed. [K+] was measured by flame photometry in serum from apparently normal men from Austria (n = 30), China (53), Brazil (100), the Dominican Republic (38), and the US (103), and in plasma from Nigerian men (82). The mean (SD) for [K+] in Chinese men, 3.82 (0.27) mmol/L, was lower than that in Brazilians [4.06 (0.29) mmol/L], Austrians [4.14 (0.44) mmol/L], Dominicans [4.37 (0.33) mmol/L], or Americans [4.38 (0.37) mmol/L]. Apparently there are regional differences in average serum [K+], with men in China having lower serum [K+] than men elsewhere. This may predispose them to hypokalemia.

Adolescent↗

PubMed1992

Free levonorgestrel index and its relationship with luteal activity during long-term use of Norplant implants.

Levonorgestrel serum levels and sex hormone binding globulin (SHBG) were measured in 82 women during different years of use of Norplant implants. The ratio between levonorgestrel and SHBG was calculated as an indicator of the free biologically active fraction of levonorgestrel (free levonorgestrel index, FLI). These parameters were then correlated with the presence of luteal activity, as determined by progesterone levels above 9.6 nmol/L, in a sampling run of 10 samples taken twice a week for five consecutive weeks. Levonorgestrel serum levels remained constant around 1.0 nmol/L during the five-year period. SHBG levels were below normal for the first 18 months of use, returning to normal levels during the last three years of use. The FLI in the first two years was significantly higher than that observed in the later years. The frequency of cycles with luteal activity was 12% during the first 2 years, increasing to 44% in the latter years, when FLI levels were lower. Our results suggest that the changes in SHBG and consequently in the free biologically active fraction of levonorgestrel may largely account for the differences in degree of ovarian suppression observed between the first two years of use of Norplant implants and the latter three, even in the absence of a significant variation in total levonorgestrel concentrations.

Drug Implants↗

PubMed1992

Evaluation of four different contraceptive vaginal rings: steroid serum levels, luteal activity, bleeding control and lipid profiles.

Four different models of contraceptive vaginal rings were tested during three cycles for luteal activity, bleeding control, plasma lipoproteins and serum levels of the contraceptive steroids. Two progestins, levonorgestrel acetate (LNGA) and ST 1435, alone or in combination with ethynyl-estradiol (EE) were tested. The rings released 100 ug/day of the progestins and 30 ug/day of EE. Luteal activity was detected among users of the progestin-only rings: 4 of 8 cycles with ST 1435 and 2 of 10 with LNGA. Only one of the 18 cycles studied with the two combined rings showed luteal activity, but the measurement of contraceptive steroid in plasma suggested that this subject delayed reinsertion of the ring for about one week in that particular cycle. Breakthrough bleeding was observed in 12 of 30 cycles of use of the progestin-only rings, and in only 2 of 27 cycles with the combined models. No significant changes in total cholesterol or its HDL-fraction were observed. However, the only reduction observed in HDL-cholesterol was among users of the LNGA-only ring. It is concluded that the two combined CVR models offer good possibilities of high effectiveness and bleeding control and merit further development.

Administration, Intravaginal↗

PubMed1992

Rates and outcomes of planned pregnancy after use of Norplant capsules, Norplant II rods, or levonorgestrel-releasing or copper TCu 380Ag intrauterine contraceptive devices.

OBJECTIVES: The objectives were to measure rates of planned pregnancy and factors affecting these rates after use of very-long-acting contraceptive methods (Norplant or Norplant II implants, a levonorgestrel-releasing intrauterine contraceptive device, or the copper T (model TCu 380Ag) intrauterine contraceptive device. STUDY DESIGN: The design was a concurrent, multicenter prospective study of 372 women who stopped contraception for planned pregnancy. Analysis was by life-table, log-rank, and standard chi 2 methods. RESULTS: Pregnancy rates 12 and 24 months after cessation of contraceptive use were 82 and 89 per 100, respectively. Age at removal and family planning intentions at initiation of contraception were both significantly correlated with pregnancy rates (p less than 0.05), but former contraceptive regimen and duration of contraceptive use were not. Pregnancy outcomes did not deviate from normal limits and did not differ by contraceptive formerly used. CONCLUSION: Contraceptive implants releasing 30 micrograms/day of levonorgestrel or intrauterine contraceptive devices releasing 20 micrograms/day of levonorgestrel or having copper surface areas of 380 mm2 are associated with normal fertility after use for women seeking pregnancy at termination. Durations of use do not affect pregnancy rates.

Adult↗

PubMed1991

Hormonal changes associated with bleeding during low dose progestogen contraception delivered by Norplant subdermal implants.

The main side effect associated with the use of Norplant contraceptive implants is a disruption of the menstrual bleeding pattern. To explore the relationship between bleeding and hormonal changes, we analyzed the estradiol (E2) and progesterone (P) patterns that preceded bleeding episodes or that corresponded to periods of amenorrhea in 103 cycles observed among 82 women using Norplant subdermal implants. Five different bleeding patterns were defined: 'normal' (24-45 day cycles), oligomenorrhea (46-90 day cycles), amenorrhea (over 90 day cycles), irregular/frequent bleeding (less than 25 day cycles), and prolonged bleeding (continuous bleeding/spotting for more than 10 days). All 'normal' cycles were associated with a rise followed by a fall in E2 levels preceding bleeding. In half of the 'normal' cycles (28/54), a rise and fall of P was also observed. The same pattern was found in oligomenorrheic cycles, but only two of 12 cycles had a rise and fall of both E2 and P. None of the subjects with amenorrhea had luteal activity. Six of the nine amenorrheic cycles displayed persistently low E2 levels (below 75 pg/ml). The remaining three had a moderate elevation in E2 levels during the sampling period. Sixty percent of the subjects who showed irregular/frequent bleeding (15/25) had low E2 levels (less than 75 pg/ml), without luteal activity, and bleeding occurred without clear evidence of a further drop in E2 levels. In the remaining 40%, bleeding was preceded by a rise and drop of E2 without luteal activity, with the exception of one women, who exhibited a rise and fall of both E2 and P. Samples were obtained in only three subjects during continuous bleeding. One had low E2 levels, and the remaining two bled continuously, in spite of having E2 levels in the normal range. We conclude that ovarian hormones continue to influence endometrial shedding during the use of Norplant contraceptive implants.

Amenorrhea↗

PubMed1991

Prolonged intrauterine contraception: a seven-year randomized study of the levonorgestrel 20 mcg/day (LNg 20) and the Copper T380 Ag IUDS.

A levonorgestrel-releasing IUD and the Copper T 380Ag IUD were in randomized comparison for seven years in five clinics. In two other clinics the randomized study was truncated at five years, but use of the Copper T continued. No pregnancies occurred to users of either device in years 6 and 7. Cumulative pregnancy rates were 1.1 per 100 at seven years for the steroid-releasing and 1.4 per 100 for the copper-releasing IUDs. Cumulative rates of PID did not differ between devices. Infection rates appeared to be lowest during the sixth and seventh years of the study. Termination attributable to amenorrhea was the principal contributor to differences in cumulative continuation rates between devices. At the five clinics that carried the comparative study to seven years, cumulative continuation rates were 24.9 per 100 for LNg20 IUD users and 29.4 per 100 for TCu 380Ag users. Women who used either method for periods of five to seven years experienced, on average, marked to mild increases in hemoglobin as compared with levels at admission. The Copper T380 family and the LNg20 IUDs represent the most effective reversible contraceptive methods yet studied in long-term randomized trials.

Adolescent↗

PubMed1991

Ovulatory dysfunction during continuous administration of low-dose levonorgestrel by subdermal implants.

OBJECTIVE: To study the endocrinologic profile of regularly menstruating users of levonorgestrel subdermal implants. DESIGN: Observational, prospective, case-controlled comparative study. SETTING: The Family Planning Clinic of PROFAMILIA, in Santo Domingo, Dominican Republic. PATIENTS, PARTICIPANTS: Thirty one regularly cycling Norplant users and 12 nonhormonal contraceptors who volunteered to participate. INTERVENTIONS: Norplant contraceptive implants were inserted in 31 subjects between 13 and 77 months before this study. MAIN OUTCOME MEASURES: Follicle-stimulating hormone, luteinizing hormone, estradiol (E2), and progesterone (P) were serially assayed for one menstrual cycle. RESULTS: Almost half of the cycles among Norplant users were anovulatory; all the rest (55%) had some form of dysfunction: diminished gonadotropin surge, luteal phase insufficiency (low P levels and shortened luteal phase), and E2 profiles different from normal controls. CONCLUSIONS: Anovulation is clearly one of the main mechanisms of action of Norplant, but even in presumptive ovulatory cycles, the dysfunctions described possibly contribute to the high contraceptive effectiveness of Norplant.

Adult↗

PubMed1991

Norplant implants: the mechanism of contraceptive action.

OBJECTIVE: To determine if fertilization occurs unnoticed among Norplant users who are ovulatory. DESIGN: Serial blood samples were obtained during 1 month from sexually active Norplant users experiencing regular menstrual bleeding patterns and a control group of noncontracepting women trying to conceive. The sequential blood samples were assayed for the presence of human chorionic gonadotropin (hCG). SETTING: All samples were obtained from women receiving contraceptive service and health care at the Center for Research and Services in Human Reproduction and Contraception, Santo Domingo, The Dominican Republic. Assays for hCG were performed at the Department of Biomedical Sciences, University of Tampere, Finland. PATIENTS, PARTICIPANTS: A total of 32 women using Norplant implants were enrolled in the treatment group, and 20 women of proven fertility who were attempting to conceive served as a control group. INTERVENTIONS: Duration of Norplant use was as follows: 4 in the 2nd year of use, 13 in the 3rd year, 11 in the 4th year, 3 in the 5th year, and 1 in the 7th year. MAIN OUTCOME MEASURE: The determination of pregnancy was based on the presence of hCG in the luteal phase, using a sensitive and specific immunoenzymatic assay that can detect dimeric hCG as early as 7 days after ovulation. RESULTS: Nine pregnancies were detected. All were in the control group trying to conceive. Six of these advanced to clinical pregnancies, and three did not proceed beyond the next expected menses. None of the Norplant users had evidence of hCG production, whether the observed cycles were anovulatory or ovulatory. The probability of finding no pregnancies in the ovulatory months at risk among Norplant users is between 1 in 50 and 1 in 150,000. The null hypothesis that Norplant users conceive at a natural rate can be rejected at the 0.05 level. CONCLUSION: Interruption of early pregnancy (menstrual abortion) does not play a role in the mechanism of action of Norplant contraceptive implants.

Chorionic Gonadotropin↗

PubMed1990

Long-term contraception with the levonorgestrel 20 mcg/day (LNg 20) and the copper T 380Ag intrauterine devices: a five-year randomized study.

An intrauterine device, releasing approximately 20 micrograms/day of levonorgestrel (LNg 20), used by 1124 women, was studied in a randomized trial of five years duration in comparison with the Copper T, model TCu 380Agm in 1121 women. At five years, the gross cumulative pregnancy rate of 1.1 +/- 0.5 per 100 among users of the LNg 20 devices was not significantly different from the rate of 1.4 +/- 0.4 per 100 experienced by users of the Copper T 380Ag. The steroid-releasing IUD had significantly higher termination rates for expulsion and amenorrhea, a significantly lower termination rate for other menstrual problems and pain, and a lower continuation rate. The five-year continuation rate among women using the TCu 380Ag was 40.6 per 100 as compared with that of 33.0 per 100 among women randomized to the LNg 20 device (P less than .001). Terminations attributed to amenorrhea with the LNg device primarily account for differences in continuation. These two intrauterine devices are the most effective long-term, reversible IUDs yet reported in the literature. No other contraceptive methods have exhibited such low long-term pregnancy rates in randomized comparative trials.

Adolescent↗

PubMed1990

A randomized trial of the Gyne T 380 and Gyne T 380 Slimline Intrauterine Copper devices.

To facilitate manufacture and insertion of the Gyne T 380 IUD, design changes were instituted. Copper collars were seated flush at the ends of the horizontal crossbar of the device. A randomized study of the Gyne T 380 Slimline, the new design, was undertaken in comparison with the standard Gyne T 380. A total of 996 women were enrolled, with 698 Slimline insertions and 298 of the standard Gyne T. No statistically significant difference in ease of insertion or in performance was detected between the models. At one year, the pregnancy rate of each model was below 0.5 per 100 and the continuation rate was 79-80 per 100. Pelvic inflammatory disease or endometritis was found in one percent of subjects in the first year. This is the seventh multicenter randomized study of a collared T IUD with 380 mm2 of copper surface. In all seven, the one-year gross pregnancy rate has been 1.2 per 100 or lower.

Adult↗

PubMed1990

Ovarian endocrine function through five years of continuous treatment with NORPLANT subdermal contraceptive implants.

Ovarian endocrine function was assessed in 88 women using NORPLANT subdermal implants during different periods of use and in a control group of 15 women using non-hormonal contraception. Blood samples for estradiol (E2) and progesterone (P) assays were obtained twice a week for five consecutive weeks. Three distinct E2 patterns were observed: one was characterized by fluctuating levels within a normal range (20 to 400 pg/ml), a second pattern corresponded to continuous low E2 levels (below 75 pg/ml in the 10 samples) and the third was characterized by high broad estradiol peaks reaching over 400 pg/ml. The proportion of sampling runs characterized by normal fluctuating levels increased from 38% in the first two years of use to 80% during the fifth year of use. Low E2 profile was only observed during the first two years of use (27%) and in only 1 case at the beginning of the third year of use (5%). The percentage of cycles with high broad estradiol peaks remained between 20-40% without a clear tendency to change in either direction with duration of use. Thirty-three percent of the observed sampling runs had luteal activity (P above 3 ng/ml). The proportion of runs with luteal activity increased from 14% during the first two years of use to 40% during the third and fourth, and 60% during the fifth year of use. All control subjects had luteal activity. The mean highest progesterone level was lower in the NORPLANT runs (8.7 +/- 3.9 ng/ml) as compared to the controls (11.3 +/- 3.8 ng/ml). NORPLANT sampling runs with luteal activity had normal fluctuating E2 levels with only one exception. However, not all cycles with normal E2 levels showed luteal activity. On the other hand, all runs with low E2 levels or high broad E2 peaks were without luteal activity. In summary, women using continuous low-dose levonorgestrel contraception through NORPLANT subdermal implants, have a variable degree of ovarian activity as compared with the more complete depression of ovarian function observed among pill or injectables' users. Ovarian activity becomes closer to normal during the third through fifth year of use.

Contraceptive Agents, Female↗

PubMed1989

Prospective study of the pituitary-ovarian function after tubal sterilization by the Pomeroy or Uchida techniques.

Surgical sterilization has become one of the most widely used methods of fertility regulation in the world. A common concern is the not yet clarified possible disturbance of the ovarian function resulting from the surgical procedure. A prospective study was carried out to contribute toward answering this question. Twenty subjects were enrolled in a longitudinal study of ovarian endocrine function before, and 2 and 6 months after, tubal ligation. The Pomeroy technique, which may compromise ovarian circulation, and the Uchida technique, which is free of this risk, were used randomly. Eight women who underwent to the Pomeroy technique and 9 who underwent the Uchida technique completed the protocol. Luteinizing hormone, follicle-stimulating hormone, estradiol, and progesterone were measured daily from days 10 through 18 of the cycle and every other day until the onset of the next menses. No change in any of the hormones studied was observed, with the exception of a significant increase in progesterone 2 months after tubal ligation by the Uchida technique.

Female↗

PubMed1988

The role of the levonorgestrel intrauterine device in the prevention and treatment of iron deficiency anemia during fertility regulation.

Hematocrit and blood ferritin were assayed in 43 women using a levonorgestrel intrauterine device (LevoNg-IUD), 49 using the Copper T-380 Ag (T-Cu 380 Ag), 27 using the Lippes loop and 30 non-IUD users as controls. The mean duration of use was 41 months for the three IUD groups. Women not using IUDs and with similar age, parity, years of schooling and family income as users had a normal mean hematocrit and ferritin, but 30% had low hematocrit (below 38%) and 43% had low ferritin (below 11 ng/ml). After prolonged use of the IUDs, 26% of users of Lippes loop, 22% of users of T-Cu 380 Ag and only 2% of users of LevoNg-IUD had subnormal hematocrit; 70%, 55% and 14%, respectively, had low ferritin. Thus, in a population with high incidence of anemia, the use of LevoNg-IUD appears to reduce the proportion of women with clinical anemia and with depletion of their iron store.

Adult↗

PubMed1988

New insights on the mode of action of intrauterine contraceptive devices in women.

To gain a better understanding of the mechanism of action of intrauterine devices (IUDs), a search was made for ova in the genital tracts of 115 women using no contraception and of 56 women using IUDs, all of whom volunteered for study in conjunction with surgical sterilization. Ova were recovered from tubal flushings between 48 and 120 hours after the midcycle peak of luteinizing hormone in 39% of the IUD users compared with 56% of women in the control group (0.05 less than P less than 0.10). This suggests an action of the IUD before the ovum reaches the uterus. Eggs with a microscopic appearance consistent with fertilization were recovered from the fallopian tubes of half of the women using no contraception who had intercourse within the fertile period of the reproductive cycle and from whom ova were recovered. In contrast (P less than 0.01), no eggs with this appearance were recovered in IUD users who had intercourse within the fertile period. No ova were recovered from the body of the uterus of any of the IUD users. Fertilized ova are less likely to reach the uterine cavity containing an IUD. Thus, the principal mode of IUDs is by a method other than destruction of live embryos.

Fallopian Tubes↗